Chorionic villi-derived nanofibers enhanced mesenchymal stem cell extracellular vesicle secretion and bioactivity for endometrium regeneration toward intrauterine adhesion treatment

Intrauterine adhesion (IUA) is one of the main causes of female infertility. Extracellular vesicles (EVs) secreted by mesenchymal stem cells (MSCs), are consisted of a complete lipid bilayer structure, rich in multiple factors and miRNAs related to tissue regeneration, which are the main effective paracrine components of MSCs to treat IUA. However, the poor secretion and bioactivity of EVs leading to the unexpected therapeutic efficacy of MSC-EVs, have been obstacles to their widespread use in clinical practice. Here, we developed human chorionic villi (CV)-derived nanofibers that mimic the tissue-specific ECM microenvironment of CV-derived MSCs, maintain the stemness of MSCs for a long time, and are rich in apolipoproteins, HSP90, ANXA1-A6, etc., which can enhance EV secretion and bioactivity. Then, the CV-nanofiber bionic culture system for mesenchymal stem cells was constructed to achieve large-scale cultivation of MSCs for continuous collection of high-concentration EVs enrichment supernatant. Additionally, EVs obtained by this system were encapsulated with CV-nanofibers to form EVs-ECM aggregate, which can effectively promote endometrium regeneration toward supporting fetal development and live births. Our study provides a new idea for enhancing EV secretion and bioactivity, and a cell-free therapy for treating IUA by EVs, thus promoting the potential of clinical application.