Investigating the photo-thermo-radiosensitization effects of folate-conjugated gold nanorods on KB nasopharyngeal carcinoma cells.

In this article, we report a targeted cancer treatment strategy using nano-photo-thermal therapy (NPTT) and radiotherapy (RT) methods. Gold nanorods (AuNRs) without and with folic acid (FA) conjugation were firstly synthesized and then characterized. Cytotoxicity of various methods; NPTT (nanoparticles; 808 nm laser; 2 W/cm2) or RT (6 MV X-ray; 2 Gy) or combination of NPTT and RT; was separately investigated on KB nasopharyngeal carcinoma cells. The effects of different treatments were studies using MTT assay, inductively coupled plasma-mass spectrometry (ICP-MS) and transmission electron microscopy (TEM). Both TEM and ICP-MS confirmed the internalization of nanoparticles into the KB cells. ICP-MS analysis revealed that AuNR-FA cell uptake was higher than AuNRs. Viability of the cells received NPTT was lower than those cells received laser or nanoparticles alone. Furthermore, it was found that combination of NPTT and RT notably decreased the viability of KB cells. Following such a combinatorial treatment (NPTT + RT), intensive damages were identified in TEM images obtained from treated cells. It may be concluded that AuNR-FA nanoconjugate is a good candidate to be used as a targeted sensitizer agent for nano-photo-thermo-radiotherapy of head and neck cancer cells.