Histologic changes of nonbiodegradable and biodegradable biomaterials used to repair right ventricular heart defects in rats
Histologic changes of nonbiodegradable and biodegradable biomaterials used to repair right ventricular heart defects in rats
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DOI：
10.1067/mtc.2002.127449
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发表时间：
2002-12-01
影响因子：
6
通讯作者：
Li, RK
中科院分区：
文献类型：
--
作者：
Ozawa, T;Mickle, DAG;Li, RK
目的：非生物降解性合成材料已广泛应用于心脏缺损的修复。然而，与材料相关的故障（例如缺乏生长、血栓形成和感染）确实会发生。由于生物可降解支架可以被患者自身细胞替代，并且在有限的时间内将作为异物进行治疗，因此我们比较了四种生物可降解材料（明胶、聚乙醇酸（PGA）和由ε-己内酯和L-乳酸制成的共聚物，并用聚-L-丙交酯针织物[KN-PCLA]或编织织物[WV-PCLA]进行增强）与不可生物降解的聚四氟乙烯（PTFE）材料。一种动物心脏模型进行了测试，模拟在体内的临床条件，其中合成材料将被used.Methods：五个补丁被用来修复透壁缺陷手术中创建的成年大鼠心脏（n = 5，每个补丁组）的右心室流出道。PTFE补片组作为对照组。植入后8周，切除生物材料。补丁大小，补丁厚度，浸润细胞数，细胞外基质成分，和补丁degradations.Results：PTFE补片本身并没有改变大小，除了增加厚度，因为成纤维细胞和胶原蛋白覆盖其两个表面。宿主细胞没有迁移到PTFE生物材料中。相反，细胞迁移到生物降解明胶，PGA，和KN-PCLA和WV-PCLA支架。KN-PCLA补片中每单位补片面积的细胞向内生长最高。KN-PCLA补片的尺寸和厚度适度增加。WV-PCNA斑块的大小和厚度没有变化。成纤维细胞和胶原是生物降解支架中形成的主要细胞浸润和细胞外基质。生物材料降解、变薄和扩张的体内速率具有材料特异性。所有内膜下补片表面均覆盖有内皮细胞。结论：独特的，海绵状基质结构的PCLA补丁有利于细胞定植相对于其他补丁。这些补片中坚固耐用的聚-L-丙交酯织物外层相对于研究的其他生物可降解材料具有物理、生物相容性和生物可吸收性优势。宿主细胞迁移到所有生物材料中。细胞分泌基质并形成组织，组织在内皮细胞表面内皮化。生物材料降解速率和组织形成速率与材料相关。PCLA移植物有望成为手术修复的合适补片。
Objectives: Nonbiodegradable synthetic materials have been widely used to repair cardiac defects. Material-related failures, however, such as lack of growth, thrombosis, and infection, do occur. Because a biodegradable scaffold can be replaced by the patient's own cells and will be treated as a foreign body for a limited period, we compared four biodegradable materials (gelatin, polyglycolic acid, (PGA), and copolymer made of epsilon-caprolactone and L-lactic acid reinforced with a poly-L-lactide knitted [KN-PCLA] or woven fabric [WV-PCLA]) with a nonbiodegradable polytetrafluoroethylene (PTFE) material. An animal heart model was tested that simulates the in vivo clinical condition to which a synthetic material would be used.Methods: The five patches were used to repair transmural defects surgically created in the right ventricular outflow tracts of adult rat hearts (n = 5, each patch group). The PTFE patch group served as a control group. At 8 weeks after implantation, the biomaterials were excised. Patch size, patch thickness, infiltrated cell number, extracellular matrix composition, and patch degradation were evaluated.Results: The PTFE patch itself did not change in size except for increasing in thickness because of fibroblast and collagen coverage of both its surfaces. Host cells did not migrate into the PTFE biomaterial. In contrast, cells migrated into the biodegrading gelatin, PGA, and KN-PCLA and WV-PCLA scaffolds. Cellular ingrowth per unit patch area was highest in the KN-PCLA patch. The KN-PCLA patch increased modestly in size and thinness. The WV-PCNA patch did not change in size or thickness. Fibroblasts and collagen were the dominant cellular infiltrate and extracellular matrix formed in the biodegrading scaffolds. The in vivo rates of biomaterial degradation, thinning, and expansion were material specific. All the subendocardial patch surfaces were covered with endothelial cells. No thrombi were seen.Conclusions: The unique, spongy matrix structure of the PCLA patch favored cell colonization relative to the other patches. The strong, durable outer Poly-L-lactide fabric layers in these patches offered physical, biocompatible, and bioresorbable advantages relative to the other biodegradable materials studied. Host cells migrated into all the biomaterials. The cells secreted matrix and formed tissue, which was endothelialized on the endocardial surface. The biomaterial degradation rates and the tissue formation rates were material related. The PCLA grafts hold promise to become a suitable patch for surgical repair.