Ginsenoside Rb1/TGF-β1 loaded biodegradable silk fibroin-gelatin porous scaffolds for inflammation inhibition and cartilage regeneration

Creating a microenvironment with low inflammation and favorable for the chondrogenic differentiation of endogenous stem cells plays an essential role in cartilage repairing. In the present study, we design a novel ginsenoside Rb1/TGF-β1 loaded silk fibroin-gelatin porous scaffold (GSTR) with the function of attenuating inflammation and promoting chondrogenesis. The scaffold has porous microstructure, proper mechanical strength, degradation rate and sustained release of Rb1 and TGF-β1. Rat bone marrow-derived mesenchymal stem cells (rBMSCs) seeded into GSTR scaffolds are homogeneously distributed and display a higher proliferation rate than non-loaded scaffolds (GS). GSTR scaffolds promote the chondrogenic differentiation of rBMSCs and suppress the expression of inflammation genes. Under the stimulation of IL-1β, the inflammation level of the chondrocytes seeded in GSTR scaffolds is also significantly down-regulated. Moreover, GSTR scaffolds implanted into the osteochondral defects in rats effectively promote the regeneration of hyaline cartilage 12 weeks after surgery when compared with other groups. It is demonstrated that this scaffold loaded with Rb1 and TGF-β1 can synergistically create a microenvironment favorable for cartilage regeneration by promoting the chondrogenesis and suppressing the inflammation levels in vivo. These results prove it has a great potential to develop this Rb1/TGF-β1 releasing scaffold into a novel and promising therapeutic for cartilage repair. Biodegradable silk fibroin-gelatin porous scaffolds loaded with Rb1 and TGF-β1 can sustainedly release the two bioactive substances, therefore promote the chondrogenic differentiation of rBMSCs, suppress the inflammation levels of rBMSCs as well as IL-1β treated chondrocytes in vitro and exert synergetic effect on promoting cartilage matrix formation and suppressing inflammation in vivo, demonstrating it can be a novel and promising therapeutic for cartilage repair. [Display omitted] •GS scaffolds with porous structure and proper degradation are obtained.•SF coating can improve the mechanical property of the scaffolds.•GS can sustainedly release TGF-β1 and ginsenoside Rb1.•Rb1&TGF-β1 play a synergic role on anti-inflammation&chondrogenic differentiation.•GSTR scaffolds significantly promoted in sute cartilage repair in rats.