Effective delivery of hydrophobic drugs to breast (MCF-7) and Liver (HepG2) cancer cells: A detailed investigation using Cytotoxicity assays, fluorescence imaging and flow cytometry

This study aimed to develop a drug carrier system consisting of a polymer containing hydroxyapatite (HAp) shell and a magnetic core of iron oxide nanoparticles. Doxorubicin and/or curcumin were loaded into the carrier via a simple diffusion deposition approach, with encapsulation efficiencies (EE) for curcumin and doxorubicin of 93.03 ± 0.3% and 97.37 ± 0.12% respectively. The co-loading of curcumin and doxorubicin led to a total EE of 76.02 ± 0.48%. Release studies were carried out at pH 7.4 and 5.3, and revealed higher release was at pH 5.3 expressing the potential application in tumor microenvironments. Cytotoxicity assays, fluorescence imaging and flow cytometry showed the formulations could effectively inhibit the growth of MCF-7 and HEpG2 cancer cells, being more potent than the free drug molecules both in dose and time dependent manner. Additionally, hemolysis tests and cytotoxicity evaluations determined the drug-loaded carriers to be non-toxic towards non-cancerous cells. These formulations thus have great potential in the development of new cancer therapeutics