周围神经受损通常会导致患者运动或感知能力受损甚至永久性丧失，会严重影响患者的生活质量。所以周围神经再生修复引起人们的重视。血旺细胞的髓鞘化对周围神经再生至关重要，并且生物材料作为支架能促进血旺细胞释放神经营养因子有益于神经修复。密歇根大学生物医学工程学院、高分子科学与工程中心、生物与材料科学学院的Peter X. Ma教授，制备了一种生物降解性高度可调的、柔性、生物相容性、具有电化学活性的聚氨酯（GSAP）材料，应用于周围神经再生修复。导电聚氨酯（GSAP）具体制备了过程如下：丙三醇、葵二酸缩聚，再与不同比例的苯胺五聚体共聚，用6-亚甲基二异氰酸进行交联（HDI），通过浇筑法制备交联导电聚氨酯膜。证明了聚氨酯（GSAP）膜能够促进血旺细胞持续分泌神经营养因子以及髓磷脂基因的表达。通过研究细胞内ca2+水平和血旺细胞髓鞘质的形成关系，明确了血旺细胞在PGSAP膜上神经营养因子释放机制。此外, 进一步证明了PGSAP膜上培养血旺细胞释放神经营养因子的悬液，可以诱导PC12细胞的神经生长和伸长。充分证明了导电的可降解的PGSAP聚氨酯能够能够促进血旺细胞的髓磷脂基因表达和神经营养因子的分泌，在外周神经组织工程中有潜在的应用价值。
Peripheral nerve injury usually results in the devastating and permanent loss of sensory and motor function, causing the decrease in life quality of patients. So peripheral nerve regeneration should be pay more attention. Myelination of Schwann cells (SCs) is critical for the success of peripheral nerve regeneration, and biomaterials that can promote SCs’ neurotrophin secretion as scaffolds are beneficial for nerve repair.
Peter X. Ma who working in the school of Department of Biomedical Engineering, Department of Biologic and Materials Sciences, Macromolecular Science and Engineering Center University of Michigan, Department of Materials Science and Engineering, University of Michigan, made the following outcome. In this work, a highly biodegradable, highly flexible, biocompatible, electrochemically active polyurethane (GSAP) material for peripheral nerve tissue engineering was prepared. Polyurethane (GSAP) was prepared as follows: glycerol, sunflower acid polycondensation, and then with different proportions of aniline pentamer copolymerization, crosslinking with HDI, cast on a Teflon mold, the crosslinked conductive polyurethane film was prepared. SCs are cultured on these conductive polymer films, and the biocompatibility of these films and their ability to enhance myelin gene expressions and sustained neurotrophin secretion are successfully demonstrated. The mechanism of SCs’ neurotrophin secretion on conductive films is demonstrated by investigating the relationship between intracellular Ca2+ level and SCs’ myelination. Furthermore, the neurite growth and elongation of PC12 cells are induced by adding the neurotrophin medium suspension produced from SCs-laden conductive films. These data suggest that these conductive degradable polyurethanes that enhance SCs’ myelin gene expressions and sustained neurotrophin secretion perform great potential for nerve regeneration applications.