IN-VITRO BIOCOMPATIBILITY OF FLUORINATED POLYURETHANES

The in vitro biocompatibility of fluorinated polyurethanes (FPUs), labelled as FPU 42, 52, 58, and 60, was evaluated by means of thrombogenicity, cytoxicity and cytocompatibility tests. Cardiothane(R) was taken as control material. The thrombogenicity was tested on thin material films by measuring the activation of prekallikrein (PKK) to kallikrein (KK). Level I cytoxicity tests of the bulk materials, i.e. Neutral Red (NR) uptake, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and Kenacid Blue (KB) assays, were performed to assess the influence of the polymer extracts on, respectively, lysosomes, mitochondria and cell proliferation. The cytocompatibility was evaluated, on thin membranes made by a spraying phase-inversion process, by measuring the area of the polymer surface covered by human umbilical vein endothelial cells (HUVEC) 1 week after seeding. The results indicate that all the polymers are not thrombogenic, and not cytotoxic. The FPUs that contain polycaprolactone glycol (PCLG) (FPU 52 and 60) instead of poly(tetramethylene ether) glycol (PTMEG) (FPU 42 and 58) as soft segment show the lowest thrombogenicity and the best cytocompatibility.