title: Lyophilized Silk Sponges: A Versatile Biomaterial Platform for Soft Tissue Engineering.
abstract: We present a silk biomaterial platform with highly tunable mechanical and degradation properties for engineering and regeneration of soft tissues such as, skin, adipose, and neural tissue, with elasticity properties in the kilopascal range. Lyophilized silk sponges were prepared under different process conditions and the effect of silk molecular weight, concentration and crystallinity on 3D scaffold formation, structural integrity, morphology, mechanical and degradation properties, and cell interactions in vitro and in vivo were studied. Tuning the molecular weight distribution (via degumming time) of silk allowed the formation of stable, highly porous, 3D scaffolds that held form with silk concentrations as low as 0.5% wt/v. Mechanical properties were a function of silk concentration and scaffold degradation was driven by beta-sheet content. Lyophilized silk sponges supported the adhesion of mesenchymal stem cells throughout 3D scaffolds, cell proliferation in vitro, and cell infiltration and scaffold remodeling when implanted subcutaneously in vivo.
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States ; Graduate School of Biomedical Engineering, UNSW Australia , Sydney, NSW 2052, Australia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Rnjak-Kovacina
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States.
authors.forename: Lindsay S
authors.initials: LS
authors.lastname: Wray
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States ; Chemical & Biomolecular Engineering Department, University of Connecticut , 191 Auditorium Road, Storrs, Connecticut 06269-3222, United States.
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Burke
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States.
authors.forename: Tess
authors.initials: T
authors.lastname: Torregrosa
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States.
authors.forename: Julianne M
authors.initials: JM
authors.lastname: Golinski
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Huang
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States.
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
keywords: biomaterial; lyophilized sponge; scaffold; silk; soft tissue engineering