Specifics of self-organization and properties of highly dilute aqueous solutions of polyoxidonium

Abstract

Using a combination of physicochemical methods (dynamic and electrophoretic light scattering (DLS and ELS, respectively), nanoparticle tracking analysis, atomic force and transmission electron microscopy (AFM and TEM, respectively), UV spectroscopy, conductometry, pH-metry, dielcometry), it was found that dilute solutions of a multicomponent drug immunomodulator polyoxidonium (PO) are nanoheterogeneous disperse systems, with their disperse phase undergoing considerable restructurings when diluting the solution in the range of calculated concentrations from 1∙10–1 to 1∙10–16 mg mL–1, which is reflected in the non-monotonous concentration dependencies of specific electroconductivity, dielectric permittivity, and pH of the solutions. Using ELS, AFM, TEM, and UV spectroscopy methods, it was found that the disperse phase with a size of hundreds of nanometers which forms at concentrations of ≤1∙10^–5 mg mL^–1, contains organized water structures substantiating the negative values of ζ-potential, which vary non-monotonously from–5 to–16 mV. Radioprotective properties of dilute solutions of PO (1∙10^–1 and 1∙10^–9 mg mL^–1) were demonstrated for the first time when exposing the test mutant bacterial strain Salmonella typhimurium TA 100 (Ames test) to X-ray radiation in a dose of 7.50 mGy used for medical diagnostics.