title: Coating with a modular bone morphogenetic peptide promotes healing of a bone-implant gap in an ovine model.
abstract: Despite the potential for growth factor delivery strategies to promote orthopedic implant healing, there is a need for growth factor delivery methods that are controllable and amenable to clinical translation. We have developed a modular bone growth factor, herein termed "modular bone morphogenetic peptide (mBMP)", which was designed to efficiently bind to the surface of orthopedic implants and also stimulate new bone formation. The purpose of this study was to coat a hydroxyapatite-titanium implant with mBMP and evaluate bone healing across a bone-implant gap in the sheep femoral condyle. The mBMP molecules efficiently bound to a hydroxyapatite-titanium implant and 64% of the initially bound mBMP molecules were released in a sustained manner over 28 days. The results demonstrated that the mBMP-coated implant group had significantly more mineralized bone filling in the implant-bone gap than the control group in C-arm computed tomography (DynaCT) scanning (25% more), histological (35% more) and microradiographic images (50% more). Push-out stiffness of the mBMP group was nearly 40% greater than that of control group whereas peak force did not show a significant difference. The results of this study demonstrated that mBMP coated on a hydroxyapatite-titanium implant stimulates new bone formation and may be useful to improve implant fixation in total joint arthroplasty applications.
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconson, United States of America. luy@svm.vetmed.wisc.edu
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Lee
authors.forename: Brett
authors.initials: B
authors.lastname: Nemke
authors.forename: Ben K
authors.initials: BK
authors.lastname: Graf
authors.forename: Kevin
authors.initials: K
authors.lastname: Royalty
authors.forename: Richard
authors.initials: R
authors.lastname: Illgen
authors.forename: Ray
authors.initials: R
authors.lastname: Vanderby
authors.forename: Mark D
authors.initials: MD
authors.lastname: Markel
authors.forename: William L
authors.initials: WL
authors.lastname: Murphy
mesh_terms: D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000737:chemistry / Q000494:pharmacology*; D002113:Calcification, Physiologic; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology*; D054893:Cone-Beam Computed Tomography; D003692:Delayed-Action Preparations / Q000737:chemistry / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry; D005260:Female; D005269:Femur / Q000601:surgery / Q000648:ultrastructure*; D016348:Osseointegration / Q000502:physiology*; D019736:Prostheses and Implants; D012756:Sheep; D034561:Sheep, Domestic; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry; D014945:Wound Healing
chemical_list: D019485:Bone Morphogenetic Proteins; D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D017886:Durapatite; D014025:Titanium