Viscoelastic relaxation measurements on Stirene-Butadiene rubbers (SBR) doped with Carbon Nanotube (CNT) at different concentration show the time-temperature superposition (TTS). This process is described in terms of the Mode Coupling Theory (MCT) approaches to the viscoelasticity by considering the frequency behavior of the loss modulus E”(ω), and shown that the corresponding TTS is linked to a (ω)1/2 decay. From of the analysis of the obtained data we observe that the interaction between the SBR and CNT determine different decays different decays according to their concentration. The rubbers with the lowest CNT concentration are only characterized, in the studied T-range, by a fragile glass forming behavior. Whereas those at the highest ones instead show, at a specific temperature TL, a crossover towards a pure Arrhenius, that according to the MCT, indicates the presence of a kinetic glass transition (KGT); where the system response functions are characterized by scaling behaviors.

The by-products of the juice and cider industry in forms of pomace and peels are rich sources of pectin which further can be used in the food, cosmetic and non-food industries. The aim of the research was to use by-products from fruits and berries grown in Latvia: Rhubarb (Rheum rhabarbarum); Apples (Malus domestica); Plums (Prunus domestica); Red Currants (Ribes rubrum); Black Currants (Ribes nigrum); Gooseberries (Ribes uva-crispa); Sour Cherries (Prunus cerasus); Pumpkins (Cuccurbita spp.) for pectin extraction. Citric acid (0.1 N) was used for the hot water extraction. The yield of pectin (PY = 4.47 – 17.8 % DM) and physicochemical parameters of obtained pectin were determined: methoxy degree (ME = 4.27 – 8.13 %), esterification degree (DE = 45.16 % – 64.06 %), anhydrouronic acid content (AUA = 38.23.% - 84.74 %); moisture content (5.2 – 7.4 %), ash content (1.42 - 2.88 g 100 g-1), total phenolic content (TPC = 2.076 – 4.668 GAE, mg L-1) and antiradical scavening activity (DPPH Method (0.56 – 37.29 %)). Pectin analysis was performed by FT-IR and the rheological properties of pectin gels were determined.

The synthesis these past few years of novel organic molecules that spontaneously self-assemble into a large variety of molecular architecture, particularly generating organogels, has opened up new horizons for preparing functional materials. Here, we present an original preparation path of such materials through the making of hybrid gels of these molecules together with covalent polymers. Three types of systems are described: i) intermingled gels where a polymer gel and an organogel pervade one another; ii) encapsulation of self-assembled filaments in polymer fibrils, which provides a system with unusual magnetic properties; iii) the reverse situation where self-assembled nanotubes sheathe polymer fibrils. Here two covalent polymers are considered: a neutral polymer, namely stereoregular polystyrene (isotactic or syndiotactic), and a semi-conducting polymer, P3BT. In the latter case, semi-conducting nanowires are obtained.

Biological gels (bio-gels) are hydrated polymer networks that serve diverse biological functions, which often lead to intentional or unintentional exposure to particulate matter. In this work, we derive a microscopically motivated framework that enables the investigation of penetration mechanisms into bio-gels. We distinguish between two types of mechanisms: spontaneous (unforced) penetration and forced penetration. Using experimental data available in literature, we exploit the proposed model to characterize and compare between the micro-structures of respiratory, intestinal, and cervicovaginal mucus and two types of biofilms. Next, we investigate the forced penetration process of spherical and ellipsoidal particles into a locally quadrilateral network. The proposed framework can be used to improve and complement the analysis of experimental findings in vitro, ex vivo, and in vivo. Additionally, the insights from this work pave the way towards enhanced designs of nano-medicines and allow to assess risk factors related to the nano-pollutants exposure.

Slow and controlled release systems for drugs, have attracted increasing interest recently. A highly efficient metal-organic gels (MOGs) drug delivery carrier, i.e., MIL-100(Al) gels, has been fabricated by a facile, low cost and environment friendly one-pot process. The unique structure of MIL-100(Al) gels leads to a high loading efficiency (620 mg/g) towards doxorubicin hydrochloride (DOX) as a kind of anticancer drugs. DOX-loaded MOGs exhibited high stability under physiological conditions and sustained release capacity of DOX for up to 3 days (under acidic environments). They further showed sustained drug release behavior and excellent antitumor effects in in vitro experiments on HeLa cells, in contrast with the extremely low biotoxicity of MOGs. Our work provides a promising way for the anticancer therapy, by utilizing this MOGs-based drug delivery system, as an efficient and safe vehicle.

Human Platelet lysate, a hemoderivative product rich in growth factors, holds significant promise in tissue engineering and regenerative medicine. However, its practical utility in liquid or gel form is hampered by challenges such as limited stability and handling difficulties. This study aimed to engineer dry and porous aerogels from platelet lysate hydrogel using an environmen-tally friendly supercritical CO2-based shaping process customized for tissue engineering appli-cations. The resulting aerogels demonstrated remarkable mechanical robustness and improved manageability. Notably, they exhibited a high-water absorption capacity. Moreover, these aer-ogels exhibited a sustained and favourable biological response in-vitro. They demonstrated the ability to release functional growth factors, sustaining cellular metabolic activity similar to that of conventional culture conditions, even after prolonged storage. Furthermore, they supported the adhesion and proliferation of murine fibroblasts (BALB-3T3) and the migration of Human Um-bilical Vein Endothelial Cells (HUVEC). In addition to serving as excellent matrices for cell culture, these proposed aerogels also function as efficient growth factor delivery systems. This multi-functional capability positions them as promising candidates for various tissue regeneration strategies. Importantly, the elaborated aerogels can be conveniently stored and considered as ready-to-use products, enhancing their practicality and applicability in regenerative medicine

Natural fibers have attracted increasing interest as an alternative to produce environmentally friendly and sustainable materials. Particularly, hemp fibers have revealed to be widely used in various industrial applications due to their extremely unique properties. However, hemp can generate a large amount of agro-waste, and results in an attractive source of biopolymers for the development of low-cost materials in alternative to the raw materials and conventional petroleum-based plastics. In addition, deep eutectic solvents (DESs), a new type of truly green solvents, have been tested to remove gums, lignin, and other non-cellulosic components from hemp fibers. Reusing these components dissolved into the DESs to fabricate new materials directly by electrospinning is a very attractive but still unexplored endeavor. Thus, this innovative research to venture new upcycling pathways is focused on the fabrication of composite nanofibers by electrospinning of a gel-based blend of Poly(vinyl alcohol) (PVA) and hemp agro-waste (HW) dissolved into choline chloride (ChCl) : Glycerol (1:2) and ChCl : Urea (1:2) DES mixtures. The results obtained revealed that the produced nanofibers displayed uniform appearance with diameters ranging from 257.72 ± 65.63 nm to 380.78 ± 133.98 nm. In addition, the mechanical properties of the electro-spun composite nanofibers produced from the gel-based blends of HW dissolved in DESs and PVA (HW-DESs_PVA) were found to be superior, resulting in an enhanced tensile strength and Young’s modulus. Furthermore, the incorporation of HW into the nanofibers was able to provide bioactive antioxidant and antibacterial properties. Overall, this study demonstrated a promising, more sustainable, and eco-friendly way to produce electrospun composite nanofibers using HW in a circular economy perspective.

Background: DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia’s oxidative stress in vitro. Methods: Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwash and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM. Results: DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but not in its prevention. Gel formulation did not express adequate activity compared to the mouthwash. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules’ effect. Conclusion: A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Surfactant agents showed harmful activity against oral epithelia.

Oral and parenteral delivery of first-line anticonvulsant Valproic cid (VA) are associated with serious adverse effects, high hepatic metabolism, high clearance, and low bioavailability in brain. GastroPlus program was used to predict in vivo performance of immediate (IR) and sustained release (SR) products in human. HSPiP software predicted excipients with maximum possible miscibility of the drug. Based on GastroPlus and HSPiP program, various excipients were screened for experimental solubility study and prepared cationic nanoemulsions and respective gels for nasal to brain delivery. These were characterised for size, size distribution, polydispersity index, zeta potential, morphology, pH, % transmittance, drug content, and viscosity. In vitro drug release, ex vivo permeation profile (goat nasal mucosa), and penetration studies were conducted. Result showed that in-vivo oral drug dissolution and absorption were predicted as 98.6 mg and 18.8 mg, respectively from both tablets (IR and SR) at 8 h using GastroPlus. The drug access to the portal vein was relatively predicted high in IR (115 mg) as compared to SR (82.6 mg). Plasma drug concentration-time profile predicted was in good agreement with published reports. The program predicted duodenum and jejunum as the prime site of drug absorption and no effect of nanonization on Tmax for sustained release formulation. Hansen parameters suggested suitable selection of excipients. The program recommended for nasal to brain delivery of the drug using cationic mucoadhesive product. The optimized stable CVE6 was associated with optimal size (113 nm), low PDI (0.26), high zeta potential (+34.7 mV), high transmittance (97.8%), and high strength (0.7 %w/w). In vitro release and ex vivo permeation of CVE6 were found to be substantially high as compared to anionic AVE6 and respective gels. Penetration study executed high fluorescence intensity with CVE6 and CVE6-gel as compared to suspension and ANE6 which may be attributed to electrostatic interaction between mucosal membrane and nanoglobules. Thus, cationic nanoemulsion and respective mucoadhesive gel are promising strategy for delivery of VA to brain through intransal administration for the treatment of seizure and convulsion.

Radio-fluorogenic (RFG) gels become permanently fluorescent when exposed to high-energy radiation with the intensity of the emission proportional to the local dose of radiation absorbed. An apparatus is described, FluoroTome 1, that is capable of taking a series of tomographic images (thin slices) of the fluorescence of such an irradiated RFG gel on-site and within minutes of radiation exposure. These images can then be compiled to construct a 3D movie of the dose distribution within the gel. The historical development via a laboratory-bench prototype to a readily transportable, user-friendly apparatus is described. Instrumental details and performance tests are presented.

The acylation of unsymmetrical N-benzylbispidinols in aromatic solvents without external base led to formation of supramolecular gels, which possess different thickness and stability depending on the substituents in para-positions of benzylic group and nature of acylating agent as well as on the nature of the solvent used. Structural features of the native gels as well as of their dried forms were studied by complementary techniques including FT IR- and ATR-spectroscopy, AFM, TEM, SEM, SAXS. Structures of the key crystalline compounds were established by X-ray diffraction. Analysis of obtained data allowed speculating on the crucial structural and condition factors that governed the gel formation. The most important factors were: (i) absence of base, either external or internal; (ii) presence of HCl; (iii) presence of carbonyl and hydroxyl groups to allow hydrogen bonding; (iv) presence of two (hetero)aromatic rings at both sides of the molecule. The hydrogen bonding involving amide carbonyl, hydroxyl at 9th position and, very probably, ammonium N-H+ and Cl- anion appear to be responsible for the formation of infinite molecular chains required for the first step of gel formation. Subsequent lateral cooperation of molecular chains into fibers occured, presumably, due to the aromatic pi-pi-stacking interactions. sc-CO2 drying of the gels gave rise to aerogels morphology different from that of air dried samples.

The necessity to reduce the effect of the greenhouse phenomenon imposed the turn of the food packaging technology to the use of biobased raw materials decreasing the carbon dioxide fingerprint. In this direction alginates derived from brown algae species are of the most promising biobased biopolymers, used for development of edible active coatings, capable to protect food from oxidation/bacterial spoilage. In this study sodium alginate, which was plasticized with glycerol and mixed with a biobased thymol/natural halloysite nanohybrid, was used to develop novel edible active coatings. Active nanocomposite coatings developed by mixing of pure halloysite with sodium alginate/glycerol matrix were produced for comparison purposes. X-Ray and Fourier Transform Infrared Spectroscopy indicated higher compatibility of thymol/halloysite nanohybrid with sodium alginate/glycerol matrix compared to the relevant of pure halloysite. This increased compatibility led to higher tensile properties, water/oxygen barrier properties, and total antioxidant activity. All coating samples were applied as edible active coatings for “tsalafouti” spreadable soft cheese, exhibited a reduction of mesophilic microbial population of more than one log10(cfu/g) unit comparing with uncoated cheese. Moreover, the reduction of mesophilic microbial population was increased by increasing halloysite and thymol content which indicates the sodium alginate/glycerol/thymol/halloysite as promising edible active coatings for “tsalafouti”.