Imaging-Based Evaluation of Gold Nanoparticles In MCF-7 Cells for Nanobrachytherapy Applications.
Abstract
Purpose
To synthesize gold nanoparticles Au197 and Au198 and to evaluate their interaction with MCF-7 breast cancer cells using imaging techniques based on Raman spectroscopy and CLSM Confocal Microscopy.
Methods
Gold nanoparticles were synthesized using a widely established sodium citrate reduction method and subsequently functionalized with bovine serum albumin (BSA). The same chemical procedure was applied to both radioactive and non-radioactive nanoparticles. The physicochemical properties of the nanoparticles were characterized using Dynamic Light Scattering (DLS). For fluorescent labeling, the AuNPs were conjugated with fluorescein isothiocyanate (FITC, Merck) and incubated with MCF-7 breast cancer cells for 24 h. After incubation, cellular membranes and nuclei were stained with the far-red lipophilic carbocyanine dye DiD and Hoechst 33342, respectively, to facilitate fluorescence microscopy analysis. Image acquisition was performed using a Leica TCS SP8 DLS Hyvolution confocal microscope and a HORIBA LabRAM HR Evolution Raman microscope.
Results
The analyses indicated that the nanoparticles exhibited an average size of 16.6 nm, with measurements performed in triplicate to ensure data reproducibility and accuracy. After 24 h incubation with MCF-7 cells, nanoparticle internalization was confirmed by confocal microscopy, as evidenced by the detected fluorescence, indicating efficient cellular uptake and enabling the assessment of nanoparticle interactions within the cellular microenvironment. Fluorescence signals were obtained using Raman spectroscopy, with excitation of FITC in the 492–495 nm range and DiD in the 645–646 nm range, corresponding to the green and red spectra, respectively. Raman spectra were acquired from regions of the cell membrane located near the nucleus.
Conclusion
The results demonstrate the promising potential of gold nanoparticles as therapeutic tools, suggesting that these nanostructures may be explored in the future as agents for nanobrachytherapy, an innovative approach in cancer treatment.