Preparation Of Hydroxy Apatite And Calcium Phosphate Materials And The Biological Effects Of α-tricalcium Phosphate

Bone is an organism which has a life of hard tissue and organ, it is the mostimportant component of the body. With the population aging in our country isincreasingly serious, and the trauma caused by social development in industry,transportation, sports competition and other aspects is sharply increasing, peoplegrowing demand for bone substitute materials is also sending up. Since calciumphosphate materials on the chemical composition and biological properties are similarto human bone mineral ingredients, it is widely used in bone tissue engineering andclinical medicine. Calcium phosphate materials is a hot topic in the study of allscientific research scholars.Due to the size of nano-bio-ceramics with pore structure is similar to humanbone and it has the function of drug carrier, it is the best in the field of bone repairapplication. In this thesis, calcium carbonate and calcium hydrogen phosphate are rawmaterials, the introduction of formic acid make them full reaction. Using sodiumhydroxide to adjust to strong alkaline solution. By hydrothermal method synthesisporous nanometer hydroxyapatite(HA), then discuss the impact on the crystal shape,structure, morphology and properties by the reaction temperature, reaction time,concentration of sodium hydroxide, and other conditions. By XRD, SEM, N2adsorption-desorption testing methods for sample characterization, we know that thepreferred conditions for the final synthetic samples is hydrothermal synthesistemperature of200℃, reaction time12h, concentration of sodium hydroxide3M.This method is simple, the synthetic porous nanometer hydroxyapatite is uniform andcontrollable in size, shape rules, less product reunion, purity and high crystallinity.α-tricalcium phosphate(α-TCP) compared with β-TCP and HA has more superior biological properties, its biocompatibility and biodegradability are better thanthe other two, have bone conduction and bone inductivity, does not generate heat afterimplantation in the human body, easily absorbed rapidly, will not cause partialacid-base disorder. It is the most promising materials of bone tissue engineering intfuture. In this thesis, calcium nitrate, diammonium phosphate and ammoniumbicarbonate are raw materials, by co-precipitation method to synthesize α-TCP, thendiscuss the impact on the the generation of the product by the calcination temperature,reaction solution pH and other conditions. Evaluation of its physical and chemicalproperties by XRD, SEM, TEM and other testing methods. Eventually we get theoptimum conditions for the synthetic samples are reaction solution pH=7.5, thecalcination temperature1280℃and calcination time2h.The performance of materials in biological properties and clinical applications isthe basis of evaluating itself good or bad and its application value. In this thesis, theabove method obtained α-TCP and rat BMSCs in vitro co-culture. Evaluate itsbiosafety by MTT detection. Detect mRNA expression of ALP, COL-Ⅰ, SP7,RUNX2osteoblast-related factors by Real Time PCR and discuss the impact ofα-TCP for osteogenic differentiation of BMSCs. The results showed that, the materialbio-security is good when the concentration of α-TCP is between10-50μg/ml, and itdoes not inhibit the proliferation of rat BMSCs. α-TCP can promote osteogenicdifferentiation of rat BMSCs through raising mRNA levels of ALP, Col-Ⅰ, SP7,Runx2. This provides a certain theoretical basis for the application of α-TCP in bonetissue engineering.