Department of Medical Physics, School Of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Magnetic resonance imaging (MRI), accounts for one of the best accessible approaches in molecular soft tissue and cancer diagnostic imaging. Yet, the low sensitivity of MRI, as the main disadvantage, leads to low detectability and poor contrast between normal and cancer tissues. To enhance tumor contrast in the MRI, a unique targeted contrast agent based on polyethylene glycol (PEG) bounded on Fe3O4@Au nanoparticles (NPs) was developed.
The prepared system was fully characterized and related parameters including relaxivity, cytotoxicity, colloidal stability, cell targeting ability as well as MR contrast enhancement were evaluated.
The mean size of Fe3O4@Au-PEG NPs was determined about 70 nm. The cytotoxicity assay indicated that NPs had perfect cyto-compatibility after 24 h and 48 h on both SKBr-3 and MCF 10A cell lines. In vitro, MR imaging experiments were induced negative signals in cells affirming that the NPs enable targeted contrast T2-weighted MR imaging of SKBr-3 as over-expressing HER-2 receptor cells. Besides, MRI images of the treated tumor-bearing BALB/c mice indicated high tumor uptake and the ability of NPs to create a better negative contrast effect. The NPs showed excellent stability and blood compatibility (zeta potentials of −19 mV), proper relaxivity (r2 = 54.96 mM-1s-1), negligible in vitro cytotoxicity (82.1% cell viability), and obvious in vivo MR signal enhancement effect (the T2 MR signal intensity for NPs in SKBr-3 cells was around 3-fold higher than of MCF 10A cells).
The developed Fe3O4@Au-PEG NPs could be suggested as an encouraging candidate as a contrast agent for early detection of cancer due to its low toxicity, proper blood, and higher MRI relaxivity