HA/PLGA复合材料的凝胶浇铸法制备工艺研究

用PVB、(NH₄)₂CO₃和NH₄HCO₃粒子作造孔剂, 制备了多孔HA中间层。采用凝胶浇铸法, 将PLGA-HA凝胶与多孔HA中间层复合。研究表明, 孔隙率达到53.6%的多孔HA中间层的孔径范围为100～200 μm和5～50 μm, 并且孔洞相互贯通; 凝胶的粘度随着PLGA浓度的增大而增大; 粘度为25.8 mPa·s的凝胶利于复合, 易与孔洞相粘结, 能充分填充孔洞; 随着pH值减小, 凝胶较易填充孔洞, 但pH值小于4.289时, 充填效果反而降低; 该复合材料的弹性模量接近于自然骨, 将有望作为骨替换材料。

Study on Preparation of HA/PLGA Composites by Gel-casting

Porous hydroxyapatite (HA) intermediate layer is prepared using PVB, (NH₄)₂CO₃ and NH₄HCO₃ particles as pore-forming materials. Hydroxyapatite/polylactic-co-glycolic acid(HA/PLGA)composites are prepared by gel-casting. Research results show that the porosity of HA reaches 53.6% with pores connecting with each other in sizes ranging from 100 μm to 200 μm for the large and from 5 μm to 50 μm for the small. The viscosity of the gelatin increases with the increase of the concentration of PLGA. When the viscosity reaches 25.8 mPa·s, the gelatin can easily bond with the pores and fill in the holes completely. The gelatin gets easier to fill in the holes with the reducing of pH value. But the filling effect reduces when the pH is lower than 4.289. The HA/PLGA composites are expected to be used in bone tissue replacing and grafting in the future since its modulus of elasticity approaches that of natural bones.