A redox-responsive delivery system for paclitaxel based on heparin—pluronic F127 nanogel

Paclitaxel (PTX), a chemo-drug widely used in cancer chemotherapy for a variety of tumors, has been still faced with several problems in therapeutic applications due to its poor water solubility, low content in natural sources, expensive multistep processes of synthesis and side effects. In this study, a nanogel system based on the conjugation of Heparin and Pluronic F127 via disulphide bridges was developed for PTX delivery in a redox responsive way to over these mentioned drawbacks. The obtained Hep-F127 system were proved and characterized through H-NMR, zeta potential, DLS, TEM and FT-IR methods. TEM result showed that the nanogel Hep-F127 was spherical, non-agglomerated and relatively uniform with an average particle diameter of 80 nm. PTX was effectively encapsulated into the nanogel thanks to poly(propylene oxide) (PPO) units of F127 molecules with DLE and DLC values of about 92% and 18%, respectively. Meanwhile, the nanogel was stable in physiological condition but broken under reducing condition, leading to a well-controlled release in physiological condition and a fast release in simulating tumor-microenvironmental condition. This contributed to reducing side effects and increasing the effectiveness of treatment of PTX. In addition, cytotoxicity of Hep-F127 and PTX@Hep-F127 was in vitro tested on the L929 cell line. This study suggested that the nanogel Hep-F127 would to be a promising carrier for enhancing the solubility of PTX and release PTX in a redox-responsive way in cancer treatment.