ABSTRACT
In the present paper, the influence of carbon phase components of three kinds of diamond like carbon (DLC) films, viz. DLC, DLC rich in graphite and DLC rich in diamond films, on adsorption of human serum albumin (HSA), human serum fibrinogen (HFG) and immunoglobin (IgG) was quantitatively analyzed by use of T-type correlation degree in the grey system theory. Through the analysis, the rational explanation for adsorptive amounts variations of the serum proteins with phase components in the experiment is reached and some essential conclusions have been obtained: (1) The effect of graphite phase and C-H phase on HSA adsorption are greater than that of other phase components; with the increase of these two phase coumponents, the adsorptive amounts of HSA decrease; (2) The powerful influence on HFG adsorption stems from DLC phase and C-O phase; with the decrease of DLC phase or the increase of C-O phase, the adsorptive amounts of HFG increase; (3) All of the carbon phase components have only limited influence on IgG adsorption in positive or negative fashion with a little difference in degree; (4) DLC phase has both effects of enhancing adsorption for HSA and weakening adsorption for HFG and IgG, thus its influence on the hemocompatibility of DLC films is much more important than that of other phase components.
Subject(s)
Humans , Adsorption , Carbon , Chemistry , Coated Materials, Biocompatible , Chemistry , Diamond , Chemistry , Materials Testing , Membranes, Artificial , Serum Albumin , Chemistry , Surface PropertiesABSTRACT
Diamond-like carbon(DLC) was prepared by means of plasma source ion implantation-ion beam enhanced deposition. Through the heat treatment upon DLC in air and in depressed Ar gas, the DLC rich in graphite, DLC rich in diamond, and other kinds of DLC used in the study were obtained respectively. For the three kinds of DLC, the components of carbonaceous phase were analysed by X-ray photoelectron spectroscopy (XPS), the adsorptive amounts of human serum albumin (HSA), human serum fibrinogen (HFG) and human serum immunoglobin (IgG) on their surfaces in the condition of constant temperature were determined by radio isotope 125I labelling method. Results showed the graphite phase and diamond phase in DLC increased by two times or so respectively after the aforementioned different heat treatment. In pace with the increase of these foreign phases, the adsorptive amounts of HFG and IgG on DLC greatly increase but the adsorptive amounts of HSA on DLC decrease; furthermore, there is a change from non-selective adsorption of three human serum proteins into selective adsorptions of HFG and IgG prior to HSA. These results indicate that the foreign phases in DLC such as graphite, diamond, C-H phase and C-O phase have a great effect on protein adsorption on DLC and hence a negative effect on the hemocompatibility of DLC. The mechanisms for the increase of graphite phase and diamond phase in the process of heat treatment were also discussed in this paper.
Subject(s)
Humans , Adsorption , Biocompatible Materials , Chemistry , Carbon , Chemistry , Diamond , Chemistry , Fibrinogen , Metabolism , Immunoglobulin G , Metabolism , Proteins , Metabolism , Serum Albumin , Metabolism , Surface PropertiesABSTRACT
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.