Evaluation of an injectable, photopolymerizable three-dimensional scaffold based on D: ,L: -lactide and epsilon-caprolactone in a tibial goat model.

An in situ crosslinkable, biodegradable, methacrylate-encapped porous bone scaffold composed of D: ,L: -lactide, epsilon-caprolactone, 1,6-hexanediol and poly(ortho-esters), in which crosslinkage is achieved by photoinitiators, was developed for bone tissue regeneration. Three different polymer mixtures (pure polymer and 30% bioactive glass or alpha-tricalcium phosphate added) were tested in a uni-cortical tibial defect model in eight goats. The polymers were randomly applicated in one of four (6.0 mm diameter) defects leaving a fourth defect unfilled. Biocompatibility and bone healing properties were evaluated by serial radiographies, histology and histomorphometry. The pure polymer clearly showed excellent biocompatibility and moderate osteoconductive properties. The addition of alpha-TCP increased the latter characteristics. This product offers potentials as a carrier for bone healing promoter substances.