Green process to prepare water-insoluble silk scaffolds with silk I structure.

Silk porous scaffolds have shown promising applications in tissue regenerations as cellular scaffolds to incorporate cells in vitro and in vivo, and facilitate cell proliferation and production of extracellular matrix. It remains strong needs to optimize the microstructures and performances of silk scaffolds for better biocompatibility. Here, a green process was developed to form water-insoluble scaffolds. Repeated freezing-dissolving procedures and silk nanofibers were introduced to tune the performances of the scaffolds, resulting in amorphous conformations and nanofibrous structures. Controllable degradation and mechanical properties as well as improved cell compatibility were then achieved for these scaffolds, suggesting their promising future in tissue regenerations. Our present results confirmed the possibility of actively designing silk scaffolds with preferable properties used in various tissue regenerations.