# Corneal Nerve Regeneration via MSC‐Derived EVs: Tissue Source and Culture Dimensionality Dictate miRNA Cargo and Therapeutic Efficacy

## TL;DR

This paper explores how extracellular vesicles from different stem cell sources and culture conditions can promote corneal nerve regeneration, with 3D culture showing better results.

## Contribution

The study reveals that tissue source and culture dimensionality influence EV miRNA cargo and therapeutic efficacy for corneal nerve repair.

## Key findings

- 3D-derived EVs show superior efficacy in promoting neurite outgrowth compared to 2D-derived EVs.
- Corneal MSC-derived EVs demonstrate a trend toward enhanced regenerative effects compared to bone marrow MSC-derived EVs.
- EV cargo is influenced by tissue origin and culture dimensionality, affecting neurotrophic and ECM pathways.

## Abstract

Extracellular vesicles (EVs) are emerging as critical mediators of intercellular communication and tissue repair, offering a promising cell‐free platform for regenerative therapies. In the cornea, sensory nerves are critical for maintaining epithelial integrity and ocular homeostasis. Nerve injury resulting from trauma, surgery, or disease leads to persistent epithelial defects and impaired vision, with limited treatment options. Here, the neuro‐regenerative potential of mesenchymal stem cell‐derived EVs (MSC‐EVs) isolated from human cornea (Co‐MSC) and bone marrow (BM‐MSC) cultured under 2D and 3D conditions is investigated. EVs are characterized by nanoparticle tracking analysis, ExoView profiling, and Western blot, and their effects on nerve regeneration are evaluated using primary trigeminal ganglion neurons in vitro and a murine corneal injury model in vivo. EVs from both tissue sources promoted neurite outgrowth; however, 3D‐derived EVs demonstrate superior efficacy compared to 2D‐derived EVs in vitro and in vivo. Co‐MSC‐EVs show a consistent trend toward enhanced regenerative effects over BM‐MSC‐EVs. Small RNA sequencing reveals that EV cargo is influenced by both tissue origin and culture dimensionality, with Co‐MSC‐EVs enriched in miRNAs regulating the extracellular matrix and immune pathways, while BM‐MSC‐EVs are enriched in neurotrophic signaling miRNAs. These findings support the rational design of MSC‐EV‐based therapies for neuro‐ophthalmic repair.

Mesenchymal stem cell‐derived extracellular vesicles (EVs) from human cornea and bone marrow, cultured in 2D and 3D conditions, are characterized and tested for corneal nerve repair. 3D‐derived EVs show superior therapeutic efficacy and in vivo reinnervation. Small‐RNA sequencing reveals tissue‐ and dimensionality‐dependence for EV cargo that implicates neurotrophic and ECM‐remodeling pathway activation, guiding EV design for neuro‐ophthalmic therapy.