Commonly macrophages are categorized into M1 and M2 subsets. M1 macrophages are defined as inflammatory cells and may contribute to tissue injury, while, M2 macrophages play a central role in tissue remodeling and control of immune responses. It seems that the existence of these cells in graft location is effective for control of inflammation and improvement of transplantation consequences. Although the relative contribution of M2 cells in organ transplantation is not clear, the accumulation of these cells in acute and chronic injury models of transplantation was shown. In some cases, the depletion of M2 cells leads to the amelioration of disease; however in other causes, skewing the response in M2 cells leads to an augmentation of graft fibrosis and worsening of graft condition. In spite of these findings, the benefits of such strategies and their implications in human disease are not clearly understood. The purpose of this mini-review is to highlight the role of alternatively activated M2-type macrophages in the improvement or reduction of the kidney transplantation outcome.

Acute and chronic transplant rejections due to alloreactivity are essential contributors to graft loss. However, the strength of alloreactivity is biased by non-immunological factors such as ischemia reperfusion injury (IRI). Accordingly, protection from IRI could be favorable in terms of limiting graft rejection. Caveolin-1 (Cav-1) is part of the cell membrane and an important regulator of intracellular signaling. Cav-1 has been demonstrated to limit IRI and to promote survival of a variety of cell types including renal cells under stress conditions. Accordingly, Cav-1 could also play a role in limiting anti-graft immune responses. Here, we evaluated a possible association between pretransplant serum concentrations of Cav-1 and the occurrence of rejection during follow up in a pilot study. Therefore, Cav-1-serum concentrations were analyzed in 91 patients at the time of kidney transplantation and compared to the incidence of acute and chronic rejection. Higher Cav-1 levels were associated with lower occurrence of acute rejection episodes. Moreover, Cav-1 could be therapeutically useful for attenuating graft rejection.

The aim of this study was to evaluate the use of a flexible synthetic polymer bone graft to provide implant stability in the absence of implant stability during implant placement in a dense cortical bone model. Sockets were prepared on polyurethane blocks according to the standard implant socket drilling protocol in the control group, both oversizing and deepening in group 2, and oversizing only in group 3. In groups 2 and 3, flexible synthetic polymer bone grafts were placed in the sockets prior to implant placement. The implants were placed at bone level in all groups. The highest torque value obtained was recorded as the insertion torque. 75 implant sites in 3 groups were included in the study. The torque values of the implants in the control group were significantly higher than those of the implants with the oversized and deepened sockets and the oversized-only sockets (p<0.05; p<0.01).The torque values of the implants with the oversized and deepened sockets were significantly higher than those of the implants with the oversized-only sockets (p<0.01). In this study, flexible synthetic polymer bone graft was shown to be effective in achieving implant stability in the management of implants with loss of primary stability.

Background: Systemic treatment options for hepatocellular carcinoma (HCC) after liver transplantation (LT) are limited in patients in whom sorafenib treatment was failed. The purpose of our study was to compare outcomes among sorafenib, regorafenib, and nivolumab treatment groups in patients with recurrent HCC after LT. Methods: This study retrospectively evaluated patients who received sorafenib for recurrent HCC treatment after LT at a single center from March 2007 to December 2018. Some patients received regorafenib or nivolumab after sorafenib treatment failure. Results: Fifty-six patients were treated with sorafenib due to HCC recurrence. Among these, 38 patients (67.9%) continued treatment with sorafenib only; the other 18 patients (32.1%) were converted to regorafenib treatment. Ten patients (17.9%) of these 18 were converted to nivolumab after sorafenib and regorafenib therapy failed. The disease-free survival and overall survival (OS) from LT were not different among the three groups. In addition, OS from HCC recurrence, sorafenib usage, and usage of each systemic therapeutic agent were not different among the three groups. Three cases in the nivolumab group developed acute rejection; one of these led to graft failure and death due to antibody-mediated rejection. Conclusion: Sequential regorafenib or nivolumab treatment in recurrent HCC LT patients does not improve OS compared sorafenib treatment.

Transplanted organs experience several episodes of ischemia and Ischemia-reperfusion. The graft injury resulting from ischemia-reperfusion (IRI) remains a significant obstacle to the successful survival of transplanted grafts. Temperature plays an important role in cellular metabolic rates since biochemical reactions are highly temperature dependent. Therefore, ischemia-triggered degradative reactions could be mitigated by lowering temperature. Whether a local hypothermia on liver before blockage of blood flow protects liver grafts against IRI has not been investigated. In this study, we applied local hypothermia to mouse donor livers for a specific duration before stopping blood flow to liver lobes, a procedure called "liver precooling." Mouse donor liver temperature in control groups was controlled at 37ºC. Subsequently, the liver donors were preserved in cold University of Wisconsin solution for various durations followed by orthotopic liver transplantation. Liver graft injury, function and inflammation were assessed at 1- and 2-days post-transplantation. Liver precooling exhibited a significant improvement in graft function, revealing more than a 47% decrease in plasma aspartate transaminase (AST) and alanine aminotransferase (ALT) levels, coupled with a remarkable reduction of approximately 50% in liver graft histological damage compared to the control group. The protective effects of liver precooling were associated with the preservation of mitochondrial function, substantial reduction in hepatocyte cell death, and a significantly attenuated inflammatory response. A retrospective analysis of patient data revealed a close correlation between hypothermia and enhanced liver graft function. Taken together, reduction of the cellular metabolism and enzymatic activity to a minimum level before ischemia protects against IRI during transplantation.

Wound healing in the pediatric population is known to be a challenge and poorly studied. Split-thickness skin grafts, full-thickness skin grafts and flaps overlap their applications with the growing field of cellular and tissue-based therapies. However, their role in pediatric reconstruction has yet to be defined. The Kerecis® Omega3 wound patch, derived from decellularized codfish skin, has garnered attention due to its preserved microscopic architecture resembling the human extracellular matrix. This acellular dermal matrix acts as a scaffold, fostering dermal cell and capillary adhesion while harnessing omega-3 polyunsaturated fatty acids for granulation acceleration and antimicrobial effects. This study presents a comprehensive review and surgical protocol for utilizing Kerecis® fish skin in pediatric wound care. The research embraces a case series involving five patients with diverse wound locations. The Kerecis® Omega3 wound patch underwent meticulous application and careful monitoring. The results highlight an average time of 48.6 days for complete epithelialization, yielding favorable outcomes with no hypertrophic scarring and mild retraction. Notably, this innovative approach may eliminate donor site morbidity and improve pain control, promising a novel avenue for pediatric wound management.

The lack of suitable autologous grafts and poor compliance of existing prostheses have prompted the study of novel materials for vascular graft design. Polyurethanes (PUs) were used in the past because they have high compliance and properties that are similar to those of native tissue. In this work, the mechanical properties of a group of PUs in two states (non-hydrated and hydrated) were studied using uniaxial tensile tests, strain sweep tests, and multi-step creep recovery tests. Additionally, a hyper-elastic model based on the Mooney–Rivlin strain density function was fitted and used to model the performances of the PUs under physiological pressure and geometry conditions. The tensile tests revealed a softening phenomenon after hydration, which could potentially reduce patient discomfort and risk of vascular trauma. The ultimate strength values after hydration were similar to those reported for other vascular conduits. The strain sweep showed a strong strain dependency of the modulus indicating non-linear viscoelasticity. In the creep-recovery tests, increasing the polyethylene glycol(PEG) content enhanced the viscous flow, while the elastic behavior was enhanced with the largest concentration of polycaprolactone diol (PCL). On the other hand, under simulated physiological conditions, the compliance of the PUs showed a cyclic behavior with the time and pressure but was not affected by the radii and thickness variation, which could increase the graft compliance and geometry mismatch. Nevertheless, the compliance could be tuned using the material composition. This paper studied the biomechanics of a group of materials under simulated physiological conditions (Temperature, hydration, and pressure) to select those that could perform better for further vascular graft design.

Patients with chronic renal failure and vascular diseases require the vascular access for hemodialysis procedure to be performed with the most possible comfort for the patient. Native vein graft has a longer-lasting term in the patients’ limb, lower risk of graft infection and lower price. Native vein graft is constructed from the great saphenous vein, if the diameter of the vessel is smaller than the diameters of vessels (brachial artery, cephalic vein) it is connected to in the cubital fossa region due to the risk of graft folding, that might occur, if the graft diameter is bigger than the diameter of one or both vessels, on which anastomosis is made. The most important sizes, that were taken before graft placement, are the length of the forearm compartment, the distance between the brachial artery and cephalic vein in the cubital fossa region, distance from an expected incision in the brachial artery to the middle of the forearm compartment, the distance between incision in cephalic vein to the middle of the forearm compartment, length of the great saphenous vein (the graft) and diameters of blood vessels, used in the procedure. Finally, the right position of the graft should be determined for the successful outcome of anastomosis creating procedure.

Pecan (Carya illinoinensis), as a popular nut tree, is widely planted in China in recent years. Grafting is an important technique for its cultivation. For a successful grafting, graft union development generally involves the formation of callus and vascular bundles at the graft union. To explore the molecular mechanism of graft union development, we applied high through-put RNA sequencing to investigate transcriptomic profiles of graft union at four time points (0d, 8d, 15d, and 30d) during pecan grafting process. We identified a total of 12,180 differentially expressed genes. In addition, we found that the content of auxin, cytokinin and gibberellin were accumulated at the graft unions during the grafting process. Correspondingly, genes involved in those hormone signaling were found to be differentially expressed. Interestingly, we found that most genes associated with cell division were up-regulated at callus formative stages, while genes related to cell elongation, secondary cell wall deposition, and programmed cell death were generally up-regulated at vascular bundle formative stages. In the meantime, genes responsible for reactive oxygen species were highly up-regulated across the graft union developmental process. These results will aid in our understanding of successful grafting in the future.

The Anterior Cruciate Ligament (ACL) is a crucial stabilizing ligament in the knee, essential for maintaining knee joint stability and proper biomechanical function. ACL rupture is one of the most common injuries, especially prevalent among athletes participating in high-demand sports that involve pivoting, cutting, and jumping. Such injuries not only lead to immediate functional impairment but also predispose individuals to long-term consequences, including osteoarthritis if left untreated. ACL reconstruction using a graft, whether autograft or allograft, has become the gold standard treatment method aimed at restoring knee stability and function. However, the postoperative healing process of the graft within the bone tunnel presents significant challenges due to its complexity. This healing involves a coordinated sequence of molecular and cellular events, including inflammation, proliferation, and remodeling phases. These phases are governed by a myriad of molecular signals, growth factors, and cellular interactions that ultimately determine the success of the graft integration and the restoration of ligamentous function. The review article "Molecular Biology of ACL Graft Healing: Early Mechanical Loading Perspective" delves deeply into these intricate biological processes. It provides a comprehensive analysis of the underlying molecular mechanisms that facilitate graft healing. Furthermore, it emphasizes the critical role of early mechanical loading in this context. Mechanical loading, when applied appropriately, has been shown to positively influence graft healing by enhancing cellular responses, collagen fiber alignment, and overall biomechanical properties of the graft. By exploring the impact of early mechanical loading, the review sheds light on how mechanical stimuli can be optimized to improve clinical outcomes. This understanding is vital for developing effective rehabilitation protocols that promote faster and more robust graft healing. The article offers valuable insights for clinicians and researchers, aiming to bridge the gap between molecular biology and practical rehabilitation strategies in ACL reconstruction. Overall, this review underscores the importance of an integrated approach that considers both the biological and mechanical aspects of ACL graft healing. Such an approach holds promise for advancing patient care and improving the success rates of ACL reconstruction surgeries.

(1) Background : When placing implants in the maxillary posterior region with insufficient alveolar bone, a maxillary sinus elevation is necessary. Autogenous bone, though biologically ideal, poses risks and discomfort due to donor site harvesting. Block-type autogenous tooth bone graft material, made from the patient’s own extracted tooth, offers similar biological stability without these drawbacks; (2) Methods : This study observed the progress of 19 implant patients who were treated with maxillary sinus elevation procedures using block-type autogenous tooth bone graft material at the Daegu Catholic University Medical Center. Extracted teeth were processed into demineralized tooth block bone. After elevating the sinus membrane, implants and the tooth bone graft material were placed in the space, and the bony window was repositioned. Postoperative evaluations through clinical observation and radiographic imaging assessed sinus membrane elevation, alveolar bone height increase, and implant osseointegration; (3) Results : Results showed proportional increases in alveolar bone height to the graft material size, with long-term stability. No postoperative complications occurred, even with sinus membrane perforation, and implants remained stable; (4) Conclusions : The study concludes that maxillary sinus lifts using block-type autogenous tooth bone graft material provide excellent bone induction and biocompatibility, making it a highly beneficial method for both dentists and patients.

Malnutrition problems are related to diets that lack one or more essential elements, which it is extremely important to food enrichment to improve the content of compounds effective for health. The objective of this study is to evaluate the effect of the addition of Ca2+, K+ and Mg2+ on the induction of nutraceutical quality in grafted tomatoes grown in the NFT (Nutrient Film Technique) system. In the experiment, two factors were evaluated: plants with and without grafting and the foliar application of 10 ml L−1 Ca2+, 4 ml L−1 K+ and 10 ml L−1 Mg2+ cations separately for each case, in addition to the control. The treatments were evaluated using a completely randomized design, with 5 repetitions per treatment. The interactive effects between grafting and foliar application of Ca2+ induced a greater content lycopene, β-carotene and total flavonoids in fruits of tomato. The interactive effects between the graft and the Mg2+ foliar applications obtained the best results in the phenol content. As regards, capacity DPPH and ABTS, the graft decreased concentration, increasing the content of these through foliar applications of calcium. Regarding the enzymatic variables, graft factor increased activity catalase, glutathione peroxidase and phenylalanine ammonium lyase, obtained the best results graft interaction and foliar application of calcium and magnesium. The results obtained demonstrate the influence of the use of grafts and foliar applications of cal-cium and magnesium as tools that could improve the nutraceutical quality content of tomato crop

Although COVID-19 primarily affects the respiratory system, it can have various effects on other organs, including the cardiovascular system. COVID-19 can lead to a prothrombotic status, promoting bloodclotting, which can potentially affect native vessels and implanted de-vices. The exact mechanisms by which it leads to increased clotting are not yet fully understood but may involve inflammation, endothelial dysfunction, and a hyperactive immune response. In the present report, we describe a case of an acute aortic stent-graft thrombosis four days after resolution of Sars-Cov2 infection. The patient required emergent explantation of the stent-graft, after the failure of endovascular bailout procedures.

Mandibular critical size defect (CSD) due to pathological conditions, trauma, and congenital disease can not heal spontaneously and predominantly filled with fibrous tissue. Therefore, a Guided Bone Regeneration (GBR) combined with bone grafting can be performed. The researchers considered using Demineralized Dentin Material Membrane (DDMM) from bovine dentine as an alternative GBR. This study aimed to determine the amount of fibroblast and collagen density after DDMM and bone graft implantation on CSD. Thirty-six Rattus norvegicus rats were used as samples. Mandibular bone defect 5x5 mm was made, then filled with bone graft and covered with Bovine Pericardium Collagen Membrane (BPCM) in the control group and DDMM in the treatment group. Six samples were sacrificed on 7, 14, and 21 days post-surgical for histology examination. There were no significant differences in the amount of fibroblast and collagen density (p-value > 0,05). The amount of fibroblast is lower and the collagen density is higher in treatment group. DDMM has microporosity to prevent connective tissue ingrowth and dentine tubules to allow growth factors release. DDMM and bone graft implantation can reduce the amount of fibroblasts and increase collagen density of CSD which potentially being used as a CSD alternative treatment for bone regeneration.

Allogeneic hematopoietic stem cell transplantation (allo-HCT) is a potentially curative treatment modality, frequently applied in patients suffering from haematological malignancies. In the last two decades, there have been multiple randomised controlled trials (RCTs), review articles, and meta-analyses addressing the efficacy of rabbit anti-thymocyte globulin (r-ATG) as a graft-versus-host disease (GvHD) prophylaxis. Nevertheless, only a few aimed to compare the effectiveness of different r-ATG formulations. We performed a systematic literature review of articles published since 2017 to this day utilising PubMed, Scopus, Cochrane, and MEDLINE, with the main endpoints being prophylaxis of acute GvHD (aGvHD) and chronic GvHD (cGvHD). We subjected to scrutiny a total of 5 studies, of which 4 compared the differences between Thymoglobulin (ATG-T) and Grafalon (ATG-G), and 1 discussed the impact of ATG-T dose. Overall cGvHD, aGvHD grades II-IV, TRM, OS, NRM, LFS, relapse, overall infections, and EBV reactivation do not seem to be affected by the type of utilised rATG. However, data on aGvHD grades III-IV, GRFS, moderate-severe cGvHD, and CMV reactivation is conflicting. Through our research, we sought to summarise the most recent findings concerning r-ATGs in allo-HCT, and provide insight into the differences between the targets and origin of various ATG formulations.

The cross-linkable PCL-PEG analogues block-graft copolymer was designed and synthesized, which with the copolymer of the MEO₂MA and OEGMA as graft chains to improve the mPEG-b-PCL-b-mPEG copolymer the aqueous solution properties. And successfully prepared two hydrogels via a copper-catalyzed 1, 3-dipolar azide-alkyne cycloaddition reaction of alkyne-terminated poly[glycidyl methacrylate-co-2-(2-methoxyethoxy) ethyl methacrylate-co-oligo (ethylene glycol) methacrylate] [P(GMA-co-MEO₂MA-co-OEGMA)] with azide end-functionalized PCL-PEG analogues block-graft copolymer, and tetrakis (2-propynyloxymethyl) -methane (TPOM) and with azide end-functionalized PCL-PEG analogues block-graft copolymer. The copolymer's chemical structure was characterized by proton nuclear magnetic resonance spectroscopy and fourier transform infrared spectroscopy. The molecular weights of the copolymers were decided with gel permeation chromatography. The water solubility and temperature sensitivity of the copolymers were studied by taking digital photos and transmittance change measured by UV spectrophotometer at different temperatures. Fluorescence probes, surface tension, dynamic light scattering and transmission electron microscopy were used to analyze the micelles that copolymers self-assembly in aqueous solution. The sol-gel behavior of copolymer solutions at high concentrations was explored by vial inversion experiments. Finally, the network structure of the gels was observed by scanning electron microscopy. These conclusions indicate that these hydrogels are expected to be used as a new material in the field of biomedicine.

Therapeutic measures aimed at optimising organ function prior to transplantation - whether by conditioning the donor after determination of brain death or by improving organ preservation after kidney removal - have the potential to enhance outcomes after transplantation. The particular advantage is that, unlike any optimised immunosuppressive therapy, a positive effect can be achieved without side effects for the organ recipient. In recent years, several such measures have been tested in controlled clinical trials on large patient cohorts following kidney transplantation. Hypothermic pulsatile machine perfusion in particular has become the focus of interest, but interventions in the donor prior to organ removal, such as the administration of low-dose dopamine until the start of cold perfusion as an example of conditioning antioxidant therapy, and therapeutic donor hypothermia in the intensive care unit after brain death confirmation have also significantly reduced the frequency of dialysis after transplantation with far less effort and cost. With regard to a favourable effect on graft survival in the long-term, the database for all procedures is less clear and controversial. The aim of this review article is to re-evaluate the available clinical evidence on the basis of the large multicentre controlled trials, which have also significantly influenced later meta-analyses, and to assess the significance for use in routine clinical practice.

Objectives: This study aims to explore the use of murine models in peripheral nerve transection research, evaluating and synthesizing key methods for analyzing nerve regeneration to guide future research and clinical interventions. Methodology: A systematic review was conducted in February 2024, adhering to Cochrane and PRISMA 2020 guidelines, using Medline, Scielo, and Lilacs databases. The focus was on experimental studies of nerve regeneration in animal models post-transection. Only experimental clinical trials reporting nerve regeneration outcomes were included; studies lacking a comparator group or functional evaluation methods were excluded. Results: Out of 273 studies initially identified from MEDLINE, 19 were selected for detailed analysis. The average study included 32.5 subjects, with about 10.16 subjects per intervention subgroup. The predominant model was the sciatic nerve injury with a 10mm gap. The most common intervention involved unprocessed adipose-derived stem cells, utilized in 14 articles. Conclusions: The review underscores the significant potential of current methodologies in peripheral nerve regeneration, particularly highlighting the use of murine models and thorough evaluation techniques. These studies significantly contribute to our understanding of nerve regeneration processes and inform directions for future research.

End-stage heart failure (ESHF) leads to hypoperfusion and edema formation in the whole body and is accompanied by neurohormonal and immunological alterations. Orthotopic heart transplantation (HTX) has been used as a beneficial option for ESHF. Due to the shortage of donor hearts, the ideal matching and timing of donors and recipients has become more important. Our aim was to explore the relationship between the clinical outcome of HTX and the cytokine and apolipoprotein profiles of the recipient pericardial fluid obtained at transplantation after opening the pericardial sac. The clinical data and the interleukin, adipokine and lipoprotein levels in the pericardial fluid of twenty recipients were investigated. Outcome variables included primer graft dysfunction (PGD), need for posttransplantation mechanical cardiac support (MCS), International Society for Heart and Lung Transplantation grade ≥ 2R rejection and mortality. Recipient risk scores were also investigated. Leptin levels were significantly lower in patients with PGD than in those without PGD (median: 6.36 [IQR: 5.55-6.62]; versus 7.54 [IQR=6.71-10.44]; p = 0.029). Higher ApoCII levels (median: 14.91 [IQR: 11.55-21.30] versus 10.31 [IQR=10.02-13.07]; p = 0.042) and ApoCIII levels (median: 60.32 [IQR: 43.00-81.66] versus 22.84 [IQR=15.84-33.39]; p=0.005) were found in patients (n=5) who died in the first 5 years after HTX. In patients who had rejection (n=4) in the first month after transplantation, the levels of adiponectin (median: 74.48 [IQR: 35.51-131.70] versus 29.96 [IQR: 19.86-42.28]; p=0.039), ApoCII (median: 20.11 [IQR: 13.06-23.54] versus 10.32 [IQR: 10.02-12.84]; p=0.007) and ApoCIII (median: 70.97 [IQR: 34.72-82.22] versus 26.33 [IQR: 17.18-40.17; p=0.029) were higher than those in the nonrejection group. Moreover, the pericardial thyroxine (T4) levels (median: 3.96 [IQR: 3.49-4.46] versus 4.69 [IQR: 4.23-5.77]; p=0.022) were lower in patients with rejection than in patients who did not develop rejection. Our results indicate that apolipoproteins can facilitate the monitoring of rejection and could be a useful tool in the forecast of early and late complications.

Background: Arthroscopic revision rotator cuff repair (ARRCR) is challenging. Biologic strategies seem to be promising. The aim was to evaluate the effectiveness of combination of microfractures of the greater tuberosity, augmentation with collagen patch graft, and platelet concentrate injections in ARRCR. Methods: A retrospective comparative study was conducted on patients that underwent ARRCR with minimum two-years follow-up. Patients in the augmentation group underwent ARRCR combined with microfractures, collagen patch graft, and postoperative subacromial injections of platelet concentrate. A standard rotator cuff repair was performed in the control group. Primary outcome: Constant Murley score (CMS). Secondary outcomes: disease-specific health-related quality of life by using the Disabilities of the Arm, Shoulder and Hand (DASH) score; assessment of tendon integrity with magnetic resonance at least six months after surgery. Significance was set at p < 0.05. Results: Forty patients were included. Mean follow-up was 36.2 + 8.7 months. The mean CMS was greater in the augmentation group (p = 0.022). No differences could be found for DASH score. Healing failure rate was higher in the control group (p = 0.002). Conclusion: Biologic augmentation of ARRCR by combination of microfractures, collagen patch graft and subacromial injections of platelet concentrate is an effective strategy in improving tendon healing rate.

Abstract A variety of surgical techniques have been developed to reconstruct the posterior maxilla when bone volume is insufficient. A barrier membrane or bone window pushed inside the sinus cavity as the ‘‘roof’’ of the sinus cavity for preserve the space and help bone. The heterologous cortical lamina is used for the mechanical support, without any grafting material, of sinus membranes resulting in only bone tissue formation and not mixed with the graft.

The literature study delves into novel therapeutic strategies in transplantation medicine, highlighting unique approaches that could revolutionize current practices. It emphasizes novel patterns that have the potential to transform the current landscape. Commencing with a thorough examination of the historical environment, it traces crucial advances and changes in transplantation. The focus is on traditional techniques, emphasizing their limitations and challenges. An extensive examination of contemporary transplantation therapies offers valuable insights into the most recent progress in organ, cellular, and tissue transplantation. This analysis examines the immunological obstacles and outlines the current advancements and constraints. The exploration further navigates into novel models and concepts such as immunomodulation, developments in organ preservation techniques, gene editing, biomaterials, scaffold-based solutions, and the integration of precision medicine, artificial intelligence, and machine learning applications. Each section analyzes the potential for change and current progress in various areas, backed by relevant scientific sources up to 2023. The subsequent sections delve into innovative cellular therapies, biotechnological progress, current clinical trials, and case studies demonstrating effective applications. This examination delves into the ethical and regulatory considerations of innovative therapeutic procedures, emphasizing ethical implications, regulatory frameworks, and the importance of balancing innovation with patient welfare. The literature review concludes by offering a forward-looking perspective, emphasizing potential progress, anticipated challenges, and advocating for collaboration and interdisciplinary approaches to overcome limitations in the field of transplantation medicine.

Chronic graft-versus-host disease (cGvHD) occurs in 20-50% of recipients following allogeneic haematopoietic stem cell transplantation (allo-HSCT). Corticosteroids (CS) remain the first line treatment but have suboptimal efficacy and carry the risk of long-term side effects. New agents with a better safety profile and higher efficacy, ideally combining immunomodulatory and antifibrotic properties, are urgently needed. From 2016 to 2020, we conducted a phase 2 clinical trial with ATO in chronic GvHD (ClinicalTrials.gov ID NCT02966301 - GMED16-001). This study aimed to evaluate the efficacy and safety of a first-line combination of arsenic trioxide (ATO) and CS in adult patients with cGvHD who require systemic therapy after a first allo-HSCT for a haematological disease. In this prospective, national, multicenter, single-arm, open-label phase II study, conducted in 5 university hospital centers in France, ATO was initiated within 10 days of starting CS at 1 mg/kg/day. Patients received 11 infusions of ATO per 4-week cycle, at a dose of 0.15 mg/kg per infusion. Patients received 1 or 2 cycles of treatment depending on the clinical response and the assessment of the treating physician. The results were published in July 2022 in a paper entitled "High Response Rate and Corticosteroid Sparing with ATO-Based First-Line Therapy in Chronic Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation". The GMED16-001 study demonstrated convincing efficacy and safety characteristics of the intravenous drug (Trisenox^®/Arscimed^®): the first-line use of ATO in addition to corticosteroids was associated with a high clinical response rate and correlated with rapid corticosteroid (CS) sparing in moderate to severe cGvHD after allo-HSCT. We performed a post-hoc analysis of the data to determine the best schedule for treating cGvHD patients with ATO. Our post-hoc analysis leads us to the conclusion that two cycles of ATO, at 0.15 mg/kg/day, 5 days per week for 4 weeks each, separated by a 4-week therapy-free interval, appears to be the most promising treatment schedule.

Background: The current standard technique for vascular grafting in cerebral revascularization surgery is through the interposition of an autologous blood vessel. Technical complications have necessitated the development of a synthetic alternative, but classical biomaterials are not suited for small caliber vascular grafting due to neointimal hyperplasia and thrombosis. Electrospinning of polymers is a promising technique for the development of small vascular grafts. The in vivo performance and efficacy of electrospun polyurethane (ePU) grafts with an internal diameter of < 1.5 mm have thus far not been evaluated. Methods: We developed a novel ePU graft with a diameter of 1.25 mm for implantation into the infrarenal aorta of rats. Results: Patency rates of grafts after a four-month-period were equal to those reported in other studies with larger ePU graft diameters, and equal or higher than in studies with other biomaterials. We observed some loss in flow velocity throughout the grafts, which suggests a decreased elasticity of the graft compared to native rat aorta. However, the grafts demonstrated good neo-endothelialization and minimal neointimal hyperplasia. Their porosity promoted cellular infiltration, as shown on tissue slide examination. Conclusion: Our results show that ePU vascular grafts with internal diameter of < 1.5 mm are promising candidates for vascular grafting in cerebral revascularization surgery.

In cancer patients, hyponatremia is detected in about 40% of cases at hospital admission and has been associated to a worse outcome. We have previously observed that cancer cells from differ-ent tissues show a significantly increased proliferation rate and invasion potential, when cul-tured in low extracellular [Na+]. We have recently developed an animal model of hyponatremia using Foxn1nu/nu mice. The aim of the present study was to compare tumor growth and inva-sivity of the neuroblastoma cell line SK-N-AS in hyponatremic vs. normonatremic mice. Ani-mals were subcutaneously implanted with luciferase-expressing SK-N-AS cells. When masses reached about 100 mm3, hyponatremia was induced in a subgroup of animals via desmopressin infusion. Tumor masses were significantly greater in hyponatremic mice, starting from day 14 and until the day of sacrifice (day 28). Immunohistochemical analysis showed a more intense vascularization and higher levels of expression of the proliferating cell nuclear antigen, chro-mogranin A and heme oxigenase-1 gene in hyponatremic mice. Finally, metalloproteases were also more abundantly expressed in hyponatremic animals compared to control ones. To our knowledge, this is the first in vivo demonstration that hyponatremia is associated to increased cancer growth by activating molecular mechanisms that promote proliferation, angiogenesis and invasivity.

Recipients of uterus transplantation have unique factors that may increase their risk of cervical insufficiency. This report describes a uterus transplant recipient with cervical insufficiency resulting in two second-trimester miscarriages. After McDonald cerclages (one that failed), she underwent an interval transabdominal cerclage and delivered a healthy term child in her third pregnancy. The longitudinal information of this case provides observations from which we can propose testable hypotheses that address venous outflow and inflammation. This case also suggests that there could be a role for prophylactic cerclage placement at the time of transplantation.

Aim. Atherosclerotic complex femoropopliteal lesions have traditionally been treated with bypass surgery. A prosthetic graft is used to save the vein graft for more distal revascularization or when unavailable. However, the endovascular approach has gained popularity and is offered as first-line strategy for complex lesions. This study aimed to evaluate whether endovascular procedures for complex femoropopliteal native lesions can be a first-line treatment strategy over open surgery with prosthetic bypass in patients with peripheral arterial disease (PAD). Methods. A retrospective study was conducted between 2013 and 2021 to identify patients with symptomatic PAD who required limb revascularization at the femoropopliteal segment and complex lesions (TASC II C and D). Primary endpoints were technical success, primary patency, freedom from clinically driven target lesion revascularization (cdTLR), freedom from major adverse limb and cardiovascular events (MALE and MACE), freedom from limb loss, and survival. Secondary endpoints were length of in-hospital stay, duration of the procedure, and costs. Results. We identified 185 limbs among 174 suitable candidates for comparison, wherein 105 were treated with endovascular procedure and 80 with femoral popliteal prosthetic bypass. Most patients in both groups presented with chronic limb-threatening limb ischemia, and all were ASA >3. There were more octogenarians (p = 0.02) and patients with coronary disease (p = 0.004) in the endovascular group. Median follow-up was 30 months. Technical failure rate for endovascular procedures was 4.8% vs 0% in the open group (p 0.003). Freedom from MACE was similar in both groups. The endovascular group showed superior primary patency (p<0.0001), cdTLR (p<0.0001), MALE (p<0.0001), and freedom from limb loss (p = 0.0018) at 24 months. Further analysis performed for the open above-the-knee subgroup showed that the aforementioned endpoints were similar at 12 months, and favoured the endovascular group at 24 months. Procedural time and in-hospital stay were longer in the open group (p<0.0001 and p<0.001). Finally, procedural cost was 10-fold lower in the endovascular bypass group than in the prosthetic bypass group. Conclusion. Endovascular procedures for complex femoropopliteal lesions are safe in patients at high risk for surgery and show better outcomes at 24 months than prosthetic bypasses. The latter may be considered as an alternative in cases of endovascular failure.

Objectives Bone fractures are very common diseases, which can be caused by impact injuries or physiological disorders. Thus, the present review aimed to study the use of medicinal plants in the healing mechanism of bone fractures. Evidence acquisition Through research in the PubMed, Google Academic, and Scielo databases, this article reviews 11 ethnopharmacological studies and 34 preclinical studies on the biological actions of different plants in bone fracture healing mechanism. Results Indian tribes have highlighted in the plants ethnopharmacological study for various diseases, including bone fractures. However, despite the large citations of traditional use, technical-scientific studies are still scarce in the literature. Chenopodium ambrosioides, Piper sarmentosum, quadrangular Cissus, Ricinus communis and Radix salvia miltiorrhiza plants were the most studied in the literature regarding their osteogenic, angiogenic, anti-inflammatory and remodeling effects, acting on bone receptors, stimulating bone metabolism, increasing minerals uptake, and assisting in free radicals breakdown. Conclusion Thus, the medicinal plants use is promising in the field of bone regeneration, as well as being alternative when conventional therapies are unfeasible, increasing herbal medicines demand and popularity.

The production and consumption of nuts are increasing in the world due to strong economic returns and the nutritional value of their products. With the increasing role and importance given to nuts (i.e., walnuts, hazelnut, pistachio, pecan, almond) in a balanced and healthy diet and in the prevention of various diseases, breeding of the nuts species has also been stepped up. Most recent fruit breeding programs have focused on scion genetic improvement. However, the use of locally adapted grafted rootstocks also enhanced the productivity and quality of tree fruit crops. Grafting is an ancient horticultural practice use in nut crops to manipulate scion phenotype and productivity and overcome biotic and abiotic stresses. There are complex rootstock breeding objectives and physiological and molecular aspects of rootstock–scion interactions in nut crops. In this review, we provide an overview of these, considering the mechanisms involved in nutrient and water uptake, regulation of phytohormones, and rootstock influences on the scion molecular processes, including long-distance gene silencing and trans-grafting. Understanding the mechanisms resulting from rootstock × scion × environmental interactions will contribute to developing new rootstocks with resilience in the face of climate change, but also of the multitude of diseases and pests and of the possible increase of their aggressiveness. They will also have to offer the premises of economic production, respectively yield and the quality, according to multiple destinations of nuts in the current consumption and food industry, but also the increasing exigencies of the consumer market and the profile industry.

A microwave technique prepared a superabsorbent polymer (SAP) by grafting two hydrophilic monomers onto a polysaccharide substrate. The monomers used are acrylic acid (AA) or acrylamide (AM) to graft onto a pullulan substrate (PUL) to form PUL-g- AA (SAP1) and PUL-g- AM (SAP2), respectively. The monomers (AM/AA) graft together onto a PUL substrate to form PUL-g-(AM/AA) (SAP3). Grafting parameters such as grafting efficiency with percentage, conversion of monomer to polymer, gel content, water retention, water adsorption capacity, and swelling kinetics were determined. Additionally, the effect of environmental pH (2, 4, 7, 9, and 12) and sodium dodecylbenzene sulfonate (SDBS) surfactant was evaluated, where SDBS was added by 1,2,3,4 and 5 mM to form (SAP4 to SAP8). FTIR results show that AM grafted on PUL through an aliphatic C-N bond, while AA grafting occurred through a single C-C bond. The grafting efficiency with AM is higher than with AA, as well as their gel contents. Water absorbance capacity increased with grafting of AA or AM separately, and water retention was enhanced. The highest absorbent capacity, water retention, gel content, and grafting parameters values were obtained with 3 mM SDBS content and pH7. The swelling kinetics showed that the increases in the theoretical and experimental swelling equilibriums were 72 % and 82%, respectively, at SAP6 compared to the values of these parameters in SAP3. The water absorption capacity of the hydrogel increases with increasing pH to 7 and then gradually decreases. XRD improves the crystallinity and crystalline size of the hydrogel after grafting polymerization for AM/AA into PUL, in addition to enhancing thermal stability. On the contrary, FE-SEM demonstrated that SDBS improves the porosity and pore size of the hydrogel surface in SAP6.

Introduction The placement of implants is often hindered by a severely atrophic mandibular edentulous ridge. A sufficient volume of bone graft is crucial for successful implant restoration. The required bone graft volume directly correlates with the deficiency present in the edentulous ridge. If the residual crestal bone height is so low that the distance between the crestal ridge and the inferior alveolar nerve is less than 2 mm, a significant bone augmentation procedure is necessary. This procedure must ensure the implants are surrounded by a sufficient margin of bone, aiming for a final height of more than 8 mm and a width of more than 7 mm. Achieving primary closure with adequate soft tissue is vital for the success of the bone graft procedure. The key to successful bone grafting lies in the effective management of the soft tissue covering. Case Report This case report details the treatment of a patient with severely atrophic edentulous ridges on both sides, addressed using Self Inflating Tissue Expanders (SITEs) to facilitate bone grafting and implant placement. Following soft tissue expansion, bone grafting and implant placement were successfully performed. The implants supported a fixed restoration, which remained stable and complication-free over a seven-year observation period. Conclusion The SITE (Self-Inflating Tissue Expander) proved effective in obtaining a substantial amount of bone graft needed for implant installation. A seven-year follow-up confirmed the implants were well-functioning with stable bone support, healthy soft tissue coverage, and adequate vestibular depth.

Maxillary sinus augmentation with a lateral approach (MSA) is a well-established treatment. In this prospective study, we evaluated risk factors for postoperative bone-graft displacement and report the clinical application of long-term resorbable GMEM-B-2 (L-lactic acid/-caprolactone [P(LA/CL)]) as a barrier membrane to cover the open window in the lateral wall in MSA. Twenty-four patients underwent MSA according to the relevant criteria; CT data obtained before and 1 week (1W) and 5–6 months (5M) post-MSA, bone height changes, bone height reduction rates at 1W and 5M post-MSA, bone-graft displacement measurements, and risk factors were examined. All patients showed bone height increments (p &lt; 0.005). However, no difference was observed between 1W and 5M post-MSA. Bone-graft displacement was observed in eight patients; the reduction rate from 1W to 5M post-MSA was 8.38% ± 4.88%. Sex, septa, maxillary sinus floor–palatal bone distance, and maxillary sinus floor–natural mouth distance were associated with bone-graft displacement (p &lt; 0.05). Height from the maxillary sinus floor to the palatal bone and the sinus angle influenced the augmentation amount (p &lt; 0.05). The L-lactic acid/ε-caprolactone [P(LA/CL)] membrane compared favourably with other membranes and may be useful as a barrier membrane for the MSA open window.

Various vestibuloplasty techniques have been reported to increase the attached mucosa (AM) and vestibular depth around dental implants. However, these surgical methods have disadvantages, such as limitations in manipulation, necessity of suturing, postoperative discomfort, swelling, and pain. This study aimed to evaluate the efficacy of laser-assisted periosteal fenestration (LA-PF) in treating a patient with a shallow vestibule and insufficient AM around dental implants. The LA-PF technique was performed using an Er:YAG laser. First, a partial-thickness apically positioned flap (APF) was performed. Horizontal periosteal fenestration was performed using an Er:YAG laser to expose the bones. Periosteal suturing was not required. After 12 months, sufficient AM and deepened vestibule were obtained and maintained. Thus, the LA-PF technique may be a simple and predictable treatment modality for vestibuloplasty around dental implants.

The potential of sericin, a protein derived from silkworms, is explored in bone graft applications. Sericin's biocompatibility, hydrophilic nature, and cost-effectiveness make it a promising candidate for enhancing traditional graft materials. Its antioxidant, anti-inflammatory, and UV-resistant properties contribute to a healthier bone-healing environment, and its incorporation into 3D-printed grafts could lead to personalized medical solutions. However, despite these promising attributes, there are still gaps in our understanding. The precise mechanism through which sericin influences bone cell growth and healing is not fully understood, and more comprehensive clinical trials are needed to confirm its long-term biocompatibility in humans. Furthermore, the best methods for incorporating sericin into existing graft materials are still under investigation, and potential allergic reactions or immune responses to sericin need further study.

Mesenchymal Stromal Cells (MSCs) are multipotent, non-hematopoietic progenitor cells with a wide range of immune conditioning and regenerative potential which qualify them as potential component of cell based therapy for various autoimmune / chronic inflammatory ailments. Their immunomodulatory properties include the secretion of immunosuppressive cytokines, the ability to suppress T-cell activation and differentiation, and the induction of regulatory T-cells. In view of this and our interest, we here discuss the significance of MSC for the management of Graft-versus-Host Disease (aGVHD), one of the autoimmune manifestation in human.. In pre-clinical models, MSCs have been shown to reduce the severity of aGVHD symptoms, including skin and gut damage, which are the most common and debilitating manifestations of this disease. While initial clinical studies of MSCs in aGVHD cases were promising, the results were variable in randomized studies. So, further studies are warranted to fully understand their potential benefits, safety profile, and optimal dosing regimens. In view of these inevitable issues, here we discuss various mechanisms, how MSCs can be employed in managing aGVHD, as a therapeutic option for this disease.

This study compares the efficacy of the two most commonly used surgical methods for pterygium in the Polish population, conjunctival autograft versus amniotic membrane transplantation, and to evaluate the postopera-tive recurrence rate. We retrospectively analysed the medical records of 65 patients who underwent surgery for primary or recurrent pterygium at an ophthalmology clinic in Bialystok, Poland between 2016 and 2020. Surgical success (no regrowth) occurred in almost half of the amniotic membrane patients (44%) and in most of the conjunctival autograft patients (79%); this was a significant relationship. The odds of successful surgery were 79% lower for subjects with amniotic membranes than for those with conjunc-tival autografts (OR with 95% CI = 0.21 (0.05; 0.94]; p = 0.045). Our study confirms that in Polish Caucasian population the success rate of the pro-cedure using conjunctival autograft versus the use of amniotic membrane, is in favoured for the procedure with conjunctival graft.

Different types of engineered cardiac constructs are being developed nowadays by many research groups. However, the immunological properties of such artificial tissues are not yet clearly understood. Previously, we have studied microfiber scaffolds carrying iPSC-derived cardiomyocytes. In this work, we evaluated the ability of these tissue-engineered constructs to activate the expression of CD28 and CTLA-4 proteins in T-lymphocytes which are early markers of the immune response. For this purpose electrospun PLA nanofibrous scaffolds were seeded with human iPSCs-CM and cultivated for 2 weeks. After, allogeneic mononuclear cells were co-cultured during 48 hours with 3 groups of samples that were tissue-engineered constructs, pure culture of cardiomyocytes and bare scaffolds followed by analysis of CD28/CTLA-4 expression on T-lymphocytes via flow cytometry. PLA scaffolds and concanavalin A (positive control) stimulation statistically significantly increased CD28 expression on CD4+ cells (up to 61.3% and 66.3%) and on CD8+ cells (up to 17.8% and 21.7%). CD28/CTLA-4 expression didn’t increase during co-cultivation of T-lymphocytes with cardiac engineered constructs and iPSC-CM monolayers. Thus, iPSCs-CM in monolayers and on PLA nanofibrous scaffolds didn’t cause T-cell activation, which allows us to expect that such cardiac constructs are not a cause of rejection after implantation.

The occurrence of bone-related disorders and diseases has increased dramatically in recent years around the world. Demineralized bone matrix (DBM) has been widely used as a bone implant due to its osteoinduction and bioactivity. However, the use of DBM is limited because it is a particulate material, which makes it difficult to manipulate and implant with precision, in addition, these particles are susceptible to migrate to other sites. To address this situation, DBM is commonly incorporated into a variety of carriers. An injectable scaffold has advantages over bone grafts or preformed scaffolds, such as the ability to flow and fill the bone defect. The aim of this research is to develop a DBM carrier with such viscoelastic properties to obtain an injectable bone substitute (IBS). The DBM carrier developed consisted of a PVA/glycerol network cross-linked with borax and reinforced with CaCO3 as a pH neutralizer, porosity generator, and source of Ca. The physicochemical properties were determined by the injectability test, FTIR, SEM, and TGA. Porosity, degradation, bioactivity, possible cytotoxic effect, and proliferation in osteoblasts were also determined. The results show that the developed material has great potential to be used in bone tissue regeneration

Purpose: Kidney Transplant Recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation and outcome. While infective endocarditis (IE) is among such complications in KTRs, literature is scarce. We describe the presentation, epidemiology, and factors associated with IE in KTRs. Methods: We performed a retrospective case/control study which included patients from two centers. First episodes of definite or possible IE (Duke criteria), in adult KTRs from January 2007 to December 2018 were included, as well as two controls per case, and followed until December 31 2019. Clinical, biological, and microbiological data and the outcome were collected. Survival was studied using the Kaplan-Meier method. Finally, we searched for factors associated with the onset of IE in KTRs by the comparison of cases and controls. Results: Seventeen cases and 34 controls were included. IE was diagnosed after a mean delay of 78 months after KT, mostly on native valves of the left heart only. Pathogens of digestive origin were most frequently involved (six Enterococcus spp, three Streptococcus gallolyticus and one Escherichia coli), followed by Staphylococci (three cases of S. aureus and S. epidermidis each). Among the risk factors evaluated only age was significantly associated with the occurrence of IE in our study (63.8 years for cases vs. 55.6 years for controls, P=0.03) Patient and death-censored graft survival were greatly diminished five years after IE compared to controls being 50.3% vs. 80.6% (p<0.003) and 29.7% vs. 87.5% (p<0.002), respectively. Conclusion: IE in KTRs is a disease that carries significant risks both for the survival of the patient and the transplant.

Purpose: The aim of the present experimental 3D-finite element study was to evaluate the influence of an augmented sinus lift with an additional inserted bone graft block. The bone graft block stabilizes the implant in addition to conventional augmented bone. We placed the block in three different positions. The implants were loaded with axial force and forces secondary to laterotrusion and protrusion. Material and Methods: A simplified U-shaped 3D finite element model of the upper jaw and a more complex anatomical model of the left maxilla were created. The bone graft block was placed in three positions: in the lower third in contact with the sinus floor, the middle, and the upper third of the implant. Van Mises’ stress distribution was calculated and analyzed for the different models. We also compared the complex anatomical model with the simplified one. Results: The position of the bone graft block significantly influences the magnitude of stress distribution. A bone graft block positioned in the upper third or middle of the implant reduces the quantity of stress compared to the reference model without a bone graft block. The low bone graft block position is clearly associated with lower stress distribution in compact bone. We registered no significant differences in stress in compact bone with regard to laterotrusion or protrusion. Conclusions: Maximum values of von Mises stresses in compact bone can be reduced significantly by using a bone graft block. The reduction of stress is nearly the same for positions in the upper third and the middle of the implant. It is much more pronounced when the bone graft block is in the lower third of the implant near the sinus floor, which appeared to be the best position in the present study.

Acute and chronic graft versus host disease (a/cGVHD) are major complications of allogeneic stem cell transplantation and a frequent cause of non relapse-mortality. The treatment of a/cGVHD consists of steroid administration at full dose. In the case of aGVHD, around 60 % of patients with grade III/IV fails to respond (steroid-resistant, SR), requiring a second line therapy. Extracorporeal photopheresis (ECP) represents a good option for second line treatment, leading to multiorgan response in several patients. Here, we have evaluated the performances of a cytofluorimetric quality control of the first ECP procedure in 29 patients with severe SR aGVHD who underwent ECP. The quality control represents a check control of in vitro cell apoptosis/death induction in collected and irradiated CD3+ cells by ECP. Our analysis shows that in more than 70 % quality controls a relevant apoptotosis/death of CD3+ cells was observed after cell irradiation, as compared to non-irradiated controls. Albeit observed in a small patients’ series, the occurrence of relevant in vitro effect after ECP relates to less procedures and/or to a better survival on ECP. Age, disease, gender, aGVHD grade and time from transplant to the first ECP had not impact on ECP efficacy in this patients’ series.

There was no significant difference in bacterial adhesion between the 3 bone graft types tested, regardless of the bacterial strain used (p &gt; 0.22). After 72 hours of culture, there was no significant difference between the Fresh and Frozen bone groups, while the number of CFU in the Decellularised group was significantly lower (p &lt; 0.01), averaging -0.72 +/- 0.08 lg, -0.20 +/- 0.01 lg and -0.78 +/- 0.48 lg with S. epidermidis, S. aureus and E. coli respectively. Absolute values differences are low, and considering fresh bone (equivalent to autograft) as the gold standard due to its low infection rates in clinical studies, we can conclude that adhesion and biolfilm development characteristics are similar between Fresh, Frozen and Decellularised bone grafts..

The different cell subsets of the immune system express vitamin D receptor (VDR). Through VDR, vitamin D exerts different functions which influences on immune responses, as previously shown in different preclinical models. Based on this background, retrospective studies have explored the impact of vitamin D levels on the outcome of patients undergoing allogeneic hematopoietic stem cell transplantation, showing that vitamin D deficiency is related to an increased risk of complications, especially graft-versus-host disease. These results have been confirmed in a prospective cohorts trial, although further studies are required to confirm this data. In addition, the role of vitamin D on the treatment of hematologic malignancies has also been explored. Considering this dual effect both on the immune system as well as on tumor cells in patients with hematologic malignancies, vitamin D might be useful in this setting both to decrease graft-versus-host disease and relapse rates.

This study aimed to investigate the healing effect of advanced platelet-rich fibrin (A-PRF) clot membranes in the reduction of palatal wounds resulting from free gingival graft (FGG) harvesting, in the re-epithelization rate and in the pain experience after surgery. Twenty-five patients requiring soft tissue augmentation (gingival recession coverage or keratinized gingiva augmentation) participated in this prospective randomized clinical study. After FGG harvesting, the test group (n=14) received A-PRF clot membranes at the palatal wound and the control group (n=11) a gelatin sponge. Epithelialization rate of the palatal wound, wound healing area, correspondent percentage of reduction and post-surgical pain experience were assessed. The follow-up period was 90 days. There was a significantly higher reduction of the palatal wound area in the A-PRF group vs. the control group, at 7 (p<0.001), 14 (p=0.009) and 30 days (p<0.001) follow-up. The maximum difference between groups was attained at 30 days (91.5% for A-PRF vs. 59.0% for the control group). At 14 days a significant difference in the proportion of patients showing total epithelization was found: 64.3% for A-PRF vs. 9.1% for the control group (p=0.012). At 90 days, both groups showed total recovery. Overall, the control group experienced a higher level of pain and discomfort until the 14th day, being significantly higher on the second day (p=0.013). The results suggest that A-PRF membranes haste the healing process by promoting a greater reduction along the recovery period and an apparent less painful postoperative period.

In this work, the surface of poly(ethylene terephthalate) track-etched membranes (PET TeMs) with pore sizes of 670-1310 nm was hydrophobized with 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate (DFHA) by photoinitiated graft polymerization. Attenuated total reflection FTIR spec-troscopy (ATR-FTIR), scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray spectrometer (EDX), and contact angle measurement were used to identify and characterize the TeMs. The optimal parameters for graft polymerization were determined as follows: polymeriza-tion time 60 min, monomer concentration of 30% and distance from the UV-source 7 cm. The wa-ter contact angle of the modified membranes reached 97° which is 51o for pristine membranes. The modified membranes were tested for water desalination using direct contact membrane distillation (DCMD) method. The effect of membrane pore size, the degree of grafting and salt concentration on the performance of membrane distillation process was investigated. According to the results obtained, it has been concluded that large pore size hydrophobic TeMs modified by using DFHA could be used for desalinating water.

The functionalization of polymeric substances is of great interest for the development of innovative materials for advanced applications. For many decades, the functionalization of chitosan has been a convenient way to improve its properties with the aim to prepare new materials with specialized characteristics. In the present article, we summarize the latest methods for the modification and derivatization of chitin and chitosan, trying to introduce specific functional groups under experimental conditions, which allow a control over the macromolecular architecture. This is motivated because an understanding of the interdependence between chemical structure and properties is an important condition for proposing innovative materials. New advances in methods and strategies of functionalization such as click chemistry approach, grafting onto copolymerization, coupling with cyclodextrins and reactions in ionic liquids are discussed.

Despite notable advancements in immunotherapy in the past decades, allogeneic hematopoietic stem cell transplantation (allo-HCT) remains a promising, potentially curative treatment modality. Only a limited number of studies has performed a direct comparison of two prevalent rabbit anti-thymocyte globulin (r-ATG) formulations — specifically, Thymoglobuline (ATG-T, formerly Genzyme) and Grafalon (ATG-G, formerly Fresenius). The primary objective of our retrospective analysis was to compare the outcomes of adult patients undergoing matched or mismatched unrelated donor (MUD/MMUD) allo-HCT, with a graft-versus-host disease (GvHD) prophylaxis based on either ATG-T or ATG-G. A total of 87 patients undergone allo-HCT between 2012 and 2022 were included. We observed no significant differences between ATG-T and ATG-G concerning the occurrence of acute graft-versus-host disease (aGvHD), regardless of its severity. Conversely, chronic graft-versus-host disease (cGvHD) occurred less frequently in the ATG-T group compared to ATG-G (7.5% vs. 38.3%, p=0.001). Patients treated with ATG-T manifested a higher incidence of cytomegalovirus (CMV) reactivations (70% vs. 31.9%, p&lt;0.001), with a shorter time between transplant and CMV (&lt;61 days, 77.8% vs. 33.3%, p=0.008) and a higher median CMV copy number (1000 vs. 0, p=0.004). Notably, despite a higher occurrence of CMV reactivations in the ATG-T cohort, most patients were asymptomatic compared to ATG-G (85.7% vs. 43.8%, p=0.005). Finally, we observed no significant differences in terms of 5-year overall survival (OS) and 3-year probability of relapse while comparing ATG-T and ATG-G (32.0% vs 40.3%, p=0.423; 63.9% vs 55.7%, p=0.438, respectively).

Cardiovascular diseases remain the leading cause of mortality worldwide. Although new therapies are actively being developed and used for cardiovascular pathologies, these attempts have not significantly decreased mortality rates. Regenerative medicine has made enormous progress and set promising approaches over the past half-century. However, since autologous (donor-derived) vascular grafts are lacking, an alternative prosthesis must be constructed for cardiovascular disease patients. In vascular tissue manufacturing and regenerative medicine, scientists seek to improve this significant clinical challenge using bio-fabrication techniques combining additive manufacturing, biomaterials science, and advanced cellular biology. In the last few decades, many improvements and changes in various approaches have helped develop bioengineered concepts that reflect native blood vessels’ structure and function. However, numerous challenges must be overcome to clinically translate the next generation of tissue-engineered vascular transplants. This review provides update on the cell sources, scaffold essential for cardiovascular tissue engineering, and tissue engineering approaches as prospective options for curative therapy for blood vessel disease.

The increase in the rate and prevalence of diseases associated with the localized and general loss of bone mass calls for an investigation into therapeutic alternatives that largely involve the de-velopment of new biomaterials and cell therapy, converting tissue bioengineering into a prom-ising option. An experimental model of a critical mandibular lesion in rats has been used to study bone re-generation by treating the ostectomy with the biomaterials Evolution® and Gen-Os® (OsteoBiol®, Italy) combined, or not, with dental pulp stem cells (DP-MSC). The results obtained through the Micro-CT and histological study reveal the almost complete re-covery of the lesion in the group with DP-MSC. These results are supported by increases in endoglin, TGF-β, protocollagen I, parathormone, and calcitonin, generating an environment of bone generation and development when combining Evolution® and Gen-Os® (OsteoBiol®, Italy) with DP-MSC. These promising results confirm the transcendental role of DP-MSC in combina-tion with osteogenic biomaterials for bone regeneration, and warrant further studies, including its assessment in clinical trials.

The selection of biomaterials for biomedical application is a significant challenge. In the last few decades, various bioabsorbable and stable biopolymers have been applied for use as biomedical devices in orthopedic applications. Ultra-high molecular weight polyethylene (UHMWPE) has been extensively used in medical implants, notably in the bearings of hip, knee, and other joint prostheses, owing to its biocompatibility and high wear resistance. For the ACL graft, synthetic UHMWPE is an ideal candidate due to its biocompatibility and its extremely high tensile strength. Despite the appeal of new advanced materials such as carbon fiber, poly-ether-ether ketone, and other load-bearing materials, UHMWPE remains a primary load-bearing candidate material for ACL reconstructions because of its extremely high strength, the simplicity of the fabrication process, its biocompatibility, and low friction. However, some significant problems are observed in UHMWPE based implants, such as wear debris, and oxidative degradation due to the generation of free radicals when exposed to irradiation with gamma rays for grafting or sterilization. Various innovative methodologies have been developed to resolve those problems and enhance the properties of UHMWPE. In this review, we will explore in detail the methods for surface functionalization of UHMWPE and will apply these findings to the case study of UHMWPE for Anterior Cruciate Ligament repair.

The clinical requirement for a good esthetic result for immediate implant placement is the absence of dehiscence in the anterior facial alveolar bone. In the presence of a dehiscence, it is recommend-ed to use a connective tissue graft in addition to immediate implant placement or to change to ear-ly implant placement. However, the literature focusing on dehiscence is scarce, and the influence of different placement times and combined use of connective tissue graft on postoperative esthetics in cases with dehiscence is unclear. Therefore, we quantitatively evaluated the pre-extraction de-hiscence morphology and postoperative changes in the facial tissue of implants in three groups: immediate implant placement (Group I), immediate implant placement with connective tissue graft (Group IC), and early implant placement (Group E). Fifty-two implants were obtained (20 in Group I, 16 in Group IC, and 16 in Group E). A wider dehiscence increases the risk of soft tissue regression, which was one reason for choosing early implant placement. A combination of imme-diate implant placement and connective tissue graft, or early implant placement, tended to result in less soft tissue regression due to the thicker postoperative facial soft tissue volume.

The binary metal oxide mesoporous interfacial layers (bi-MO meso IF layer) templated by a graft copolymer is synthesized between a fluorine-doped tin oxide (FTO) substrate and nanocrystalline TiO2 (nc-TiO2). Amphiphilic graft copolymers, Poly(epichlorohydrin)-graft-poly(styrene), PECH-g-PS, was used as a structure-directing agent, and the fabricated bi-MO meso IF layer exhibits good interconnectivity and high porosity. Even if the amount of ZnO in bi-MO meso IF layer increased, it was confirmed that the morphology and porosity of bi-MO meso IF layer was well maintained. In addtion, bi-MO meso IF layer coated onto FTO substrates show higher transmittance compared with a pristine FTO substrate and dense-TiO2/FTO, due to the reduced surface roughness of FTO. The overall conversion efficiency (η) of a solid state photovoltaic cells, dye-sensitized solar cell (DSSC) fabricated with nc-TiO2 layer/bi-MO meso IF layer TZ1 used as a photoanode reaches 5.0% at 100 mW cm-2, which is higher than that of DSSC with a nc-TiO2 layer/dense-TiO2 layer (4.2%), resulting from enhanced light harvesting, good interconnectivity, and reduced interfacial resistance. The cell efficiency of the device did not change after 15 days, indicating that the bi-MO meso IF layer with solid-state electrolyte has improved electrode/electrolyte interface and electrochemical stability. Additionally, commercial scattering layer/nc-TiO2 layer/bi-MO meso IF layer TZ1 photoanode fabricated solid state photovoltaic cells (DSSC) achieved an overall conversion efficiency (η) of 6.4% at 100 mW cm-2.

Posterior dislocations of the sterno-clavicular joint (SCJ) are rare events, most commonly due to motor vehicle accidents or sports injuries and they often occur in young and active patients. This injury can represent a real emergency because of the vital structures located posterior to the medial clavicle such as anonymous artery, anonymous vein, trachea, subclavian artery and vein, esophagus and thoracic duct. The diagnosis could be insidious given the not peculiar clinical presentation and it is often necessary to perform a computed tomography to identify it. In case of failure of reduction maneuvers, the surgical treatment becomes a mandatory choice, but unfortunately literature reports a restricted cohort of cases and proposes different stabilization techniques without showing a significant comparison of results. Moreover, due to the rarity and high risk of complications, other than the lack of knowledge about the injury and its repair techniques, the management of these injuries are mutually discharged from orthopedic surgeon to the thoracic surgeon and vice-versa. A deep study of the joint anatomical characteristics and its biomechanics allow the surgeon to face surgery more safely, choosing the most appropriate technique. Given the importance of the SCJ for the movement of the shoulder girdle, authors believe that the surgeon’s goal should be to restore the complete range of movement of the joint in case of dislocation. For this reason, stabilization with semitendinosus tendon graft has to be considered one of the best solutions at our disposal to date.

Background: Delayed graft function (DGF) is common after kidney transplantation from de-ceased donor and may significantly affect post-transplant outcomes. This study aimed to evaluating whether an innovative approach, based on the administration of intravenous prostaglandin-analogue iloprost, could be beneficial in reducing the incidence of DGF occurring after kidney transplantation from deceased donors. Methods: This prospective, randomised (1:1), place-bo-controlled study enrolled all consecutive patients who received a kidney transplantation from a deceased donor from January 2000 to December 2012 and who were treated in the peri-transplant period with the prostaglandin-analogue iloprost at 0.27 μg/min through elastomeric pump (treatment group) or placebo (control group). Results: A total of 476 patients were included : DGF was reported in 172 (36.1%) patients in the entire cohort. The multivariate analysis showed that donor’s age > 70 years (OR 2.50, 95% Confidence Interval (CI) 1.40-3.05, p < .001), cold ischemia time > 24 h (OR 2.60, 95 CI 1.50-4.51, p < .001), donor’s AKI (OR 2.71, 95% CI 1.61-4.52, p = .021) and, above all, recipient’s arterial hypotension (OR 5.06, 95% CI 2.52-10.1, p < .0001) were the strongest risk factors for developing post-transplant DGF. The incidence of DGF was 21.4% in the treatment group and 50.9% in the control group (p< .001). Interestingly, among patients who developed DGF, those who received iloprost had a shorter duration of post-transplant DGF (10.58.3 v s13.46.7, days, p= .016). Conclusions: This study showed that the use of a continuous infusion of iloprost could safely and effectively reduce the incidence of DGF in recipients of deceased donor kidneys, allowing a better graft functionality as well as a better graft survival.

The plant graft healing process is an intricate development influenced by numerous endogenous and environmental factors. This process involves the histological changes, physiological and biochemical reactions, signal transduction, and hormone exchanges in the grafting junction. Studies have shown that applying exogenous plant growth regulators can effectively promote the graft healing process and improve the quality of grafted plantlets. However, the physiological and molecular mechanism of graft healing formation remains unclear. In our present study, transcriptome changes in the melon and cucurbita genomes were analyzed between control and NAA treatment, and we provided the first view of complex networks to regulate graft healing under exogenous NAA application. The results showed that the exogenous NAA application could accelerate the graft healing process of oriental melon scion grafted onto squash rootstock through histological observation, increase the SOD, POD, PAL, and PPO activities during graft union development and enhance the contents of IAA, GA3, and ZR except for the IL stage. The DEGs were identified in the plant hormone signal-transduction, phenylpropanoid biosynthesis, and phenylalanine metabolism through transcriptome analysis of CK vs. NAA at the IL, CA, and VB stage by KEGG pathway enrichment analysis. Moreover, the exogenous NAA application significantly promoted the expression of genes involved in the hormone signal-transduction pathway, ROS scavenging system, and vascular bundle formation.

The aim of this study is to emphasize on the clinical uses of amniotic membrane (AM) in multiple ocular disorders. AM possesses many properties including promotion of epithelialization, anti-fibrotic, anti-apoptotic, anti-angiogenic properties. Epithelial wound healing on the eye surface is promoted due to several epidermal and keratocyte growth factors as well as by its anti-inflammatory and anti-scarring effects due to interleukin-10, interleukin-1 receptor antagonists and inhibition of transforming growth factor- beta (TGF-β) signal transduction by AM in the corneal and conjunctival fibroblasts respectively. It plays a crucial role by functioning as a substitute of basement membrane (BM) and as a temporary graft material. It is not only being used as an eye graft but also its extract can be used as an eye drop for corneal and external eye diseases. So its proper preparation, preservation and clinical application can bring a revolutionary change in the treatment of different ocular disorders.

Patients from regions without stem cell transplant (SCT) facilities often seek treatment abroad and return home for post-transplant care. While extensive data exists on GVHD and its risk factors, the prevalence of GVHD in international SCT patients returning to countries without transplant facilities, where multiple factors compromise post-transplant care, is not well documented. We screened 149 transplant recipients and analyzed data from 91 who received transplants abroad and were followed at our center from January 2019 to December 2022. This observational study used data from electronic medical records (EMR) and employed descriptive statistics, inferential tests, and relative risk calculations with forest plots to analyze GVHD prevalence and key risk factors. Of the recipients, 31.8% were residents from nine countries living in the UAE, and 67.2% were UAE citizens. Adults comprised 48.3% of the recipients, and 51.7% were pediatric. Hematological malignancies were the most common indication (49%), primarily in adults. Siblings were the majority of donors (52.6%), followed by related donors (23.09%), and unrelated donors (8.9%). Most (69.2%) received HLA-identical transplants followed by 21.9% who received haploidentical. Among adults, 62.2% developed GVHD, compared to 26% of pediatric patients. Recipients with related HLA-identical donors had a 50% GVHD prevalence, while those with unrelated identical donors had 71%. The overall GVHD prevalence was 50% among the 87.9% who received allogeneic SCTs. Despite favorable factors, GVHD prevalence remains high. Larger multicenter studies are needed to identify and assess the impact of contributing factors.

Objetives: Adequate donor-recipient matching is necessary to achieve the best renal function after transplantation. The nephron load received from the donor, which can be reflected in variables such as age, sex and body mass index, may influence the evolution of the graft. Our objetive was develop a combined score according to the donor-recipient pairing in age, sex and body mass index, and assess its influence on the evolution of the renal graft. Materials and methods: Transplant patients between 2013 and 2020 who had at least 1 year of post-transplant follow-up. A ranking of 0 to 2 points was awarded according to the match between donor and recipient for sex, age and body mass index individually, with higher rank to greater mismatch. Subsequently, a Score with value of 0 to 6 points was created with the combined ranking of the indivudual variables, analyzing its influence on the evolution of the graft by multivariate linear regression. Results: 280 patients followed for 4.3 years of median. Worse renal function was observed at the end of follow-up as the range of each variable increased separately, and the Score created, with a worsening of renal function as the combined Score increased in the multivariate analysis: Coefficient B= -2.4 ml/min, p=0.018. Conclusions: An adequate match between donor and recipient in age, sex and body mass index using this combined Score can help achieve better kidney function after transplantation.

Abstract: The aim of this study is to emphasize on the clinical uses of amniotic membrane (AM) in multiple ocular disorders. AM possesses many properties including promotion of epithelialization, anti-fibrotic, anti-apoptotic, anti-angiogenic properties. Epithelial wound healing on the eye surface is promoted due to several epidermal and keratocyte growth factors as well as by its anti-inflammatory and anti-scarring effects due to interleukin-10, interleukin-1 receptor antagonists and inhibition of transforming growth factor- beta (TGF-β) signal transduction by AM in the corneal and conjunctival fibroblasts respectively. It plays a crucial role by functioning as a substitute of basement membrane (BM) and as a temporary graft material. It is not only being used as an eye graft but also its extract can be used as an eye drop for corneal and external eye diseases. So its proper preparation, preservation and clinical application can bring a revolutionary change in the treatment of different ocular disorders.

Background: In regenerative dentistry the graft material influences the success. It should act as an osteoconductive scaffold, providing a mineral substrate during resorption and inducing the activity of osteoinductive cells capable of producing new bone, platelet growth factors, and cell differentiation factors inducing the differentiation of undifferentiated mesenchymal cells into. Given that dentin shares many biochemical characteristics with bone tissue, it has recently attracted considerable interest as a biomaterial for bone repair. The aim of this study is to compare two grinder types in order to determine the optimal method for producing dentinal particles using a mechanical grinder. Materials and methods: A sample of 40 natural human teeth without restorations, prostheses or root canal treatments was used and divided into two groups subjected to two different grinder speeds (high-speed and low-speed). The high-speed showed a greater dispersion (53.5+-9.89% of the tooth) due to the pulverisation (highly thin granules) of part of the tooth. The low-speed grinder does not pulverize the dentin and the percentage of tooth loss is 9.16+/-2.34%. Conclusion: The low-speed gringer allows to save a major part of the tooth and to have a maximum quantity of graft material but requires more time. Further studies must be promoted to optimise the grinding procedures.

The enzyme-coupled transient receptor potential channel subfamily M member 7, TRPM7, has been associated with immunity and immune cell signalling. Here, we review the role of this remarkable signalling protein in lymphocyte proliferation, differentiation, activation and survival. We also discuss its role in mast cell, neutrophil and macrophage function and highlight the potential of TRPM7 to regulate immune system homeostasis. Further, we shed light on how the cellular signalling cascades involving TRPM7 channel and/or kinase activity culminate in pathologies as diverse as allergic hypersensitivity, arterial thrombosis, and graft versus host disease (GVHD), stressing the need for TRPM7 specific pharmacological modulators.

Background: The ageing process starts in the center of the face, in the periocular region and around the mouth, with a combination of volume loss and tissue descent, wrinkles deepen, and loss of skin structure and quality. Recently, several studies proved the efficacy of therapies based on the autologous adipose tissue grafting that leverages the properties of stromal vascular fraction (SVF) and adipose derived mesenchymal stem cells (ADSCs) to accelerate the regenerative processes of the skin. This study aimed to verify the ability of the guided Superficial Enhanced Fluid Fat Injection (SEFFI) in the facial area to correct volume loss and skin aging and proved the very low rate of complications of this standardized procedure . Methods: we retrospectively collected data from 2,365 procedures performed in Italian centers between 2019 and 2021. Guided SEFFI was performed alone or combined with cosmetic treatments, including the use of hyaluronic acid filler, suspension threads, synthetic calcium hydroxylapatite, botulin toxin, and microneedling. Results: SEFFI was used alone in more than 60% of the patients, and in all face areas. In about one tenth of patients SEFFI was combined with botulin toxin treatment or hyaluronic acid filling. Other procedures were used more rarely. Ecchymosis in the donor or injection sites was the most frequent event, and yet observed in only 14.2% and 38.6% of patients, respectively. Conclusions: The SEFFI technique is standardized and minimally invasive, leading to very few complications. It can be a promising antiaging medical treatment that combines effectiveness, safety, and simplicity.

Investigations reporting positive effects of Extracorporeal Shock Wave Therapy (ESWT) on nerve regeneration are limited to the rat sciatic nerve model. The effects of ESWT on muscle-in-vein conduits (MVCs) have also not been investigated yet. This study aimed to evaluate the effects of ESWT after repair of the rat median nerve with either autografts (ANGs) or MVCs. In male Lewis rats, a 7-mm segment of the right median nerve was reconstructed either with an ANG or MVC. For each reconstructive technique, one group of animals received one application of ESWT while the other rats served as controls. Animals were observed for 12 weeks and nerve regeneration was assessed via computerized gait analysis, the grasping test, electrophysiological evaluations and histological quantification of axons, blood vessels and lymphatic vasculature. Here we provide for the first time a comprehensive analysis of ESWT effects on nerve regeneration in a rat model of median nerve injury. Furthermore, this study is among the first reporting the quantification of lymphatic vessels following peripheral nerve injury and reconstruction in vivo. While we found no significant direct positive effects of ESWT on peripheral nerve regeneration, results following nerve repair with MVCs were significantly inferior to those after ANG repair.

(1) Background: donor-derived circulating free DNA (dd-cfDNA) is an innovative biomarker with great potential for the early identification and prevention of graft damage; (2) Methods: Prospective study to analyze dd-cfDNA plasma levels in 30 kidney transplant patients during their post-transplant follow-up (15 days, 3, 6 and 9 months), to determine if the result could be of interest in the identification of possible adverse events, specially allograft rejection. In addition, the aim is also to verify the obtained data on sensitivity, specificity, NPV and PPV; (3) Results: Plasma levels of dd-cfDNA could be considered a novel biomarker of graft rejection after first term post-transplant up to several months before its clinical presentation, mainly in TCMR or ABMR. In this study, it appears to have no positive predictive value for borderline rejection or TCMR IA. Our results show a low NPV of the technique because other pathologies or biological post-transplant complications can also affect dd-cfDNA levels and they must be considered in the interpretation of the result.; (4) Conclusions: dd cfDNA could allow, together with other additional biomarkers in the context of a future score, avoid invasive biopsies in most cases, mainly in the case of suspected TCMR or ABMR.

Autoimmune limbic encephalitis (LE) is a rare, but devastating complication of allogeneic hem-atopoietic stem cell transplantation (HSCT). There is currently limited evidence describing the risk factors, laboratory features, and underlying mechanisms of this neurologic adverse event. We retrospectively reviewed available clinical, imaging, and laboratory data from adult patients with hematological malignancies who underwent haploidentical HSCT with cyclophosphamide (PTCy) at Chungnam National University Hospital from June 2016 to May 2020. Patients who developed LE were compared to those who did not based on clinical assessment, serum inflam-matory biomarkers, and reconstitution of various T cell populations. Of 35 patients, four devel-oped LE. There were no differences in patient demographics, donor demographics, or treatment conditions between patients that did and did not develop LE. Overall, patients with LE had worse clinical outcomes and overall survival than those without. In addition, they tended to have higher markers of systemic inflammation in the early post-transplant period, including fever, C-reactive protein (CRP), and cytokines. Remarkably, baseline interleukin-6 levels before HSCT were found to be higher in patients who developed LE than those who did not. In addition, analysis of T cell subsets showed impaired expansion of CD25+FOXP3+ regulatory T (Treg) cells in LE compared to non-LE patients despite appropriate reconstitution of the total CD4+ T cell population. Patients that developed LE within the first 30 days of HSCT were likely to have high serum IL-6 among other inflammatory cytokines coupled with suppression of regulatory T cell differentiation. Further work is needed on the mechanisms underlying impaired Treg expansion following HSCT and potential therapies.

Perhaps the greatest challenge in the graft copolymerization of acrylic acid onto starch initiated by Fenton’s is the selectivity of the grafting reaction. Low selectivity means that too much of unwanted homopolymer polyacrylic acid is produced. In this paper, it has been analyzed why with this reaction system, involving a water soluble monomer and indirect initiation, the graft selectivity is such a challenge. Several other grafting reactions, especially with monomers of low water solubility or when direct initiation is applied, show a better grafting performance. A scheme is presented based on reaction engineering principles, that supports an explanation of the observed differences. A more selective activation of starch is a factor, but perhaps even more important is a low monomer to starch ratio at the starting sites of graft reactions. Based on these insights, several methods to improve the graft selectivity are evaluated, with the help of literature data but mostly by experimental explorations in our laboratory. Most promising appears to be a dedicated dosage method, to add monomer in portions over time, tested in a batch reactor with gelatinized cassava starch. This way, both grafting percentage and graft selectivity could be improved. Such could not be realized with the more conventional dosage, which is to add all monomer before the start of the reaction. This can be considered a principal breaktrough. Still, more research and development would be needed to refine the method and to implement the idea also in a continuous reactor at larger scale.