Drug Release is Determined by the Chain Length of Fatty Acid-Conjugated Anticancer Agent as One Component of Nano-Prodrug

Abstract Effective control of drug release from “nano-prodrugs”, which are nanoparticles composed of water-insoluble prodrug compounds is one of the most important determinants of the balance between drug efficacy and side effects. However, the chemical behaviors of nano-prodrugs in relation to drug release are poorly characterized. We created nano-prodrugs using a series of fatty acid ester (C2–C18) derivatives of 7-ethyl-10-hydroxycamptothecin (SN-38) and found that their in vitro cytotoxic activities decreased as the length of the fatty acid chain increased. The cytotoxicities of these nano-prodrugs were unrelated to particle size or efficacy of cellular uptake, but critically depended on their hydrolysis rate within cancer cells. These results indicated that the drug release rate from nano-prodrugs can be controlled successfully by changing the length of the introduced fatty acid chain.