The aim of the present study was to evaluate the cytotoxicity of pristine graphene monolayer and its utility as a scaffold for murine fibroblast L929 cell line. Cell viability, morphology, cytoskeleton architecture (microfilaments and microtubules), cell adhesion and migration into the scratch-wound area were determined using pristine graphene-coated microscopic slides. We found that fibroblasts cultured on pristine graphene monolayer exhibited changes in cell attachment, motility and cytoskeleton organization. Graphene was found to have no cytotoxicity on L929 fibroblasts and increased cell adhesion and proliferation within 24 h of culture. The area of cells growing on graphene was comparable to the area of fibroblasts cultured on glass. Migration of cells on the surface of graphene substrate appeared to be more regular in comparison to uncoated glass surface, however in both control (glass) and experimental (graphene) groups the scratch wound was closed after 48 h of culture. Taken together, our results indicate that pristine graphene monolayer is non-toxic for murine subcutaneous connective tissue fibroblasts and could be beneficial for recovery of damaged tissues after injury. These studies could be helpful in evaluating biocompatibility of graphene, which still remains ambiguous.

This study provides a review of the therapeutic potential of graphene dressing scaffolds and mesenchymal stem cells (MSCs) and their synergistic effects with respect to cutaneous wound healing. This study also considers their putative action mechanism based on the antibacterial, immunomodulating, angiogenic, matrix remodeling effects of materials belonging to the graphene family and MSCs during the wound healing process. In addition, this study discusses the cytocompatibility of graphene, its uses as a platform for skin substitutes, the properties it possesses with respect to providing protection against microbial invasion as well as strategies aimed at minimizing the chance of the occurrence of sepsis. MSCs are capable of secreting several factors that exert a therapeutic impact on reparative processes and tissue regeneration. In light of experiments conducted to date, graphene combined with MSCs appears to have the potential to enhance both the wound healing process and infection control at the injury site.

This study investigates the effect of graphene scaffold on morphology, viability, cytoskeleton, focal contacts, mitochondrial network morphology and activity in BALB/3T3 fibroblasts and provides new data on biocompatibility of the “graphene-family nanomaterials”. We used graphene monolayer applied onto glass cover slide by electrochemical delamination method and regular glass cover slide, as a reference. The morphology of fibroblasts growing on graphene was unaltered, and the cell viability was 95% compared to control cells on non-coated glass slide. There was no significant difference in the cell size (spreading) between both groups studied. Graphene platform significantly increased BALB/3T3 cell mitochondrial activity (WST-8 test) compared to glass substrate. To demonstrate the variability in focal contacts pattern, the effect of graphene on vinculin was examined, which revealed a significant increase in focal contact size comparing to control-glass slide. There was no disruption in mitochondrial network morphology, which was branched and well connected in relation to the control group. Evaluation of the JC-1 red/green fluorescence intensity ratio revealed similar levels of mitochondrial membrane potential in cells growing on graphene-coated and uncoated slides. These results indicate that graphene monolayer scaffold is cytocompatible with connective tissue cells examined and could be beneficial for tissue engineering therapy.

A microbioanalytical method of stem cell (SC) differentiation towards cardiac cells using a newly developed digitally controlled microdispenser.

Trivalent chromium is considered an essential element in the nutrition of both animals and humans. Animal studies confirm many beneficial effects of organic and inorganic chromium compounds on carbohydrate, protein and lipid metabolism in the body. Glucose tolerance factor (GTF) has been demonstrated to involve an active form of trivalent chromium, which sustains normal glucose metabolism. Cr(III) compounds form enzymes and ribonucleic acids, accelerate blood clotting and increase β-glucuronidase activity. Chromium also participates in antioxidant processes, in the synthesis of RNA and DNA and in the immune response, as well as affects secretion of hormones and some vitamins. It has been demonstrated that chromium improves lean body mass in animals, increases growth rate and feed conversion and improves feed intake and energy efficiency. Organic chromium reduces mortality and improves animal reproduction parameters. It also enhances immunity and strengthens response to preventive vaccination. It has been noted in many animal species that a diet low in chromium leads to deficiency symptoms, such as reduced feed intake, lower weight gains, reproductive disorders and increased lipid levels. Chromium deficiency can also result from stress. Moderate chromium deficiency is a risk factor of ischemic heart disease with myocardial infarction. Such a condition may pose a great risk of coronary artery disease. Dietary chromium requirement of an animal body is probably 300 μg Cr/kg d.w. of feed, which is usually satisfied by the ration provided. The highest concentration of chromium is found in the hair, skin and teeth, followed by the liver, kidneys, spleen, and slightly lower in the heart, muscles, pancreas, lungs, bones and brain. Chromium absorption rates in the human intestine range between 0.5 and 2% of the daily intake of inorganic Cr forms, and from 25 to 30% of the element ingested as organic complexes. Clinical studies show that the kinetics of chromium excretion from the system are complex and can be described by a multi-range model, the half-life ranging from 13 min to 192 days. Dietary chromium nanocomposite supplementation (CrNano) used in pigs nutrition has significantly increased Cr content in the blood, longissimus muscle, heart, liver, kidneys, jejunum and ileum. Chromium nanocomposite supplementation acts more effectively on the tissues and, as a consequence, increases the accumulation of the element. .