Develop novel nanoparticle formulations of disulfiram copper for cancer therapy

Despite remarkable progress in cancer treatment, drug resistance remains a significant issue for prostate cancer, breast cancer, and others. Disulfiram (DSF), an alcohol-aversion drug, has been repurposed for cancer treatment and overcome drug resistance. DSF and copper ions form a copper diethyldithiocarbamate (Cu-DSF) complex which has a potent anticancer activity. However, the poor aqueous solubility of Cu-DSF creates a significant formulation challenge, and there is no formulation available for clinical use. We developed a S tabilized M etal I on L igand Nanocompl e x ( SMILE ) technology to prepare Cu-DSF nanoparticle (NP) formulations where in situ formed DSF-Cu NPs were stabilized by an optimal amount of stabilizers ( e.g. poly(ethylene glycol)-poly(lactide)). The SMILE technology involves a novel formulation design and an innovative preparation process using a 3D-printed microfluidic device. After optimizing the protocol, we can prepare Cu-DSF NPs with size in the sub-100 nm range which are suitable for intravenous injection and can target solid tumors through enhanced permeability and retention (EPR) effects. Cu-DSF NPs prepared with SMILE method showed high drug loading efficiency (above 90%) and high drug concentration (at least 2 mg/mL). The drug concentration of Cu-DSF NPs developed in our study was much higher than those in micelle NP formulations prepared with the classical film-dispersion method. Since we used generally recognized as safe (GRAS) excipients approved by the US Food and Drug Administration (FDA) or other excipients with well-recognized safety profiles, the developed NP formulations will have less regulatory hurdle for FDA approval. Because of the novel preparation process and unique formulation design, the SMILE technology can produce Cu-DSF NPs on a large scale and thus paved the way for its mass production and commercialization. We also determined the anticancer effects of Cu-DSF NPs with multiple assays including MTT assay, colony-forming assay, calcein-AM/propidium iodide staining, and others. Cu-DSF NPs showed excellent anticancer activity against various prostate cancer and breast cancer cells as well as drug-resistant cancer cells. In summary, we developed a novel SMILE method to prepare Cu-DSF NP formulations which could address drug delivery and formulation challenges of DSF-based chemotherapy and facilitate the clinical translation. Citation Format: Wu Chen, Wen Yang, Landon F. Stewart, David T. Coombs, Jianzhong Shen, Pengyu Chen, Feng LI. Develop novel nanoparticle formulations of disulfiram copper for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3626.