Decorated small intestinal submucosa (SIS) based bio-patch with anti-fouling and vascularized capacity to accelerate chronic wound regeneration via TGF-β and MAPK pathway

Chronic wounds in diabetes take a lifetime risk of developing into diabetic foot ulcers (DFUs). Conventional wound dressings and commercial products fail for ideal tissue regeneration in DFUs due to the incapacity to promote vascularization and prevent bacterial infections during wound repair. In this study, the small intestinal submucosa (SIS) with enriched vascularized bioactive factors, was chemically decorated by 2-methacryloyloxy ethyl phosphorylcholine (MPC) through Michael-type addition to be endowed anti-fouling ability, in order to treat chronic wound regeneration in diabetes. In the diabetic skin injury experiment, we established the animal model by 5-mm diameter defects in the SD rats and implanted the bio-patches to the located sites. The SIS-MPC bio-patch showed superior advantages in bacterial anti-adhesion (100-fold foul resistance than commercial patches), while maintained affinity for fibroblast growth and collagen formation, as demonstrated by immunohistochemical staining from the local tissues, outperforming commercial wound dressings in tissue regeneration, which was attributed to acceleration in neovascularization and inflammation modulation through TGF-β and MAPK pathway. This novel SIS-MPC bio-patch would be a promising candidate for medical translations into diabetes and chronic wound treatments.