title: Controllable biodegradability, drug release behavior and hemocompatibility of PTX-eluting magnesium stents.
abstract: Cardiovascular magnesium-based stents have been already applied in patients. However, their high corrosion rate hinders their clinical application. In this study, we adopt a new approach in the design of a Mg-based stent to improve the biodegradation rate and the drug release rate. By fabricating a micro-arc oxidation/poly-l-lactic acid (MAO/PLLA) composite coating on the magnesium alloy AZ81 substrate, the corrosion resistance decreased and the biodegradation rate became controllable. The drug release coating was composed of one Poly(dl-lactide-co-glycolide)/paclitaxel (PLGA/PTX) layer and one pure PLGA blank layer without paclitaxel, and this coating also functions to provide controlled biodegradation rate of the stent. The drug release rate was controlled by controlling the ratio of the LA:GA of the PLGA without PTX. The scanning electron microscopy (SEM) images were used to demonstrate the morphology of the samples before and after this modification. The blood compatibility of the samples was demonstrated by the platelet adhesion test. The drug release was determined by ultraviolet-visible (UV-visible) spectrophotometer. The result showed that the PLLA effectively sealed the micro-cracks and micro-holes on the surface of the MAO coating to give controllable biodegradation of the AZ81. The drug release rate of PTX exhibited a nearly linear sustained-release profile with no significant burst releases that would come from the uncontrolled oxidation/corrosion of AZ81. The samples modified had better hemocompatibility than 316L stainless steel.
authors.affiliation: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.forename: Hainan
authors.initials: H
authors.lastname: Fan
authors.forename: Yin
authors.initials: Y
authors.lastname: Liu
authors.forename: Lu
authors.initials: L
authors.lastname: Cao
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Wu
authors.forename: Xinhua
authors.initials: X
authors.lastname: Xu
mesh_terms: D001673:Biodegradation, Environmental / Q000187:drug effects; D002152:Calorimetry, Differential Scanning; D020099:Coated Materials, Biocompatible / Q000494:pharmacology; D054855:Drug-Eluting Stents; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D017239:Paclitaxel / Q000494:pharmacology*; D010973:Platelet Adhesiveness / Q000187:drug effects; D011092:Polyethylene Glycols / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D013499:Surface Properties / Q000187:drug effects
chemical_list: D020099:Coated Materials, Biocompatible; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011092:Polyethylene Glycols; D008274:Magnesium; D017239:Paclitaxel