Chitosan and Poly(N-vinyl-pyrrolidone) Interaction Properties. Pharmaceutical and Biomedical Applications

The naturally occurring polymers, chitosan (CH) and poly(N-vinyl-pyrrolidone (PVP), have attracted the interest of researchers in a variety of biomedical and pharmaceutical applications areas, such as drug delivery, cosmetics, and tissue engineering. However, PVP and CH have certain limitations for use in controlled aqueous CH/PVP mixed solutions. In this study aqueous solutions of PVP and CH with the same concentration of 10 g/l and pH 6 were mixed under atmospheric conditions. The effects of temperature and molar volume fraction, X1, of CH on the decreased dynamic viscosity of the CH/PVP mixed solutions were studied at various temperatures ranging from 15 °C to 80 °C. We highlighted that different regions can be distinguished in the aqueous CH/PVP complexes, depending on the composition and electrostatic interactions of the solutions, which are associated with significantly different phase behaviors.