Affiliations 

  • 1 Biomaterial Group, Faculty of Biomedical Engineering (Center of Excellence), Amirkabir University of Technology, Tehran 1591634311, Iran
  • 2 Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
  • 3 Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Tehran, Tehran 1417466191, Iran
  • 4 Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran 14496-14535, Iran
  • 5 Institute of Biomedical Research, University of Tehran, Tehran 1417466191, Iran
  • 6 Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran 14496-14535, Iran
ACS Biomater Sci Eng, 2020 05 11;6(5):2985-2994.
PMID: 33463293 DOI: 10.1021/acsbiomaterials.9b01789

Abstract

Hypoxia, the result of disrupted vasculature, can be categorized in the main limiting factors for fracture healing. A lack of oxygen can cause cell apoptosis, tissue necrosis, and late tissue healing. Remedying hypoxia by supplying additional oxygen will majorly accelerate bone healing. In this study, biphasic calcium phosphate (BCP) scaffolds were fabricated by robocasting, an additive manufacturing technique. Then, calcium peroxide (CPO) particles, as an oxygen-releasing agent, were coated on the BCP scaffolds. Segmental radial defects with the size of 15 mm were created in rabbits. Uncoated and CPO-coated BCP scaffolds were implanted in the defects. The empty (control) group received no implantation. Repairing of the bone was investigated via X-ray, histological analysis, and biomechanical tests at 3 and 6 months postoperatively, with immunohistochemical examinations at 6 months after operation. According to the radiological observations, formation of new bone was augmented at the interface between the implant and host bone and internal pores of CPO-coated BCP scaffolds compared to uncoated scaffolds. Histomorphometry analysis represented that the amount of newly formed bone in the CPO-coated scaffold was nearly two times higher than the uncoated one. Immunofluorescence staining revealed that osteogenic markers, osteonectin and octeocalcin, were overexpressed in the defects treated with the coated scaffolds at 6 months of postsurgery, demonstrating higher osteogenic differentiation and bone mineralization compared to the uncoated scaffold group. Furthermore, the coated scaffolds had superior biomechanical properties as in the case of 3 months after surgery, the maximal flexural force of the coated scaffolds reached to 134 N, while it was 92 N for uncoated scaffolds. The results could assure a boosted ability of bone repair for CPO-coated BCP scaffolds implanted in the segmental defect of rabbit radius because of oxygen-releasing coating, and this system of oxygen-generating coating/scaffold might be a potential for accelerated repairing of bone defects.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.