Preparation And Properties Of Porous Biological Composites

From the perspective of porous materials and composites design idea, porous hydroxyapatite(HA) ceramics with different HA contents and porous hydroxyapatite/ultra-high molecular weight polyethylene(referred to HA/UHMWPE) scaffolds were prepared to culture Mouse Embryonic Fibroblasts(MEF-3T3) cells. And the structure, mechanical property, hydrophilic performance and cell compatibility of the porous scaffolds were studied, which were shown as follows.(1) The nano-sized HA powders were synthesized by chemical co-precipitation method, which was studied by X-ray diffraction(XRD) and scanning electron microscopy(SEM) to analyze the material composition and morphology of HA. Porous ceramics with HA were prepared by adding pore-forming agent such as salt particles. The results show that the porous structure of HA ceramics has different morphologies and mechanical strength with the size and number of the pore-forming agent.(2) HA powders were pelletized by using polyvinyl alcohol(PVA) as solvent, and then mixed uniformly with UHMWPE particles. By hot-press approach and acid treatment, a series of porous scaffolds with excellent biological activity and high mechanical strength were prepared for bone repair and used to culture MEF-3T3 cells. Porous structure in the surface of composite scaffolds contributed to the adsorption and growth of seed cells, while the gradient structure showed the simulation of human body skeleton. The pure UHMWPE layer at the bottom was to improve mechanical strength of the scaffolds. The internal morphology, mechanical property, hydrophilic behavior and biocompatibility of HA/UHMWPE porous scaffolds were investigated by XRD, SEM, Fourier transform infrared spectrum(FTIR), Contact Angle test, MTT assay and Confocal laser scanning microscopy(CLSM). The results show that, the incorporation of HA has affected biological activity and mechanical strength of porous HA/UHMWPE scaffolds. The pore number and tensile strength of porous HA/UHMWPE scaffolds which have high hydrophilic ability will increase with the addition of the HA content. When the content of HA was 30wt%, HA/UHMWPE porous scaffold showed better wettability with the contact angle of 48°. Cells adhesion and spreading on the surface of porous HA/UHMWPE scaffolds were higher than that of pure UHMWPE due to the incorporation of HA, which has excellent biocompatibility. The porous structure and good hydrophilicity are also good to adsorption of DMEM, which contributed to cell growth in scaffolds.