基于SKP-SCs来源的胞外囊泡构建的组织工程神经移植物的生物安全性评价

Biosafety evaluation of nerve grafts incorporated with extracellular vesicles from skin-derived precursor Schwann cells

目的:评价基于皮肤源性前体细胞(skin-derived precursors,SKPs)分化成的施万细胞(Schwann cells,SCs)来源的细胞外囊泡(extracellular vesicles,EVs)构建的组织工程神经移植物(tissue engineered nerve graft,TENG)的生物安全性。方法:将SKP-SCs来源的EVs(SKP-SC-EVs)注射至带有3根纤维支架的壳聚糖导管中制备成TENGs,修复比格犬坐骨神经40 mm缺损。术后6个月,取心、肝、脾、肺、肾、脑,通过HE染色进行形态学观察,并收集血液进行血液常规和生化指标分析,包括:白细胞、中性粒细胞、红细胞、血小板、总蛋白、白蛋白、谷丙转氨酶和血糖等。结果:形态学分析显示TENGs组比格犬的各脏器组织结构清晰,与自体移植组、壳聚糖导管组相比,各项血液指标差异均无统计学意义(均P>0.05),且未见毒性反应改变。结论:基于SKP-SC-EVs构建的TENGs植入比格犬体内具有良好的生物安全性,为临床应用TENGs治疗周围神经损伤提供安全性数据支持。

Objective:To evaluate the biosafety of the tissue engineered nerve graft(TENG)incorporated with extracellular vesicles from skin-derived precursor(SKP)Schwann cells(SCs).Methods:Matrigel loaded EVs from SKP-SCs were injected into the chitosan tube to prepare TENGs.Then,TENGs were used to bridge 40 mm sciatic nerve defects in Beagle dogs.After 6 months,morphological analyses were performed on the hearts,livers,spleens,lungs,kidneys and brains using HE staining.Blood samples were taken to detect blood routine and blood biochemical indexs,including white blood cells,neurophils,red blood cells,platelets,total protein,albumin,alanine aminotransferase,and blood glucose and so on.Results:Morphological analysis showed that the tissue structure was clear in the TENGs group;compared with the autograft group and tube group,there was no significant difference in blood indexes in the TENGs group(P>0.05).TENGs group of Beagle dogs have no toxic reaction change.Conclusion:TENGs constructed based on SKP-SC-EVs implanted into Beagle dogs showed good biological safety,which provided safety data support for clinical application of TENGs in the treatment of peripheral nerve injury.