Therapeutic effects of adipose mesenchymal stem cell-derived exosomes on limbal stem cells deficiency in cats.

Corneal transparency is maintained by the limbus and its stem cells, and damage or deficiency in this region leads to conjunctivalization and subsequent vision impairment. This study aims to evaluate the therapeutic effects of feline adipose mesenchymal stem cell-derived exosomes (fAD-MSCExo) in the treatment of limbal stem cell deficiency in cats. For this purpose, 30 animals presenting with severe conjunctivalization were included in the study. Cats were randomly assigned to two groups: Group 1 (n = 15), serving as the control group and receiving steroid treatment, Group 2 (n = 15), receiving fAD-MSCExo therapy. Exosomes were produced from fAD-MSCs isolated from intra-abdominal adipose tissue obtained from three healthy donor cats. Detailed ophthalmologic examination and impression cytology were performed on all animals preoperatively and on postoperative days 0, 10, and 30. Periodic acid-schiff staining was used to detect goblet cells, while Immunofluorescence staining was performed to identify K13 cytokeratin antibodies. At postoperative day 10, no significant clinical or histological differences were observed between the two groups. However, after treatment discontinuation, by postoperative day 30, clinical improvement had regressed in the steroid-treated group, whereas corneal epithelial regeneration and, consequently, limbal repair had progressed satisfactorily in the exosome-treated group. This study demonstrated that even short-term use of exosomes is effective in the treatment of limbal stem cell deficiency in cats. The presented data suggest that fAD-MSCExo may offer a potential definitive solution for the management of this widespread pathology, which requires long-term follow-up, thereby generating significant interest in further research in this field.