Effect of Exogenous Mesenchymal Stem Cells on Wound Healing Following Corneal Alkali Burn

Abstract

Abstract: : Purpose: To evaluate whether exogenous mesenchymal stem cells (MSC) involve in wound healing after corneal alkali burn in normal and suppressed bone marrow condition of rabbit model. Methods: A standardized 6mm diameter corneal and limbal alkali wound was induced in one eye of each of 80 rabbits. CM-DiI prelabeled rabbit MSC were cultured to 2^nd generation before application. We divided rabbits into two different conditions: (1) Normal groups--group A: intravenous injection of 1×10⁷ MSC; group B: local subconjunctival injuction of 1×10⁷ MSC; group C: temporary amniotic membrane patch (TAMP) with 1×10⁷ MSC seeded on stroma side; group D: TAMP; group E: control. (2) Bone marrow suppressed groups (treated with cyclophosphamide)--group F: intravenous injection of 1×10⁷ MSC; group G: TAMP with 1×10⁷ MSC seeded on stroma side; group H: control. The clinical outcomes and the presence of exogenous CM-DiI-MSC in peripheral blood, bone marrow and wounded cornea were evaluated. Results: (1) The infiltration of exogenous MSC into wounded corneal three layers occurred on the second day after application. (2) Under normal condition: the best clinical outcomes with stabilized ocular surface was revealed in group A, in which neovascularization appeared in wounded limbal cornea (3 days post injury) where the massive infiltration (89.0±25.8) of typical spindle-shaped MSC was found. The next is group B showing later onset neovascularization (4-5 days post injury) with less corneal infiltrated MSC (58.2±14.3) and moderate corneal opacification (grade 1.5). (3) Under suppressed condition, corneal wound healing was delayed with less difference of final outcomes among these groups. Conclusions: Exogenously applied MSC may enhance corneal wound healing by potentially being differentiated into corneal cells. Differentiation of these cells may need to be supported by other types of hematopoietic stem cells.

Keywords: cornea: clinical science • wound healing • neovascularization