Infrared-active quadruple contrast FePt nanoparticles for multiple scale molecular imaging

Area of Science:

• Nanomaterials Science
• Biomedical Imaging
• Theranostics

Background:

• Multiscale theranosis requires single nanomaterials with diverse imaging capabilities.
• Existing nanomaterials often lack the multi-contrast functionality for comprehensive diagnosis and therapy.

Purpose of the Study:

• To develop and characterize a single nanomaterial for simultaneous multiscale molecular imaging.
• To evaluate the performance of iron-platinum alloy nanoparticles (FePt NPs) for computed tomography (CT), magnetic resonance imaging (MRI), photoacoustic (PA) imaging, and high-order multiphoton luminescence (HOMPL) microscopy.

Main Methods:

• Synthesis of 1-1.9 μm infrared-active FePt alloy nanoparticles (FePt NPs).
• Evaluation of PA imaging performance against gold nanorods.
• Assessment of HOMPL microscopy resolution and in vivo imaging capabilities.
• In vivo validation of FePt NPs for CT, MRI, PA imaging, and HOMPL microscopy.

Main Results:

• FePt NPs demonstrated unprecedented four-contrast-in-one molecular imaging.
• PA response of FePt NPs was 3- to 5.6-fold superior to gold nanorods.
• HOMPL microscopy achieved sub-diffraction-limit resolution (432 nm and 300 nm FWHM).
• Successful in vivo visualization of targeting functions across all four imaging modalities.

Conclusions:

• FePt NPs represent a single nanomaterial system for multiscale theranosis.
• This system integrates optical/PA/CT/MRI contrast for microscopic to whole-body investigations.
• FePt NPs offer a versatile platform for advanced molecular imaging and theranostic applications.