Biobased Agents for Single-Particle Detection with Optoacoustics

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Materials Science

Background:

• Optoacoustic (OA) imaging combines optical contrast with ultrasound resolution in biological tissues.
• Contrast agents are crucial for deep-tissue OA imaging sensitivity and clinical translation.
• Inorganic particles offer tracking capabilities but raise concerns about biodegradability and toxicity.

Purpose of the Study:

• To develop novel bio-based, biodegradable contrast agents for optoacoustic imaging.
• To evaluate the performance of these agents in vivo for both imaging and particle tracking.
• To address the limitations of inorganic contrast agents in OA imaging.

Main Methods:

• Fabrication of nano- and microcapsules using an inverse emulsion approach with a cross-linked casein shell.
• Encapsulation of clinically-approved indocyanine green (ICG) in the aqueous core.
• In vivo optoacoustic imaging and individual microcapsule tracking experiments.

Main Results:

• Demonstrated successful contrast-enhanced in vivo OA imaging using the developed nanocapsules.
• Showcased the localization and tracking of individual microcapsules (4-5 µm) in vivo.
• Confirmed the safety of all capsule components for human use.

Conclusions:

• Developed bio-based, biodegradable casein capsules serve as effective OA contrast agents.
• The inverse emulsion method is versatile for creating various functional capsules.
• These agents facilitate enhanced OA imaging and single-particle detection, paving the way for clinical translation.