壳聚糖改性的聚乳酸-羟基乙酸共聚物神经导管的制备、表征及其生物学性能

Study on preparation, characterization and biological properties of chitosan-modified PLGA neural conduits

目的:制备用于神经修复及再生的壳聚糖改性聚乳酸-羟基乙酸共聚物(PLGA)神经导管支架。方法:利用静电纺丝技术制备不同比例的PLGA纤维膜,并按聚乳酸比例依次增长的顺序层层卷绕制备梯度降解的PLGA神经导管支架,用壳聚糖通过截留法对导管进行改性,电镜观察其微观形貌,红外光谱分析壳聚糖的截留情况,利用接触角测量仪检测导管亲水性,通过测量导管体积和干重计算孔隙率,通过拉伸实验检测导管力学性能。利用CCK-8实验检测大鼠神经施万细胞RSC96在壳聚糖改性的PLGA神经导管预处理培养基中的增殖情况,荧光显微镜下观察RSC96细胞在壳聚糖改性的PLGA纤维膜上的生长情况。结果:静电纺丝得到的PLGA纤维直径均匀,呈现取向分布。经壳聚糖改性,PLGA神经导管的亲水性有所提高,孔隙率有所下降,力学强度显著提高。RSC96细胞在壳聚糖改性的PLGA神经导管预处理培养基中增殖良好,在壳聚糖改性的PLGA纤维膜上的生长方向与纤维膜的取向一致。结论:壳聚糖改性的PLGA神经导管具有良好的亲水性和力学性能以及细胞相容性,可作为神经修复再生支架。

Aim:To prepare chitosan-modified PLGA nerve conduit scaffolds for nerve repair and regeneration.Methods:PLGA fiber membranes with different ratios were prepared with electrospinning and the layers were wound in order of increasing PLA ratio to produce gradient-degraded PLGA conduits.The microscopic morphology of chitosan-modified PLGA was observed with an electron microscope,and the retention of chitosan was analyzed by infrared spectroscopy.The hydrophilicity of the conduits was measured using a contact angle meter.The porosity was calculated by measuring the volume and dry weight of the conduits.Tensile test was used to evaluate mechanical strength.CCK-8 assay was used to detect the proliferation of Schwann cells of rat nerve RSC96 in chitosan/PLGA conduit pretreatment medium,and the growth of RSC96 cells on the surface of fiber membrane was observed under a fluorescence microscope.Results:PLGA fibers showed a uniform and orientation distribution.Although the hydrophilicity was improved,the porosity of chitosan-modified PLGA conduits was decreased.The mechanical strength of chitosan-modified PLGA conduits was significantly enhanced.RSC96 cells proliferated well in the chitosan/PLGA conduit pretreatment medium,and the growth direction on the chitosan/PLGA fiber membrane was consistent with the fiber membrane orientation.Conclusion:The chitosan-modified PLGA conduits have proper hydrophilicity,mechanical properties and cell compatibility,and can be used as a nerve repair and regeneration scaffold.