Smart nanoconjugates of functionalized cashew gum for targeted co-delivery of curcumin and paclitaxel

Carboxymethylated cashew gum (CMCG) was successfully conjugated with curcumin (CUR) forming an acid-sensitive prodrug. Paclitaxel (PTX) was then encapsulated in CMCG-CUR nanoparticles (CMCG-CUR/PTX) via hydrophobic interaction with CUR. These nanoparticles were designed for co-delivery of CUR and PTX to tumor cells. FTIR and ¹H NMR confirmed the structures of the CMCG-CUR and CMCG-CUR/PTX. Self-assembly into nanoparticles, was observed, with fluorescence spectroscopy, dynamic light scattering and atomic force microscopy indicating good dispersion and diameters of 190 nm (CMCG-CUR) and 181 nm (CMCG-CUR/PTX). Drug loading capacity (DLC) values for CUR in CMCG-CUR and CMCG-CUR/PTX nanoparticles were 7.0 and 3.0 % respectively. Nanoparticles promoted the protection of CUR against degradation processes and exhibited a pH-responsive and controlled release of PTX and CUR. Furthermore, the nanoparticles exhibited antitumor activity against the CT-26 (murine colorectal carcinoma) cells and 4T1 (murine breast carcinoma) cells line and reduced cytotoxicity against non-tumor cells (RAW 264.7). The cellular uptake study showed that the nanoparticles were readily taken up by CT-26 cells. Taken together, obtained data suggest that the pH-responsive CMCG-CUR/PTX nanoparticle would be an effective carrier for simultaneous delivery of CUR and PTX to CT-26 tumor cells.