Recellular human corneal SMILE lenticule seeded with mesenchymal stem cells is a safe graft in an experimental animal model

Purpose: to evaluate in vivo safety of human Wharton s jelly derived mesenchymal stem cells - (WJSC) in a decellularized SMILE lenticules scaffold and relevant clinical results in an experimental animal model. Methods: Human corneal lenticules of about 100 μm thickness derived from SMILE laser eye surgery were decellularized and verified for ultrastructure integrity, transparency, and cytotoxicity. 12 rabbits underwent unilateral stromal pocketing with implantation of decellularized lenticules . In 6 rabbits, implantation was followed with multiple injections of 2.5 × 105 isolated labeled WJSC in the graft. All Rabbits were evaluated for relevant clinical findings and underwent anterior segment imaging. Rabbits were euthanized after 1 month (n=6) and 3 months (n=6) to evaluate the progression of graft bio-integration and viability of injected WJSCResults: Decellularization occurred at a rate of about 98% with acceptable lack of cytotoxicity and relatively intact ultrastruture of the lenticules. After implantation, at the first month 1, only one cornea had severe haze with central neovascularization due to keratitis and one cornea had central neovascularization with mild haze. After 3months,all 6 corneas were totally transparent without haze. After three months, labelled WJCS was detected representing the viability of stem cells in the host. In histopathological analysis, grafts were integrated well with reduced distortion of surrounding collagen and glycosaminoglycan at the third month compared to the first month. Conclusion: This model of lamellar keratoplasty is associated with acceptable bio-integration and optical transparency. Viable stem cells showed the potential of recruiting these cells as a keratocyte progenitor cells to reinforce the corneal ultrastructure.