Chitosan/Sterculia striata polysaccharides nanocomplex as a potential chloroquine drug release device

Nanoparticles are produced by means of polyelectrolyte complexation (PEC) of oppositely charged polycationic chitosan (CH) with polyanionic polysaccharide extracted from Sterculia striata exudates (rhamnogalacturonoglycan (RG)-type polysaccharide). The nanoparticles formed with low-molar-mass CH are larger than those formed with high-molar-mass CH. This behavior is in contrast with that previously observed for other systems and may be attributed to different mechanisms related to the association of CH with RG of higher persistence length chain than that of CH. Nanoparticles harnessed with a charge ratio (n+/n−) of <1 are smaller than particles with an excess of polycations. Particles with hydrodynamic sizes smaller than 100 nm are achieved using a polyelectrolyte concentration of 10−4 g mL−1 and charge ratio (n+/n−) of <1. The CH/RG nanoparticles are associated with chloroquine (CQ) with an efficiency of 28% and release it for up to ∼60% within ∼10 h, whereas in the latter, only ∼40% of the CQ was released after 24 h. The main factor that influenced drug release rate is the nanoparticle charge ratio.