Department of Bioengineering, The University of Texas at Arlington, Arlington, TX, USA.
Biotechnol Appl Biochem. 2011 Sep-Oct;58(5):335-44. doi: 10.1002/bab.44. Epub 2011 Sep 16.
Porogen leaching is a widely used and simple technique for the creation of porous scaffolds in tissue engineering. Sodium chloride (NaCl) is the most commonly used porogen, but the current grinding and sieving methods generate salt particles with huge size variations and cannot generate porogens in the submicron size range. We have developed a facile method based on the principles of crystallization to precisely control salt crystal sizes down to a few microns within a narrow size distribution. The resulting NaCl crystal size could be controlled through the solution concentration, crystallization temperature, and crystallization time. A reduction in solution temperature, longer crystallization times, and an increase in salt concentration resulted in an increase in NaCl crystal sizes due to the lowered solubility of the salt solution. The nucleation and crystallization technique provides superior control over the resulting NaCl size distribution (13.78 ± 1.18 μm), whereas the traditional grinding and sieving methods produced NaCl porogens 13.89 ± 12.49 μm in size. The resulting NaCl porogens were used to fabricate scaffolds with increased interconnectivity, porous microchanneled scaffolds, and multiphasic vascular grafts. This new generation of salt porogen provides great freedom in designing versatile scaffolds for various tissue-engineering applications.
致孔剂萃取是组织工程中制造多孔支架的一种广泛应用且简单的技术。氯化钠（NaCl）是最常用的致孔剂，但目前的研磨和筛分方法会产生粒径变化巨大的盐颗粒，而且无法生成亚微米级的致孔剂。我们基于结晶原理开发了一种简单的方法，可以精确控制盐晶体的粒径，使其在几微米的范围内具有较窄的粒径分布。通过溶液浓度、结晶温度和结晶时间可以控制得到的 NaCl 晶体粒径。降低溶液温度、延长结晶时间和增加盐浓度会导致盐溶液的溶解度降低，从而使 NaCl 晶体粒径增大。成核和结晶技术可以更好地控制得到的 NaCl 粒径分布（13.78±1.18μm），而传统的研磨和筛分方法得到的 NaCl 致孔剂粒径为 13.89±12.49μm。所得的 NaCl 致孔剂用于制造具有更高连通性的支架、多孔微通道支架和多相血管移植物。这种新一代盐致孔剂为各种组织工程应用设计多功能支架提供了更大的自由度。
