title: A dual-task design of corrosion-controlling and osteo-compatible hexamethylenediaminetetrakis- (methylene phosphonic acid) (HDTMPA) coating on magnesium for biodegradable bone implants application.
abstract: Magnesium as well as its alloys appears increasingly as a revolutionary bio-metal for biodegradable implants application but the biggest challenges exist in its too fast bio-corrosion/degradation. Both corrosion-controllable and bio-compatible Mg-based bio-metal is highly desirable in clinic. In present work, hexamethylenediaminetetrakis (methylenephosphonic acid) [HDTMPA, (H2 O3 P-CH2 )2 -N-(CH2 )6 -N-(CH2 -PO3 H2 )2 ], as a natural and bioactive organic substance, was covalently immobilized and chelating-deposited onto Mg surface by means of chemical conversion process and dip-coating method, to fullfill dual-task performance of corrosion-protective and osteo-compatible functionalities. The chemical grafting of HDTMPA molecules, by participation of functional groups on pretreated Mg surface, ensured a firmly anchored base layer, and then sub-sequential chelating reactions of HDTMPA molecules guaranteed a homogenous and dense HDTMPA coating deposition on Mg substrate. Electrochemical corrosion and immersion degradation results reveal that the HDTMPA coated Mg provides a significantly better controlled bio-corrosion/degradation behavior in phosphate buffer saline solution as compared with untreated Mg from perspective of clinic requirement. Moreover, the HDTMPA coated Mg exhibits osteo-compatible in that it induces not only bioactivity of bone-like apatite precipitation but also promotes osteoblast cells adhesion and proliferation. Our well-controlled biodegradable and biocompatible HDTMPA modified Mg might bode well for next generation bone implant application.
authors.affiliation: Key Laboratory of Advanced Technologies of Materials, Ministry of Education, College of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhao
authors.forename: Yingqi
authors.initials: Y
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Meiyun
authors.initials: M
authors.lastname: Chen
authors.forename: Jinlong
authors.initials: J
authors.lastname: Mao
authors.forename: Hairuo
authors.initials: H
authors.lastname: He
authors.forename: Yuancong
authors.initials: Y
authors.lastname: Zhao
authors.forename: Nan
authors.initials: N
authors.lastname: Huang
authors.forename: Guojiang
authors.initials: G
authors.lastname: Wan
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001842:Bone and Bones / Q000187:drug effects*; D002130:Calcium Phosphates / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D011232:Chemical Precipitation; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D003343:Corrosion; D055664:Electrochemical Techniques; D007101:Immersion; D008274:Magnesium / Q000494:pharmacology*; D008422:Materials Testing; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D010757:Phosphorous Acids / Q000494:pharmacology*; D056951:Photoelectron Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014867:Water
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D010757:Phosphorous Acids; D014867:Water; C570063:phosphonic acid; C020243:calcium phosphate; D008274:Magnesium
keywords: biodegradable metals; corrosion; magnesium; methylenephosphonic acid-HDTMPA; osteo-biocompatibility