Aggregates of sodium hyaluronate with cationic and aminoxide surfactants in aqueous solution — light scattering study

Aggregation properties of sodium hyaluronate (NaHA) with different types of surfactants in aqueous sodium chloride solution have been studied by using static and dynamic light scattering method. Molecular weight, second virial coefficient, radius of gyration, and hydrodynamic radius have been calculated. The polymer — surfactant aggregate growth was found in complexes of NaHA with an ionic surfactant (dodecyltrimethylammonium bromide) and ionic, dimeric surfactants (dodecanediyl-α,ω-bis(dimethyloctylammonium bromide) and N,N′-bis(dodecyldimethyl)-4,13-dioxo-3,14-dioxahexadecane-1,16-diyldiammonium dibromide). In case of dodecyldimethylamine oxide (DDAO), the decreasing molecular weight and aggregate size of the NaHA — DDAO complex with increasing DDAO concentration were found above the surfactant critical micelle concentration, indicating the absence of electrostatic interactions between NaHA and DDAO that would lead to the increase in aggregate size. This behaviour may be ascribed to the non-ionic character of DDAO.