title: Cobalt chromium alloy with immobilized BMP peptide for enhanced bone growth.
abstract: Cobalt chromium (CoCr) alloys are widely used in orthopedic practice, however, lack of integration into the bone for long-term survival often occurs, leading to implant failure. Revision surgery to address such a failure involves increased risks, complications, and costs. Advances to enhancement of bone-implant interactions would improve implant longevity and long-term results. Therefore, we investigated the effects of BMP peptide covalently grafted to CoCr alloy on osteogenesis. The BMP peptide was derived from the knuckle epitope of bone morphogenic protein-2 (BMP-2) and was conjugated via a cysteine amino acid at the N-terminus. X-ray photoelectron spectroscopy and o-phthaldialdehyde were used to verify successful grafting at various stages of surface functionalization. Surface topography was evaluated from the surface profile determined by atomic force microscopy. Osteoblastic cells (MC3T3-E1) were seeded on the substrates, and the effects of BMP peptide on osteogenic differentiation were evaluated by measuring alkaline phosphatase (ALP) activity and calcium mineral deposition. The functionalized surfaces showed a twofold increase in ALP activity after 2 weeks incubation and a fourfold increase in calcium content after 3 weeks incubation compared to the pristine substrate. These findings are potentially useful in the development of improved CoCr implants for use in orthopedic applications.
authors: Department of Orthopaedic Surgery, National University of Singapore, Kent Ridge, Singapore 119074, Singapore.
authors: Chye Khoon
authors: CK
authors: Poh
authors: Zhilong
authors: Z
authors: Shi
authors: Xiao Wei
authors: XW
authors: Tan
authors: Zhen Chang
authors: ZC
authors: Liang
authors: Xue Mei
authors: XM
authors: Foo
authors: Hark Chuan
authors: HC
authors: Tan
authors: Koon Gee
authors: KG
authors: Neoh
authors: Wilson
authors: W
authors: Wang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000497:Alloys; D001861:Bone Regeneration / Q000187:drug effects*; D001842:Bone and Bones; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002857:Chromium; D003035:Cobalt; D020007:Implants, Experimental; D018625:Microscopy, Atomic Force; D016348:Osseointegration / Q000187:drug effects; D010006:Osteoblasts / Q000187:drug effects* / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology*; D019736:Prostheses and Implants; D011474:Prosthesis Design; D013499:Surface Properties
chemical_list: D000497:Alloys; D010446:Peptide Fragments; C558392:bone morphogenetic binding peptide, human; D002857:Chromium; D003035:Cobalt; D000469:Alkaline Phosphatase; D002118:Calcium