Topical application of BM–derived stem cells enhances the repair of corneal injuries.

Abstract

Abstract: : Purpose: To investigate cellular therapy applications, considered nowadays as a new approach for the healing of tissue injuries. In the ophthalmic field the use of autologous cells in the treatment of several ocular diseases has involved, not always successfully, limbal stem cells therapy. This approach, however, involve surgery, hospitalization of the patience and a strict follow–up. We propose a new approach for the healing of corneal injuries using hematopoietic stem cells. Methods:Female mice were injuried in both the eyes under anesthesia with ethanol 20% for 90 secs and corneal epithelium was scraped. Hematopoietic Lineage negative cells were selected from whole bone marrow (BM) of male donors, suspended in PBS and applied topically in one eye only (experimental group) while the fellow eye was treated with PBS eye drops (control group). Animals were daily evaluated for corneal re–epithelization grading, transparency and other optical properties. Mice were sacrificed after 1, 2 and 3 weeks and the corneas dissected and processed to perform a DNA PCR for Y–chromosome. Each procedure was performed in triplicate. Results:At each time point, we observed in the experimental group a progressive enhancement of the corneal epithelium healing rate, moving progressively from the periphery to the center of the injury. The optical properties of the corneal tissue were used as signs of a physiological healing. On the contrary, the control group showed a slower healing rate, associated in some cases with partial loss of corneal transparency, scarring and abnormal optical properties. We demonstrated the presence of donor cells in the corneal epithelium, revealing the presence of male Y–chromosome DNA, and its absence in the control group. Conclusions: Our data suggest that hematopoietic stem cells are capable of enhancing the in vivo healing rate of injured corneas, and of integration in the corneal epithelium preserving the optical characteristics of this tissue.

Keywords: cornea: epithelium • regeneration • transplantation