title: A surface-eroding poly(1,3-trimethylene carbonate) coating for fully biodegradable magnesium-based stent applications: toward better biofunction, biodegradation and biocompatibility.
abstract: Biodegradable magnesium-based materials have a high potential for cardiovascular stent applications; however, there exist concerns on corrosion control and biocompatibility. A surface-eroding coating of poly(1,3-trimethylene carbonate) (PTMC) on magnesium (Mg) alloy was studied, and its dynamic degradation behavior, electrochemical corrosion, hemocompatibility and histocompatibility were investigated. The PTMC coating effectively protected the corrosion of the Mg alloy in the dynamic degradation test. The corrosion current density of the PTMC-coated alloy reduced by three orders and one order of magnitude compared to bare and poly(ε-caprolactone) (PCL)-coated Mg alloy, respectively. Static and dynamic blood tests in vitro indicated that significantly fewer platelets were adherent and activated, and fewer erythrocytes attached on the PTMC-coated surface and showed less hemolysis than on the controls. The PTMC coating after 16 weeks' subcutaneous implantation in rats maintained ~55% of its original thickness and presented a homogeneously flat surface demonstrating surface erosion, in contrast to the PCL coated control, which exhibited non-uniform bulk erosion. The Mg alloy coated with PTMC showed less volume reduction and fewer corrosion products as compared to the controls after 52 weeks in vivo. Excessive inflammation, necrosis and hydrogen gas accumulation were not observed. The homogeneous surface erosion of the PTMC coating from exterior to interior (surface-eroding behavior) and its charge neutral degradation products contribute to its excellent protective performance. It is concluded that PTMC is a promising candidate for a surface-eroding coating applied to Mg-based implants.
authors: Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China; The Institute of Biomaterials and Surface Engineering, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China; National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA.
authors: Juan
authors: J
authors: Wang
authors: Yonghui
authors: Y
authors: He
authors: Manfred F
authors: MF
authors: Maitz
authors: Boyce
authors: B
authors: Collins
authors: Kaiqin
authors: K
authors: Xiong
authors: Lisha
authors: L
authors: Guo
authors: Yeoheung
authors: Y
authors: Yun
authors: Guojiang
authors: G
authors: Wan
authors: Nan
authors: N
authors: Huang
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000648:ultrastructure; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D003343:Corrosion; D004146:Dioxanes / Q000494:pharmacology*; D055664:Electrochemical Techniques; D005260:Female; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008274:Magnesium / Q000494:pharmacology*; D008422:Materials Testing; D010973:Platelet Adhesiveness / Q000187:drug effects; D011091:Polyesters / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015607:Stents; D014057:Tomography, X-Ray Computed
chemical_list: D020099:Coated Materials, Biocompatible; D004146:Dioxanes; D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; C059299:polytrimethylene carbonate; D008274:Magnesium
keywords: Biocompatibility; Biodegradable stent; Magnesium; Poly(1,3-trimethylene carbonate); Surface-eroding coating