Free electron laser induces specific immobilization of heparin on polysulfone films

Abstract

Covalent immobilization of heparin has been developed to reduce the amount of heparin administered systematically during long-term dialysis. Recently, it was doubted partially because of the complexion during immobilization process. In this study, we investigated a novel method for specific immobilization of heparin on polysulfone (PSF) via free electron laser (FEL) irradiation. Laser wavelengths of 6.18 or 6.31 microm, the typical absorption bands of carboxyl groups of heparin and aromatic rings in PSF, respectively, were chosen to irradiate the thin heparin membrane formed on PSF surfaces. The amount of heparin immobilized on PSF was measured by the toluidine blue method. The binding of heparin on PSF was analyzed by X-ray photoelectron spectroscopy (XPS). The immobilization of heparin resulted in a hydrophilic surface on which decreased platelet adhesion was observed. The efficiency differences, depending on laser wavelengths, were discussed from the point of view of structural and environmental differences of light-absorbing groups.

Physicochemical and blood compatibility characterization of polypyrrole surface functionalized with heparin

“…The adhered platelets were then fixed with 2.0 vol% glutaraldehyde aqueous solution for 2 h at 4°C. The film was then washed successively with PBS, water, and ethanol (three times each), and dried under vacuum before being subjected to SEM observation (Xu et al, 2001;Zhang et al, 2001).…”

“…The modification of polymers with biomolecules to produce blood-or tissue-compatible materials to suppress blood coagulation and immunological and hyperplastic response, as well as to stimulate rapid growth of endothelial cells, is an area of great interest (Steffen et al, 2000). Among the biomolecules (e.g., urokinase, prostacyclin, trombomodulin, collagen, heparin, albumin), heparin is well known for many biological activities (Akashi et al, 1996), such as anticoagulant activity (Xu et al, 2001), cell growth stimulation (Zhou et al, 1999), and antivirus and plasma clearing activity. Heparin's role as an anticoagulant is to catalyze and enhance the binding of antithrombin III (ATIII) and thrombin to its specific site.…”

Utilization of star-shaped polymer architecture in the creation of high-density polymer brush coatings for the prevention of platelet and bacteria adhesion

“…The polymer-coated PET substrates were incubated with PRP at 37 °C for 30 min, based on the standard protocol in the literature. 40 The platelet adhesion on the coated surfaces was characterized using SEM. The numbers of platelets that adhered to star-PHEMA and star-H71M29 coatings were significantly smaller than those for the noncoated PET and other star and linear polymers (Fig.…”

Polypyrrole‐polysaccharide thin films characteristics: Electrosynthesis and biological properties

“…For instance, some authors studied the immobilization of large polyanions,3, 4 namely heparin (Hep) or hyaluronic acid (HA), into the polypyrrole chains. Heparin is widely used for many biological functions because of its anticoagulant and antinflammatory activity,5 cell growth stimulation,6 and antivirus and plasma clearing activity 7. It can also be used for releasing systems,8 chromatographic devices,9 biosensors,10 tissue for tissue engineering, and drug delivery systems 11, 12.…”