Photothermal effects of metallic carbon nanotubes on human breast cancer cells

SWNTs are a mixture of 1/3 metallic SWNTs (m-SWNTs) and 2/3 semiconducting SWNTs (s-SWNTs). It is desirable to separate the metallic SWNTs from the semi-conducting ones. In this study m-SWNTs was separated by using a poly(m-phenylenevinylene)-alt-(p-phenylenevinylene) (PmPV) derivative and used as photo-thermal media instead of SWNTs. The separation effects of m-SWNTs were evaluated by Raman spectra, molecular modeling and TEM images. The effects of m-SWNTs on MCF-7 cell proliferation and apoptosis were evaluated with MTT assay and flow cytometry, respectively. m-SWNTs were separated with high purity. A strong inhibition of MCF-7 cell growth was observed with the m-SWNTs under near-infrared (NIR) light irradiation. Our results will be helpful for the potential applications of m-SWNTs in clinical photo- thermal cancer therapy.