A Dual-Mode Near-Infrared Optical and Photoacoustic Imaging Agent Based on a Low Energy Absorbing Ytterbium Complex

Area of Science:

• Biomedical Imaging
• Materials Science
• Nanotechnology

Background:

• Near-infrared (NIR) luminescence and photoacoustic (PA) imaging are crucial for deep-tissue biological sample monitoring.
• High absorption in the red-NIR range is essential for effective imaging agents to improve contrast.
• Developing dual-mode agents offers enhanced sensitivity and resolution for real-time analysis.

Purpose of the Study:

• To evaluate a novel ternary complex, Cy[Yb(tta)4], as a dual-mode NIR luminescence and PA imaging agent.
• To investigate the potential of encapsulating this complex into polystyrene nanoparticles for improved imaging performance.
• To assess the agent's capability to generate both NIR Yb3+ emission and a PA signal.

Main Methods:

• Synthesis of a ternary complex involving ytterbium(III) tetrakis(2-thenoyltrifluoroacetonate) ([Yb(tta)4]-) and 1,1'-diethyl-2,2'-dicarbocyanine (Cy+).
• Encapsulation of the Cy[Yb(tta)4] complex into polystyrene nanoparticles.
• Excitation of the nanoparticles with red-NIR light to induce luminescence and PA signal generation.
• Performance evaluation using an imaging experiment in a tissue-mimicking phantom.

Main Results:

• The Cy[Yb(tta)4] complex, when encapsulated in polystyrene nanoparticles, successfully generated NIR Yb3+ emission upon red-NIR light excitation.
• The nanoparticles also produced a detectable PA signal under the same excitation conditions.
• The dual-mode imaging agent demonstrated potential in a tissue-mimicking phantom, indicating its applicability in biological imaging.

Conclusions:

• The developed Cy[Yb(tta)4] encapsulated in polystyrene nanoparticles serves as an effective dual-mode NIR luminescence and PA imaging agent.
• This agent holds promise for advancing real-time biological sample monitoring with enhanced sensitivity and resolution.
• Further research can explore its in vivo applications and optimize its performance for clinical settings.