Enhanced Therapeutic potential of AEBP1 silencing via engineered Apoptotic Mesenchymal Stem Cell- derived Nanovesicles in Atrial Fibrillation

Background Chronic inflammation and fibrosis contribute markedly to the progression and recurrence of Atrial Fibrillation (AF), which is the most common form of arrhythmia. Despite ongoing therapeutic advancements, effective treatments to modulate inflammatory and fibrotic processes in AF remain limited. To overcome these limitations, we developed a novel nanotherapeutic system using apoptotic mesenchymal stem cell-derived nanovesicles (ANV) as biocompatible and immunomodulatory delivery platforms for siRNA targeting the AEBP1 gene, leading to concurrent attenuation of fibrosis. Results ANV were constructed via an extrusion method and loaded with adipocyte enhancer binding protein 1 (AEBP1)-targeting small interfering RNA (siRNA) (siAEBP1) through electroporation to form ANV-siAEBP1. ANV-siAEBP1 were then incubated with antibody-conjugated iron oxide magnetic nanoparticles (MNP), forming ANVP-siAEBP1 complex. For targeted delivery to the AF myocardium, an anti-myosin light chain 3 (MLC3) antibody was incorporated to facilitate localized accumulation in MLC3-enriched atrial cardiomyocytes. Once localized, the nanovesicles fused with cardiomyocyte membranes, allowing for the intracellular release of siAEBP1, which in turn silenced AEBP1 expression, thereby downregulating pro-fibrotic signaling and mitigating atrial fibrosis. Simultaneously, the intrinsic anti-inflammatory effects of ANV in stressed cardiomyocytes, prevented excessive inflammatory responses. Conclusions This dual mechanism of action, involving siRNA-mediated gene silencing and ANV-induced immunomodulation, results in a synergistic therapeutic effect. Thus, ANVP-siAEBP1 significantly attenuated both inflammation and fibrosis in AF myocardium with enhanced targeting efficiency, offering a promising strategy for next-generation precision therapeutics in AF.