In-vivo immunocompatibility and induced regenerative potential of silk fibroin modified decellularized porcine liver scaffolds in rat subcutaneous and full-thickness abdominal wall defect models.

For reconstructive surgical applications, humoral and cell-mediated immune response to scaffolds is important in determining its structural and functional integration and performance. A decellularized porcine liver matrix(DPL) mechanically augmented with impregnating silk fibroin(SF100DPL) and silk fibroin-gelatin blends(SFG5050DPL and SFG3070DPL) following citric acid crosslinking were evaluated in-vitro and in-vivo (subcutaneous and abdominal wall defect models) in comparison to unmodified DPL. Ensuring the preservation of glycosaminoglycan and the potential to induce cell migration in L929 cell line, the host immunocompatibility of the scaffolds was confirmed by implanting sub-cutaneously in rat. The modified scaffolds in the full-thickness rat abdominal wall defect model showed better integration at the defect site without any evidence of mechanical failure. The inflammatory cell response was evidently reducing with prominent neovascularization. Masson's trichrome (MT) staining and immunohistochemistry (IHC) demonstrated skeletal muscle island formation initially at the host-graft interface while extending towards the mid-graft region as time progressed. A significant decrease in the collagen III/I ratio at 90 days indicated that the neocollagen deposited at 21 days was replaced by mature collagen type I. Among the modified scaffolds evaluated, the SF100DPL and SFG5050DPL exhibited comparatively high immunocompatibility and regenerative potential that makes them suitable for various scaffold based regenerative therapies.