In this study, we investigated two formulations of chitosan-Pluronic P123 with different folate ligand designation for targeted delivery of Paclitaxel (PTX), in which folic acid (FA) was directly conjugated to chitosan (FA-Cs-P123) or substituted onto P123 (Cs-P123-FA). The results showed that the FA content of Cs-P123-FA was determined at 0.71 wt/wt% which was significantly higher than that of FA-Cs-P123 (0.31 wt/wt%). Two copolymers were low critical gel concentrations (CGC). FA-Cs-P123 and Cs-P123-FA nanogels performed high PTX encapsulation efficiency reaching 95.57 ± 5.51 and 92.51 ± 6.68 wt/wt%, respectively. Transmission electron microscopy (TEM) and zeta potential analysis indicated that the PTX-loaded nanogels were spherically formed around 60 nm in diameter along with positive charge. Furthermore, the PTX release profile was slow and it was controlled by the pH of the medium. In particular, in vitro biocompatibility assays indicated that both FA-Cs-P123 and Cs-P123-FA exhibited good biological compatibility with a human foreskin fibroblast cell line and well uptake efficiency into MCF-7 cancer cells. Cs-P123-FA nanogel significantly enhanced the cytotoxicity of PTX in comparison with FA-Cs-P123. The result indicates that Cs-P123-FA nanogels with a higher decorated FA content perform a better targeting efficiency; therefore, they could have great potential application towards breast cancer treatment.
Keywords: Breast cancer; Chitosan-Pluronic; MCF-7 cells; folic acid ligand; paclitaxel loaded nanoparticles; pluronic P123.