ABSTRACT
In this paper, the adsorption of human serum albumin(HSA), human serum fibrinogen (HFG) and human serum immunoglobin(IgG) on diamond like carbon film(DLC) has been studied in comparison with diamond film (DF) and graphite. The isothermal adsorption of the protein solution with single component and the competitive adsorption of binary protein system have been investigated by radio isotope 125I labelling method. Results showed that (1) the adsorptive amounts of three proteins on three material surfaces are all increased with the increasing concentration of protein solution, then the adsorption tends to reach an equilibrium; (2) the adsorptive amounts of three protein on graphite far exceed that on DLC and DF; (3) the adsorptive amounts of HSA on DLC are more than that on DF, while the adsorptive amounts of HFG and IgG on DF and graphite are apparently more than that on DLC; (4) the differences among the adsorptive amounts of three proteins on DLC are small, but adsorptive amounts of HFG and IgG on DF and graphite are much more than that of HSA; (5) the relative competitive adsorption ability of three proteins on DF and graphite is HFG > IgG > HSA, but on DLC, the sequence is HFG approximately HSA > IgG. Comparing with HSA, HFG has no apparent competitive adsorption superiority to DLC. These results indicate that there is no apparent difference for the adsorption of three human serum proteins on DLC, but the adsorption of HFG and IgG on DF and graphite takes precedence of various degrees. It probably makes a rational explanation for the result of hemocompatibility tests in vitro that DLC is superior to, DF and graphite.