Segmental mandibular bone reconstruction with a carbonate-substituted hydroxyapatite-coated modular endoprosthetic poly(ɛ-caprolactone) scaffold in Macaca fascicularis.

A bio-degradable scaffold incorporating osteoinductive factors is one of the alternative methods for achieving the regeneration of a mandibular bone defect. The current pilot study addressed such a bone reconstruction in a non-human primate model, Macaca fascicularis monkeys, with an engineered poly(ɛ-caprolactone) (PCL) scaffold, provided with a carbonate-substituted hydroxyapatite coating. The scaffolds were implanted into unilaterally created mandibular segmental defects in 24 monkeys. Three experimental groups were formed: (1) scaffolds with rhBMP-2 (n = 8), (2) scaffolds with autologous mixed bone marrow cells (n = 8), and (3) empty scaffolds as a control group (n = 8). Evaluation was based on clinical observation as well as micro-CT, mechanical, and histological analyses. Despite a high infection rate, the overall results showed that the currently designed PCL scaffolds had insufficient load-bearing capability, and complete bone union was not achieved after 6 months of implantation. Nevertheless, the group of PCL scaffolds loaded with rhBMP-2 showed evidence of bone-regenerative potential, in contrast to PCL with autologous mixed bone marrow cells and the control group.