Graphene quantum dot-based theranostic agents for active targeting of breast cancer

A novel graphene quantum dot (GQD)-based nanocarrier labeled with Herceptin (HER) and beta-cyclodextrin (beta-CD) was developed as a promising theranostic candidate for the treatment of breast cancer. Each component of this nanocarrier plays a critical role in providing multiple functions to achieve enhanced anticancer activities. HER provides active targeting to HER2-overexpressed breast cancer to enhance accumulation in the cancer cells. beta-CD provides a site for loading of a hydrophobic anticancer drug, doxorubicin (DOX), via host-guest chemistry. The nanocarriers also provide diagnostic effects due to the blue-color emission of the GQDs. In response to the acidic environment of cancer cells, the GQD-complex degraded rapidly and the DOX was released in a controlled manner to inhibit proliferation of cancer cells. This multi-functional drug delivery system leads to a synergistically enhanced anticancer strategy which provides treatment and diagnosis. The intracellular trafficking results, along with cell viability and confocal laser scanning microscopy, suggest that the GQD-complex offers a viable strategy for HER2-overexpressed breast cancer-targeting drug delivery applications.