Optical and X-ray Fluorescent Nanoparticles for Dual Mode Bioimaging

Area of Science:

• Nanotechnology
• Biomedical Imaging
• Materials Science

Background:

• Nanoparticle (NP)-based contrast agents offer promising noninvasive diagnostic strategies.
• Multimodal imaging agents combine properties for versatile detection.
• Existing X-ray fluorescence computed tomography (XFCT) agents lack optical capabilities.

Purpose of the Study:

• To develop core-shell nanoparticles with combined optical and X-ray fluorescence properties.
• To enhance NP biocompatibility for in vitro and in vivo applications.
• To demonstrate the utility of these multimodal NPs for advanced bioimaging.

Main Methods:

• Coating ceramic (molybdenum oxide) and metallic (rhodium, ruthenium) NPs with silica (SiO2) shells using ethanolamine.
• Conjugating a fluorophore (Cy5.5 dye) to the silica layer.
• Evaluating biocompatibility using Real-Time Cell Analysis (RTCA) on RAW 264.7 macrophage cells.
• Assessing multimodal properties and intracellular localization via confocal microscopy.
• Testing in vivo imaging capabilities using in situ XFCT.

Main Results:

• A novel silica coating method was successfully applied to both ceramic and metallic NPs.
• Hybrid core-shell NPs exhibited both X-ray fluorescence and optical fluorescence (Cy5.5).
• SiO2 coating improved NP biocompatibility in vitro.
• Confocal microscopy confirmed intracellular NP localization.
• In situ XFCT demonstrated successful in vivo multiplexed bioimaging with low radiation dose.

Conclusions:

• Core-shell nanoparticles with combined optical and X-ray fluorescence properties were successfully synthesized.
• These multimodal NPs show enhanced biocompatibility and are suitable for advanced bioimaging.
• The developed NPs serve as effective tools for both macroscopic and microscopic imaging in vivo.