Zein - laponite coacervate aided co-delivery of curcumin and cisplatin towards MDA-MB-231 breast cancer cells: Validating the concept

Cancer cell resistance towards drugs leads to limited drug efficacy and therefore, combination therapy of drugs has emerged as a solution. In addition to this, the importance of a carrier system for the co-delivery of drugs to improve the potential of anti-cancer drug efficacy cannot be overlooked. Nowadays, polymer-rich dense phases of liquid droplets, known as coacervates, have emerged as an appealing option to be utilised as drug carriers. Our previous study which reported the complexation between zein and laponite to form coacervates and their future prospect as dual drug carriers has been extended in this work. The present work has validated the usefulness of the synthesized coacervate as a dual-drug carrier for a hydrophilic drug (cisplatin) and a hydrophobic drug (curcumin) towards a breast cancer cell line (MDA-MB-231). The MTT assay and flow cytometry data for MDA-MB-231 cells suggested that the coacervate carrying dual drugs effectively transported anticancer drugs to the cancer cells, thereby arresting their cell cycle in the S phase (by neutral coacervates, X₁) and in the G₂/M phase (by charged coacervates, X₂). Further, it is also revealed that the amount of cisplatin needed to achieve half maximal inhibitory concentration (IC₅₀) was reduced by a maximum of 70% when flavonoid (curcumin) was used in combination with cisplatin due to synergistic effect.