Macroporous interconnected dextran scaffolds of controlled porosity for tissue-engineering applications
Macroporous interconnected dextran scaffolds of controlled porosity for tissue-engineering applications
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DOI：
10.1016/j.biomaterials.2005.05.054
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发表时间：
2005-12-01
期刊：
影响因子：
14
通讯作者：
Shoichet, MS
中科院分区：
文献类型：
--
作者：
Lévesque, SG;Lim, RM;Shoichet, MS
葡聚糖水凝胶已经被研究作为药物递送载体，但不是作为组织工程的支架，这可能是因为先前合成的葡聚糖水凝胶的孔太小而不能穿透细胞。我们的目标是创造大孔的，相互连接的葡聚糖支架。为此，我们利用聚（乙二醇）和甲基丙烯酸化葡聚糖在甲基丙烯酸化部分的自由基交联过程中的液-液不溶性。通过控制甲基丙烯酸酯在葡聚糖上的取代度、葡聚糖的摩尔质量和PEG浓度，制备了大孔水凝胶。溶液中PEG的存在对葡聚糖水凝胶的最终形态具有显著影响，导致形成不同类型的结构，从微孔凝胶到大孔凝胶壁再到大孔互连珠状结构。制备了一系列配方图，使我们能够确定哪些条件导致大孔互连珠状支架的形成。葡聚糖大孔互连珠状凝胶具有89%至94%的高含水量，通过扫描电子显微镜测定的均匀形态，具有互连的大孔，通过蛋白质扩散率测定，其中BSA的有效扩散系数计算为3.1 X 10（-7）cm（2）/s（Dex-MA 40 kDa DS 5）和1 X 10（-7）cm（2）/s（Dex-MA 40 kDa DS 5）。Dex-MA 6 kDa DS 10的S，与BSA在水中的S相似，5.9 x 10（-7）cm（2）/s。压汞孔隙率测定法显示，大孔互连珠状支架具有双峰分布的大孔，中值直径为41 μ m，由中值直径为11 μ m的喉部互连。总之，这些数据表明，右旋糖酐支架在需要互连的大孔几何形状的应用中将是有利的，例如组织工程中的那些，其中细胞渗透和营养扩散是组织再生所必需的。(c)2005爱思唯尔有限公司保留所有权利。
Dextran hydrogels have been studied as drug delivery vehicles but not as scaffolds for tissue-engineering likely because previously synthesized dextran hydrogels had pores too small for cell penetration. Our goal was to create macroporous, interconnected dextran scaffolds. To this end, we took advantage of the liquid-liquid immiscibility of poly(ethylene glycol) and methacrylated dextran during radical crosslinking of the methacrylated moieties. By controlling the degree of methacrylate substitution on dextran, dextran molar mass and PEG concentration, macroporous hydrogels were created. The presence of PEG in solution had a significant effect on the final morphology of the dextran hydrogel leading to the formation of different types of structures, from microporous gel to macroporous gel-wall to a macroporous interconnected-beaded structure. A series of formulation diagrams were prepared which allowed us to determine which conditions led to the formation of macroporous interconnected-beaded scaffolds. Dextran macroporous interconnected-beaded gels had a high water content, between 89% and 94%, a homogeneous morphology, determined by scanning electron microscopy, with interconnected macroporous pores, as determined by protein diffusivity where the effective diffusion coefficients of BSA were calculated to be 3.1 X 10(-7)cm(2)/s for Dex-MA 40 kDa DS 5 and 1 X 10(-7)cm(2)/S for Dex-MA 6 kDa DS 10, which are similar to that of BSA in water, 5.9 x 10(-7) cm(2)/s. Mercury intrusion porosimetry showed that the macroporous interconnected-beaded scaffolds had a bimodal distribution of macropores, with a median diameter of 41 Am, interconnected by throats, which had a median diameter of I I Am. Together, these data suggest that the dextran scaffolds will be advantageous in applications that require an interconnected macroporous geometry, such as those of tissue engineering where cell penetration and nutrient diffusion are necessary for tissue regeneration. (c) 2005 Elsevier Ltd. All rights reserved.