Engineered Biosynthetic Gas Vesicles for Dual-Modality Ultrasound/NIR-II Imaging

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Medical Imaging

Background:

• Gas vesicles (GVs) are genetically encoded ultrasound contrast agents.
• Current GVs lack tumor-targeting specificity and multimodal imaging capabilities, limiting their clinical utility.

Purpose of the Study:

• To engineer RGD-displaying GVs integrated with a near-infrared II (NIR-II) fluorophore (CH1055) for dual-modal ultrasound/NIR-II imaging.
• To evaluate the targeted tumor accumulation and imaging performance of the novel CH1055@GVs-RGD nanoprobe.

Main Methods:

• Genetic and chemical modifications were employed to functionalize GVs with RGD peptides and CH1055 fluorophore.
• In vitro studies assessed cellular uptake in U87 MG cells and 3D tumor spheroids.
• In vivo studies evaluated ultrasound and NIR-II fluorescence signals after intratumoral and intravenous administration in tumor-bearing models.

Main Results:

• The engineered CH1055@GVs-RGD maintained the acoustic properties of native GVs.
• Efficient cellular and spheroid uptake was observed in vitro.
• In vivo, the nanoprobe demonstrated sustained ultrasound and NIR-II signals, with significantly enhanced tumor accumulation via RGD-mediated targeting compared to controls.

Conclusions:

• The genetically and chemically programmed CH1055@GVs-RGD nanoprobe is a novel class of targeted dual-modal contrast agent.
• This dual-modal approach offers efficient and specific imaging of solid tumors.
• The RGD-targeting strategy significantly improves tumor accumulation for enhanced diagnostic potential.