Surface modification of a biodegradable magnesium alloy with phosphorylcholine (PC) and sulfobetaine (SB) functional macromolecules for reduced thrombogenicity and acute corrosion resistance.

Siloxane functionalized phosphorylcholine (PC) or sulfobetaine (SB) macromolecules (PCSSi or SBSSi) were synthesized to act as surface modifying agents for degradable metallic surfaces to improve acute blood compatibility and slow initial corrosion rates. The macromolecules were synthesized using a thiol-ene radical photopolymerization technique and then utilized to modify magnesium (Mg) alloy (AZ31) surfaces via an anhydrous phase deposition of the silane functional groups. X-ray photoelectron spectroscopy surface analysis results indicated successful surface modification based on increased nitrogen and phosphorus or sulfur composition on the modified surfaces relative to unmodified AZ31. In vitro acute thrombogenicity assessment after ovine blood contact with the PCSSi and SBSSi modified surfaces showed a significant decrease in platelet deposition and bulk phase platelet activation compared with the control alloy surfaces. Potentiodynamic polarization and electrochemical impedance spectroscopy data obtained from electrochemical corrosion testing demonstrated increased corrosion resistance for PCSSi- and SBSSi-modified AZ31 versus unmodified surfaces. The developed coating technique using PCSSi or SBSSi showed promise in acutely reducing both the corrosion and thrombotic processes, which would be attractive for application to blood contacting devices, such as vascular stents, made from degradable Mg alloys.

[1]  Y. Yagcı,et al.  Influence of Type of Initiation on Thiol–Ene “Click” Chemistry , 2010 .

[2]  W. Wagner,et al.  Flow cytometric assays for quantifying activated ovine platelets. , 2008, Artificial organs.

[3]  Neil B. Cramer,et al.  Mechanism and Modeling of a Thiol−Ene Photopolymerization , 2003 .

[4]  K. Ishihara,et al.  Surface modification of a titanium alloy with a phospholipid polymer prepared by a plasma-induced grafting technique to improve surface thromboresistance. , 2009, Colloids and surfaces. B, Biointerfaces.

[5]  W. Cook,et al.  Thermal polymerization of thiol-ene network-forming systems , 2007 .

[6]  Wei-min Liu,et al.  Preparation of silane‐terminated polystyrene and polymethylmethacrylate self‐assembled films on silicon wafer , 2004 .

[7]  Christopher N Bowman,et al.  Thiol-ene click chemistry. , 2010, Angewandte Chemie.

[8]  W. J. van der Giessen,et al.  Biocompatibility of phosphorylcholine coated stents in normal porcine coronary arteries , 2000, Heart.

[9]  Neil B. Cramer,et al.  Kinetics of thiol-ene and thiol-acrylate photopolymerizations with real-time Fourier transform infrared , 2001 .

[10]  Raimund Erbel,et al.  Temporary scaffolding of coronary arteries with bioabsorbable magnesium stents: a prospective, non-randomised multicentre trial , 2007, The Lancet.

[11]  Yufeng Zheng,et al.  In vitro corrosion and biocompatibility of binary magnesium alloys. , 2009, Biomaterials.

[12]  L. Gamble,et al.  Covalent surface modification of a titanium alloy with a phosphorylcholine-containing copolymer for reduced thrombogenicity in cardiovascular devices. , 2009, Journal of biomedical materials research. Part A.

[13]  Charles E. Hoyle,et al.  Thiol–enes: Chemistry of the past with promise for the future , 2004 .

[14]  Longqin Li,et al.  Organic coatings silane-based for AZ91D magnesium alloy , 2010 .

[15]  F. Prati,et al.  Acute and mid‐term results of phosphorylcholine‐coated stents in primary coronary stenting for acute myocardial infarction , 2001, Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions.

[16]  J. Kubásek,et al.  Mechanical and corrosion properties of newly developed biodegradable Zn-based alloys for bone fixation. , 2011, Acta biomaterialia.

[17]  Jiang Yuan,et al.  Platelet adhesive resistance of segmented polyurethane film surface-grafted with vinyl benzyl sulfo monomer of ammonium zwitterions. , 2003, Biomaterials.

[18]  K. Ishihara,et al.  Simple synthesis of a library of zwitterionic surfactants via Michael-type addition of methacrylate and alkane thiol compounds. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[19]  F. Houllier,et al.  Photoinitiated cross-linking of a thiol–methacrylate system , 2001 .

[20]  Mark J. Schulz,et al.  Corrosion protection of biodegradable magnesium implants using anodization , 2011 .

[21]  Mitsuo Umezu,et al.  In vivo evaluation of a MPC polymer coated continuous flow left ventricular assist system. , 2003, Artificial organs.

[22]  Kenji Yamazaki,et al.  Preclinical biocompatibility assessment of the EVAHEART ventricular assist device: coating comparison and platelet activation. , 2007, Journal of biomedical materials research. Part A.

[23]  Yufeng Zheng,et al.  Corrosion resistance and surface biocompatibility of a microarc oxidation coating on a Mg-Ca alloy. , 2011, Acta biomaterialia.

[24]  S. Armes,et al.  The biocompatibility of crosslinkable copolymer coatings containing sulfobetaines and phosphobetaines. , 2004, Biomaterials.

[25]  P. Lu,et al.  Evaluation of magnesium ions release, biocorrosion, and hemocompatibility of MAO/PLLA-modified magnesium alloy WE42. , 2011, Journal of biomedical materials research. Part B, Applied biomaterials.

[26]  A R Boccaccini,et al.  Biomedical coatings on magnesium alloys - a review. , 2012, Acta biomaterialia.

[27]  Frank Witte,et al.  The history of biodegradable magnesium implants: a review. , 2010, Acta biomaterialia.

[28]  R. Garrell,et al.  Thiol—Ene Click Reaction as a General Route to Functional Trialkoxysilanes for Surface Coating Applications. , 2011 .

[29]  Raimund Erbel,et al.  Safety and performance of the drug-eluting absorbable metal scaffold (DREAMS) in patients with de-novo coronary lesions: 12 month results of the prospective, multicentre, first-in-man BIOSOLVE-I trial , 2013, The Lancet.

[30]  A. N. Khramov,et al.  Sol gel coatings with phosphonate functionalities for surface modification of magnesium alloys , 2006 .

[31]  Yufeng Zheng,et al.  Surface characteristics and corrosion behaviour of WE43 magnesium alloy coated by SiC film , 2012 .

[32]  Shuichi Takayama,et al.  Zwitterionic SAMs that Resist Nonspecific Adsorption of Protein from Aqueous Buffer. , 2001, Langmuir : the ACS journal of surfaces and colloids.

[33]  Cong Wang,et al.  Selective Defect‐Patching of Zeolite Membranes Using Chemical Liquid Deposition at Organic/Aqueous Interfaces , 2008 .

[34]  N Nakabayashi,et al.  Why do phospholipid polymers reduce protein adsorption? , 1998, Journal of biomedical materials research.

[35]  C. Bode,et al.  Differences of platelet adhesion and thrombus activation on amorphous silicon carbide, magnesium alloy, stainless steel, and cobalt chromium stent surfaces , 2009, Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions.

[36]  Fuzhai Cui,et al.  Surface Modifications of Magnesium Alloys for Biomedical Applications , 2011, Annals of Biomedical Engineering.

[37]  H. Kitano,et al.  Molecular recognition at the exterior surface of a zwitterionic telomer brush. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[38]  Yong Wang,et al.  Evaluation of cyto-toxicity and corrosion behavior of alkali-heat-treated magnesium in simulated body fluid , 2004 .

[39]  K. Ishihara,et al.  Simple surface modification of a titanium alloy with silanated zwitterionic phosphorylcholine or sulfobetaine modifiers to reduce thrombogenicity. , 2010, Colloids and surfaces. B, Biointerfaces.

[40]  B. Gersh.  Temporary scaffolding of coronary arteries with bioabsorbable magnesium stents: a prospective, non-randomised multicentre trial , 2008 .

[41]  R. Raman,et al.  Electrochemical impedance spectroscopic investigation of the role of alkaline pre-treatment in corrosion resistance of a silane coating on magnesium alloy, ZE41 , 2011 .

[42]  Dong-Choon Sin,et al.  Surface coatings for ventricular assist devices , 2009, Expert review of medical devices.

[43]  Fritz Thorey,et al.  Biomechanical testing and degradation analysis of MgCa0.8 alloy screws: a comparative in vivo study in rabbits. , 2011, Acta biomaterialia.