Biomimetic Synthesis And Property Of Hydroxy Apatite Influenced By L-Dopamine

Hydroxyapatite (HAP) acts as excellent bone repair replacement materials owing to its good biological properties. However, its application is limited by characterization with large brittleness, low strength, high temperature decomposition. HAP with specific morphology and structural characteristics can improve its performance. Recently, inspired by biomimetic mineralization, size and morphology control of HAP templated by biological molecular in the reaction system has drew more attention and has been used for the preparation of organic/composite material, which improve its the biological properties and mechanical strength. Therefore, how to control shape, structure, growth orientation and configuration of materials, which templated by biological molecules-biomimetic mineralization method, is the important mean to improve the performance of organic-inorganic composite materials. At present non-biological macromolecules, such as surfactants and high molecular polymer, were used to regulate the structure characteristics of HAP and researches on the synergistic effect between the template agent and inorganic is less. This paper has carried on biomimetic synthesis and property of hydroxyapatite Influenced by L-DOPA (L-3,4-dihydroxyphenylalanine, L-Dopamine). This paper reports HAP/L-DOPA composite powder with unique morphology and structure properties was prepared by L-DOPA-template hydrothermal method and the research of biological properties. And it is proposed HAP/L-DOPA composite powder technology by biological molecules-biomimetic mineralization method, developed the theory of HAP/L-DOPA composite powders with special morphology and the formation mechanism of HAP/L-DOPA composite powders with the special morphology. Moreover, it is to aim at understanding of nucleation, growth and regulating effect of morphology of HAP crystal during the hydrotermal process, and then discussion on mechanism and biological properties of HAP/L-DOPA composite powder. It is significant for preparation technology of biological molecules/HAP composite powder.The main content of this paper summarized as follows:(1) Hydrothermal process parameters had a greater influence on the phase structure of the HAP/L-DOPA composite powders. Phase transformation of HAP/L-DOPA composite powders from Monetite (CaHPO4)—Calcium hydrogen phosphate (Ca9HPO4(PO4))—hydroxyapatite (HAP) when pH value adjusting from5to10; HAP/L-DOPA composite powders phase transformation from CaPO3(OH) to hydroxyapatite (HAP) when increasing hydrothermal time; phase of HAP/L-DOPA composite powder is pure HAP phase when hydrothermal temperature ranged from120℃to180℃.(2) The results showed that:hydrothermal process parameters result in diverse morphology of HAP/L-DOPA composite powder. Surface morphology of HAP/L-DOPA composite powders varied from one-dimensional rod-like morphology-two-dimensional angular plate-like morphology-wo-dimensional leaf-like morphology when increasing the concentration of L-DOPA biological molecules; Phase transformation of HAP/L-DOPA composite powders from rod-like morphology-flat-like morphology when pH value adjusting from pH5to pH10. Bamboo leaf-like morphology of HAP/L-DOPA compound powder was prepared when pH value was5and concentration of L-DOPA was83%; Surface morphology of HAP/L-DOPA composite powders from nano-particle morphology-cellular-like morphology-flower-like morphology-rod and sheet morphology-plate-like morphology when increasing hydrothermal time; Surface morphology of HAP/L-DOPA composite powders from Irregular lamellar morphology-rod and sheet morphology-rod morphology-flat-like morphology when hydrothermal time increasing from120℃to180℃.(3) Results of Mineralization experiment in vitro show that after mineralization, phosphate deposited on the surface of HAP/L-DOPA composite powder, and it surface became thiner and curlyer. pH value of SBF solution was stable with increasing of mineralization time. It shows that acid and alkali environment of human physiological fluid was stable when HAP/L-DOPA composite powders as implants.(4) Result of MTT experiments show that:toxicity grade evaluation of HAP/L-DOPA composite powders was determined by MTT method, and toxicity grade in the range from0to1grade. It show that samples are good for L-929cell growth, proliferation and metabolism, and cell proliferation rate of L-929cells were over85%. Sample has the good cell compatibility.