title: Tyrosine-derived polycarbonate scaffolds for bone regeneration in a rabbit radius critical-size defect model.
abstract: The aim of the study was to determine bone regeneration in a rabbit radius critical-size defect (CSD) model using a specific polymer composition (E1001(1k)) from a library of tyrosine-derived polycarbonate scaffolds coated with a calcium phosphate (CP) formulation (E1001(1k) + CP) supplemented with recombinant human bone morphogenetic protein-2 (rhBMP-2). Specific doses of rhBMP-2 (0, 17, and 35 μg/scaffold) were used. E1001(1k) + CP scaffolds were implanted in unilateral segmental defects (15 mm length) in the radial diaphyses of New Zealand White rabbits. At 4 and 8 weeks post-implantation, bone regeneration was determined using micro-computed tomography (µCT), histology, and histomorphometry. The quantitative outcome data suggest that E1001(1k) + CP scaffolds with rhBMP-2 were biocompatible and promoted bone regeneration in segmental bone defects. Histological examination of the implant sites showed that scaffolds made of E1001(1k) + CP did not elicit adverse cellular or tissue responses throughout test periods up to 8 weeks. Noteworthy is that the incorporation of a very small amount of rhBMP-2 into the scaffolds (as low as 17 μg/defect site) promoted significant bone regeneration compared to scaffolds consisting of E1001(1k) + CP alone. This finding indicates that E1001(1k) + CP may be an effective platform for bone regeneration in a critical size rabbit radius segmental defect model, requiring only a minimal dose of rhBMP-2.
authors.affiliation: Bone Tissue Engineering Center, Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15219, USA. Department of Bio and Chemical Engineering, Hongik University, Sejong 339-701, Korea.
authors.forename: Jinku
authors.initials: J
authors.lastname: Kim
authors.forename: Sean
authors.initials: S
authors.lastname: McBride
authors.forename: Amy
authors.initials: A
authors.lastname: Donovan
authors.forename: Aniq
authors.initials: A
authors.lastname: Darr
authors.forename: Maria Hanshella R
authors.initials: MH
authors.lastname: Magno
authors.forename: Jeffrey O
authors.initials: JO
authors.lastname: Hollinger
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D011076:Polycarboxylate Cement / Q000737:chemistry*; D011817:Rabbits; D011884:Radius / Q000293:injuries / Q000473:pathology / Q000502:physiology; D011994:Recombinant Proteins / Q000008:administration & dosage; D054457:Tissue Scaffolds / Q000737:chemistry*; D016212:Transforming Growth Factor beta / Q000008:administration & dosage; D014443:Tyrosine / Q000737:chemistry; D055114:X-Ray Microtomography
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D018786:Bone Substitutes; D002130:Calcium Phosphates; D011076:Polycarboxylate Cement; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; C005506:polycarbonate; D014443:Tyrosine; C020243:calcium phosphate