School of Materials Science and Engineering, Pusan National University, Pusan, 609-735, South Korea.
J Mater Sci Mater Med. 2010 May;21(5):1495-502. doi: 10.1007/s10856-010-4000-1. Epub 2010 Jan 23.
A novel freeze-gel casting/polymer sponge technique has been introduced to fabricate porous hydroxyapatite scaffolds with controlled "designer" pore structures and improved compressive strength for bone tissue engineering applications. Tertiary-butyl alcohol (TBA) was used as a solvent in this work. The merits of each production process, freeze casting, gel casting, and polymer sponge route were characterized by the sintered microstructure and mechanical strength. A reticulated structure with large pore size of 180-360 microm, which formed on burn-out of polyurethane foam, consisted of the strut with highly interconnected, unidirectional, long pore channels (approximately 4.5 microm in dia.) by evaporation of frozen TBA produced in freeze casting together with the dense inner walls with a few, isolated fine pores (<2 microm) by gel casting. The sintered porosity and pore size generally behaved in an opposite manner to the solid loading, i.e., a high solid loading gave low porosity and small pore size, and a thickening of the strut cross section, thus leading to higher compressive strengths.
一种新型的冷冻凝胶铸造/聚合物海绵技术已被引入，用于制造具有可控“设计”孔结构和改善抗压强度的多孔羟基磷灰石支架，用于骨组织工程应用。在这项工作中，叔丁醇（TBA）被用作溶剂。通过烧结微观结构和机械强度来表征每个生产工艺（冷冻铸造、凝胶铸造和聚合物海绵路线）的优点。由聚氨酯泡沫燃烧形成的具有 180-360 微米大孔径的网状结构，由通过冷冻 TBA 的蒸发形成的具有高度互连、单向、长孔道（直径约 4.5 微米）的支柱以及凝胶铸造形成的具有少量孤立细孔（<2 微米）的密集内壁组成。烧结孔隙率和孔径通常与固体负载呈相反的方式，即高固体负载会导致低孔隙率和小孔径，以及支柱横截面的增厚，从而导致更高的抗压强度。
