Negatively charged chitosan nanoparticles prepared by ionotropic gelation for encapsulation of positively charged proteins.

The nanoprecipitation of hydrogel nanoparticles by complex coacervation is investigated through a systematic study of the popular chitosan-polyphosphate pair of polyelectrolytes with opposite charges at pH 4. Polyphosphates of varying molar masses and electrical charges are investigated as alternatives to the commonly used tripolyphosphate, so as to assess the influence of the strength of electrostatic interactions on the fabrication possibility, the size of hydrogel particles, and their overall charge. Sodium hexametaphosphate and sodium polyphosphate allow the manufacture of such nanoparticles with either a positive or a negative charge, depending on the chitosan/polyphosphate ratio and the order of mixing.

Morphological study of electrospun chitosan/poly(vinyl alcohol)/glycerol nanofibres for skin care applications.

This study aimed to evaluate the influence of formulation and procedure parameters in obtaining thick and continuous chitosan/PVA/glycerol nanofibres to be applied in skin care. For that, the polymers were characterized by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, and size-exclusion chromatography. After this, 96 chitosan/PVA/glycerol nanofibre scaffolds were prepared by electrospinning method, using factorial designs.