Mesenchymal stromal cell–derived magnetic nanovesicles for enhanced skin retention and hair follicle growth

Background aims Extracellular vesicles and exosome-mimetic nanovesicles (NVs) derived from mesenchymal stromal cells (MSCs) have emerged as promising to promote hair growth. However, short local skin retention after subcutaneous administration hinders their clinical applications. Methods In this study, we prepared magnetic nanovesicles (MNVs) from iron oxide nanoparticle–incorporated MSCs. MNVs contained more therapeutic growth factors than NVs derived from naive MSCs, and their localization and internalization were manipulated by external magnetic field. Results Following the subcutaneous injection of MNVs into a mouse model of depilation-induced hair regeneration, the magnetic attraction increased their skin retention. Then, the cellular proliferation and β-catenin signaling in hair follicles (HF) were markedly enhanced by MNV injection and magnetic field application. Furthermore, an acceleration of HF growth was revealed by histological analysis. Conclusions The proposed strategy can enhance the therapeutic potential of MSC-derived NVs for hair regeneration and other dermatological diseases.