Effect of Gold Nanoparticles based Photothermal therapy on induced autophagy in neuroblastoma SH-SY5Y cell line

Abstract

Introduction: In this study, at first, the gold nanorods were synthesizes and their surface were modified for biological application.Then the effect of induced tempratures caused by radiation of different laser intensities, which has cellular implications, including apoptosis, necrosis and autophagy, has been investigated using these modified gold nanorods.we conclude with this study that: the induction temperatures caused by the photothermal may be affected the percentage of autophagy activation. Methods: At first, the gold nanorods were synthesized using seedless methods. Then, the surfaces of gold nanorods were further modified with BSA to enhance biocompatibility. After the cells were treated with the these nanorods, they were exposed to different laser power power levels to reach temperatures of 42◦, 45◦ and 48◦. Then, the level of activated autophagy, apoptosis and necrosis in each temperature was quantitatively and qualitatively analyzed by flow cytometry technique and flurescence microscope, respectively. Results: Our finding showed that the amount of autophagy in human neuroblastoma cells in response to thermal stress induced by photothermal therapy increases with the use of gold nanoparticles under temperature-dependent manner. Moreover, the death behavior of necrotic and apoptotic cells is also temperature dependent amd they behave in the opposite manner. In the other hand, at higher temperatures, more cell death occurs in the form of necrotic and at milde temperatures through apoptosis. Conclusion: The results of this study showed that in the future therapeutic strategies of photothermal therapy using nanoparticles, the amount of temperature applied to the cell by different nanoparticles, as well as different intensities, should be adjusted and designed to not inadvertently stimulate the growth of cancer cells. The ewsults of this study emphasize the importance of autophagy amount due to ability to increase the growth of cancerous tumors and should be considered in future treatment protocols.