Polydopamine-modified decellularized intestinal scaffolds loaded with adipose-derived stem cells promote intestinal regeneration.

Regeneration of gastrointestinal tissues remains a great challenge due to their unique microenvironment. Functional composite decellularized scaffolds have shown great potential in gastrointestinal repair and inducing gastrointestinal tissue-specific proliferation. In this study, polydopamine (PDA)-mediated surface modification of decellularized intestinal scaffolds (DIS), combined with adipose tissue-derived stem cells (ADSC), was used to promote intestinal wound healing while avoiding intestinal resection. The results showed that DIS had good biocompatibility and could maintain the growth and proliferation of ADSC. Moreover, PDA-coated DIS not only had anti-infection ability but could also further promote the secretory activity for the paracrine effects of ADSC. ADSC cultured on PDA-DIS produced significantly higher levels of anti-inflammatory and proangiogenic cytokines than those cultured on plastic plates or DIS. In vivo, ADSC-PDA-DIS significantly promoted intestinal wound closure in rat intestinal defect models. Moreover, ADSC-PDA-DIS was able to induce more neovascularization at 4 weeks postoperatively and promoted macrophage recruitment to accelerate wound healing. Taken together, the results showed that PDA-modified DIS could significantly improve the efficacy of stem cell therapy, and ADSC-PDA-DIS could improve the wound healing process with anti-infection effects, enhancing neovascularization and immunoregulation, which may be of great clinical significance for gastrointestinal regeneration.