title: Immobilization of NaIO4-treated heparin on PEG-modified 316L SS surface for high anti-thrombin-III binding.
abstract: Poor compatibility between blood and metallic coronary artery stents is one reason for arterial restenosis; however, the immobilization of anticoagulant agents on the surface of the stent is a feasible method of improving stent compatibility. Heparin, a well-known anticoagulant, has been frequently used to coat the surfaces of certain biomaterials to attain blood compatibility. The compound 1-ethyl-3-(3-dimethyl-aminopropyl) carbodiimide has often been utilized for the immobilization of heparin, but the critical carboxyl groups of heparin (with regards to heparin's anticoagulant activity) will be reduced by this method. This study examined possible methods of heparin immobilization without consuming these carboxyl groups. The 316L stainless steel surface was first activated with hexamethylene diisocyanate and then coupled with bis-amine-terminated poly (ethylene glycol) (BA-PEG) so as to create active amine groups. Sodium periodate (NaIO(4); SP) was then used to oxidize heparin to form aldehyde groups. The treated heparin could then be grafted onto the activated surface of the test material without losing its carboxyl groups. Effective surface modification of the hexamethylene diisocyanate-activated and BA-PEG-grafted 316L SS surface was confirmed using Fourier Transform Infrared Spectroscopy, electron spectroscopy for chemical analysis and a water contact angle test. After the heparin was immobilized on the BA-PEG-grafted 316L SS surface by SP, the surface showed an improvement in antithrombrin III (AT III) binding ability, its anticoagulant property, and hemocompatibility in comparison with heparin grafted by 1-ethyl-3-(3-dimethyl-aminopropyl) carbodiimide.
authors.affiliation: Institute of Biomedical Engineering, National Taiwan University Taipei, Taiwan, Republic of China.
authors.forename: Tzu-Wen
authors.initials: TW
authors.lastname: Chuang
authors.forename: Dong-Tsamn
authors.initials: DT
authors.lastname: Lin
authors.forename: Feng-Huei
authors.initials: FH
authors.lastname: Lin
mesh_terms: D000327:Adsorption; D000328:Adult; D000925:Anticoagulants / Q000494:pharmacology; D000990:Antithrombin III / Q000378:metabolism*; D003485:Cyanates / Q000378:metabolism; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000378:metabolism; D006493:Heparin / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D010504:Periodic Acid / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D013193:Stainless Steel / Q000737:chemistry*; D013927:Thrombosis; D014048:Tolonium Chloride; D014867:Water
chemical_list: D000925:Anticoagulants; D003485:Cyanates; D014867:Water; D010504:Periodic Acid; D013193:Stainless Steel; D014048:Tolonium Chloride; D011092:Polyethylene Glycols; C013606:methylene bis(4-cyclohexylisocyanate); D000990:Antithrombin III; D006493:Heparin; C009288:metaperiodate; D005022:Ethyldimethylaminopropyl Carbodiimide