title: Comparison of degradation behavior and the associated bone response of ZK60 and PLLA in vivo.
abstract: The aim of this study was to investigate whether ZK60, an extruded magnesium alloy, reacts in vivo with an appropriate host response, and to investigate how microarc oxidation treatment influences this in vivo corrosion behavior. Twelve cylinders were machined from as-extruded ZK60, with six cylinders treated with MAO and six left untreated; poly-l-lactic acid pins were used as a control to compare biocompatibility. These cylinders were implanted into the right distal femur of mice along the transepicondylar axis from the medial condyle. Microcomputerized tomography was used to quantitatively analyze corrosion in a nondestructive manner in vivo and the corrosion rate was calculated based on the volume measurements of the residual implants. The physiological response of the rats postimplantation was obtained by clinical observation and blood biochemical analysis. Histological analyses of the soft tissue around the implants were used to assess bone response in relation to the implants. The results obtained clearly indicate that the untreated ZK60 alloy showed high degradation rates in vivo, and that MAO treatment had a significant but unsatisfying effect on protecting the implant from further corrosion. Compared with PLLA, the ZK60 alloy showed good osteoconductivity and osteoinductivity, and, according to biochemical indicators, had good biocompatibility in vivo.
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, China.
authors.forename: Zheng-Rong
authors.initials: ZR
authors.lastname: Qi
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Tan
authors.forename: Xiao
authors.initials: X
authors.lastname: Lin
authors.forename: Yi
authors.initials: Y
authors.lastname: Yin
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000497:Alloys / Q000494:pharmacology*; D000818:Animals; D003343:Corrosion; D004602:Elements; D005269:Femur / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D021621:Imaging, Three-Dimensional; D020007:Implants, Experimental; D019344:Lactic Acid / Q000494:pharmacology*; D008297:Male; D008422:Materials Testing; D051379:Mice; D010084:Oxidation-Reduction / Q000187:drug effects; D011091:Polyesters; D011108:Polymers / Q000494:pharmacology*; D051381:Rats; D013194:Staining and Labeling; D013997:Time Factors; D055114:X-Ray Microtomography
chemical_list: D000497:Alloys; D004602:Elements; D011091:Polyesters; D011108:Polymers; C586529:ZK60 magnesium alloy; D019344:Lactic Acid; C033616:poly(lactide)
keywords: biocompatibility; bone response; degradation; in vivo; magnesium alloy