Abstract In this study, retinoic acid loaded-PLGA-gelatin matrixes were prepared with both freeze-casting and freeze-drying techniques. Herein, the effect of unidirectional microstructure with tunable pores on release profile, cellular adhesion, migration, and differentiation was compared. Morphological observation determined that highly interconnected porous structure can be formed, but lamellar pore channels were observed in freeze-casting prepared constructs. The absorption ratio was increased, and the biodegradation rate was decreased as a function of the orientation of microstructure. The in-vitro release study illustrated non-Fickian release mechanism in both methods, so that erosion has predominated over diffusion. Accordingly, PLGA-gelatin scaffolds prepared with freeze-drying technique showed no adequate erosion due to the rigid structure, while freeze-casting one presented more favorable erosion. Microscopic observations of adhered P19 embryonic cells on the scaffolds showed that the freeze-casting matrixes with unidirectional pores provide a more compatible microenvironment for cell attachments and spreading. Besides, it facilitated cell migration and penetration inside the structure and may act as guidance for neuron growth. Improvement in the expression of neural genes in unidirectionally oriented pores proved the decisive role of contact guidance for nerve healing. It seems that the freeze-cast PLGA-gelatin-retinoic acid scaffolds have initial features for nerve tissue regeneration studies.

中文翻译：

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维甲酸负载基质层状微结构对P19胚胎癌细胞理化性质、迁移和神经分化的影响

摘要 在本研究中，采用冷冻浇铸和冷冻干燥技术制备了负载视黄酸的 PLGA-明胶基质。在此，比较了具有可调孔的单向微结构对释放曲线、细胞粘附、迁移和分化的影响。形态观察确定可以形成高度互连的多孔结构，但在冷冻铸造制备的构造中观察到层状孔道。作为微观结构取向的函数，吸收率增加，生物降解率降低。体外释放研究说明了两种方法中的非 Fickian 释放机制，因此侵蚀在扩散中占主导地位。因此，用冷冻干燥技术制备的 PLGA-明胶支架由于刚性结构没有表现出足够的侵蚀，而冷冻铸造则表现出更有利的侵蚀。对粘附在支架上的 P19 胚胎细胞的显微镜观察表明，具有单向孔的冻铸基质为细胞附着和扩散提供了更兼容的微环境。此外，它促进了结构内部的细胞迁移和渗透，并可作为神经元生长的指导。单向孔中神经基因表达的改善证明了接触引导对神经愈合的决定性作用。似乎冻铸 PLGA-明胶-视黄酸支架具有用于神经组织再生研究的初步特征。对粘附在支架上的 P19 胚胎细胞的显微镜观察表明，具有单向孔的冻铸基质为细胞附着和扩散提供了更兼容的微环境。此外，它促进了结构内部的细胞迁移和渗透，并可作为神经元生长的指导。单向孔中神经基因表达的改善证明了接触引导对神经愈合的决定性作用。似乎冻铸 PLGA-明胶-视黄酸支架具有用于神经组织再生研究的初步特征。对粘附在支架上的 P19 胚胎细胞的显微镜观察表明，具有单向孔的冻铸基质为细胞附着和扩散提供了更兼容的微环境。此外，它促进了结构内部的细胞迁移和渗透，并可作为神经元生长的指导。单向孔中神经基因表达的改善证明了接触引导对神经愈合的决定性作用。似乎冻铸 PLGA-明胶-视黄酸支架具有用于神经组织再生研究的初步特征。单向孔中神经基因表达的改善证明了接触引导对神经愈合的决定性作用。似乎冻铸 PLGA-明胶-视黄酸支架具有用于神经组织再生研究的初步特征。单向孔中神经基因表达的改善证明了接触引导对神经愈合的决定性作用。似乎冻铸 PLGA-明胶-视黄酸支架具有用于神经组织再生研究的初步特征。