Osteoinductive 3D printed scaffold healed 5 cm segmental bone defects in the ovine metatarsus

Sci Rep. 2021 Mar 23;11(1):6704. doi: 10.1038/s41598-021-86210-5.

Abstract

Autologous bone grafts are considered the gold standard grafting material for the treatment of nonunion, but in very large bone defects, traditional autograft alone is insufficient to induce repair. Recombinant human bone morphogenetic protein 2 (rhBMP-2) can stimulate bone regeneration and enhance the healing efficacy of bone grafts. The delivery of rhBMP-2 may even enable engineered synthetic scaffolds to be used in place of autologous bone grafts for the treatment of critical size defects, eliminating risks associated with autologous tissue harvest. We here demonstrate that an osteoinductive scaffold, fabricated by combining a 3D printed rigid polymer/ceramic composite scaffold with an rhBMP-2-eluting collagen sponge can treat extremely large-scale segmental defects in a pilot feasibility study using a new sheep metatarsus fracture model stabilized with an intramedullary nail. Bone regeneration after 24 weeks was evaluated by micro-computed tomography, mechanical testing, and histological characterization. Load-bearing cortical bridging was achieved in all animals, with increased bone volume observed in sheep that received osteoinductive scaffolds compared to sheep that received an rhBMP-2-eluting collagen sponge alone.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Bone Morphogenetic Protein 2 / pharmacology
  • Bone Regeneration* / drug effects
  • Bone Transplantation*
  • Disease Models, Animal
  • Fracture Healing*
  • Fractures, Bone / diagnosis
  • Fractures, Bone / therapy
  • Histocytochemistry / methods
  • Humans
  • Imaging, Three-Dimensional
  • Metatarsal Bones
  • Recombinant Proteins / pharmacology
  • Sheep
  • Tissue Scaffolds*
  • Transforming Growth Factor beta / pharmacology
  • Translational Research, Biomedical
  • Transplantation, Autologous
  • X-Ray Microtomography

Substances

  • Bone Morphogenetic Protein 2
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • recombinant human bone morphogenetic protein-2