Cationic amphiphilic polysaccharide nanoballs: protein stabilization and intracellular delivery by nano-encapsulation

A new intracellular protein delivery nanocarrier with protein stabilizing ability was constructed of cationic amphiphilic polysaccharide nanoballs. Amphiphilic enzymatically synthesized glycogen (ESG) made by modification of hydrophobic cholesterol groups to ESG, which is a monodispersed spherical hyper-branched polysaccharide nanoparticle, formed self-assembled cluster nanogels (CHESG nanogels) in water. Cationic amphiphilic ESG derivatives where the diethylethylenediamine (DEAE) group was introduced into CHESG (CHESG-DEAE) were positively charged, monodispersed, and non-aggregated amphiphilic nanoballs with hydrophobic nanodomains provided by the cholesterol groups. The CHESG-DEAE strongly interacted with proteins and stabilized them against thermal denaturation. Furthermore, the cationic CHESG effectively internalized a number of proteins into HeLa cells. This cationic ESG nanoball-based material shows great potential as an effective protein delivery nanocarrier.