C/C Composite Material Surface Modification and Its Cell Toxicity Research
|School||Central South University|
|Keywords||C/C coating material cytotoxicity human osteoblasts cellculture biological assessment|
Objective:In this study, the biocompatibility, cytotoxicity of carbon-carbon, pure titanium and hydroxyapatite as well as their influence to the adherence, priliferation,differentition and viability of osteoblasts in vitro were investigated. And the difference between the surface-coating carbon-carbon material and powder scattering carbon-carbon material in vivo were observed. In the meanwhile, the possibility of this surface-coating carbon-carbon material as a novel implant was evaluated.Furthermore, SEM,XRD were also employed to study the morphology and phase status of the two materials coated with HA and carbon-carbon respectively, which provided a pre-research basis for further clilical application and experiment proof for the possibility of C/C material as a novel implantMethod:The biocompatibility of the materials was evaluated according to the items and rules of GB/T16886.1-2001of People’s Republic of China in this study.The powder-scattering carbon-carbon materials, carbon-carbon coating materials and two metal materials were implanted into gluteus medius muscle of12News Zealand rabbits respectively. The extent of powder-scattering was observed by HE staining at2,4,8weeks respectively.Human osteoblast-like cells were cultured and passaged stably and co-cultured with the three materials.The materials were divided into three groups:Group A, negative control (pure titunium); Group B’.positive control(hydroxyaptite);Group C:carbon/carbon. Each batch was40pieces which subjected sonication and sterilization.Fluoresent staining of AM+PI+DAPI was used to identify the adherence and proliferation of human osteoblast cells.And MTT assay was employed to measure the cell viability.Immunofluoresence staining for actin+β-tublin+DAPI and alkaline phosphate activity assay of osteoblasts were emplyed to evaluate the differentiation and maturation of osteoblast cells.The mRNA expressing level of collagen I of osteoblast cells seeded on the materials and the SEM image of the cells on the materials were studied to measure the osteogenesis and calcification activity of osteoblast cells.Data was shown in x±s. Experiment data was analysed by SPSS17.0in which one-way ANOVE analysis method was used in parallel groups and LSD-t test was used for multiple comparisons of multiple sample averages. P<0.05signified statistiResults:1. The implanted materials were still at the site where they were in the beginning by observation of HE staining.Heavy powder scattering still presented in the powder scattering carbon-carbon materials while it was much better in the carbon-carbon coating materials by surface modification.cs significance.Immunofluoresence staining for actin+β-tublin+DAPI and alkaline phosphate activity assay of osteoblasts indicated that group B and C were more benificial to cell proliferation than group A with time went by. Statistical significance was observed; No statistical significance was observed in cytotoxicity comparision between group B and C(P>0.05).Results from immunofluoresence staining for actin+(3-tublin+DAPI and alkaline phosphate activity assay indicated that material group B and C were more beneficial to the differentiation and maturation of osteoblast cells than group A in which statistical significance was observed (P<0.05); While no statistical significance was observed between group B and C (P>0.05)The mRNA expressing level of collagen I of osteoblast cells seeded on the materials and the SEM image of the cells on the materials demonstrated that osteoblast cells on materials group B and C possessed high osteogenesis and calcification activity than that on material group A in which statistical significance was observed (P<0.05); While no statistical significance was observed between group B and C (P>0.05)Conclusion:C/C coating materials after surface modification exhibited no significant cytotoxicity which is similar with hydroxyapatite in terms of biocompatibility, cell proliferation, calcification activity etc and provided a certain experiment proof to the application of implant as a biomaterial.