Exosome Nanotherapy Rescues Male Fertility by Delivering Integrin β1 to Repair Environmental Stress-Damaged Testes.

Environmental thermal-mechanical (T&M) stress threatens male fertility globally, yet no molecular therapies exist for stress-induced testicular damage. We demonstrate that macrophage-derived exosomes (Mφ-EVs) function as precision nanomedicines restoring fertility by delivering Integrin β1 (ITGB1) to repair damaged spermatogenic cytoskeletons. Using validated T&M stress models in C57BL/6 mice and GC-2 spermatocytes, we characterized severe reproductive dysfunction: 14.4% motility reduction (83.0 ± 2.0% to 71.3 ± 1.7%), 69.2% increased abnormalities (8.7 ± 2.3% to 14.7 ± 2.3%), and disrupted cytoskeletal homeostasis with Layilin (2.87-fold), Talin (3.90-fold), and Vinculin (4.24-fold) upregulation (P < 0.05). Mφ-EVs treatment achieved remarkable therapeutic efficacy: motility recovered to 80.8 ± 6.8%, abnormalities normalized to 11.6 ± 1.6% (all P < 0.05). Biodistribution tracking showed that exosomes accumulate in testicular tissue (peak 8 h). Molecular docking and cellular thermal shift assays revealed exosomal ITGB1 forms high-affinity ITGA1 complexes (score -222.76), stabilizing protein structure and normalizing cytoskeletal expression. This first proof-of-concept establishes exosome-based nanotherapy as a clinically translatable, noninvasive intervention for occupational and climate-related fertility disorders, with scalable manufacturing addressing millions of men worldwide.