Keywords: cancer stem–like cells, CD133 monoclonal antibody, gold nanorods, near–infrared laser irradiation, photothermolysis, nanotechnology, cancer cells, tumours, markers, molecular targets, cell destruction, anisotropic nanomaterials, therapeutic thermal coupling nanoscalpel
Cancer stem–like cells photothermolysed by gold nanorod–mediated near–infrared laser irradiation
Several studies have recently identified CD133 as a marker of cancer stem–like cells (CSCs) for various tumours. Such findings make CD133 a potential molecular target for tumour–selective therapeutic approach. In this study, fluorescence–tagged CD133 monoclonal antibody (anti–CD133) was conjugated to gold nanorods (GNRs), which are one of the anisotropic nanomaterials that can absorb near–infrared (NIR) laser light and convert it to heat for the destruction of tumour–initiating cells. To examine the specific targeting feature of GNRs conjugated with anti–CD133, CD133+ and CD133− glioblastoma cells were separately cultivated in the presence of the functionalised GNRs. Our results showed that anti–CD133–conjugated GNRs were extensively endocytosed by CD133+ cells, whereas anti–CD133 bound GNRs were not internalised by CD133− cells. To examine the efficacy of photothermolysis, anti–CD133–conjugated GNRs were first incubated with a mixed population of CD133+ and CD133− cells for 6 h, and the treated cells were then irradiated with 808–nm NIR laser light for a total of 15 min under different intensities. When examined by cell live/death dye, CD133+ cells were selectively targeted and killed, whereas non–CD133 expressing cells remained viable. On the basis of our study, GNRs bound with anti–CD133 monoclonal antibody have the potential to be utilised as a therapeutic thermal–coupling nano–scalpel to effectively target and destroy CSCs under NIR laser light exposure.