Nanodrug delivery system constructed with dopamine-based functional molecules for efficient targeting of tumour cells

In order to enhance the water solubility of chemotherapeutic drugs, improve their biodistribution and narrow therapeutic window, two molecules of PDAO and FA-DAO with acid-sensitive Schiff base structure were designed and synthesized based on dopamine linolenate (DAO) in this paper, and subsequently drug-loaded nanoparticles were prepared by simply mixing of them with curcumin (Cur) in aqueous solution. These nanoparticles can release a large amount of the drug in response to pH changes in the tumor microenvironment through passive targeting. The cumulative rate of drug release can reach up to 70% within 24 hours under pH = 5.0 conditions as a release medium. Furthermore, the drug-carrying nanoparticles achieve active targeting through folic acid (FA) on their surface, which further enhances targeting efficiency. The inhibitory effect of drug-loaded nanoparticles was nearly 8-fold enhanced than that of its loaded Active Pharmaceutical Ingredient (API) Cur on HepG2 cell lines at the administration concentration of 6.25 μg mL^-1. In conclusion, the nanoparticles prepared in this work improved the aqueous solubility of the loaded drug Cur, where passive targeting provided by pH-responsiveness and active targeting provided by FA endowed the loaded drug Cur with highly efficient targeting of HepG2 cell lines.