Interaction between reacetylated chitosan and albumin in alcalescent media.

Interaction of chitosan and its derivatives with proteins of animal blood at blood pH relevant conditions is of a particular interest for construction of antimicrobial chitosan/protein-based drug delivery systems. In this work, the interaction of a series of N-reacetylated oligochitosans (RA-CHI) having M of 10-12 kDa and differing in the degree of acetylation (DA 19, 24, and 40 %) with bovine serum albumin (BSA) in alkalescent media is described in first. It is shown that RA-CHI forms soluble complexes with BSA in solutions with pH 7.

Exploiting specific properties of squid pens for the preparation of oligochitosan hydrochloride.

Herein, we describe in first the application of squid pens for the preparation of pharmaceutical-grade oligochitosan hydrochloride with the physicochemical characteristics corresponding with the requirements of the European Pharmacopoeia. It is shown that the use of specific properties of squid pens as a source of parent chitosan allows preparing the product with a high yield at relatively moderate process conditions used for squid pens treatments and chitosan depolymerization.

Complexation between chitosan and carboxymethyl cellulose in weakly acidic, neutral, and weakly alcaline media.

The interaction between carboxymethyl cellulose and partially reacetylated chitosan soluble in acidic and alkaline aqueous media is studied by light scattering and isothermal titration calorimetry in a wide pH range. It is shown that the formation of polyelectrolyte complexes (PEC) can occur in the pH range of 6-8, while this pair of polyelectrolytes loses the ability to complexation upon transition to a more alkaline medium. The revealed dependence of the observed enthalpy of interaction on the ionization enthalpy of the buffer indicates the participation of proton transfer from the buffer substance to chitosan and its additional ionization in the binding process.

Peculiarities of the interaction of sodium dodecyl sulfate with chitosan in acidic and alkaline media.

In this work, the interaction between the negatively charged surfactant sodium dodecyl sulfate (SDS) and partially N-reacetylated chitosan (RA-CHI), which is soluble at pH range up to pH 12, is studied in a wide pH range including alkaline media by light scattering (LS) and isothermic titration calorimetry (ITC). It is shown that in the weakly alkaline medium (pH 7.4), RA-CHI/SDS interaction is exothermic and cooperative.

Investigation of the Binding of Lectins with Polymer Glycoconjugates and the Glycoconjugates Containing Silver Nanoparticles by Means of Optical Spectroscopy and Light Scattering.

The synthesis of glycoconjugates, lectin-specific polymers containing a carbohydrate ligand (spacered residue of N-acetyl-D-glucosamine, β-N-Gly-GlcNAc) has been carried out. Glyconanoparticles (glycol-NPs) containing a label detectable by means of spectrophotometry, silver nanoparticles, have been prepared on the basis of the glycoconjugates. Copolymers of maleic anhydride with ethylene or -vinylpyrrolidone have been used as a carrier to introduce the carbohydrate ligand and a stabilizer of silver nanoparticles.