Hydrophobization of polyanionic polymers

Hydrophobization of Polyanionic Polymers to Achieve Higher Biological Activity... 

There was no distinct difference between polymers having different molecular weights. From the data in Figures 2, 4, 5, and 6, it seems to be established that the affinity of polyanionic polymers for cell membrane is adjustable by a simple grafting of hydrophobic groups. 

Based on these observations in Figs. 8 and 9, it is suggested that the hydrophobic group modification (hy-drophobization) is an effective method for improving the immuno-stimulating activity of polyanionic polymers. 

We modified polyanionic polymers by use of a grafting reaction of hydrophobic groups onto the polymers. After an extensive evaluation for the affinity of the hy-drophobically modified (hydrophobized) polymers to cell membrane, the immuno-stimulating activity of polymers was investigated by in vitro or ex vivo experiments. Consequently, the increased biological activity was found in the hydrophobized polymer, indicating that... 

Based on the data in Figs. 2 and 4, it appears that the affinity of the polyanionic polymer for cell membrane can be increased by the hydrophobization of polymers. 

Kapui et al. prepared a novel type of polypyrrole films [168]. The film was impregnated by spherical styrene-methacrylic acid block copolymer micelles with a hydrophobic core of 18 nm and a hydrophilic corona of 100 nm. The properties of the micelle-doped polypyrrole films were investigated by cyclic voltammetry and SECM. It was found that the self-assembled block copolymer micelles in polypyrrole behave as polyanions and the charge compensation by cations has been identified during electrochemical switching of the polymer films. 

In Table 14-1 a Nafion 1 (sulfonated perfluoroalkyl polyanion polymer) membrane is often used since it is a stable cation-exchange polymer able to adsorb cationic compounds easily. A Nafion membrane is composed of hydrophilic columns incorporating anionic sulfonate groups, hydrophobic columns composed of main chains, and interlayer regions between the hydrophilic and hydrophobic columns. When a cationic substrate is adsorbed from an aqueous solution, the adsorbed material is located only in the hydrophilic columns or interlayer regions, so that a real local concentration of... 

Y. Suda, H. Yamamoto, M. Sumi, N. Oku, E Ito, S. Yamashita, T. Nadai, and R.M. Ottenbrite, Modified polyanionic polymers. 1 Grafting of hydrophobic group onto poly(maleic acid-alt-3,4-dihydroxyphenylprop-l-ene) to improve the affinity for cell membranes,/. Bioact Compat Pol, 7,15-24,1992. 

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