Heparin-poly

Na K, Kim S, Park K, Kim K, Woo DG, Kwon IC, Chung HM, Park KH (2007) Heparin/poly(L-lysine) nanoparticle-coated polymeric microspheres for stem-cell therapy. J Am Chem Soc 129 5788-5789. 

Table 5. Thromboresistance of heparinized poly(tetrafluoroethylene) as a function of the diameter of uncoated regions62 ...

Displacement by plasma of radiolabeled thrombin and radio-labeled thrombin-antithrombin III inactive complex from a heparinized surface was measured and found to be significant for example, removing 63% of the thrombin and 90% of the complex that could not be removed by phosphate-buffered saline alone. Heparin-poly(vinyl alcohol) (PVA) gel beads with a very low heparin release rate, prepared by acetal coupling of the heparin to the PVA, adsorbed thrombin and potentiated the inactivation of thrombin by antithrombin 111, as measured by both thrombin time and chromogenic substrate assays. 

Jiang T, Wang G, Qiu J, Luo L, Zhang G (2009) Heparinized poly(vinyl alcohol)-small intestinal submucosa composite membrane for coronary covered stents. Biomed Mater 4 025012... 

In vitro biocompatibility tests were also performed by Neenan et al. (1982). They used heparinized poly[(organo)phosphazenes] to enhance the anti-thrombogenic properties of polyphosphazenes. Films of these materials containing heparine were subjected to bovine blood clotting tests (Figure 29). 

Neenan, XX. and Allcock, HR. (1982) Synthesisof a heparinized poly(organophosphazene). Biowateriafa, 3, 78-80. 

Sulfated poly(ethylene) Heparinized poly(ethylene)... 

Grainger DW, Kim SW, and Feijen J. Poly(dimethyl siloxane)-poly(ethylene oxide)-heparin block copolymers. I Synthesis and characterization. J Biomed Mater Res, 1988, 22, 231-242. 

FIGURE 2 Bromination, quaternization, and binding of heparin to the surface of poly[bis-(2 niethylphenoxy)phosphazene]. 

Surface Heparinization of Poly(ethylene terephthalate) Films Modified with Acrylic Hydrogels... 

A semi-interpenetrated network was obtained by bulk polymerization of 2-hydroxye-thyl methacrylate incorporated in DMF treated PET films by solvent-exchange technique, followed by treatment of films in e-lectrical discharges. Heparinization was accomplished by reacting glutaraldehyde with heparin and poly(2-hydroxyethyl methacrylate) present on the surface of modified polyester films. The immobilization of heparin was indirectly evidenced by chromatographying the silylated hydrolyza-tes of heparinized PET films and heparin, respectively. In vitro experiments demonstrated the enhanced thromboresistance of heparinized films. 

The aim of this paper is to report the bonding of heparin on poly(ethylene terephthalate) films containing an acrylic hydrogel (pHEMA), the method of preparation of the support material and some of its properties. 

N. Ramamurthy, N. Baliga, J. Wahr, U. Schaffer, V.C. Yang, and M.E. Meyerhoff, Improved poly cation-sensitive membrane electrode for monitoring heparin levels in whole blood via protamine titration. Clin. Chem., 606-613 (1998). 

In practice, some anticoagulation agents such as heparin or antiplatelet agents, e.g. nitric oxide (NO) are delivered to sensor sites in order to reduce the risk of thrombus formation. Nitric oxide (NO), which is a potent inhibitor of platelet adhesion and activation as well as a promoter of wound healing in tissue, has been incorporated in various polymer metrics including PVC (poly(vinyl-chloride)), PDMS (poly-dimethyl-siloxane) and PU (poly-urethanes). Those NO release polymers have been tested in animals as outer protection coatings and have shown promising effects for the analytical response characteristics of the sensor devices [137],... 

Figure 3.16. Effects on the fluorescence of anthrylpolyamme 14 on titration by four biological polyanions, o—O, Heparin A—A. poly-L-glutamate — , dsDMA a—A, ssDNA. (Reproduced from Ref. 25.

The heparin and poly-L-glutamate titrations show a markedly different behavior than do the DNA titrations. As polyanion is added, the fluorescence of the an-thrylpolyamine solution decreases until a well-defined minimum is reached. A new emission at 510 nm, which we assign to the anthracene excimer of 14, increases and decreases coincidently with the titrated fluorescence minimum. Likewise, the UV spectrum of 10 fiM 14 with added heparin shows hypochromism that occurs and disappears coincidently with the fluorescence minimum and a 2-nm red shift. We have proposed template-directed excimer formation as the physical basis for these observations. In the absence of heparin, fluorescence of the unassociated probe is observed. As heparin is added, the fluorescence decreases as a result of heparin-directed interaction between probe molecules. Additional heparin permits the fluorophore population to diffuse over the length of the poly anion, thus avoiding excimer formation and yielding a net CHEF. 

Specihc poly anions such as dextran sulfate (DS) appear to exhibit strong anti-HIV activity in vitro [36,37]. Human oral administration of DS is poorly absorbed, but intravaneous administration does result in increased plasma lipolytic activity [38]. Poly anions that have been considered for intravaginal anti-HIV activity include DS, carrageenan, heparin, heparan sulfate, dermatan sulfate, pentosan polysulfate, fucoidan chondroitin sulfate, keratan sulfate, and PAVAS [21,22,39,40],... 

---