Insight into the photothermal therapeutic impacts of silica-coated iron oxide nanocomposites

Abstract

Recently, near-infrared photothermal therapy combined with targeted nano-sensitizer has been used for cancer eradication as it protects the surrounding tissues. Although iron oxide nanoparticles (INPs) are efficient photo-heat conversion agents, they tend to agglomerate, restricting their utility in medical applications. We prepared silica-coated INPs (SCINPs) to overcome this obstacle. The physical properties of INPs and SCINPs were evaluated using transmission electron microscope (TEM), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), atomic force microscope (AFM) and X-RAY diffraction (XRD). The polydispersity index (PDI) value was 0.21 and 0.44 for INPs and SCINPs, respectively. Zeta potential measurements showed that the prepared nanoparticles had negative net surface charges with average values of −28 ± 4.21 and −48 ± 5 mv for INPs and SCINPs, respectively. This is a pioneered study that evaluate the photothermal therapeutic effect of silica coated iron oxide nanoparticles. In addition to evaluate their photothermal therapeutic effect, as nano photothermal agents, using comet assay and oxidative stress parameters. Also, their photothermal therapeutic effect were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Photothermal assessment indicated that SCINPs could improve the photothermal therapy (PTT) because of their reproducible hyper-thermic and hypo-thermic effects with repeated treatment. Compared to INPs, SCINPs significantly improved the photothermal therapeutic behavior in treated cells by around 1.88 folds. SCINPs were more effective photothermal therapeutic agents and had considerable potential as novel therapeutic agents.