Salt fusion: An approach to improve pore interconnectivity within tissue engineering scaffolds
Salt fusion: An approach to improve pore interconnectivity within tissue engineering scaffolds
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DOI：
10.1089/107632702753503045
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发表时间：
2002-02-01
影响因子：
--
通讯作者：
Mooney, DJ
中科院分区：
文献类型：
--
作者：
Murphy, WL;Dennis, RG;Mooney, DJ
由生物可降解聚合物组成的大孔支架已被广泛用作三维基底，用于体外细胞接种随后移植，或用作体内直接植入的导电基底。用于产生用于组织工程的大孔支架的方法很多，并且常用方法通常在三维聚合物基质内使用固体致孔剂以产生明确限定的孔径、孔结构和总支架孔隙率。本研究描述了一种方法，赋予改进的孔隙互连聚合物支架组织工程的固体致孔剂部分融合在一起之前，创建一个连续的聚合物基质。三维，多孔支架的共聚物85：15聚（丙交酯-共-乙交酯），通过溶剂浇铸/颗粒沥滤过程，或气体发泡/颗粒沥滤过程。在形成连续的聚合物基质之前，作为固体致孔剂的NaCl晶体通过在95%湿度下处理而部分熔融。扫描电子显微照片清楚地显示了熔盐晶体和通过溶剂浇铸和气体发泡制备的盐熔支架中的孔互连性的增强，并且孔互连性的程度随着处理时间的延长而增强。熔融盐晶体24小时增加了盐晶体的曲率半径，并导致溶剂浇铸支架的压缩模量增加两倍（总孔隙率为97 +/-1%）。在气体发泡之前NaCl晶体的融合导致支架压缩模量从277 +/-60 k Pa降低至187 +/-30 k Pa（总孔隙率为94 +/- 1%）。由此产生的高度互连的支架具有促进细胞迁移、丰富的细胞-细胞相互作用以及潜在地改善组织工程支架内的神经和血管生长的意义。
Macroporous scaffolds composed of biodegradable polymers have found extensive use as three-dimensional substrates either for in vitro cell seeding followed by transplantation, or as conductive substrates for direct implantation in vivo. Methods abound for creation of macroporous scaffolds for tissue engineering, and common methods typically employ a solid porogen within a three-dimensional polymer matrix to create a well-defined pore size, pore structure, and total scaffold porosity. This study describes an approach to impart improved pore interconnectivity to polymer scaffolds for tissue engineering by partially fusing the solid porogen together prior to creation of a continuous polymer matrix. Three dimensional, porous scaffolds of the copolymer 85:15 poly(lactide-co-glycolide) were fabricated via either a solvent casting/particulate leaching process, or a gas foaming/particulate leaching process. Prior to creation of a continuous polymer matrix the NaCl crystals, which serve as the solid porogen, are partially fused via treatment in 95% humidity. Scanning electron micrographs clearly display fused salt crystals and an enhancement in pore interconnectivity in the salt fused scaffolds prepared via both solvent casting and gas foaming, and the extent of pore interconnectivity is enhanced with longer treatment times. Fusion of salt crystal for 24 h increased the radius of curvature of salt crystals, and led to a twofold increase in the compressive modulus of solvent cast scaffolds (total porosity of 97 +/- 1%). Fusion of NaCl crystals prior to gas foaming resulted in a decrease in scaffold compressive modulus from 277 +/- 60k Pa to 187 +/- 30k Pa (total porosity of 94 +/- 1%). The resulting highly interconnected scaffolds have implications for facilitated cell migration, abundant cell-cell interaction, and potentially improved neural and vascular growth within tissue engineering scaffolds.