6-mercaptopurine is a cytotoxic and immunosuppressant drug. The use of this drug is limited due to its poor bioavailability and short plasma half-life. Chitosan nanoparticles exhibit great interest for nanomedicine, biomedical engineering and development of new therapeutic drug release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity. The main objective of this study is to formulate 6mercaptopurine (6MP) encapsulated chitosan nanoparticles (6-MP-CNPs) using with Tripolyphosphate (TPP) as cross-linker for anti-cancer therapy in order to enhance cytotoxcicty and bioavailability . Chitosan nanoparticles exhibited a small particle
size and a high surface charge .The prepared nanoparticles were characterized by transmission electron microscopy, zeta potential. The average particle size determined through TEM was found to be 90 ± 10 nm and after encapsulation the particle size show an obvious increase. Zeta potential 26.2±6.35 mV. 6-MP-CNPs showed enhancement in cellular inhibition of breast cancer cell line MCF7 compared to free 6MP.