Curcumin-Poly(sodium 4-styrenesulfonate) Conjugates as Potent Zika Virus Entry Inhibitors

Curcumin, a natural product with recognized antiviral properties, is limited in its application largely due to its poor solubility. This study presents the synthesis of water-soluble curcumin-poly(sodium 4-styrenesulfonate) (Cur-PSSNan) covalent conjugates. The antiflaviviral activity of conjugates was validated in vitro by using the Zika virus as a model. In the development of these water-soluble curcumin-containing derivatives, we used the macromolecules reported by us to also hamper viral infections. Mechanistic investigations indicated that the conjugates exhibited excellent stability and bioavailability. The curcumin and macromolecules in concerted action interact directly with virus particles and block their attachment to host cells, hampering the infection process.

Concentration Dependent Single Chain Properties of Poly(sodium 4-styrenesulfonate) Subjected to Aromatic Interactions with Chlorpheniramine Maleate Studied by Diafiltration and Synchrotron-SAXS

The polyelectrolyte poly(sodium 4-styrenesulfonate) undergoes aromatic–aromatic interaction with the drug chlorpheniramine, which acts as an aromatic counterion. In this work, we show that an increase in the concentration in the dilute and semidilute regimes of a complex polyelectrolyte/drug 2:1 produces the increasing confinement of the drug in hydrophobic domains, with implications in single chain thermodynamic behavior. Diafiltration analysis at polymer concentrations between 0.5 and 2.5 mM show an increase in the fraction of the aromatic counterion irreversibly bound to the polyelectrolyte, as well as a decrease in the electrostatic reversible interaction forces with the remaining fraction of drug molecules as the total concentration of the system increases. Synchrotron-SAXS results performed in the semidilute regimes show a fractal chain conformation pattern with a fractal dimension of 1.7, similar to uncharged polymers. Interestingly, static and fractal correlation lengths increase with increasing complex concentration, due to the increase in the amount of the confined drug. Nanoprecipitates are found in the range of 30–40 mM, and macroprecipitates are found at a higher system concentration. A model of molecular complexation between the two species is proposed as the total concentration increases, which involves ion pair formation and aggregation, producing increasingly confined aromatic counterions in hydrophobic domains, as well as a decreasing number of charged polymer segments at the hydrophobic/hydrophilic interphase. All of these features are of pivotal importance to the general knowledge of polyelectrolytes, with implications both in fundamental knowledge and potential technological applications considering aromatic-aromatic binding between aromatic polyelectrolytes and aromatic counterions, such as in the production of pharmaceutical formulations.

Study of Polyaniline/Poly(Sodium 4-Styrenesulfonate) Composite Deposits Using an Electrochemical Quartz Crystal Microbalance for the Modification of a Commercial Anion Exchange Membrane

One of the intended applications for the modification of ion exchange membranes with polyaniline (PAni) is to use it as a matrix to include chemical species that confer a special property such as resistance to fouling or ion selectivity. In particular, the inclusion of polyelectrolyte molecules into the PAni matrix appears to be the way to modulate these properties of selective membranes. Therefore, it must be clearly understood how the polyelectrolyte is incorporated into the matrix of polyaniline. Among the results obtained in this paper using poly(sodium 4-styrenesulfonate) (PSS) and an electrochemical quartz crystal microbalance, the amount of polyelectrolyte incorporated into PAni is found to be proportional to the PSS concentration in solution if its value is between 0 and 20 mM, while it reaches a maximum value when the PSS in solution is greater than 20 mM. When the anion exchange membranes are modified with these composite deposits, the transport number of chloride was found to decrease progressively (when the PSS concentration in solution is between 0 and 20 mM) to reach a practically constant value when a concentration of PSS greater than 20 mM was used.

Development and Characterization of New Pervaporation PVA Membranes for the Dehydration Using Bulk and Surface Modifications

In the present work, the novel dense and supported membranes based on polyvinyl alcohol (PVA) with improved transport properties were developed by bulk and surface modifications. Bulk modification included the blending of PVA with chitosan (CS) and the creation of a mixed-matrix membrane by introduction of fullerenol. This significantly altered the internal structure of PVA membrane, which led to an increase in permeability with high selectivity to water. Surface modification of the developed modified dense membranes, based on composites PVA-CS and PVA-fullerenol-CS, was performed through (i) making of a supported membrane with a thin selective composite layer and (ii) applying of the layer-by-layer assembly (LbL) method for coating of nano-sized polyelectrolyte (PEL) layers to increase the membrane productivity. The nature of polyelectrolyte type-(poly(allylamine hydrochloride) (PAH), poly(sodium 4-styrenesulfonate) (PSS), poly(acrylic acid) (PAA), CS), and number of PEL bilayers (2⁻10)-were studied. The structure of the composite membranes was investigated by FTIR, X-ray diffraction, and SEM. Transport properties were studied during the pervaporation separation of 80% isopropanol⁻20% water mixture. It was shown that supported membrane consisting of hybrid layer of PVA-fullerenol (5%)⁻chitosan (20%) with five polyelectrolyte bilayers (PSS, CS) deposited on it had the best transport properties.