In this study, we investigated the active targeted delivery of a hydrophobic
drug,
paclitaxel (PTX), via receptor-mediated endocytosis by
folate receptors expressed on
cancer cells using a
protein-based nanoparticle system. PTX was loaded on
zein nanoparticles and conjugated with
folate (PTX/
Zein-FA) to estimate its chemotherapeutic efficacy in
folate receptor-expressing KB
cancer cells. PTX/
Zein-FA nanoparticles were successfully developed, with a nanoparticle size of ~180 nm and narrow polydispersity index (~0.22). Accelerated release of PTX in an acidic environment was observed for PTX/
Zein-FA. An in vitro cellular study of PTX/
Zein-FAs in KB cells suggested that PTX/
Zein-FA improved the cytotoxic activity of PTX on
folate receptors overexpressed in
cancer cells by inducing proapoptotic
proteins and inhibiting
anti-apoptotic proteins. In addition, PTX/
Zein-FA exhibited anti-migratory properties and could alter the cell cycle profile of KB cells. A549 cells, which are
folate receptor-negative
cancer cells, showed no significant enhancement in the in vitro cellular activities of PTX/
Zein-FA. We describe the antitumor efficacy of PTX/
Zein-FA in KB
tumor-bearing mice with minimum toxicity in healthy organs, and the results were confirmed in comparison with free
drug and non-targeted nanoparticles.