同轴骨组织工程支架降解特性研究

Degradation Characteristics of Coaxial Bone Tissue Engineering Scaffold

为使抗骨结核药物在病灶区长期维持一定浓度,并促进术后缺损处的骨修复,应用羟基磷灰石、聚乙烯醇、丝素蛋白作为药物载体材料,结合自制机械式挤出装置制备同轴梯度骨组织工程支架。为使骨组织工程支架顺利植入体内,且保证支架负载的药物持续缓慢地释放,现对药物载体材料骨组织工程支架降解性能进行测试。研究发现降解10周后,无丝素蛋白的单轴支架的降解率为40.14%,同轴骨组织工程支架降解率为28.15%,说明复合丝素后降解速率明显变缓,这为药物长期释放提供可能。降解10周后,降解液pH值为6.8,溶液呈弱酸性。高倍扫描电镜图显示同轴骨组织工程支架微孔结构分布均匀,孔径尺寸随降解时间延长不断变大,可为新骨生长提供空间。力学实验测试结果表明同轴骨组织工程支架降解10周后抗压强度是12.61MPa,满足人体松质骨承载要求。

In order to maintain a certain concentration of anti-tuberculosis drugs in the lesion area for long time and promote bone repair in the defect site,hydroxyapatite,polyvinyl alcohol and silk fibroin are used as drug carrier materials.A coaxial gradient bone tissue engineering scaffold was prepared through self-made mechanical extrusion device.In order to allow the bone tissue engineering scaffold implant into the body smoothly and to ensure the sustained release of the drug loaded by the scaffold,the degradation performance of the drug carrier material bone tissue engineering scaffold shoulated.It was found that after 10 weeks of degradation,the degradation rate of the silk fibroin-free uniaxial scaffold was 40.14%,and the degradation rate of the coaxial bone tissue engineering scaffold was 28.15%,The degradation rate was obviously slowed,which provided the possibility of long-term drug release.After 10 weeks of degradation,the pH of the degradation solution was 6.8.The solution was weakly acidic.The high-power scanning electron micrograph shows that the micropore structure of the coaxial bone tissue engineering scaffold is evenly distributed.With the prolongation of the degradation time the pore size increases,which can provide space for new bone growth.The mechanical test results show that the compressive strength of the coaxial bone tissue engineering scaffold is 12.61MPa after 10 weeks of degradation,which basically meets the requirements of human cancellous bone bearing.