背景:泌尿系统组织工程支架不仅需要生物相容性良好的生物材料,而且一定要利于组织周围细胞的生长.目的:制备聚乳酸-羟基乙酸共聚物可降解输尿管支架,观察其植入后犬输尿管周围组织学变化.方法:制备纳米聚乳酸-羟基乙酸共聚物输尿管支架,并以多聚赖氨酸对支架进行交联、改性,将交联后支架截成长约0.8 cm小段,植入犬损伤输尿管中进行体内观察实验.结果与结论:①支架制备:支架具有纳米结构,孔隙率约90%,孔径(30±18) μm,多聚赖氨酸交联改性后纤维表面略显粗糙.②支架变化:支架植入30 d时已完全失去原始形态,与周边组织融合,可见裂解小块.③支架植入后输尿管周围组织学变化:植入后15 d炎症表现最为明显,主要是移行上皮脱落,肌层结构被破坏,固有层水肿明显;30 d后,炎症已经明显好转,但组织结构依然不规则;植入后45 d,输尿管全层组织基本恢复正常,组织结构成规则分布.说明聚乳酸-羟基乙酸共聚物输尿管支架具有良好的组织相容性,符合泌尿系统组织工程支架的要求.%BACKGROUND: Biomaterials as urinary system tissue engineering scaffolds should have excellent biocompatibility and beconducive to the cellular growth around tissue.OBJECTIVE: To explore the feasibility of preparing poly(lactic-co-glycolic acid) copolymer as a biodegradable urethral scaffold,and to evaluate ureteral histological changes after scaffold implantation.METHODS: Nanometer poly(lactic-co-glycolic acid) copolymer was prepared as an urethral scaffold, which was cross-linked andmodified with polylysine. The cross-linked scaffold was cut into 0.8-cm fragments, and then implanted into canine ureter for in vivoobservation experiments.RESULTS AND CONCLUSION: Nanometer scaffold tube had a nano-structure, about 90% porosity, and (30±18) μm aperture,and fiber surface became rough after polylysine cross-linked modification. At 30 days after scaffold implantation, the scaffold wasfused with the surrounding tissues and cleavage into small pieces. At 15 days after scaffold implantation, fiber epithelial shedding,structural disorders, and obvious inflammation were visible; at 30 days, inflammation was significantly improved, but tissuestructure remains irregular; at 45 days, ureteral full-thickness tissue returned to be normal, and inflammation was improved.Experimental findings indicate that, poly(lactic-co-glycolic acid) copolymer implanted into the canine ureteral scaffold shows goodbiocompatibility, which is consistent with the requirements for urinary system tissue engineering scaffolds.
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