title: Injectable silk foams for soft tissue regeneration.
abstract: Soft tissue fillers are needed for restoration of a defect or augmentation of existing tissues. Autografts and lipotransfer have been under study for soft tissue reconstruction but yield inconsistent results, often with considerable resorption of the grafted tissue. A minimally invasive procedure would reduce scarring and recovery time as well as allow the implant and/or grafted tissue to be placed closer to existing vasculature. Here, the feasibility of an injectable silk foam for soft tissue regeneration is demonstrated. Adipose-derived stem cells survive and migrate through the foam over a 10-d period in vitro. The silk foams are also successfully injected into the subcutaneous space in a rat and over a 3-month period integrating with the surrounding native tissue. The injected foams are palpable and soft to the touch through the skin and returning to their original dimensions after pressure is applied and then released. The foams readily absorb lipoaspirate making the foams useful as a scaffold or template for existing soft tissue filler technologies, useful either as a biomaterial alone or in combination with the lipoaspirate.
authors.affiliation: Biomedical Engineering, Tufts University, Medford, MA, 02155, USA.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Bellas
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Lo
authors.forename: Eric P
authors.initials: EP
authors.lastname: Fournier
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Brown
authors.forename: Rosalyn D
authors.initials: RD
authors.lastname: Abbott
authors.forename: Eun S
authors.initials: ES
authors.lastname: Gil
authors.forename: Kacey G
authors.initials: KG
authors.lastname: Marra
authors.forename: J Peter
authors.initials: JP
authors.lastname: Rubin
authors.forename: Gary G
authors.initials: GG
authors.lastname: Leisk
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000273:Adipose Tissue / Q000166:cytology* / Q000502:physiology; D000818:Animals; D001672:Biocompatible Materials; D002465:Cell Movement; D004867:Equipment Design; D005260:Female; D006801:Humans; D007267:Injections / Q000295:instrumentation / Q000379:methods*; D008422:Materials Testing; D017207:Rats, Sprague-Dawley; D012038:Regeneration; D047011:Silk / Q000008:administration & dosage* / Q000737:chemistry* / Q000494:pharmacology; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D047011:Silk
keywords: biomedical applications; porous scaffolds; regenerative medicine; silk; soft tissue