The presence of an osseous cyst-like lesion (OCLL) severely affects the sports career of a horse and its economic value. Thus far, therapeutic approaches fail to meet the expected demands in terms of functional recovery and/or absence of radiographic evidence of OCLL after treatment. In this project, we aim to restore full functionality of horses suffering from lameness due to the presence of OCLL and eliminate any radiographic abnormality associated with OCLL. The higher success rate of symptomatic OCLL treatment will lead to an increased quality of life of the affected horse, resulting in a better performance and a longer sports’ careers. Furthermore, asymptomatic OCLL can be preventivally treated in order to maximize the horse’s sports potential and its economic value.

Currently, there is no veterinary stem cell-based product commercially available to treat OCLL preventively or symptomatically. In this project, a new product consisting of an injectable hydrogel and mesenchymal stem cells (MSCs) will be designed to treat OCLL. More specifically, by combining MSCs with a matrix that is optimally adapted for their survival and osteogenic differentiation, both a mechanical and functional recovery will be achieved. The optimized product, called the ‘BoneCystGel’, will be characterized in vitro and evaluated with and without mechanical stimulation to mimic the in vivo biomechanical forces. Moreover, a proof-of-concept study will be conducted using an in vivo sheep model to assess (1) the safety and potential of the BoneCystGel, and (2) the filling of the bone lesion, in specific radiographic disappearance of the OCLL. This project and its outcomes will serve as proof-of-concept to attract potential licensees or if required for follow-up studies in equine as preventive and/or symptomatic treatment for OCLL.