Functional Derivatives of Chitosan, Soluble in a Neutral Medium for Drugs and Genetic Material Carriers: Preparation and Properties

A 2-stage method of chitosan modification providing controlled addition of the quaternized block has been proposed. The structure of the products obtained was studied by FT-IR and NMR spectroscopy; their solubility and acid-base properties was characterized by turbodimetry and potentiometry, respectively. The presence about 50% of quaternized amino groups was shown to be necessary to obtain soluble products. The difference in pH-sensitivity of modified derivatives with different types of quaternized block attachment was revealed by studying their interaction with a model polystyrene sulfonate anion. The possibility of preparing complexes based on the obtained derivatives with DNA, polyplexes, stable under conditions close to physiological ones has been demonstrated. It is shown that the presence of primary amino groups on the polycation chains leads to a decrease in the polyplexe size. The data we obtained can form the basis for development of drug and genetic material delivery systems.