Bionic Scaffolds Design Based On Human Bone Microstructure

The study was decidated to macroporous three-dimensional (3-D) titanate nanowirebioscaffold which possesses of highly ductility, specific surface, good mechanical behaviour,excellent permeability, biocompatibility, and bioactivity. Along with the characteristic oftitanate nanowire bioscaffold, the application of bioscaffold as bone graft materials was furtherinvestigated.Frist, the paper introduced the research progress of the bioscaffold, and simple discussedthe prinpical problem of the new bioscaffold materials and alternative therapies. Based on theexisting research, the orientation of the dissertation’s research and the program of the newbioscaffold materials were proposed.Hydroxyapatite-modified titanate nanowire scaffolds as alternative materials for tissueengineering have been developed via a titanate nanowire matrix assisted electrochemicaldeposition method. The macroporous titanate nanowire matrix on Ti metal were fabricated byhydrothermal method, and the hydroxyapatite was incorporated on the titanate nanowire toform the hydroxyapatite nanoparticles modified titanate nanowire scaffolds by electrochemicalmethod with a reaction of Ca2+, PO3-4and OH-in the SBF solution. Then, the structure andcharacteristic of the3-D interconnected porous hydroxyapatite-modified titanate nanowirescaffolds were analyzed by FESEM, TEM, XRD, and FTIR-ATR. It was demonstrated that“necklace bead mode” ceramic titanate nanowire@HA nanoparticle core-shell scaffold displayssuperhydrophilicity surface and porous-like structure, which was capable of the naturalextracellular matrix, could provide a suitable microenvironment for tissue cell ingrowth anddifferentiation. Human osteoblast-like MG63cells were cultured on the ceramic titanatenanowire@HA nanoparticle core-shell structure scaffolds. Based on the imaging andbiochemical assays of the MG63cells proliferation and differentiation, maximized desirableosteoblaste-surface interactions were realized due to the matrix porous surfaces and HAnanoparticle modification on titanate nanowire matrix, which were able to enhance bioactivity,increase osteoconductivity and promote osteoblast differentiation.In other work, we have successfully been incorporate graphene sheets onto the titanate nanowire matrix for fabrication of ordered graphene reinforced macroporous titanate nanowirecomposite scaffolds on Ti metal substrate through titanate nanowire matrix assistedelectrophoretic deposition method. The macroporous titanate nanowire matrix on Ti metal wasfabricated by hydrothermal method, and subsequently followed through an electrophoreticmethod to deposit graphene sheets on titanate nanowires in the2.0mg/mL graphene solution.Then, the structure and characteristic of the3-D interconnected porous graphene reinforcedtitanate nanowire scaffolds were analyzed by FESEM, XRD, Raman, FTIR-ATR, PL andUV-vis. It was demonstrated that the morphology of graphene on the titanate nanowire scaffoldwas from the regular to random distribution, and the macroporous of titanate nanowire scaffoldwere damaged with the increasing of the deposition time. Additionally, proliferation anddifferentiation of the MG63osteoblast cells on graphene sheets reinforced titanate nanowirescaffolds were systematically investigated to evaluate the effects of ordered cellularmicroenvironment for cell growth, the bioactivity of the oriented graphene sheets for cell/tissueattachment, and the promotion of osteointegration between the bone and scaffolds.At last，the work in the dissertation was generalized, and the problems which still need todiscuss in paper were represented.