Xenopus laevis as a novel model to study long bone critical-size defect repair by growth factor-mediated regeneration.

We used the tarsus of an adult Xenopus laevis frog as an in vivo load-bearing model to study the regeneration of critical-size defects (CSD) in long bones. We found the CSD for this bone to be about 35% of the tarsus length. To promote regeneration, we implanted biocompatible 1,6 hexanediol diacrylate scaffolds soaked with bone morphogenetic proteins-4 and vascular endothelial growth factors.