Using Low Temperature Plasma (LTP) to Develop Antimicrobial Vascular Tissue Grafts

Engineered vascular grafts are gaining usage to synthesize blood vessels as a treatment for cardiovascular diseases. Dacron and ePTFE has been employed for vascular grafts, however, these does not work well for small diameter grafts (<6 mm) due to intimal hyperplasia and thrombosis. In the present study PTFE was treated with LTP to enhance cell attachment. Scaffolds were also modified with Ag-PVP nanoparticles and the antimicrobial peptides (AMPs), p753 and p359. Human umbilical vein endothelial cells (HUVEC) were plated on the developed scaffolds and cell proliferation was determined by the MTT assay. Cell attachment on scaffolds was visualized by microscopy and by expression of different cell markers. An increase in cell viability and Integrin- α 5 gene was observed in LTP treated scaffolds. MTT Assay was performed using HEK293 cells to determine toxicity of antimicrobial agents which showed it to be non-toxic to the cells. MTT Assay exhibited that Ag-PVP and AMPs were non-toxic to cells at 100μg/mL and 50μg/mL, respectively. Live/dead analysis and plate count of treated bacteria exhibited bacterial inhibition on treated scaffolds compared to non-treated scaffold. SEM was performed to analyze the structural changes of bacteria after treatment with antimicrobial agents. Based on our initial results, more scaffolds alternatives will be developed and investigated for cell growth and vascularization studies.