STEM/PROGENITOR CELLS ADHESION STRENGTHENING TO SYNTHETIC MATERIAL USING EXTRACELLULAR MATRIX

Abstract

Background: Tissue-engineered vascular grafts of small diameter have being widely used in coronary artery bypass grafting. However, the rate of settling of these grafts with endothelial cells is insufficient. Aims:The aim of the study was to selucidate the adhesion of endothelial progenitor cells and mesenchymal stem cells to synthetic materials (polystyrol, polytetrafluoroethylene) preprocessed with extracellular matrix (gelatin, fibronectin, collagen) in vitro.Materials and methods: For the study,the endothelial progenitor cells (EPC) were isolated from the peripheral blood of patients with ischemic heart disease, and mesenchymal stem cells (MSC) — from bone marrow of Wistar rats. Commercial monoclonal antibodies for flow- cytometry were used to determine the phenotype of EPC. To isolate the early and late EPC from mononuclear cells of peripheral blood, cells were raised for 8 and 16 days on a gelatin or fibronectin based substrate. The commercial kits for enzyme linked immunoassay were applied to assess levels of cytokine production and nitric oxide by early and late EPC conditioned by gelatin or fibronectin on the 8th and 16th days of growth. To conduct the study the MSC were isolated from bone marrow of rats. To determine the attachment of adherent fraction of nucleated bone marrow cells, cell morphology, the adipogenic and osteogenic differentiation were evaluated. To assess migration of MSC in real time within 24 hours on the device Cell-IQ, we used «closure/wound healing» test. The commercial kits for enzyme linked immunoassay were applied to assess levels of cytokine production and nitric oxide by MSC; and components of the extracellular matrix (fibronectin, collagen I and type IV) ― to assess the increased adhesion of MSC to the polytetrafluoroethylene. Results: The results demonstrated that endothelial progenitor cells adhere to both gelatin and fibronectin and confirmed the influence of these extracellular matrix components on the cytokine levels produced by early and late endothelial cells. The combination of fibronectin with type I or IV collagen or the combination of thereof promotes the adhesion to polytetrafluoroethylene and colonization of the graft.Conclusions: Preprocessing of synthetic material (polystyrene, polytetrafluoroethylene) enhances adhesion and growth of EPC and MSC which can be implemented when creating tissue-engineered vascular grafts for small diameter coronary artery bypass grafting with specified conditions of settlement by the cells involved in neointima formation.