Multiparametric super-resolution optoacoustic imaging with ICG-tagged microbubbles

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Medical Diagnostics

Background:

• Localization optoacoustic tomography (LOT) offers super-resolution functional microangiography beyond optical microscopy limits.
• LOT can simultaneously assess microvascular morphology, oxygen saturation, and blood flow velocity.
• Clinical adoption of LOT is hindered by the absence of human-verified intravenous contrast agents.

Purpose of the Study:

• To develop and validate a novel contrast agent for LOT.
• To enable safe intravenous administration for enhanced microangiography.
• To facilitate the clinical translation of LOT.

Main Methods:

• Formulation of polyvinyl alcohol (PVA) microbubbles coated with indocyanine green (ICG) via layer-by-layer assembly.
• Characterization of ICG-coated microbubbles for per-particle detection in blood.
• In vivo LOT imaging of murine brains to assess efficacy and safety.

Main Results:

• ICG-coated PVA microbubbles were successfully synthesized for LOT.
• Per-particle detection was achieved despite strong background light absorption in blood.
• LOT imaging of the murine brain demonstrated no acute toxicity.

Conclusions:

• ICG-coated microbubbles represent a promising, safe contrast agent for LOT.
• The established safety profiles of microbubbles and ICG support clinical translation.
• This innovation is expected to significantly advance LOT for diagnosing microcirculatory alterations.