Graphene Oxide Nanosurface Reduces Apoptotic Death of HCT116 Colon Carcinoma Cells Induced by Zirconium Trisulfide Nanoribbons.

Due to their chemical, mechanical, and optical properties, 2D ultrathin nanomaterials have significant potential in biomedicine. However, the cytotoxicity of such materials, including their mutual increase or decrease, is still not well understood. We studied the effects that graphene oxide (GO) nanolayers (with dimensions 0.1-3 µm and average individual flake thickness less than 1 nm) and ZrS3 nanoribbons (length more than 10 µm, width 0.4-3 µm, and thickness 50-120 nm) have on the viability, cell cycle, and cell death of HCT116 colon carcinoma cells. We found that ZrS3 exhibited strong cytotoxicity by causing apoptotic cell death, which was in contrast to GO. When adding GO to ZrS3, ZrS3 was significantly less toxic, which may be because GO inhibits the effects of cytotoxic hydrogen sulfide produced by ZrS3. Thus, using zirconium trisulfide nanoribbons as an example, we have demonstrated the ability of graphene oxide to reduce the cytotoxicity of another nanomaterial, which may be of practical importance in biomedicine, including the development of biocompatible nanocoatings for scaffolds, theranostic nanostructures, and others.

Synthesis, Toxicity Assessment, Environmental and Biomedical Applications of MXenes: A Review.

MXenes are a family of two-dimensional (2D) composite materials based on transition metal carbides, nitrides and carbonitrides that have been attracting attention since 2011. Combination of electrical and mechanical properties with hydrophilicity makes them promising materials for biomedical applications. This review briefly discusses methods for the synthesis of MXenes, their potential applications in medicine, ranging from sensors and antibacterial agents to targeted drug delivery, cancer photo/chemotherapy, tissue engineering, bioimaging, and environmental applications such as sensors and adsorbents. We focus on in vitro and in vivo toxicity and possible mechanisms. We discuss the toxicity analogies of MXenes and other 2D materials such as graphene, mentioning the greater biocompatibility of MXenes. We identify existing barriers that hinder the formation of objective knowledge about the toxicity of MXenes. The most important of these barriers are the differences in the methods of synthesis of MXenes, their composition and structure, including the level of oxidation, the number of layers and flake size; functionalization, test concentrations, duration of exposure, and individual characteristics of biological test objects Finally, we discuss key areas for further research that need to involve new methods of nanotoxicology, including predictive computational methods. Such studies will bring closer the prospect of widespread industrial production and safe use of MXene-based products.

Effects of different trends on the development and outcome of early kidney allograft dysfunction.

OBJECTIVES: To show the effects of different factors on development and outcome of early kidney allograft dysfunction. MATERIALS AND METHODS: Two hundred thirty-one kidney transplant recipients were divided into 2 groups: group 1 (125 patients transplanted from 1999-2004) and group 2 (106 patients transplanted from 2008-2013). Age range was 12 to 62 years (group 1) and 7 to 71 years (group 2). Deceaseddonor transplant was more frequent in group 1 (76.8%), and living-donor transplant in group 2 (68.8%). In group 1, transplant was performed for glomerulonephritis or pyelonephritis; in group 2, additional risk factors (18 patients) included diabetes (11 patients), systemic lupus erythematosus (5 patients), amyloidosis (1 patient), and aortic and mitral valve replacement because of bacterial endocarditis (1 patient). In groups 1 and 2, immunosuppression after transplant included cyclosporine, mycophenolate mofetil, and steroids; patients in group 2 also had induction with anti-CD25 monoclonal antibodies. RESULTS: Primary graft function occurred in 89 patients in group 1 (71.2%) and 83 patients in group 2 (78.3%). Immediately after transplant, delayed graft function included anuria, oliguria, adequate amount of urine, and secondary delayed function (several days of polyuria followed by decreased urine output). Ischemia was a leading cause of delayed renal graft function. Anuria after living-donor transplant was a sign of vascular thrombosis. Rejection was the main cause of secondary delayed graft function, which occurred in only group 1. Survival at 1 year in patients with delayed graft function was 80% in group 1 and 100% in group 2 because of the absence of septic complications. CONCLUSIONS: Despite extension of indications, primary functioning of kidney transplants and patient survival increased. Improved care enables long-term rehabilitation of recipients and expanding criteria for kidney transplant.