Mesenchymal stem cell derived extracellular vesicles loaded thermosensitive chitosan-based hydrogel alleviates allergic rhinitis in mouse model

Allergic rhinitis (AR) has gained an increasing prevalence over the years, a more effective and safe treatment strategy need to be carried out. Mesenchymal stem cell derived extracellular vesicles (MSC-EVs) show great therapeutic potential for AR, however, their low bioavailability through currently available delivery methods inhibits the process of clinical application. In the present study, an injectable thermosensitive chitosan based hydrogel was developed as an intranasal delivery platform for bone marrow-derived MSC-EVs (BMSC-EVs) and BMSC-EVs were proved to be effective in treating AR animal models for the first time. Our results showed that the BMSC-EVs loaded thermosensitive chitosan based hydrogel (BMSC-EVs@CHI hydrogel) could be prepared easily by ion-crosslinking and its gelation properties were suitable for intranasal administration. In vitro studies demonstrated that the BMSC-EVs@CHI hydrogel could achieve sustained release of BMSC-EVs mainly by degradation control and preserve the therapeutic functions of BMSC-EVs. An in vivo experiment revealed that the BMSC-EVs@CHI hydrogel could enhance the efficacy of BMSC-EVs for AR alleviation. This study provides a suitable delivery platform for BMSC-EVs-based AR therapy.