Moreover, we have addressed critical challenges in corneal drug delivery by developing a hydrogel-based delivery system that offers a broad time-span for release. This system initially follows diffusion-controlled release, transitioning to enzymatic (collagenase) digestion-controlled release on demand. Such release system is also a close mimic of the in vivo scenario where drug release occurs through the diffusion at the beginning followed by enzymatic degradation of the implant during implant-remodeling phase. Our study provides a physical understanding of the release mechanisms at a microscopic level, supported by quantitative evaluation and microscale insights into EV diffusion within the hydrogel matrix. Utilizing established physical diffusion models, such as the Ogston-Amsden and Clague-Phillips models, we have achieved a detailed microscale understanding of these processes. This foundational knowledge paves the way for the development of advanced hydrogel platforms tailored for EV release, accommodating diverse medical applications with varying release profiles. We believe these findings would equip researchers with a robust chemistry toolset to design hydrogels with predictable and controllable EV-diffusion and release characteristics, and thereby broadening the scope of therapeutic applications for extracellular vesicles in regenerative medicine. Cell culture of IM-HCEpiC. IM-HCEpiC were cultured following the protocol of the supplier with minor modifications. In short, the cells were cultured using an ocular epithelial cell medium supplemented with 5% of FBS, 1% of epithelial cell growth supplements and 1% of penicillin/streptomycin solution and kept in an incubator at 37°C with 5% CO2. Sub-culturing was done when cells were ~90% confluent by adding TrypLE™ Express Enzyme. When all cells were detached, the culture medium was added to inactivate the enzyme. Cells were collected by centrifuging at 200 RCF (Eppendorf Centrifuge 5810 R) for 5 min and the pellet was resuspended in culture medium. The number of cells was counted using an EVE automated cell counter (NanoEntek). Cells were seeded at a minimum density of 10 000 cells/cm 2 in collagen coated cell culture flasks (either purchased or coated in-house according to supplier´s instructions).