Electrospun and woven silk fibroin/poly(lactic-coglycolic acid) nerve guidance conduits for repairing peripheral nerve injury

We have designed a novel nerve guidance conduit（NGC） made from silk fibroin and poly（lactic-co-glycolic acid） through electrospinning and weaving（ESP-NGCs）. Several physical and biological properties of the ESP-NGCs were assessed in order to evaluate their biocompatibility. The physical properties, including thickness, tensile stiffness, infrared spectroscopy, porosity, and water absorption were determined in vitro. To assess the biological properties, Schwann cells were cultured in ESP-NGC extracts and were assessed by morphological observation, the MTT assay, and immunohistochemistry. In addition, ESP-NGCs were subcutaneously implanted in the backs of rabbits to evaluate their biocompatibility in vivo. The results showed that ESP-NGCs have high porosity, strong hydrophilicity, and strong tensile stiffness. Schwann cells cultured in the ESP-NGC extract fluids showed no significant differences compared to control cells in their morphology or viability. Histological evaluation of the ESP-NGCs implanted in vivo indicated a mild inflammatory reaction and high biocompatibility. Together, these data suggest that these novel ESP-NGCs are biocompatible, and may thus provide a reliable scaffold for peripheral nerve repair in clinical application.

丝素蛋白人工神经导管的皮肤致敏实验

目的评价本实验室自制的丝素蛋白人工神经导管对皮肤潜在的致敏性。方法以ISO 10993-10:1995标准,采用最大剂量法,将白化豚鼠分为SF-NGC组、阳性对照(甲醛溶液)、阴性对照(生理盐水)3组,先进行预试验确定主试验各阶段的浓度,然后进行主试验。在激发阶段的敷贴物去除后24h、48h、72h,观察记录各组动物激发部位的皮肤情况,按标准进行评分,并算出致敏率。结果丝素蛋白人工神经导管的皮肤反应记分为0,致敏率为0。结论在试验条件下丝素蛋白人工神经导管无潜在的皮肤致敏性。

Ames实验对丝素蛋白人工神经导管遗传毒性的研究

目的:初步评价自制的丝素蛋白人工神经导管的遗传毒性。方法:采用Ames试验常规方法进行检测。结果:丝素蛋白导管对TA97、TA98、TA100、TA102在加与不加S9条件下均无致突变性。结论:在本试验条件下丝素蛋白人工神经导管无直接或间接致突变性。

丝胶蛋白对仿生丝素蛋白神经导管的改性研究

目的探索丝胶（SS）蛋白对仿生多通道丝素（sF）蛋白神经导管（NCs）的改性作用。方法在丝素蛋白水溶液中按比例加入丝胶蛋白，通过循序冷冻工艺制备丝胶／丝素共混神经导管（SS／SF-NCs），扫描电镜（SEM）观测其通道结构，X线衍射及红外光谱检测其内部分子结构，测量其孔隙率及机械性能，MTY实验量化分析PCI2细胞与SS／SF-NCs共培养后的细胞活性，PCI2细胞被用于检测从SS／SF—NCs中释放的NGF的细胞活性。结果SEM结果显示与SF-NCs相比，SS／SF-NCs具有周围神经束仿生结构的线性化导向的多通道，通道分布均匀呈片状纵向均匀排列，且通道微观结构上发生很大变化，机械性能得到很大提升，通道的壁间距、孔隙率、机械强度随着循序冷冻温度、丝胶比例的不同而变化。MTF试验结果显示SS／SF—NCs的PCI2细胞的活性明显好于对照组（P〈0．05），从新型SS／SF-NCs中释放NGF释放时间长达4周并保持生物活性。结论通过丝胶蛋白的改性作用，新型SS／SF．NCs具有周围神经束的高度仿生结构，且具有更加优良的机械性能，可以作为人工神经导管的另一选择。