Fusogenic Hybrid Gelled Nanovesicles Combining Mesenchymal Stromal Cell Cargo with Cholesterol-Modified Macrophage...

Mesenchymal stromal cell-derived nanovesicles (MSC-NVs) prepared via a conventional top-down engineered approach hold great promise as alternatives to traditional cell therapy for cardiovascular diseases. However, these nanovesicles often suffer from substantial loss of cellular components, poor stability, and limited delivery efficiency. To overcome these limitations, we developed a hybrid gelled nanovesicle, Hy-gNVs@chol, through chitosan (CS)-based protein enrichment and functional membrane replacement, enabling efficient concentration of MSC components to form gel nanoparticles (gNPs) while conferring inflammation-targeting capability. Compared to nonenriched nanovesicles (Hy-NVs) prepared by conventional methods, Hy-gNVs@chol exhibited more than a 5-fold increase in protein cargo. Surface coating of gNPs with cholesterol-modified macrophage membrane further promoted cellular uptake and lysosomal escape. In vitro, Hy-gNVs@Chol effectively protected cardiomyocytes from ROS-induced injury, facilitated M2 macrophage repolarization, and enhanced HUVECs' function. In vivo studies further validated the therapeutic efficacy of Hy-gNVs@chol in treating myocardial infarction. Our study introduces a biomimetic design approach for engineered MSC-derived nanovesicles and highlights their potential for therapeutic cardiac repair following myocardial infarction and other cardiovascular conditions.