Kang Hyun Goo, Kim So Yeon, Lee Young Moo
School of Chemical Engineering, College of Engineering, Hanyang University, Seoul 133-791, South Korea.
J Biomed Mater Res B Appl Biomater. 2006 Nov;79(2):388-97. doi: 10.1002/jbm.b.30553.
Porous gelatin scaffolds were prepared using a modified overrun process, which is a novel method for preparing a porous matrix by injecting air and mixing polymer solution at low temperature. The pores in the scaffolds formed by the overrun process exhibited a dual-pore structure due to the injection of air bubbles and ice recrystallization. However, the morphology of the overrun-processed gelatin scaffolds had closed pore structures. The closed pore structure was reformed into a uniformly distributed and interconnected open structure by the combination of the overrun process and a particle-leaching technique (NaCl and sucrose). The mechanical strength and biodegradation rate of gelatin scaffolds were controlled by the matrix porosity and concentration of gelatin solution. Despite higher porosity, overrun processed gelatin scaffolds showed similar mechanical strength to freeze-dried scaffolds. After 1 week of in vitro culturing, the fibroblasts in overrun-processed scaffolds were widely distributed on the surface of the scaffold pores, whereas cells seeded in freeze-dried scaffolds were mainly placed on the top and bottom of the scaffolds. Therefore, the overrun process combined with a particle-leaching technique can be applied to fabricate porous scaffolds with a desirable cellular structure for tissue engineering applications.
采用改良的膨胀法制备了多孔明胶支架，这是一种通过在低温下注入空气并混合聚合物溶液来制备多孔基质的新方法。由于气泡注入和冰重结晶，通过膨胀法形成的支架中的孔呈现出双孔结构。然而，膨胀法处理的明胶支架的形态具有封闭的孔结构。通过膨胀法与颗粒浸出技术（氯化钠和蔗糖）相结合，将封闭的孔结构改造成均匀分布且相互连通的开放结构。明胶支架的机械强度和生物降解速率由基质孔隙率和明胶溶液浓度控制。尽管孔隙率较高，但膨胀法处理的明胶支架显示出与冻干支架相似的机械强度。体外培养1周后，膨胀法处理的支架中的成纤维细胞广泛分布在支架孔的表面，而接种在冻干支架中的细胞主要位于支架的顶部和底部。因此，膨胀法与颗粒浸出技术相结合可用于制造具有理想细胞结构的多孔支架，用于组织工程应用。
