Injectable gelatin-based photocurable fiber-reinforced hydrogel for the treatment of osteochondral defects

Osteochondral defects are one of the most motor-disabling conditions worldwide. A limited intrinsic regenerative capability features cartilage and bone tissues involved in large osteochondral lesions and, to date, there is no clinical treatment capable of appropriately restoring them. We report an innovative injectable composite hydrogel based on gelatin methacryloyl (GelMA) loaded with dispersed fibers made of a blend polycaprolactone (PCL)/GelMA. The fibers were produced by electrospinning, and cut in stripes using a cryostat-based cutting approach. Their embodiment in the GelMA matrix improved the compressive mechanical properties of the pristine GelMA hydrogel. Specific conditions (needle size: 18G and 20G; temperature: 30 and 37°C) were found compatible with the injection of the composite hydrogel, before crosslinking, matching the criteria reported in EN ISO 7886 1:2018 standard. These preliminary results are promising in view of the optimization of injectable reinforced GelMA-based formulations to be used for the treatment of osteochondral injuries.