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This study reports the synthesis and characterization of poly(ethylene glycol) coated gold@iron oxide core-shell nanoparticles conjugated with folic acid (FA-PEG-Au@IONP). Also, targeted therapeutic properties of such a nanocomplex were studied on human nasopharyngeal carcinoma cell line KB and human breast adenocarcinoma cell line MCF-7 in vitro. The synthesized nanocomplex was characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-Vis spectroscopy, vibrating sample magnetometry (VSM), and Fourier transform infrared (FTIR) spectroscopy. The photothermal effects of nanocomplex on both KB and MCF-7 cell lines were studied. Cell death and apoptosis were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry using an annexin V-fluorescein isothiocyanate/propidiumiodide apoptosis detection kit. It was found that nanocomplex is spherical in shape and its size is approximately 60 nm. UV-vis spectrum showed that nanocomplex has appropriate absorption near infrared region. FTIR spectra obtained from nanocomplex before and after conjugation with FA confirmed the formation of folate conjugated nanocomplex. Significant cell lethality was observed for KB (∼62%) and MCF-7 (∼33%) cells following photothermal therapy. Also, it was found that majority of the cell deaths were related to apoptosis process. It can be concluded that, the synthesized nanocomplex is an effective and promising multifunctional nanoplatform for targeted photothermal therapy of cancer.

Shakeri-Zadeh (2019) Folate-modified and curcumin-loaded dendritic magnetite nanocarriers for the targeted thermo-chemotherapy of cancer cells, Artificial

X-ray computed tomography (CT) requires an optimal compromise between image quality and patient dose. While high image quality is an important requirement in CT, the radiation dose must be kept minimal to protect the patients from ionizing radiation-associated risks. The use of probes based on gold nanoparticles (AuNPs) along with active targeting ligands for specific recognition of cancer cells may be one of the balanced solutions. Herein, we report the effect of folic acid (FA)-modified AuNP as a targeted nanoprobe on the contrast enhancement of CT images as well as its potential for patient dose reduction. For this purpose, nasopharyngeal KB cancer cells overexpressing FA receptors were incubated with AuNPs with and without FA modification and imaged in a CT scanner with the following X-ray tube parameters: peak tube voltage of 130 KVp, and tube current-time products of 60, 90, 120, 160 and 250 mAs. Moreover, in order to estimate the radiation dose to which the patient was exposed during a head CT protocol, the CT dose index (CTDI) value was measured by an X-ray electrometer by changing the tube current-time product. Raising the tube current-time product from 60 to 250 mAs significantly increased the absorbed dose from 18 mGy to 75 mGy. This increase was not associated with a significant enhancement of the image quality of the KB cells. However, an obvious increase in image brightness and CT signal intensity (quantified by Hounsfield units [HU]) were observed in cells exposed to nanoparticles without any increase in the mAs product or radiation dose. Under the same Au concentration, KB cells exposed to FA-modified AuNPs had significantly higher HU and brighter CT images than those of the cells exposed to AuNPs without FA modification. In conclusion, FA-modified AuNP can be considered as a targeted CT nanoprobe with the potential for dose reduction by keeping the required mAs product as low as possible while enhancing image contrast.

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