| Calcium phosphate family, especially hydroxyapatite (Ca10(PO4)6(OH)2,HA),its chemical composition is substantially similar to human bones and teeth,and has good biocompatible and osteoinductive. In the natural bone, mineral composition is mainly HA, but also contains a variety of other trace elements, such as copper, manganese, etc.Therefore, how to put the right amount of trace elements in synthetic bone substitute materials to improve the biological activity caused widespread concern.Multistage structural material is based on low-dimensional nano-components (such as nanoparticles, nanotubes, nanoplatelets, etc.) as building blocks, forming special morphology and complex structure by self-assembly or artificial assembly.Owing to their fantastic hierarchical architectures and superior properties which enable broader potential applications in catalysis, electronics, sensing,drug delivery, etc. The microspheres with a multi-level structure become a hot research topic due to good liquidity, high bulk density, light weight, good injection performance, etc.Combining these advantages and on the basis of similar studies at home and abroad, this article reports the successful synthesis of ion-doping hydroxyapatite microspheres with a multi-level structure through using copper or manganese as doping elements and inositol hexakisphosphate (IP6) as the regulating agent.Firstly, amount of calcium nitrate, copper nitrate (manganese nitrate)and IP6 were dissolved in 60 mL deionized water. Subsequently, Sodium monohydrogen phosphate were dissolved in it to form a milky suspension. All samples were synthesized with the atomic ratio (M+Ca)/P, M/(M+Ca) fixed at 1.67,5%, respectively. Where M represents copper or manganese.The pH was adjusted to 2-3 by adding sodium nitricacid. Then, moderate urea was added into the transparent solution.The liquid was put in a teflon vessel, sealed tightly and heated to150℃ for 12h. The obtained precipitate was collected by centrifugation, rinsed with deionized water and absolute ethanol,and dried at 60℃ for 72h.Finally,collected the powder and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 adsorption-desorption measurement (BET). And using in vitro degradation experiments to evaluated the Ca2+ and Cu2+ release rule of HA power, biological properties inspection and evaluation of the protein adsorption properties of the hydroxyapatite particles with different structures and its effect on bone marrow mesenchymal stem cell adhesion and proliferation. The results are as follows:(1) By adding Cu, Mn, IP6 synthesized HA particles with different surface micro/nano structures, which simultaneously adding M and IP6, the sphericity of HA are more complete even have a porous hierarchical structure.(2) Study the hydrothermal reaction time on the formation of Cu-HA+IP6 found with the reaction time, amorphous phase transform to HA crystalline phase, and gradually form multistage structure. IP6 induce and transiently stabilize ACP. Nanosheet may be due to IP6 highly negatively charged, readily adsorbed on the hydroxyapatite a-plane, inhibiting or reducing further growth of the plane.(3) Study the different powders adsorption properties of bovine serum albumin(BSA), the results show HA microspheres with multilevel structure show a more significant absorption advantage.(4) In vitro degradation experiments to study the calcium and copper release rule of copper doping powder in PBS and acetate buffer, the results show that doped copper may be non-cytotoxicity to cells.(5) The extraction assay for cytotoxicity test show that the incorporation of copper or manganese displayed non-cytotoxicity to osteoblast.Copper doping hydroxyapatite were co-culture with the bone marrow mesenchymal stem cell experiments showed that synthetic HA by adding copper,IP6 could well promote cell adhesion and proliferation. |
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