Evaluation of sustained release and cytotoxicity studies of 5-fluorouracil loaded chitosan nanoparticles using sodium tripolyphosphate/sodium hexametaphosphate

The primary objectives of the present work are to synthesize chitosan nanoparticles (CS-NPs) loaded with 5-fluorouracil, characterize the nanoparticles using various techniques, assess the impact of 5-FU concentration on encapsulation efficiency, study the sustained drug release from the nanoparticles, and evaluate their biocompatibility and cytotoxicity against specific cancer cell lines (MCF-7, U266, HEP G2). 5-FU are formulated with CS-NPs using sodium tripolyphosphate (STTP) and sodium hexametaphosphate (SHMP) through ionic crosslinking and are characterized via FTIR, XRD, SEM, TEM, and DLS measurements. From the SEM and TEM results, it was determined that the particle size of 5-FU-CS-NPs-SHMP air-dried and freeze-dried samples ranged between 90–120 nm and 60–80 nm, respectively. For the 5-FU-CS-NPs-TPP air-dried and freeze-dried formulation, the particle size ranged between 30–50 nm and 10–20 nm, respectively. Loading measurements confirmed a slight reduction in encapsulation efficiency from 99.8 to 98.6% when increasing the concentration of 5-fluorouracil from a ratio of 0.1 to 0.3 relative to the concentration of CS and TPP/SHMP. The in vitro drug release studies demonstrated sustained drug release, and the resulting data was fitted with kinetic models. The cytotoxicity assay indicated that the prepared drug-loaded formulation exhibited greater toxicity towards MCF-7 cancer cells compared to U266 and HEP G2 cancer cells.