Evaluation of Contrast to Noise Ratio of Targeted and Non-Targeted Gold nanoparticles in nasopharyngeal cancer cells in CT images

Introduction: In this study, we aimed to identify the benefits in image contrast enhancement of Folic acid-Cysteamine conjugated gold nanoparticles (FA-Cys-AuNPs) by comparing Contrast to Noise ratio (CNR) of gold nanoparticles (AuNPs) to iodinated compound CT images. The CNR was assessed in different tube voltages, concentrations, and incubation times in nasopharyngeal KB cancer cells. Material and Methods: FA-Cys-AuNPs and Omnipaque suspension were scanned at different concentration ranges (500-2000 μg/ml) and energy ranges (80- 140 kVp) with CT imaging modality. FA-Cys-AuNPs and AuNPs were incubated in nasopharyngeal cancer cells at different incubation times (6, 12, and 24 h) and concentration ranges (200-500 μM). Finally, the contrast enhancement was assessed using CNR value at different tube voltages. Results: Results showed that the formed FA-Cys-AuNPs with an Au core size of 15 nm in all concentrations and tube potentials from 80 to 140 kVp display greater CNR than Omnipaque. The CNR value was increased by increasing concentration and energy. At 140 kVp and 2000 μg/ml, the CNR value of FA-Cys-AuNPs was 2.25 times greater than Omnipaque. At 140 kVp, 500 μM and 24 h incubation, the CNR values of targeted cells were approximately 1.5 times higher than non-targeted cells. At 140 kVp, and 500 μM, the CNR value of targeted cells with 24 h incubation time was 2.66 times greater than the targeted cells incubated with 6 h. Conclusion: These findings suggested that the designed FA-Cys-AuNPs could be a good candidate contrast agent for molecular CT imaging.