Biologically active anionic polymers

BRESLOW Biologically Active Synthetic Anionic Polymers... 

The dopant ion required for polymer conductivity is one of the most important components of a CP. Its structure, number of available balancing charges and interaction with the polymer backbone are key to the overall performance of the material. In biomedical applicaEons the dopant also needs to be nontoxic or restrained by the polymer matrix. A number of dopant types have been invesEgated for use in biomedical applicaEons, including small anions, polymeric anions, buffer salts, and biologically active anions. Table 18.1 summarizes various dopant types and solvents that have been reported in the... 

Other applications of photochemistry include the development of sensitive fluorescent chemosensors for analysis of dilute solutions of inorganic cations and anions and the study of the diffusion of individual molecules in solution at room temperature. Fluorescent compoimds have been used as replacements for radioisotopes in the analysis of biological compoimds and the study of biologically active compounds and living systems. Photochemical reactions also offer alternative probes for the characterization of the microenvironments in diverse solid and liquid media, including crystals, zeolites, alumina, silica and clay surfaces, semiconductor surfaces, liquid crystals and host-guest inclusion complexes, polymer films, monolayers and supported multilayers of surfactant molecules, mi-celles, and dendrimers. ... 

Another method to improve the incorporation of bioactive polymers into the cells is the grafting of hydrophobic groups on the polymer, which improves the affinity for the cell membrane. Maleic copolymers are good candidates for such modifications, the anhydride cycle being easily reacted with hydrophobic amines. Poly(MA-St), poly(MA-CDA) and poly(maleic anhydride-alt-3,4-dihydroxyphenylprop-l-ene) modified with alkyl amines or aniline were proved to perturb the liposome membrane and to interact with epithelial cells or DMSO-differentiated HL-60 cells [48-50]. As a result, the biological activity, evaluated by the ability to simulate the release of superoxide anion by the cells, was enhanced when the polymer was modified with hydrophobic units [49]. 

L. Panaitescu and R.M. Ottenbrite, Biological effects and antitumor activity induced by benzocaine conjugated anionic polymers, /. Bioact. Compat. Polym., 17,357-374,2002. 

The specific interaction between a biological unit and another molecule has been also exploited for the synthesis of new process-able electroactive polymers [162] and the extraction/delivery of biologically active molecules [154, 163]. An approach to the trapping delivery of neutral drugs has been reported by Bidan and co-workers [163]. The neutral guest A7-methylphenothiazine was encapsulated in the host sulfonated cyclodextrin previously incorporated as a doping anion in PPy. This drug could be electrochem-ically released from the polymer by the application of an appropriate potential. 

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