The Research About Biocompatibility And Ossification Of Bone Marrow Stem Cells Under Effect Of Composite Calcium Phosphate Bone Cement

objective: To study the bone induced activity and cytotoxicity of Bone Marrow Stem Cells(BMSCs)under the effect of artificial composite calcium phosphate bone cement(CPC/BMG?CPC/BMG+PLGA-microspheres).In order to invent a new kind bone repair material,while can apply on the elderly,especiallysomeone who are suffering from Osteoporative vertebral compression fracture.Methods :1.We make Poly(lactic-co-glycolic)acid microsphere(PLGA)by W/O/W method,weighing and packaging after irradiation sterilization,which will be added into bone cement according to the certain proportion.Bone matrix gelatin(BMG)is extracting by Urist's method,while skims the rabbit,s limbs bone to remove the calcium and fat,weighing and packaging after using ethylene oxide to sterilize.CPC and BMG is mingle with the ratio of 5:1,then adding 5% PLGA microsphere.We need inject the mixture of curing liquid and three group material(CPC?CPC/BMG?CPC/BMG+PLGA-microspheres)into the special cylindrical mould,at the same time,getting extracts of each material.3.BMSCs is extracting from SD mice(weight is 80 grams to 100 grams,3 weeks old)by cultivating the whole bone marrow,the third generation cell while is thriving will be prepared.We set three experimental groups at all(CPC group A,?CPC/BMGgroupB?CPC/BMG+ PLGA microsphere groupC).Observing the PLGA microsphere?BMG and the three group material and the attachment of the cell to the material by scanning electron microscope(SEM)and Calculating the cell adhension rate to assenss the ability of BMSCs to adhere to material.Using the cell hemolysis experiment and the CCK-8 kit to test the cytotoxicity of three group bone cement on BMSCs,Using alkalinephosphatase kit to determin alkaline phosphatase activity,Using extracts of each group,smaterial to cultivate BMSCs and stained by Alizarin to observe osteogenesis.Results: The third generation BMSCs is thriving,form uniform ?spindle and spiral growth.SEM shows PLGA microsphere is circular,the diamenter is between 70 to 130 microns.There are lots of lacuna on the surface of CPCand BMG,BMSCs can grow well on the surface of the material of three group,more cell can be saw on the group A and groupB,some cells enter the lacuna even.The CCK-8 test result display that there is no cytotoxicity on CPC/BMG and CPC/BMG+PLGA microsphere,BMG can promote cell proliferation.The activity ofalkaline phosphatase of group Aand group B is active r than groupC,the result show that CPC/BMG and CPC/BMG+ PLGA microsphere have the differentiation and osteogesis.Conclusion:Adding PLGA microsphere into CPC/BMG can increase the lacuna,that is convenient to cell?blood vessel and nutrients to enter the artificial composite calcium phosphate bone cement.Then,the new bone forms and replaces the graft.We can conclude that adding BMG into CPCcan give artificial composite calcium phosphate bone cement the biocompatibilityand ossification,adding PLGA microsphere into CPC/BMG can increase lacuna and porosity,while is helpful for cell to adhere and enter the artificial composite calcium phosphate bone cement.