title: Poly(L-lactic acid)/hydroxyapatite/collagen composite coatings on AZ31 magnesium alloy for biomedical application.
abstract: Surface modification of biomedical magnesium alloy using composite coating shows an attemptable approach for the development of Mg-based biomaterials with excellent cytocompatibility. Hydroxyapatite/collagen composite was preliminarily fabricated by biomineralization, the bioactive poly(l-lactic acid)/hydroxyapatite/collagen composite coatings were spin coated on AZ31 magnesium alloy using poly(l-lactic acid) solution mixed with hydroxyapatite/collagen particles, and the resultant materials and coatings were characterized in structure and related properties; furthermore, the in vitro degradation behavior of modified magnesium alloy in 1.5-fold Hank's solution was investigated. The results show that hydroxyapatite/collagen composite achieved chemical bonding between hydroxyapatite and collagen similar to natural bone; composite coatings on AZ31 magnesium alloy retained the bioactive functional groups of the componential materials and improved the corrosion resistance of Mg alloy; the mass fraction of hydroxyapatite/collagen particles incorporated into the composite affected the porous structure, interfacial adhesion and thus the corrosion resistance of the composite coating due to phase separation as well as volume concentration effects of polymer solution. Composite coatings suppressed the sharp rising of pH value and the released Mg(2+) from substrate to extensive degree, and the degradation behavior of the modified magnesium alloy was supposed to be correlated to microstructure of the coating as well as the synergistic reactions among alkaline- and acidic-degraded products.
authors.affiliation: College of Materials Science and Engineering, Chongqing University of Technology, Chongqing, China.
authors.forename: Zhen-Lin
authors.initials: ZL
authors.lastname: Wang
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Yan
authors.forename: Tao
authors.initials: T
authors.lastname: Wan
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
mesh_terms: D000497:Alloys / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis*; D024042:Collagen Type I / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D019544:Equipment Failure Analysis; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D019736:Prostheses and Implants; D011474:Prosthesis Design; D013499:Surface Properties
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D024042:Collagen Type I; C586533:Mg-Al-Zn-Mn-Si-Cu alloy; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D017886:Durapatite
keywords: collagen; composite coating; hydroxyapatite; magnesium alloy; poly(l-lactic acid)