Madihally S V, Matthew H W
Department of Chemical Engineering & Materials Science, Wayne State University, Detroit, MI 48202, USA.
Biomaterials. 1999 Jun;20(12):1133-42. doi: 10.1016/s0142-9612(99)00011-3.
The wide array of tissue engineering applications exacerbates the need for biodegradable materials with broad potential. Chitosan, the partially deacetylated derivative of chitin, may be one such material. In this study, we examined the use of chitosan for formation of porous scaffolds of controlled microstructure in several tissue-relevant geometries. Porous chitosan materials were prepared by controlled freezing and lyophilization of chitosan solutions and gels. The materials were characterized via light and scanning electron microscopy as well as tensile testing. The scaffolds formed included porous membranes, blocks, tubes and beads. Mean pore diameters could be controlled within the range 1-250 microm, by varying the freezing conditions. Freshly lyophilized chitosan scaffolds could be treated with glycosaminoglycans to form ionic complex materials which retained the original pore structure. Chitosan scaffolds could be rehydrated via an ethanol series to avoid the stiffening caused by rehydration in basic solutions. Hydrated porous chitosan membranes were at least twice as extensible as non-porous chitosan membranes, but their elastic moduli and tensile strengths were about tenfold lower than non-porous controls. The methods and structures described here provide a starting point for the design and fabrication of a family of polysaccharide based scaffold materials with potentially broad applicability.
组织工程应用的广泛领域加剧了对具有广泛潜力的可生物降解材料的需求。壳聚糖是几丁质的部分脱乙酰化衍生物，可能就是这样一种材料。在本研究中，我们研究了壳聚糖在几种与组织相关的几何形状中用于形成具有可控微观结构的多孔支架的用途。多孔壳聚糖材料通过壳聚糖溶液和凝胶的控制冷冻和冻干制备。通过光学和扫描电子显微镜以及拉伸试验对材料进行表征。形成的支架包括多孔膜、块体、管子和珠子。通过改变冷冻条件，平均孔径可控制在1-250微米范围内。新鲜冻干的壳聚糖支架可用糖胺聚糖处理以形成保留原始孔结构的离子复合材料。壳聚糖支架可通过乙醇系列进行再水化，以避免在碱性溶液中再水化引起的硬化。水合多孔壳聚糖膜的可延伸性至少是非多孔壳聚糖膜的两倍，但其弹性模量和拉伸强度比非多孔对照物低约十倍。这里描述的方法和结构为设计和制造一系列具有潜在广泛适用性的基于多糖的支架材料提供了一个起点。
