Fabrication of pH-responsive co-delivery system for nano selenium and doxorubicin with PEGylated chitosan: Effect of PEGylation

Drug delivery system has shown multi advantages in cancer treatment, but the complex fabrication process limits their clinical application. This work developed a chitosan-based co-delivery system for doxorubicin and nano selenium. The one-pot co-precipitation process was utilized to form the PEGylated nanoparticles. It was found that the PEGylation might affect the co-precipitation process and result in different nanoparticle sizes and drug release behavior. The PEGylated nanoparticles (Se@DOX/CS-PEG) present a larger diameter (about 230 nm) and higher drug loading capacity (31%). A faster drug release was also observed for PEGylated Se@DOX/CS-PEG nanoparticles and drug release could be completed in 2 h at pH 5.0 while the drug release at pH 7.4 could be limited (<5%, 10 h). In vitro cell experiments confirmed the anti-cancer efficiency and intracellular delivery ability of the co-delivery system. In conclusion, this work presents a novel way to fabricate co-delivery system and may provide more insights into the development of smart drug delivery systems.