In Vitro Study On The Biological Properties Of Percutaneous Materials

Percutaneous decices is a man-made path connecting human body and outer environment.Information in body can be acquired and substance can be converted by the path .It is widely used in human signal observation and tissue or organ repair and function recovery.The poor interface reaction and combination between skin or subcutaneous tissue and percutaneous implant is the main reason leading to invalidation,so it is necessary to study biological properties of the percutaneous materials.This thesis is aim to culturing skin fibroblasts primarily and reseach cytotoxicity and hemolysis of percutaneous materials including dense reinforced hydroxyapatite ceramics,medical silicon rubber/hydroxyapatite composite and surface modified silicon rubber,it gives a basis for materials optimization,so perfect percutaneous materials can be applyed in clinic earlier.Fibroblast was cultured primarily by tissue pieces way and tryptic digestion way. The fibroblasts were subcultured ,purified and identified.Then the proliferation vigor of cells was analysed.The result showed that the biological properties of fibroblast was stable and it can provide active cells for future experiment.The cytotoxicity experiment showed that all percutaneous materials in this study had noncytotoxicity,the toxicity grade was l,it was acceptable.The HA content in a material was more, the inhibition ability of cells growth was much poor.It was beneficial to cells growth that HA was a major base material; biocompatibility of medical silicon rubber/hydroxyapatite composite and surface modified silicon rubber was improved comparing with silicon rubber;the lower concentration of material extraction ,the less inhibition of cell growth,but the liner relation between extraction concentration and inhibition extent was not obvious,the cytotoxicity of materials can be directly reflected by primary material extraction.Direct contact way and indirect contact way were adopted to evaluate hemolysis property of percutaneous materials,the result showed that hemolysis rate of all materials was less than 5%,it was coincidenced with hemolysis test standard,the materials were anhemolytic;mean absorbance of extraction in indirect contact experiment were greater than in direct contact experiment,this indicated that digestion ingredient from material extraction influenced red cell and extraction hemolysis test was effective. Biocompatibility of medical silicon rubber/hydroxyapatite composite and surface modified silicon rubber was improved comparing with silicon rubber,this point was conformity with the result of cytotocity test;in order to evaluate hemolysis property of unknown biomaterials, the best way was using both direct contact way and indirect contact way at one time,it can evaluate hemolysis property of biomaterials integrately from twofold angle of physics and chemistry.