电纺壳聚糖-聚乳酸复合神经导管的分子作用及其生物活性表征

以三氟乙酸(TFA)、二氯甲烷(DCM)的复合溶液为溶剂，壳聚糖(CS)及聚乳酸(PLA)为溶质制备CS-PLA纺丝液，采用静电纺丝与模板卷取法制备CS-PLA复合神经导管，探究了静电纺CS-PLA复合材料的综合性能。通过表征复合材料的结构与性能，分析了CS与PLA体系内的分子作用，进一步通过复合神经导管与雪旺细胞的共培养实验，提出并验证了雪旺细胞在导管内壁生长黏附时的最佳体系组分。结果表明:复合材料中CS与PLA分子间以氢键结合，其中各种氢键贡献作用大小依次是OH…OH型>OH…N型>OH…醚O型。PLA含量增加，复合材料的热性能和热稳定性提高，断裂强度提升197.7%，断裂伸长率提高53.7%。CS含量增加，复合材料的亲水性和细胞相容性逐渐增加。在组分比例CS∶PLA(3∶1)时，凹槽及微孔的大小最有利于雪旺细胞的黏附。 

Molecular action and bioactivity characterization of electrospunchitosan-polylactic acid composite nerve conduit

The chitosan (CS)-polylactic acid (PLA) spinning solution was prepared using a composite solution of trifluoroacetic acid (TFA) and dichloromethane (DCM) as the solvent, and CS and PLA as the solute. Electrospinning and template coiling were used to prepare CS-PLA composite nerve conduit, and the comprehensive properties of CS-PLA composites were investigated. By characterizing the structure and properties of composites, the molecular interactions in CS and PLA systems were analyzed. Furthermore, through the co-cultivation experiments of composite nerve conduit and Schwann cells, the best system components for Schwann cells to grow and adhere to the inner wall of the catheter were proposed and verified. The results show that CS and PLA molecules are bonded by hydrogen bonds in the composite material, and the various hydrogen bond contributions are in the order of OH...OH>OH...N>OH...ether O. With the increase of PLA content, the thermal performance and thermal stability of the composites are increased, the tensile strength is increased by 197.7%, and the breaking elongation is increased by 53.7%. With the increase of CS content, the hydrophilicity and cell compatibility of the composites gradually increase. When the component ratio of CS∶PLA is 3∶1, the size of the grooves and micropores is the most favorable for Schwann cell adhesion.