Intensely red-emitting luminescent upconversion nanoparticles for deep-tissue multimodal bioimaging

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Medical Imaging

Background:

• Contrast agents are crucial for improving diagnostic accuracy in clinical imaging.
• Multimodal imaging combining optical, CT, and MRI offers significant potential for disease diagnosis and therapy.
• Nanotechnology-based contrast agents can enhance imaging capabilities and therapeutic outcomes.

Purpose of the Study:

• To develop a novel multimodal contrast agent for deep-tissue bioimaging.
• To create nanoparticles capable of simultaneous computed X-ray tomography (CT), magnetic resonance imaging (MRI), and upconversion luminescence (UCL) imaging.
• To enhance biocompatibility for potential clinical applications.

Main Methods:

• Synthesis of PEGylated Mn2+ doped NaLuF4:Yb/Er nanoparticles (PEG-UCNPs).
• Evaluation of deep-tissue upconversion luminescence (UCL) imaging capabilities.
• Assessment of T1-weighted MRI contrast enhancement due to high longitudinal relaxivity.
• Testing of CT imaging performance leveraging the high X-ray mass absorption coefficient of Lu3+.

Main Results:

• PEG-UCNPs exhibited intense red upconversion luminescence emission for deep-tissue UCL imaging.
• The nanoparticles demonstrated effectiveness as T1-weighted MRI contrast agents.
• The nanoprobes showed suitability for CT imaging.
• PEGylation conferred high biocompatibility to the nanoprobes.

Conclusions:

• The developed PEG-UCNPs serve as a versatile multimodal contrast agent for MRI, CT, and UCL imaging.
• These nanoparticles integrate paramagnetic properties, high X-ray absorption, and upconversion luminescence in a single system.
• The high biocompatibility of PEG-UCNPs opens avenues for advanced biomedical applications in clinical settings.