title: Effect of processing on silk-based biomaterials: reproducibility and biocompatibility.
abstract: Silk fibroin has been successfully used as a biomaterial for tissue regeneration. To prepare silk fibroin biomaterials for human implantation a series of processing steps are required to purify the protein. Degumming to remove inflammatory sericin is a crucial step related to biocompatibility and variability in the material. Detailed characterization of silk fibroin degumming is reported. The degumming conditions significantly affected cell viability on the silk fibroin material and the ability to form three-dimensional porous scaffolds from the silk fibroin, but did not affect macrophage activation or β-sheet content in the materials formed. Methods are also provided to determine the content of residual sericin in silk fibroin solutions and to assess changes in silk fibroin molecular weight. Amino acid composition analysis was used to detect sericin residuals in silk solutions with a detection limit between 1.0 and 10% wt/wt, while fluorescence spectroscopy was used to reproducibly distinguish between silk samples with different molecular weights. Both methods are simple and require minimal sample volume, providing useful quality control tools for silk fibroin preparation processes.
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, USA.
authors.forename: Lindsay S
authors.initials: LS
authors.lastname: Wray
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.forename: Jabier
authors.initials: J
authors.lastname: Gallego
authors.forename: Irene
authors.initials: I
authors.lastname: Georgakoudi
authors.forename: Fiorenzo G
authors.initials: FG
authors.lastname: Omenetto
authors.forename: Daniel
authors.initials: D
authors.lastname: Schmidt
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000596:Amino Acids; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism; D005349:Fibroins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008422:Materials Testing / Q000592:standards*; D019736:Prostheses and Implants; D017433:Protein Structure, Secondary; D012038:Regeneration; D015203:Reproducibility of Results; D047030:Sericins / Q000737:chemistry / Q000378:metabolism; D047011:Silk / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D001672:Biocompatible Materials; D047030:Sericins; D047011:Silk; D005349:Fibroins