Localized insulin-like growth factor I delivery to enhance new bone formation.

Insulin-like growth factor I (IGF I) exerts an important role during skeletal growth and bone formation. Therefore, its localized delivery appears attractive for the treatment of bone defects. To prolong IGF I delivery, we entrapped the protein into biodegradable poly(lactide-co-glycolide) microspheres (PLGA MS) and evaluated the potential of this delivery system for new bone formation in two defect models of ovine long bones, i.