Polydopamine-coated mesoporous silica/gold nanoclusters for enhanced chemo-photothermal therapy of cancer

Near-infrared (NIR) light-responsive nanomaterials have been widely explored to develop alternative approaches for cancer therapy. Herein, clustered gold nanospheres were coated with mesoporous silica (AuMSS) and functionalized with polydopamine (PDA) to create a novel anticancer nanomedicine capable of combining drug delivery and photothermal therapy. The AuMSS/PDA nanoclusters exhibited a mean size inferior to 200 nm, a close to neutral surface charge (≈ -10 mV), and promoted a temperature increase of 35 °C in response to NIR irradiation (808 nm, 1.7 W cm^-2, 10 min). Additionally, AuMSS/PDA nanoclusters were successfully loaded with acridine orange (AO) and presented a faster AO release in tumor-mimicking acidic media. Cell assays demonstrated the excellent biocompatibility of the AuMSS/PDA nanostructures. Moreover, the combinatorial chemo-photothermal treatment mediated by AuMSS/PDA/AO nanoclusters showed an enhanced cytotoxic effect, leading to the death of 96 % of HeLa cancer cells. Therefore, AuMSS/PDA hybrid nanomaterials hold great potential for bioimaging and chemo-photothermal cancer therapy.