Enhancement of blood compatibility of implants by helium plasma treatment

The effect of plasma treatment to improve blood compatibility of polyurethane coatings was studied. Medical-grade polyurethane was used for coating glass substrates. Human coronary artery endothelial (HCAE) cells were cultured on glass substrate, polyurethane-coated glass with and without plasma treatment, and collagen-treated polyurethane-coated glass substrates. To quantify cell growth, HCAE cells were stained with acridine orange followed by examination under fluorescence microscopy. Cell growth on the plasma-treated polyurethane coatings was increased by 300 % greater than on the untreated polyurethane coatings. Cell growth on glass and collagen-treated polyurethane coatings was 9 % and 28 % more than plasma-treated polyurethane coatings respectively. However, the cell adhesion on the plasma-treated polyurethane film (89 %) was higher than on the glass (71 %) and the collagen-treated polyurethane film (42 %) respectively. HCAE cell adhesion was studied under shear stress in a laminar flow condition at 37 °C. X-ray photoelectron spectroscopy (XPS) showed that plasma treatment caused oxidation of the polyurethane surface with a significant increase in the carbonyl bonds. Plasma treatment of polyurethane film also resulted in significant increase in wettability. Atomic force microscope (AFM) studies indicate no significant change in surface roughness of polyurethane film due to plasma treatment.