GMP-Compliant Manufacturing of Human BM-MSC Secretome for Clinical Investigation as a Topical Eye Drop

Background: Bone marrow-derived mesenchymal stromal cell (BM-MSC) secretome is a promising cell-free therapeutic approach for tissue regeneration. However, clinical translation requires scalable manufacturing processes, rigorous quality control, and evidence of biological potency. Here, we established a GMP-compliant manufacturing workflow for BM-MSC secretome and evaluated its safety and biological activity in corneal epithelial cells. Methods: Allogeneic human BM-MSCs were expanded under controlled GMP-compliant conditions and conditioned for 72 h in protein- and phenol red-free MEM-α medium. The resulting secretome underwent predefined lot-release and quality-control testing, including protein-associated content analysis and nanoparticle tracking analysis (NTA). Cytocompatibility was evaluated using cell viability and LDH assays, while biological activity was assessed using cell proliferation and in vitro scratch-wound assays. Results: The manufacturing process consistently generated a high-quality BM-MSC secretome that met predefined microbiological, product-integrity, and release criteria. Secretome conditioning resulted in increased protein-associated content and measurable nanoparticle particle population compared with unconditioned medium, providing quantitative product-characterization attributes for the manufactured secretome. The product demonstrated favorable cytocompatibility, maintaining high corneal epithelial cell viability without substantial membrane damage. Functionally, BM-MSC secretome promoted epithelial cell proliferation and enhanced wound closure compared with control medium, with the most pronounced biological effect observed during the early stages of wound repair. Conclusions: We established a scalable, quality-controlled, GMP-compliant framework for the manufacture and characterization of BM-MSC secretome. The resulting product demonstrated favorable safety characteristics and biological activity in corneal epithelial cells, supporting its potential as a cell-free regenerative therapy for ocular surface repair. This integrated manufacturing and potency-testing strategy provides a translational foundation for further development and preclinical evaluation of BM-MSC secretome-based therapeutics.