Ao Qiang, Wang Aijun, Cao Wenling, Zhang Ling, Kong Lijun, He Qing, Gong Yandao, Zhang Xiufang
Department of Biological Sciences and Biotechnology, State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China.
J Biomed Mater Res A. 2006 Apr;77(1):11-8. doi: 10.1002/jbm.a.30593.
Multimicrotubule chitosan conduits (M-conduits) were fabricated using novel molds and a thermal-induced phase-separation technique. Hollow chitosan conduits (H-conduits) with an inner diameter of 1-5 mm and a wall thickness of 0.2-1.0 mm were made, and then a novel mold composed of a styrofoam insulating pedestal with several holes and a stainless steel cover plate was used to make M-conduits. In brief, corresponding H-conduits were inserted upright into the holes of the styrofoam pedestal, and filled with chitosan solution, then rapidly covered with the precooled stainless steel cover plate, and then placed in a freezer. The styrofoam insulating pedestal enclosing the conduits could reduce the heat transfer through the side wall of the conduits. Gradual phase separation then occurred uniaxially in the presence of a unidirectional temperature gradient from the top end to the bottom end of the chitosan conduits. The phase-separated polymer/solvent systems were then dried in a freeze-dryer. The microtubule diameters were controlled by adjusting the polymer concentration and cooling temperature. In vitro characterization demonstrated that the mold-based multimicrotubule chitosan conduits possessed suitable mechanical strength, microtubule diameter distribution, porosity, swelling, biodegradability, and nerve cell affinity, and so they showed potential for application as nerve tissue engineering scaffolds.
使用新型模具和热致相分离技术制备了多微管壳聚糖导管（M导管）。制作了内径为1 - 5毫米、壁厚为0.2 - 1.0毫米的中空壳聚糖导管（H导管），然后使用由带有若干孔的聚苯乙烯泡沫塑料绝缘基座和不锈钢盖板组成的新型模具来制作M导管。简而言之，将相应的H导管垂直插入聚苯乙烯泡沫塑料基座的孔中，填充壳聚糖溶液，然后迅速用预冷的不锈钢盖板覆盖，再放入冰箱中。包围导管的聚苯乙烯泡沫塑料绝缘基座可以减少通过导管侧壁的热传递。然后，在壳聚糖导管从顶端到底端存在单向温度梯度的情况下，逐步发生单轴相分离。然后将相分离的聚合物/溶剂体系在冷冻干燥机中干燥。通过调节聚合物浓度和冷却温度来控制微管直径。体外表征表明，基于模具的多微管壳聚糖导管具有合适的机械强度、微管直径分布、孔隙率、膨胀性、生物降解性和神经细胞亲和力，因此它们显示出作为神经组织工程支架应用的潜力。
