State Key Laboratory of Silkworm Genome Biology, Chongqing Engineering Research Center of Biomaterial Fiber and Modern Textile, College of Textile and Garment, Southwest University, Chongqing 400715, China.
State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China.
Int J Biol Macromol. 2020 Aug 1;156:633-639. doi: 10.1016/j.ijbiomac.2020.04.053. Epub 2020 Apr 11.
The air-liquid interface has been used to create micro- and nanostructured polymeric membranes. Here, we employed a novel silk fibroin (SF) solution to create ultrathin membranes effectively on the surface of subphase (30 wt% ammonium sulphate). The SF droplets spread instantaneously at the air-liquid interface driven by the surface tension difference between subphase and SF solutions. Conformational changes for SF molecules from disordered structure to ordered structure occur simultaneously. During the process, SF molecules self-assemble by rearranging hydrophobic and hydrophilic domains to minimize the free energy of the system. Dehydration and denaturation of proteins by high concentration of salt in the subphase promote the polymer solidification. Phase separation results in the porous structure of the SF membrane. Mixing aqueous gelatin with SF solution causes the reduction of pore size, porosity and mechanical properties of the membranes. More aqueous gelatin hinders the polymer solidification within short time. The as-prepared membranes have excellent transparency and cytocompatibility, which have potential for the applications of biotechnology, biomedicine and organ-on-chip.
气液界面已被用于制造微纳米结构的聚合物膜。在这里，我们采用了一种新颖的丝素（SF）溶液，有效地在亚相（30wt%硫酸铵）表面上制造了超薄膜。SF 液滴在亚相和 SF 溶液之间的表面张力差的驱动下，瞬间在气液界面上扩散。SF 分子的构象从无序结构到有序结构同时发生变化。在此过程中，SF 分子通过重新排列疏水区和亲水区来自我组装，以最小化系统的自由能。亚相中高浓度的盐使蛋白质脱水和变性，促进了聚合物的固化。相分离导致 SF 膜的多孔结构。将明胶水溶液与 SF 溶液混合会导致膜的孔径、孔隙率和力学性能降低。更多的明胶水溶液会在短时间内阻碍聚合物的固化。所制备的膜具有优异的透明度和细胞相容性，在生物技术、生物医学和器官芯片等领域有应用潜力。
