Significance of modified gold nanocages in photothermal therapy and radiosensitivity enhancement / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the significance of modified gold nanocages ( GNCs ) in photothermal therapy and radiosensitivity enhancement for murine mammary carcinoma 4T1 cells.Methods A molecule probe, CD44-PEG-GNCs, was constructed on the basis of GNCs.Inductively coupled plasma mass spectrometry ( ICP-MS) and transmission electron microscopy ( TEM) were used to analyze Au uptake by 4T1 cells.The cell counting kit-8( CCK-8) assay was used to determine the impact of the probe on the viability of 4T1 cells.The CCK-8 assay and the Hoechst/PI double staining were used to evaluate the photothermal killing effects of near infrared laser (NIR).The colony forming assay and the Hoechst/PI double staining were used to measure the viability of 4T1 cells after irradiation with 6 MV of X-ray.Results ICP-MS and TEM showed that 4T1 cells had an uptake of a large number of GNCs, in which the number of CD44-PEG-GNCs taken up by 4T1 was 3-4 times larger than that of PEG-GNCs.The cell toxicity assay revealed that in a certain range of concentration, GNCs showed little effect on the viability of 4T1 cells, which was reduced to 81.2%in 48 hours.The CCK-8 assay, the Hoechst/PI double staining, and the colony forming assay showed that after NIR irradiation and radiotherapy, large-scale apoptosis was induced in CD44-PEG-GNCs-contained tumor cells by photothermal therapy combined with radiotherapy, which had substantially better outcomes than other groups.Conclusions The GNC-based molecular probe actively targets 4T1 cells with little cytotoxicity, indicating that it enhances the sensitivity of tumor towards photothermal therapy and radiotherapy.