In situ delivery of apoptotic bodies derived from mesenchymal stem cells via a hyaluronic acid hydrogel: A therapy for intrauterine adhesions.

Stem cell-based and stem cell-derived exosome-based therapies have shown promising potential for endometrial regeneration and the clinical treatment of intrauterine adhesions (IUAs). Evidence shows that apoptosis occurs in a majority of grafted stem cells, and apoptotic bodies (ABs) play a critical role in compensatory tissue regeneration. However, the therapeutic potential of AB-based therapy and its mechanism have not been explored in detail. Here, a cell-free therapeutic strategy was developed by incorporating mesenchymal stem cell-derived ABs into a hyaluronic acid (HA) hydrogel to achieve endometrial regeneration and fertility restoration. Specifically, we found that the ABs could induce macrophage immunomodulation, cell proliferation, and angiogenesis . The HA hydrogel promoted the retention of ABs and facilitated their continuous release. In a murine model of acute endometrial damage and a rat model of IUAs, injection of the AB-laden HA hydrogel could efficiently reduce fibrosis and promote endometrial regeneration, resulting in the fertility restoration. Consequently, ABs show good potential as therapeutic vesicles, and the AB-laden HA hydrogel appears to be a clinically feasible and cell-free alternative for endometrial regeneration and IUA treatment.