Albumin-Stabilized Metal–Organic Nanoparticles for Effective Delivery of Metal Complex Anticancer Drugs

Many metal–organic complexes showed potent anticancer efficacy, but their clinical applications were limited by the lack of administration route because of their poor solubility. To make metal–organic nanoparticles (MONPs) comprising metal complex drugs is a new formulation strategy for their administration. Herein, we developed a facile synthesis of an MONP composed of bovine serum albumin (BSA), Cu2+, and an anticancer agent, 5-nitro-8-hydroxyquinoline (NQ) with albumin as a nanoreactor. The resultant BSA/Cu/NQ nanoparticle (BSA/Cu/NQ NP) showed good stability in different physiological buffers and could target tumors through the enhanced permeability and retention effect and receptor-mediated cellular uptake. As the BSA/Cu/NQ NP could be readily and efficiently internalized by cancer cells, it showed much higher cytotoxic cancer cells than the NQ + Cu(II) complex and NQ. Therefore, the treatment with BSA/Cu/NQ NP noticeably enhanced the anticancer efficacy without causing systemic toxicity, indicating that such a facile preparation method has great potential to prepare other metal complex nanoparticles for drug delivery.