Effect of allogeneic limbal mesenchymal stem cell therapy in corneal healing: role of administration route.

Aims: To investigate whether allogeneic limbal mesenchymal stem cell (LMSC) therapy affects corneal healing after a severe chemical burn and whether the route of administration of LMSCs differs in its therapeutic effect in this respect.

Methods: A total of 60 Sprague-Dawley rats with clinically proven alkali injury were divided into four equal groups (n = 15) as follows: group 1: 2 × 10(5) cells/drop LMSCs, topically applied 6 times a day for 2 days; group 2: 2.4 × 10(6) cells in 0.5 ml LMSCs, subconjunctivally applied; group 3: 2.4 × 10(6) cells in 1 ml LMSCs, intraperitoneally applied, and group 4: no LMSC treatment. The groups were compared according to grades of corneal opacity (CO), corneal neovascularization (CNV) and corneal fluorescein staining (CFS). The migration of LMSCs into the cornea and the inflammatory characteristics of the groups were evaluated with BrdU (5-bromo-2'-deoxyuridine bromodeoxyuridine) immunostaining and histopathologically in a 4-week follow-up.

Results: There were statistically significant differences between the LMSC-treated and control groups in each week regarding mean CO scores and in the 3rd week regarding the mean CNV and CFS scores (p < 0.05). The statistical significance was due to the differences between the topical and the control group and between the subconjunctival and the control group. BrdU+ LMSCs were seen in the corneal epithelium of the all LMSC-administered rats, and fewer inflammatory changes were observed in these rats.

Conclusion: Allogeneic LMSC treatment, especially topical and subconjunctival administration, seems to be helpful in affecting corneal healing after a severe corneal burn.