Initial Experimental Study About Hydroxyapatite For Mechanical Heart Valve Applications

Background:Rheumatic Heart Disease is leading cause of morbidity and mortality world-wide. Currently, the synthetic materials or bioprosthetic replacement devices for cardiovascular surgery are imperfect and subject patients to one or more ongoing risks including thrombosis, limited durability and need for reoperations.Objective: To investigate biocompatibility of the hydroxyapatite, we are searching ideal film materials for mechanical heart valve applications.Method: Transferred human umbilical cord Vein endothelial cell suspension was implanted on hydroxyapatite materials, and was placed in the incubator contained 5%(V/V) CO2 for 3 weeks. A few materials were took out at 3, 7, 21 days respectively and were fixed with 2.5% glutaraldehyde. The samples were dried with increasing concentrations of ethanol successively. The materials were characterized using scanning electron microscopy (SEM) to observe cell on the materials and determined the cell growth conditions with MTT chromatometry.Result: SEMs of human umbilical cord Vein endothelial cells seeded onto the HA surface showed good cell morphology and coverage of the HA surface.Conclusion: The hydroxyaptite has an excellent biocompatibility and safely for for mechanical heart valve applications. Objective: In order to detect cytotoxicity of the hydroxyapatite(HA)that probably exists to human umbilical cord vein endothelial cell (HUVEC) using MTT method.Method: We used MTT to evaluate the material cytotoxicity of HA. The normal and the heat temperature leaching liquor class were set up and they all had control group respectively. HUVEC in leaching liquor observed respectively under the inverted phase contrast microscope after the 72 h and in leaching liquor and at the material edge, HUVEC appearance and growth status were observed to evaluate the biocompatibility of the material. According to the standard that made by the International Organization for Standardization (ISO), ISO10993-5: 1992《cytotoxicity of the biology evaluation of the medical treatment apparatuses experiment method in vitro》,we evaluated cytotoxicity.Result: HUVEC was cultivanted in leaching liquor of HA and HUVEC appearance, amount were observed after 24h. There were no obvious difference between experimental groups and negative control group.Conclusion: HA displayed no obvious cytotoxicity and has good biocompatibility.