title: Effect upon biocompatibility and biocorrosion properties of plasma electrolytic oxidation in trisodium phosphate electrolytes.
abstract: Surface modification to improve the corrosion resistance and biocompatibility of the Mg-Al-Zn-Ca alloy was conducted via plasma electrolytic oxidation (PEO) in an electrolyte that included phosphate. Calcium phosphate can be easily induced on the surface of a PEO coating that includes phosphate in a physiological environment because Ca(2+) ions in body fluids can be combined with PO4 (3-). Cytotoxicity of the PEO coating formed in electrolytes with various amounts of Na3PO4 was identified. In particular, the effects that PEO films have upon oxidative stress and differentiation of osteoblast activity were studied. As the concentration of Na3PO4 in the electrolyte increased, the oxide layer was found to become thicker, which increased corrosion resistance. However, the PEO coating formed in electrolytes with over 0.2 M of added Na3PO4 exhibited more microcracks and larger pores than those formed in smaller Na3PO4 concentrations owing to a large spark discharge. A nonuniform oxide film that included more phosphate caused more cytotoxicity and oxidative stress, and overabundant phosphate content in the oxide layer interrupted the differentiation of osteoblasts. The corrosion resistance of the magnesium alloy and the thickness of the oxide layer were increased by the addition of Na3PO4 in the electrolyte for PEO treatment. However, excessive phosphate content in the oxide layer led to oxidative stress, which resulted in reduced cell viability and activity.
authors.affiliation: Department of Dental Biomaterials and Institute of Biodegradable Materials, Institute of Oral Bioscience and School of Dentistry (plus BK21 program), Chonbuk National University, Jeon Ju 561-756, South Korea.
authors.forename: Yu-Kyoung
authors.initials: YK
authors.lastname: Kim
authors.affiliation: Division of Advanced Materials Engineering, Research Center for Advanced Materials Development and Institute of Biodegradable Materials, Chonbuk National University, Jeonju 561-756, South Korea.
authors.forename: Il-Song
authors.initials: IS
authors.lastname: Park
authors.affiliation: Department of Orthopaedic Surgery, Research Institute of Clinical Medicine, Institute of Biodegradable Materials, Chonbuk National University Medical School, Chonbuk National University Hospital, Jeon Ju 561-756, South Korea.
authors.forename: Kwang-Bok
authors.initials: KB
authors.lastname: Lee
authors.affiliation: Department of Dental Biomaterials and Institute of Biodegradable Materials, Institute of Oral Bioscience and School of Dentistry (Plus BK21 Program), Chonbuk National University, Jeon Ju 561-756, South Korea.
authors.forename: Tae-Sung
authors.initials: TS
authors.lastname: Bae
authors.affiliation: Department of Dental Biomaterials and Institute of Biodegradable Materials, Institute of Oral Bioscience and School of Dentistry (Plus BK21 Program), Chonbuk National University, Jeon Ju 561-756, South Korea.
authors.forename: Yong-Seok
authors.initials: YS
authors.lastname: Jang
authors.affiliation: Department of Neurosurgery, Chonbuk National University Medical School, Chonbuk National University Hospital, Jeon Ju 561-756, South Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Oh
authors.affiliation: Department of Dental Biomaterials and Institute of Biodegradable Materials, Institute of Oral Bioscience and School of Dentistry (Plus BK21 Program), Chonbuk National University, Jeon Ju 561-756, South Korea.
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Lee
mesh_terms: D000497:Alloys / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D002454:Cell Differentiation; D004573:Electrolytes / Q000378:metabolism*; D010006:Osteoblasts / Q000502:physiology*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010710:Phosphates / Q000378:metabolism*; D010949:Plasma / Q000737:chemistry*; D013499:Surface Properties / Q000187:drug effects*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D004573:Electrolytes; D010710:Phosphates; C018279:sodium phosphate