WE‐D‐303A‐02: Deoxyglucose Labeled Gold Nanoparticles as X‐Ray Computed Tomography Contrast Agents for Cancer Imaging

Purpose: To study the feasibility of using 2‐Deoxy‐D‐Glucose (2‐DG) labeled gold nanoparticle (AuNP‐DG) as a metabolic functional CT contrast agent through in vitro experiments. Method and Materials: The gold nanoparticles (AuNP) were fabricated using a citrate acid reduction method. The size of the AuNP was determined from Transmission Electron Microscopy images to be 4 nm in diameter. The conjugation of the 2‐DG with the AuNP core was accomplished using mercapto group in the 2‐carbon position by condensation reaction of 2‐amino‐deoxyglucose with mercaptosuccinic acid. The human alveolar epithelial cancer cell line, A‐549, was chosen for the in vitro cellular uptake assay. Two groups of cell samples (∼1 × 105 cells per sample) were incubated with the AuNP‐DG and the unlabeled AuNP, respectively, for 30 minutes (37°C, 7% CO2). Following the incubation, the cells were washed with sterile PBS six times to remove the excess gold nanoparticles. The cells were then spun to cell pellets using a centrifuge. The cell pellets were imaged using a microCT scanner immediately after the centrifuging (75 kVp, 135 μA, 1184 × 1120 matrix size, 360 views, averaging 5 frames per view). The reconstructed CT images were analyzed using a commercial software package. Results: Significant contrast enhancement in the cell samples incubated with the AuNP‐DG with respect to the cell samples incubated with the unlabeled AuNP was observed in multiple CT slices. Quantitative analysis of the image data showed that (45.6 ± 14.2)% of the cells that were incubated with the AuNP‐DG exhibit enhanced contrast compared to the cells in the control group (incubated with AuNP). Conclusion: Results from these experiments strongly suggest enhanced uptake of the AuNP‐DG over the unlabeled AuNP by the highly glycolytic cancer cells in vitro and indicate that AuNP‐DG could served as a metabolic functional CT contrast agent with tumor‐specific targeting capability.