title: Accelerated bone growth in vitro by the conjugation of BMP2 peptide with hydroxyapatite on titanium alloy.
abstract: Titanium alloys have been widely used in orthopedic practice due to their inherent bioactivity, however it is still insufficient to truly and reliably incorporate into living bone. In this work, polydopamine film was employed to induce the growth of hydroxyapatite (HA) on titanium alloy to enhance its osteoconductivity. Bone morphogenetic protein-2 (BMP2) peptide was absorbed into the HA particles for osteoinductivity. The precipitation of HA and the existence of BMP2 peptide were examined by X-ray diffraction, X-ray photoelectron spectroscopy and fluorescence microscopy. The dissolution of HA and the release of BMP2 peptide were monitored by measuring the concentrations of calcium ions and BMP2 peptide in phosphate buffered saline solution, respectively. The effect of BMP2 peptide incorporated into HA coating on bone growth was evaluated in vitro by cell culture tests, including cell attachment, alkaline phosphatase (ALP) activity, and gene expression. The results show that the HA particles grown on the substrate are mediated by the polydopamine film. The BMP2 peptide is distributed uniformly on HA-coated substrate and released in a sustained manner. Moreover, the conjunction of HA and BMP2 peptide increases cell adhesion, ALP activity and gene expression of osteogenic markers, which are potentially useful in the development of enhanced orthopedic medical devices.
authors.affiliation: Department of Orthopaedic Surgery, National University of Singapore, Kent Ridge, Singapore 119074, Singapore.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Cai
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Orthopaedic Surgery, National University of Singapore, Kent Ridge, Singapore 119074, Singapore.
authors.forename: Chye Khoon
authors.initials: CK
authors.lastname: Poh
authors.affiliation: Department of Orthopaedic Surgery, National University of Singapore, Kent Ridge, Singapore 119074, Singapore.
authors.forename: Hark Chuan
authors.initials: HC
authors.lastname: Tan
authors.affiliation: Department of Orthopaedic Surgery, National University of Singapore, Kent Ridge, Singapore 119074, Singapore.
authors.forename: Min Tun
authors.initials: MT
authors.lastname: Soe
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Sam
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedic Surgery, National University of Singapore, Kent Ridge, Singapore 119074, Singapore. Electronic address: doswangw@nus.edu.sg.
authors.forename: Wilson
authors.initials: W
authors.lastname: Wang
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000497:Alloys / Q000737:chemistry / Q000494:pharmacology*; D001846:Bone Development / Q000187:drug effects*; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000497:Alloys; D055396:Bone Morphogenetic Protein 2; D017886:Durapatite; D014025:Titanium; D000469:Alkaline Phosphatase
keywords: BMP2 peptide; Hydroxyapatite; Osteoconductivity; Osteoinductivity; Titanium