The study of collagen immobilization on polyurethane by oxygen plasma treatment to enhance cell adhesion and growth

In order to enhance cell adhesion and growth on medical polyurethane (PU) surface, type I collagen was immobilized on the oxygen plasma treated PU (COL-P-PU) by a safe, easy, effective and one-step process. The optimal parameter of plasma treatment was 60 W for 5 min in oxygen condition. This parameter was confirmed by measuring mole number of peroxide active groups on plasma treated PU (P-PU) by iodide method. Collagen adhesive strength test was carried out to verify the improvement of the interface of collagen layer and PU film. The optimal plasma treating condition concluded by collagen adhesive strength test also accorded with calculation of oxygen active groups on P-PU. Furthermore, water contact angle was tested to evaluate hydrophilicity of the PU surface; the result indicated that plasma treatment and collagen immobilization could improve hydrophilicity of PU. Moreover, Hela cells were cultured on the surface of PU, P-PU and COL-P-PU to evaluate cell compatibility, and quantitative experiment was obtained by MTT test. The results showed that COL-P-PU and P-PU had higher cell adhesion and cell growth state compared with untreated PU. The process in the paper can be a promising way to enhance medical biocompatibility of medical PU.