Some properties of polysulfone, chlorometylated polysulfone and quaternized polysulfone were studied by viscometry, interferometry and dialysis equilibrium. Modification of intrinsic viscosity, preferential and total adsorbtion coefficients explained the changes of the hydrodynamic dimensions with solvent quality. POLYM. ENG. SCI., 46: 827–836, 2006. © 2006 Society of Plastics Engineers

Novel quaternized polysulfones (PSFs) with two ionic chlorine contents were investigated, namely, their morphology and antimicrobial activity. Atomic force microscopy (AFM) studies on their membranes showed ordered domains, in which pores and nodules of different sizes and intensities were distributed. The charge density of the quaternized PSFs and the history of the membranes formed from solutions in solvent/nonsolvent mixtures influenced the different aspects of the surface images. The adhesion of Escherichia coli ATCC 10536 and Staphylococcus aureus ATCCC 6538 microorganisms to solutions of the modified PSFs is discussed in correlation with the hydrophobic/hydrophilic properties of the studied polymers and microorganisms.

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ABSTRACT:The conformational behavior and unperturbed dimensions of polysulfone and chloromethylated polysulfone with different degrees of substitution were investigated by viscometry in N,N-dimethylformamide; we intended to use these results with more complicated structures with different properties and applications. The effects of concentration and temperature on the coil densities and dimensions and of chlorine content on the unperturbed dimension parameters are discussed.

The diagnosis and treatment of malignant melanoma by means of the formulation of active principles with dendrimeric nanoparticles is an area of great current interest. The identification and understanding of molecular mechanisms which ensure the integration of particular dendrimeric nanostructures in tumor cellular environment can provide valuable guidance in their coupling strategies with antitumor or diagnostic agents. Two structurally distinct maltose-shell modified 5th generation (G5) poly(propylene imine) (PPI) glycodendrimers fluorescently labeled, (a) with open maltose shell, cationic charged G5-PPI-OS and (b) with dense maltose shell and nearly neutral G5-PPI-DS, were tested in relation with several melanoma cell lines. We found that three melanoma cell lines internalize G5-PPI-DS structure more efficiently than non tumoral HEK297T cells. Furthermore, the internalization pathways of G5-PPI-OS and G5-PPI-DS are characteristic for each tumor cell phenotype and include more than one mechanism. As a general trend, large amounts of both G5-PPI-OS and G5-PPI-DS are internalized on cholesterol-dependent pathway in MJS primary melanoma cells and on non conventional pathways in SK28 metastatic melanoma cells. G5-PPI-OS, temporarily retained at plasma membrane in both cell lines, is internalized slower in metastatic than in primary phenotype. Unlike G5-PPI-OS, G5-PPI-DS is immediately endocytosed in both cell lines. The unconventional internalization pathway and trafficking, exclusively used by G5-PPI-DS in metastatic cells, is described at molecular level. The decay kinetics of fluorescent labeled G5-PPI-OS and G5-PPI-DS is distinct in the two cellular phenotypes. Both cationic and neutral maltose G5-PPI glycodendrimeric structures represent molecules based on which designing of new formulations for therapy or/and diagnosis of melanoma can be further developed.

Modification of intrinsic viscosity and the preferential adsorption coefficients of quaternized polysulfones with various contents of ionic chlorine in N,N-dimethylformamide/water and methanol/water mixed solvents was investigated at different compositions and temperatures. The polyelectrolyte effect induced by an enhanced dissociation of the ionizable groups determines both the modification of the swelling degree of the polymer coil and the difference in composition of the mixed solvent inside and outside the coil. The results obtained were correlated with the interaction parameters of the above-mentioned polymer/solvent/solvent systems.

The correlation between surface tension parameters and the chemical composition of polysulfone, chloromethylated polysulfone and quaternized polysulfone membranes, before and after plasma treatment, was investigated. Calculations are based on the geometric mean approach of Owens, Wendt, Rabel and Kälble, as well as on the theoretical methods involving quantitative structureproperty relationships on the basis of the group contribution techniques. The chemical modifications of polysulfone membranes and the low pressure plasma treatment affect the contact angle corresponding to different liquids. Consequently, the total surface tension and the polar component increase with the substitution degree of chloromethylated polysulfone and with the quaternization degree of the ammonium groups, in quaternized polysulfone samples. The plasma treatment modifies the surface energy of the samples, increasing their surface polarity and wettability. Surface wettability trends were also studied by means of the free energy of hydration between compounds and water.

Quaternized polysulfones with different ionic chlorine content tested for biomedical applications were obtained by quaternization reaction of chloromethylated polysulfones with N,N‐dimethylethanolamine. The relationship between the different physical and chemical characteristics of these polymers and their biocompatible and antimicrobial properties was established for maximizing the selectivity and performance of these materials for biomedical applications. Therefore, topographic reorganization of the polysulfonic films induced by the type of nonsolvent in casting solutions of polymer significantly influences films morphology, depending on the charge density of polyelectrolytes, the hydrophilic/hydrophobic characteristics, as well as on the history of the formed films. Furthermore, the study of the adhesion of red blood cells and cohesion of platelets on the surface of quaternized polysulfone films, as well as analysis of antibacterial activity, using Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 microorganisms, contribute to extending the possible applications of quaternized polysulfones as semipermeable membranes in biomedical domains. POLYM. ENG. SCI., 55:2184–2194, 2015. © 2015 Society of Plastics Engineers