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Abstract:Combinatorial drug delivery is a way of advanced cancer treatment that at present represents a challenge for researchers. Here, we report the efficient entrapment of two clinically used single-agent drugs, doxorubicin and sorafenib, against hepatocellular carcinoma. Biocompatible and biodegradable polymeric nanoparticles provide a promising approach for controlled drug release. In this study, doxorubicin and sorafenib with completely different chemical characteristics were simultaneously entrapped by the same polymeric carrier, namely poly(D,L-lactide-co-glycolide) (PLGA) and polyethylene glycol-poly(D,L-lactide-co-glycolide) (PEG-PLGA), respectively, using the double emulsion solvent evaporation method. The typical mean diameters of the nanopharmaceuticals were 142 and 177 nm, respectively. The PLGA and PEG-PLGA polymers encapsulated doxorubicin with efficiencies of 52% and 69%, respectively, while these values for sorafenib were 55% and 88%, respectively. Sustained drug delivery under biorelevant conditions was found for doxorubicin, while sorafenib was released quickly from the PLGA-doxorubicin-sorafenib and PEG-PLGA-doxorubicin-sorafenib nanotherapeutics.

Environmentally friendly, biodegradable biopolymers can be prepared via the chemical modification of starch. These biopolymers are able to partially or totally substitute synthetic additives used today in the chemical or environmental technologies. Through the building of ionic function groups into polymeric chains of the starch ion exchangers, flocculants or dispersants can be produced. In this paper, we examine water-soluble ionic derivatives called polyelectrolytes. By phosphorylating starch while preserving or maybe increasing the molecular weight of the native starch polymers, anionic flocculating agents can be prepared. If the polymer chains degrade during the reaction, the products will act as dispersing agents in aqueous suspensions. It is apparent that, during the phosphorylation reaction, the changes in the molecular weight distribution and the ionic charge of the polymers have crucial importance. In our experiments, we investigated the solid-phase reactions by following the change in the molecular weight distributions, using size exclusion chromatography, and the change in the charge densities, using a particle charge detector. The efficiency of the products was tested in the laboratory, and the results were evaluated by means of severity parameters.

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