National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, People's Republic of China.
Biomacromolecules. 2011 Apr 11;12(4):1080-6. doi: 10.1021/bm101422j. Epub 2011 Feb 25.
Controlling the degradation process of silk is an important and interesting subject in the field of biomaterials. In the present study, silk fibroin films with different secondary conformations and nanostructures were used to study degradation behavior in buffered protease XIV solution. Different from previous studies, silk fibroin films with highest β-sheet content achieved the highest degradation rate in our research. A new degradation mechanism revealed that degradation behavior of silk fibroin was related to not only crystal content but also hydrophilic interaction and then crystal-noncrystal alternate nanostructures. First, hydrophilic blocks of silk fibroin were degraded. Then, hydrophobic crystal blocks that were formerly surrounded and immobilized by hydrophilic blocks became free particles and moved into solution. Therefore, on the basis of the mechanism, which enables the process to be more controllable and flexible, controlling the degradation behavior of silk fibroin without affecting other performances such as its mechanical or hydrophilic properties becomes feasible, and this would greatly expand the applications of silk as a biomedical material.
控制丝的降解过程是生物材料领域中一个重要且有趣的课题。在本研究中，使用具有不同二级构象和纳米结构的丝素蛋白薄膜来研究在缓冲蛋白酶 XIV 溶液中的降解行为。与以前的研究不同，本研究中具有最高 β-折叠含量的丝素蛋白薄膜达到了最高的降解速率。揭示了一种新的降解机制，表明丝素蛋白的降解行为不仅与晶体含量有关，而且还与亲水性相互作用有关，然后是晶-非晶交替纳米结构。首先，丝素蛋白的亲水性链段被降解。然后，以前被亲水性链段包围和固定的疏水晶块变成自由颗粒并进入溶液。因此，基于该机制，可以使过程更加可控和灵活，在不影响丝素蛋白机械或亲水性能等其他性能的情况下控制其降解行为成为可能，这将极大地扩展丝作为生物医学材料的应用。
