This study describes a comparative in vitro study of the toxicity behavior of zinc oxide (ZnO) nanoparticles and micro-sized particles. The study aimed to understand the impact of particle size on ZnO toxicity by characterizing the particles in different media, including cell culture media, human plasma, and protein solutions (bovine serum albumin and fibrinogen). The study used various techniques such as atomic force microscopy (AFM), transmission electron microscopy (TEM), and dynamic light scattering (DLS) to characterize the particles and their interactions with proteins. Hemolytic activity, coagulation time, and cell viability assays were used to assess ZnO toxicity. The results highlight the complex interactions between ZnO NPs and biological systems, including their aggregation behavior, hemolytic activity, protein corona formation, coagulation effects, and cytotoxicity. Moreover, the study indicates that ZnO nanoparticles are not more toxic than micro-sized particles, and the 50 nm particles resulted in general the least toxic. Furthermore, the study found that at low concentrations, no acute toxicity was observed. Overall, this study provides important insights into the toxicity behavior of ZnO particles and highlights that no direct relationship between nanometer size and toxicity can be directly attributed.

Melittin, a natural antimicrobial peptide, displays a broad-spectrum antimicrobial activity, which has caused increasing attention as a potential antibiotic alternative. However, melittin has not been used widely at present due to its high hemolysis and low proteolytic stability. In this study, N-terminal fatty acid was conjugated to melittin to develop new melittin-derived lipopep-tides (MDLs) for improving the limitation of melittin. Our results showed that, the antimicrobial activity of MDLs was increased by 2 to 16 times compared with native melittin, and the stability of these MDLs against trypsin and pepsin degradation was increased by 50 to 80%. Besides, the hemolytic of the MDLs decreased when the length of the carbon chain of fatty acids exceeded 10. Among them, the newly designed analog Mel-C8 showed optimal antimicrobial activity and protease stability. The antimicrobial mechanism studied revealed that the MDLs showed a rapid bactericidal effect by interacting with LPS or LTA and penetrating the bacterial cell membrane. In conclusion, we designed and synthesized a new class of MDLs with potent antimicrobial activity, high proteolytic stability, and low hemolysis through N-terminal fatty acid conjugation.

Abstract: Sickle cell disease (SCD) is an autosomal recessive monogenic disorder caused by a homozygous mutation in the β-globin gene, which leads to erythrocyte sickling, hemolysis, vaso-occlusion and sterile inflammation. Oral l-glutamine administration has been shown to reduce the frequency of pain crisis in SCD patients, however, the long-term effect of l-glutamine in SCD remains to be determined. To understand the long-term effect of l-glutamine administration in SCD liver we used quantitative liver intravital microscopy and biochemical analysis in humanized SCD mice. We here show that chronic l-glutamine administration reduces hepatic hemoglobin-heme-iron level, but fails to ameliorate ischemic liver injury. Remarkably, we find that this failure in resolution of hepatobiliary injury and persistent liver fibrosis is associated with reduced expression of hepatic Kupffer cells post l-glutamine treatment. These findings establish the importance to investigate the long-term effects of l-glutamine therapy on liver pathophysiology in SCD patients.

(1) Background: The evaluation of ventricular assist devices requires the usage of biocompatible and chemically stable materials. The commonly used polyurethanes are characterized by versatile properties making them well suited for heart prostheses applications but simultaneously they show low stability in biological environment. (2) Methods: An innovative material - copolymer of poly(ethylene-terephthalate) and dimer linoleic acid - with controlled and reproducible physico-mechanical and biological properties was developed for medical applications. Biocompatibility (cytotoxicity, surface thrombogenicity, hemolysis and biodegradation) were evaluated. All results were compared to medical grade polyurethane currently used in the extracorporeal heart prostheses. (3) Results: No cytotoxicity was observed and no significant decrease of cells density as well as no cells growth reduction was noticed. Thrombogenicity analysis showed that the investigated copolymers have the thrombogenicity potential similar to medical grade polyurethane. No hemolysis was observed (the hemolytic index was under 2% according to ASTM 756-00 standard). These new materials revealed excellent chemical stability in simulated body fluid during 180 days ageing. (4) Conclusions: The biodegradation analysis showed no changes in chemical structure, molecular weight distribution, good thermal stability and no changes in surface morphology. Investigated copolymers revealed excellent biocompatibility and great potential as materials for blood contacting devices.

Introduction Acalypha indica (AI) is an Ayurvedic medicinal plant. Some of this plant’s phytochemicals have been reported to cause oxidative stress in red blood cells. However, we know very little about those chemicals due to a dearth of literature. We present a case in which a patient with a previously unidentified glucose-6-phosphate dehydrogenase (G6PD) deficiency experienced acute hemolysis after ingesting fresh AI plant leaves. Case Presentation A 65-year-old man presented with jaundice, pallor, and haematuria following ingestion of the "Kuppamenia mallum" dish. His peripheral blood picture showed bite cells and Heinz bodies. A positive Brewer's test raised the clinical suspicion of G6PD deficiency. Low values of the G6PD level assessment at the follow-up visit confirmed the diagnosis. Conclusion Although AI is regarded as a medicinal plant, acute hemolysis can also occur after consumption in G6PD-deficient patients. This case emphasises the need for further research to identify the phytochemicals and their concentrations that can induce toxicity.

Circulating miRNA-451a has recently emerged as an important biomolecule with potential clinical values as a diagnostic marker for several diseases. However, to be used as such, it is critical to accurately assay miRNA-451a in the clinic. Yet, pre-analytical factors that can affect such an error-free clinical assay of miRNA-451a have not been explored. This study aimed at investigating several of these pre-analytical factors that may affect the accurate quantification of miRNA-451a in human blood samples. We initially evaluated miRNA-451a levels in red blood cells (RBCs), white blood cells (WBCs), platelets, and plasma by droplet digital PCR (ddPCR). Next, we quantified miRNA-451a levels in whole blood or plasma stored at different temperatures for different time periods by ddPCR and used hemolyzed plasma samples to study the effects of hemolysis on plasma miRNA-451a concentration. We found that WBCs and platelets contain trace amounts of miRNA-451a and that about 99.9% of miRNA-451a in the blood are localized in RBCs. Hemolyzed plasma showed 58.5-fold increase in miRNA-451 concentration as compared to non-hemolyzed plasma. Importantly, plasma stored at room temperature (RT) or 4ºC showed a steady statistically significant decrease in miRNA-451a levels over a 7-day period whereas plasma samples stored at -20 or -80ºC for up to 7 days showed stable miRNA-451a levels. Together, our data indicate that hemolysis and blood storage at RT or 4ºC may have significant negative effects on the levels of circulating miRNA-451a.

Abstract Sickle cell anaemia (SCD) is a life-threatening haematological disorder which is predominant in sub-Saharan Africa and is triggered by a genetic mutation of the β-chain haemoglobin gene resulting in the substitution of glutamic acid with valine. This mutation leads to the production of an abnormal haemoglobin molecule called haemoglobin S (HbS). When deoxygenated, haemoglobin S (HbS) polymerizes and results in a sickle-shaped red blood cell which is rigid and has a significantly shortened life span. Various reports have shown a strong link between oxidative stress, inflammation, the immune response, and the pathogenesis of sickle cell disease. The consequence of these processes lead to the development of vasculopathy (disease of the blood vessels) and several other complications. The role of the immune system, particularly the innate immune system, in the pathogenesis of SCD has become increasingly clear in recent years of research, However, little is known about the roles of the adaptive immune system in this disease. This review examines the interaction between the immune system, inflammation, oxidative stress, blood transfusion, and their effects on the pathogenesis of sickle cell anaemia