title: Degradation mechanism and control of silk fibroin.
abstract: 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.
authors.affiliation: National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, People's Republic of China. Lvqiang78@suda.edu.cn
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lu
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.forename: Mingzhong
authors.initials: M
authors.lastname: Li
authors.forename: Baoqi
authors.initials: B
authors.lastname: Zuo
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.forename: Yongli
authors.initials: Y
authors.lastname: Huang
authors.forename: Hesun
authors.initials: H
authors.lastname: Zhu
mesh_terms: D002152:Calorimetry, Differential Scanning; D005349:Fibroins / Q000737:chemistry*; D006868:Hydrolysis; D018625:Microscopy, Atomic Force; D047011:Silk / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D047011:Silk; D012996:Solutions; D005349:Fibroins