两种组织工程化人工肋骨支架材料的制备及体内外降解实验研究

目的选择组织工程界常用的聚乳酸-羟基乙酸共聚物／羟基磷灰石（PLGA／HA）与多孔磷酸钙（CPC）两种支架材料，通过体内外降解实验筛选出更为符合组织工程化人工肋骨支架的材料。方法将PLGA／HA（PLGA／HA组）和CPC（CPC组）两种材料分别进行体外实验和动物体内实验，体外实验：将同等大小的PLGA／HA和CPC材料浸入0．9％NaCl溶液，并保持无菌，放入37℃温箱内，分别于2、4、8、12和24周时取出称重，比较两种材料在体外的降解速度差异；体内实验：将同等大小的PLGA／HA和CPC材料各2片分别植入20只新西兰大白兔脊柱两侧的皮下，于2、4、8、12和24周取出称重，各时间点分别处死4只大白兔；材料周围组织送组织学检查及扫描电子显微镜观察。结果薄层CT扫描（Micro—CT）和扫描电子显微镜观察结果，CPC组较PLGA／HA组具有较好的三维结构（1101．2228±0．6184mg／ccm vs．1072．5523±0．7442mg／ccm）及孔隙率（70．26％±0．45％ vs．72．82％±0．51％）；体外实验显示：两组材料在体外降解速度均较慢，至6个月时才有明显的降解，其中PLGA／HA组降解相对较多，降解了60％；体内实验显示：PLGA／HA组降解比体外更快，3个月时已基本降解完，比CPC组降解快，降解了96％；另外CPC组材料周围的炎症反应明显比PLGA／HA组轻，更适合细胞的生长和黏附。结论对再生时间较长的长段肋骨缺损，CPC比PLGA／HA更适合。

The Preparation of Two Scaffolds for Tissue Engineering Rib and Comparison of Their Degradability

Objective Choose polylactide-co-glycolide/hydroxyapatite （PLGA/HA） and porous phosphate calcium （PPC） as the object that we will study, compare their degradabality and choose one as a suitable scaffold for rib reconstruction. Methods All the experiments were divided into PLGA/HA group and CPC group. Degradabality experiment in exvivo： put the two scaffold which have the same size into 0. 9% NaCl, keep sterile, then put the container into warm cage,get out and weigh them in 2, 4, 8, 12 and 24 weeks, compare the different speed of the two scaffold. Degradability experiment in vivo： put the two scaffold which have the same size under the skin of the rabbit, and weigh them in 2, 4, 8, 12 and 24 weeks, the tissue around the scaffold was examinzed by HE and the scaffold was examined by electron scanning microscope. Results Micro-CT and Scanning electron microscopy shows that CPC group had better structure （1101. 2228±0. 6184 mg/ccm vs. 1072. 5523±0. 7442 mg/ccm）and porosity（70. 26% ± 0.45% vs. 72.82%±0.51%）than PLGA/HA group. The result of degradabality experiment in vitro shows that the speed of the two scaffolds was slow. It is at 24 weeks that the degradability is obvious, and the PLGA/HA group degraded a lot which was 60%. The result of degradabatity experiment in vivo shows that the speed of degradabality of PLGA/HA group was faster than that is in the 0.9% NaCl, also was faster than that of CPC group which was 96%. The reponse of tissue around the PLGA/HA was more sever than that of CPC group which is in favour of the growth of cells. Conclusion As for the reconstruction of large defect of rib, CPC is more suitable than PLGA/HA.