CCK8 peptide-labeled Pluronic® F127 micelles as a targeted vehicle of gold-based anticancer chemotherapeutics

The bioavailability and target selectivity of chemotherapeutics are signi fi cant issues in drug development. Here, we report the loading of the antiproliferative gold( III ) complex, dibromo[ethyl-N-(dithiocarboxy-kS,kS0)-N-methylglycinato] gold( III ) (AuL12), into the lipophilic core of micelles produced from the surfactant Pluronic® F127 (PF127). When AuL12 is encapsulated in PF127-based micelles it remains stable in saline solution up to 72 h with the gold center in the +3 oxidation state. PF127-based aggregates are effi cient carriers as they enhance the water solubility of the gold complex. In vitro studies indicate that after micelle encapsulation, AuL12 gold complex preserves its antiproliferative e ffi cacy. Moreover, by labeling the hydrophilic shell of micelles with the bioactive CCK8 peptide, the aggregates act as target-selective vehicles. In fact, cytotoxic activity towards the A431 cells overexpressing the CCK2 receptors is 10-fold higher than that towards the control cells.