Heparin polymer matrix

To investigate heparin release in response to an electric current, the swollen heparin-polymer matrix was attached to a woven platinum cathode in a continuously stirred PBS solution (pH 7.4), and an electric current of 20 mA was applied. When the electric current was on, the polymer surface facing the cathode dissolved, thereby releasing heparin. The amount of heparin released was assayed by the Azure II method at pH 11 to prevent complexation of the two dissolved polymers. The release pattern of heparin showed a complete on-off profile in response to the applied electric field, as shown in Figure 23 [50],... 

The first approach taken by Kim et al. [90] was to combine heparin and prostaglandin Ej (PGEj) together in a polymer matrix. Subsequently, a covalently... 

CBH. The sparingly water soluble compound of heparin with an organic base (BH), such as benzalkonium—e.g., Zephiran (Winthrop) or cetyl trimethyl ammonium bromide or octadecyl amine can be dissolved in ethyl alcohol and mixed with an organic polymer matrix—e.g., collodion in ether and alcohol (4). Such lacquer mixtures are designated CBH. 

Graftcopolymerization onto silicone rubber is rather difficult to achieve and is often accompanied by unwanted changes in physico-mechanical properties of the polymer caused by initiating agents. To overcome the problem, silica was introduced into the rubber matrix as an active filler capable of binding cationic compounds such a cationic compound being y-aminopropyltriethoxysilane. Schematically the pathway for heparinization of the latter may be presented as follows ... 

Matrix Conjugating agent Amount of immobilized heparin rng/g polymer Amount of heparin cofactor bound per 1 g of product, antithrombin units... 

Peptides Matrix polymers (fihronectin, heparin sulfate, hyaluronic acid) Lipid bilayer membranes... 

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