title: Effects of particle size and porosity on in vivo remodeling of settable allograft bone/polymer composites.
abstract: Established clinical approaches to treat bone voids include the implantation of autograft or allograft bone, ceramics, and other bone void fillers (BVFs). Composites prepared from lysine-derived polyurethanes and allograft bone can be injected as a reactive liquid and set to yield BVFs with mechanical strength comparable to trabecular bone. In this study, we investigated the effects of porosity, allograft particle size, and matrix mineralization on remodeling of injectable and settable allograft/polymer composites in a rabbit femoral condyle plug defect model. Both low viscosity and high viscosity grafts incorporating small (<105 μm) particles only partially healed at 12 weeks, and the addition of 10% demineralized bone matrix did not enhance healing. In contrast, composite grafts with large (105-500 μm) allograft particles healed at 12 weeks postimplantation, as evidenced by radial μCT and histomorphometric analysis. This study highlights particle size and surface connectivity as influential parameters regulating the remodeling of composite bone scaffolds.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee.|Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Edna M
authors.initials: EM
authors.lastname: Prieto
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee.|Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Anne D
authors.initials: AD
authors.lastname: Talley
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee.
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Gould
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee.
authors.forename: Katarzyna J
authors.initials: KJ
authors.lastname: Zienkiewicz
authors.affiliation: Medtronic Spinal and Biologics, Memphis, Tennessee.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Drapeau
authors.affiliation: Medtronic Spinal and Biologics, Memphis, Tennessee.
authors.forename: Kerem N
authors.initials: KN
authors.lastname: Kalpakci
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee.|Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee.|Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Guelcher
mesh_terms: D064591:Allografts; D000818:Animals; D016723:Bone Remodeling; D016025:Bone Transplantation; D002113:Calcification, Physiologic; D005269:Femur / Q000293:injuries* / Q000378:metabolism / Q000473:pathology; D010316:Particle Size; D011140:Polyurethanes / Q000737:chemistry*; D016062:Porosity; D051381:Rats
chemical_list: D011140:Polyurethanes
keywords: animal model; bone graft; composite/hard tissue; polyurethane(s); tissue engineering