Preparation Of Nano-calcium Phosphate Porous Biomaterial With Chitosan Used As Template

Porous HA-TCP/CS biomaterial, with addition of coupling agent KH-570 and NDZ-311 as modifier, was fabricated by gel-casting and vacuum freeze drying methods in this paper. Influence of ratio of HA-TCP to CS, ratio of monomer to composite powder, and the amount of coupling agent KH-570 and NDZ-311 on micro-morphology, mechanical strength and porosity of the porous biomaterial were investigated. Different dispersion methods of HA-TCP particles and biological activity of the porous biomaterial in Simulated Body Fluid (SBF) were studied. Powder and surface morphology analysis was performed with scanning electron microscopy (SEM) and TEM. Phase components were characterized by X-ray diffraction (XRD). The functional group analysis was performed by IR. Quantitative analysis of elements was performed with energy depressive spectroscopy. Further research on the performance of porous biomaterial was exploited by TG-DSC curve analysis.The results showed that the composite material fabricated by gel-casting method has the compressive strength of about 20MPa and porosity of 43%~54% after the powder of HA, HA-TCP andβ-TCP is modified by KH-570. HA-TCP composite material with compressive strength of 20.8MPa and porosity of 51% is the best among HA, HA-TCP andβ-TCP composite materials. By optimizing design of AM content, when the content of AM is 1g in composite material, the compressive strength of the composite material is 38.5 MPa and its porosity is 66%. Distribution of pore and pore size is comparative uniform. Most of pores are micropores and their sizes are about 10μm. Porous HA-TCP/CS biomaterial is fabricated by vacuum freeze drying method modified by KH-570 and NDZ-311. When the mass ratio of HA-TCP to CS is 7:3, KH-570 with 1wt% content of HA-TCP, and NDZ-311with 1wt% content of CS were added respectively, average compressive strength of the modified porous biomaterial is 11.6, which is five times higher than non-modified porous biomaterial, both of them has the same porosity of 83%. HA-TCP particles are uniformly dispersed on CS templates by mortar-ixing round-ltrasonic surging and performance of porous biomaterial is the best. The added coupling agent of KH-570 and NDZ-311 have little effect on the phase structure of the material, only the intensity of characteristic diffraction peaks in each phase of the material have little change. Bone-like apatite containing CO32- can be formed on the surface of the four porous biomaterials of HA-TCP/CS, 1wt%-KH-570+HA-TCP/CS, HA-TCP/1wt%-NDZ-311+CS and 1wt%-KH-570+HA-TCP/1wt%-NDZ-311+CS after soaked in SBF, which shows that the four porous biomaterials have good ability of forming bone-like apatite.