组织工程支架材料的制备及其孔隙性能

Preparation of tissue engineering scaffold material and research of its pore property

采用二步法制备了性能优良的生物可降解材料聚DL-乳酸（PDLLA）：第1步以DL-乳酸为原料于180～200℃、低压条件下制备出DL丙交酯（DL-LA），第2步使DL-LA于120℃真空中开环聚合生成PDLLA。制备的PDLLA的平均相对分子质量超过10万。然后利用碳酸氢钠（NaHCO3）为致孔剂制作组织工程用高分子支架材料。可以通过改变NaHCO3的用量和粒子直径来调节支架材料的孔隙率和孔隙直径，粒子用量越多，支架孔隙率越高，粒子尺寸越大，支架孔隙直径越大。经扫描电子显微镜观察，支架材料的孔隙结构为完全连通的开孔隙，孔隙直径范围为100～240μm。支架材料的最高孔隙率超过90％。

Poly DL-lactide（PDLLA） was synthesized by two steps method. First, DL- lactic acid was synthesized to DL-lactide （DL-LA） in 180- 200 ℃ and low air pressure condition. Second, the ring structure of DL-LA was opened in 120 ℃ and vacuum environment, then PDLLA was polymerized. PDLLA is a type of biodegradable polymers with excellent property of a high intensity, avirulence and biodegradation and its average molecular mass is more than 100 000. Furthermore, the intensity and biodegradation velocity of PDLLA were controlled by adjusting its average molecular mass. Tissue engineering macromolecule scaffold material, was prepared with PDLLA and pore making reagent NaHCO3. The dosage and granularity of NaHCO3 were changed to adjust the pore rate and pore diameter. Scaffold was observed by SEM, the result is that the whole pores of the scaffold are absolutely open and the pore diameter is in the range of 100 - 200 μm. The highest pore rate of the scaffold is more than 90%.