title: Long-term clinical study and multiscale analysis of in vivo biodegradation mechanism of Mg alloy.
abstract: There has been a tremendous amount of research in the past decade to optimize the mechanical properties and degradation behavior of the biodegradable Mg alloy for orthopedic implant. Despite the feasibility of degrading implant, the lack of fundamental understanding about biocompatibility and underlying bone formation mechanism is currently limiting the use in clinical applications. Herein, we report the result of long-term clinical study and systematic investigation of bone formation mechanism of the biodegradable Mg-5wt%Ca-1wt%Zn alloy implant through simultaneous observation of changes in element composition and crystallinity within degrading interface at hierarchical levels. Controlled degradation of Mg-5wt%Ca-1wt%Zn alloy results in the formation of biomimicking calcification matrix at the degrading interface to initiate the bone formation process. This process facilitates early bone healing and allows the complete replacement of biodegradable Mg implant by the new bone within 1 y of implantation, as demonstrated in 53 cases of successful long-term clinical study.
authors.affiliation: School of Advanced Materials Engineering, Kookmin University, Seoul 136-702, South Korea;
authors.forename: Jee-Wook
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Center for Biomaterials, Korea Institute of Science & Technology, Seoul 136-650, South Korea;
authors.forename: Hyung-Seop
authors.initials: HS
authors.lastname: Han
authors.affiliation: Department of Orthopaedic Surgery, Ajou University School of Medicine, Suwon 443-721, South Korea;
authors.forename: Kyeong-Jin
authors.initials: KJ
authors.lastname: Han
authors.affiliation: Center for Biomaterials, Korea Institute of Science & Technology, Seoul 136-650, South Korea;
authors.forename: Jimin
authors.initials: J
authors.lastname: Park
authors.affiliation: Center for Biomaterials, Korea Institute of Science & Technology, Seoul 136-650, South Korea; Department of Bio-medical Engineering, University of Science & Technology, Daejeon 305-350, South Korea;
authors.forename: Hojeong
authors.initials: H
authors.lastname: Jeon
authors.affiliation: Center for Biomaterials, Korea Institute of Science & Technology, Seoul 136-650, South Korea;
authors.forename: Myoung-Ryul
authors.initials: MR
authors.lastname: Ok
authors.affiliation: Center for Biomaterials, Korea Institute of Science & Technology, Seoul 136-650, South Korea; Department of Bio-medical Engineering, University of Science & Technology, Daejeon 305-350, South Korea;
authors.forename: Hyun-Kwang
authors.initials: HK
authors.lastname: Seok
authors.affiliation: Advanced Analysis Center, Korea Institute of Science & Technology, Seoul 136-650, South Korea;
authors.forename: Jae-Pyoung
authors.initials: JP
authors.lastname: Ahn
authors.affiliation: Advanced Analysis Center, Korea Institute of Science & Technology, Seoul 136-650, South Korea;
authors.forename: Kyung Eun
authors.initials: KE
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, South Korea;
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Mechatronics Engineering, Chungnam National University, Daejeon 305-764, South Korea;
authors.forename: Seok-Jo
authors.initials: SJ
authors.lastname: Yang
authors.affiliation: R&D Center, U & I Corporation, Uijongbu 480-050, South Korea;
authors.forename: Sung-Youn
authors.initials: SY
authors.lastname: Cho
authors.affiliation: School of Advanced Materials Engineering, Kookmin University, Seoul 136-702, South Korea;
authors.forename: Pil-Ryung
authors.initials: PR
authors.lastname: Cha
authors.affiliation: School of Advanced Materials Engineering, Kookmin University, Seoul 136-702, South Korea;
authors.forename: Hoon
authors.initials: H
authors.lastname: Kwon
authors.affiliation: School of Nano and Advanced Materials Engineering, Gyeongsang National University, Jinju 660-701, South Korea;
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Nam
authors.affiliation: R&D Center, U & I Corporation, Uijongbu 480-050, South Korea;
authors.forename: Jee Hye Lo
authors.initials: JH
authors.lastname: Han
authors.affiliation: Center for Biomaterials, Korea Institute of Science & Technology, Seoul 136-650, South Korea;
authors.forename: Hyoung-Jin
authors.initials: HJ
authors.lastname: Rho
authors.affiliation: Department of Orthopaedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, South Korea; chany@kist.re.kr klee@amc.seoul.kr.
authors.forename: Kang-Sik
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Center for Biomaterials, Korea Institute of Science & Technology, Seoul 136-650, South Korea; Department of Bio-medical Engineering, University of Science & Technology, Daejeon 305-350, South Korea; chany@kist.re.kr klee@amc.seoul.kr.
authors.forename: Yu-Chan
authors.initials: YC
authors.lastname: Kim
authors.affiliation: Laboratory for Biomaterials and Bioengineering, Department of Mining, Laval University, Québec City, QC, Canada G1V 0A6.
authors.forename: Diego
authors.initials: D
authors.lastname: Mantovani
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000494:pharmacology*; D000818:Animals; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000648:ultrastructure; D005500:Follow-Up Studies; D006801:Humans; D008274:Magnesium / Q000494:pharmacology*; D008297:Male; D010012:Osteogenesis / Q000187:drug effects; D019919:Prosthesis Implantation; D011817:Rabbits; D011859:Radiography; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000497:Alloys; D008274:Magnesium
keywords: biodegradable implant; bone formation; clinical application