聚乳酸多孔支架的制备研究

分别采用粒子滤出法和冷冻干燥粒子滤出复合法制备了聚乳酸多孔支架.在粒子滤出法中,采用氯化钠和碳酸氢铵作为造孔剂制备多孔支架;在冷冻干燥法中,采用碳酸氢铵和冰颗粒作为造孔剂制备多孔支架.实验结果表明:采用氯化钠或碳酸氢铵做造孔剂,生成的多孔支架有造孔剂残留;采用冰颗粒造孔则无残留.研究认为,采取适当的工艺措施,加速造孔剂向环境的传质过程,是降低支架中造孔剂残留的有效途径,并提出了在实际中可采取的改进措施,包括选用易于滤出的材料、提高氯仿和造孔剂含量、提高温度和真空度、采用特殊气氛、提高过滤溶液的流动性.

Study on fabrication of poly(lactic acid) porous scaffolds

Porous poly(l lactic acid)(PLLA) scaffolds w ere fabricated using porogen leaching and freeze drying combined porogen leac hing process. The scaffolds prepared by porogen leaching used sodium chloride or ammonium bicarbonate partic les as porogen material, while the scaffolds prepared by freeze drying combined porogen leaching process used ammonium bicarbonate or ice particles as porogen material. The experimental results show that these are remains in porous scaffolds when sodium chloride or ammonium bicarbon ate particles is used as porogen material, however no remains exist in scaffold s when ice particles is used. The effective method to reduce the remains in poro us scaffold is to speed up the transfer process of porogen to environment by pro per technologies. Some practical methods are suggested: choosing porogen materi al which can be leached out easily; increasing the amount of chloroform and poro gen; increasing temperature and degree of vacuum; choosing special gas; increasi ng fluidity of solution used to leach out porogen.