HB5 aptamer-tagged graphene oxide for co-delivery of doxorubicin and silibinin, and highly effective combination therapy in breast cancer

Using a chemotherapeutic agent, such as doxorubicin (DOX), with a natural agent, such as silibinin (Sili), is highly valuable to minimize systemic toxicity. However, Sili and DOX face disadvantages, such as low aqueous solubility and poor bioavailability. Here, we have engineered a drug delivery cargo by decorating carboxylated graphene oxide (cGO) with an aptamer, HB5, for simultaneous delivery of DOX and Sili as a combination therapy against MCF-7 and SK-BR-3 breast cancer cells. The resulting Apt-cGO displayed a typical sheet-like nanostructure with a broad surface. The maximum entrapment efficiency was 70.42% and 84.22% for Sili and DOX, respectively. When the Apt-cGO-DOX-Sili nanocomposites were selectively taken up by breast cancer cells, the interaction between cGO and drugs was cleaved, causing releasing both Sili and DOX into the tumor cells, respectively. Compared to free drugs, Apt-cGO-DOX-Sili nanocomposites displayed higher cytotoxicity in vitro. Apt-cGO-DOX-Sili nanocomposites potentially suppressed some cancer cell survival signals. They accelerated cell apoptosis and increased Rb levels as well as reduced Akt, mTOR, NF-κB, and CDK2 levels. In conclusion, the developed Apt-cGO-DOX-Sili can be suggested as a simple and efficient drug delivery approach for breast chemotherapy.