title: Effect of hydrion evolution by polylactic-co-glycolic acid coating on degradation rate of pure iron.
abstract: For biodegradable iron coronary stents, the major problem is the low degradation rate in body environment. In this study, a new strategy was proposed to increase the degradation rate of iron in vitro. The hydrion evolution was intended to be introduced into the degradation system to increase the degradation rate. To realize this strategy, polylactic-co-glycolic acid (PLGA) was coated onto the surface of pure iron. The degradation process and mechanism of pure iron coated with PLGA were investigated. The results showed that iron coated with PLGA exhibited higher degradation rate in the static immersion test all along. With the degradation of PLGA, the oligomers of PLGA could release abundant H+which could dissolve the ferrous oxide to make the electrolyte and oxygen to reach the surface of iron again and simultaneity trigger the hydrion evolution at the middle stage of the degradation. The study also revealed that the solution ions failed to permeate the PLGA coating and the deposition of calcium and phosphorus in the degradation layer was inhibited which further enhanced the degradation. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
authors.affiliation: Specialized Materials and Devices Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China; Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Jingyao
authors.initials: J
authors.lastname: Wu
authors.forename: Xi
authors.initials: X
authors.lastname: Lu
authors.forename: Lili
authors.initials: L
authors.lastname: Tan
authors.forename: Bingchun
authors.initials: B
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
keywords: PLGA coating; biodegradation; coronary stents; pure iron