The development of new cationic nanoparticles that are safe and effective for biomedical applications has attracted considerable attention. Low molecular weight polycations generally exhibit low toxicity; however, their poor efficiency in drug delivery systems hampers their application. In this work, a series of new low molecular weight 2,6-bis(1-methylbenzimidazolyl)pyridinyl (BIP)-terminated ethanolamine-functionalized poly(glycidyl methacrylate)s (BIP-PGEAs) were readily fabricated for effective codelivery of a gene and a drug. The BIP-PGEAs could form well-defined cationic nanoparticles (NPs) in an aqueous solution. They could effectively bind pDNA with an appropriate particle size and ζ-potential. More importantly, the BIP-PGEA NPs demonstrated much higher transfection efficiencies than linear PGEA (L-PGEA) and the traditional "gold-standard" branched polyethylenimine (25 kDa). Moreover, the BIP-PGEA NPs could effectively entrap a hydrophobic anticancer drug such as 10-hydroxy camptothecin (CPT). The synergistic antitumor effect of the BIP-PGEA-CPT NPs was demonstrated by employing a suicide gene therapy system, which contained cytosine deaminase and 5-fluorocytosine (CD/5-FC). The present strategy for preparing well-defined cationic nanoparticles from low-molecular-weight polycations could provide an intriguing method to produce new multifunctional, therapeutic NPs.
Keywords: ATRP; amphiphilic polymers; delivery; gene vector; nanoparticles.