National Engineering Research Center for Nanotechnology, Shanghai 200241, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Dec 24;6(24):21813-21. doi: 10.1021/am502278b. Epub 2014 May 29.
The ability of drug release from SF materials was governed largely by their secondary structure. It is known that the breakage degree of the peptide chain during the silk fibroin (SF) dissolution can affect the structure, property, and applications of SF materials. To deeply understand this effect, we designed a reaction system based on CaCl2/H2O/C2H5OH ternary solvent with different ethanol content to obtain the regenerated SF films with different morphologies and secondary structures. The results showed that the globule-like nanostructure was observed in all regenerated SF films, and their size decreased significantly with reducing the ethanol content in the solvent. Correspondingly, the β-sheet structure content of the SF films increased. In addition, the contact angle and the elongation ratio increased, and water absorption decreased significantly with decreasing the ethanol content in the solvent. The accumulated release percents of doxorubicin from these SF films were significantly different with increasing the time. With smaller nanostructure size and more β-sheet content, the SF films had a slower drug release at the beginning. This study indicated the importance of the ethanol content in the solvent in controlling the structure and properties of the regenerated SF films, which would improve the application of SF in drug delivery.
SF 材料的药物释放能力在很大程度上受其二级结构的控制。众所周知，丝素蛋白（SF）溶解过程中肽链的断裂程度会影响 SF 材料的结构、性能和应用。为了深入了解这种影响，我们设计了一个基于 CaCl2/H2O/C2H5OH 三元溶剂的反应体系，其中含有不同乙醇含量，以获得具有不同形貌和二级结构的再生 SF 薄膜。结果表明，所有再生 SF 薄膜中均观察到球状纳米结构，其尺寸随溶剂中乙醇含量的降低而显著减小。相应地，SF 薄膜的β-折叠结构含量增加。此外，接触角和伸长率增加，吸水率随溶剂中乙醇含量的降低而显著降低。这些 SF 薄膜中阿霉素的累积释放百分比随时间的增加而显著不同。随着纳米结构尺寸的减小和β-折叠含量的增加，SF 薄膜在开始时的药物释放速度较慢。这项研究表明，溶剂中乙醇含量在控制再生 SF 薄膜的结构和性能方面非常重要，这将提高 SF 在药物输送中的应用。
