Development of Sub-50 nm Core-Shell Silica Nanoparticles With Controlled In Vivo Behavior for ¹⁹F Magnetic Resonance...

Area of Science:

• Nanotechnology
• Biomedical Imaging
• Materials Science

Background:

• 19F magnetic resonance imaging (19F MRI) offers quantitative, background-free detection.
• Perfluorocarbon (PFC)-based nanoparticles are sensitive 19F MRI probes but often large (>70 nm).
• Large nanoparticle size limits tumor accumulation and leads to slow hepatic clearance.

Purpose of the Study:

• To develop sub-50 nm 19F MRI nanoprobes with high fluorine content and improved pharmacokinetics.
• To create tunable silica-based nanoprobes for controlled in vivo biodistribution.
• To establish a versatile platform for molecular imaging.

Main Methods:

• Synthesized sub-50 nm perfluoro-15-crown-5-ether (PFCE)-loaded core-shell silica nanoparticles (s-FLAME) using a one-pot double-emulsion method.
• Modified nanoparticles (s-FLAME-OH and s-FLAME-COOH) to tune size, surface chemistry, and stability.
• Evaluated nanoparticle size, fluorine signal intensity, cytotoxicity, colloidal stability, and in vivo biodistribution using 19F MRI.

Main Results:

• Developed uniform core-shell nanoparticles (s-FLAME) with a 30 nm core diameter, significantly smaller than existing systems.
• Achieved high, concentration-dependent 19F MRI signals.
• Demonstrated accelerated hepatic clearance and tumor-associated signals in vivo, confirming size-dependent biodistribution.

Conclusions:

• Sub-50 nm PFCE-loaded silica nanoparticles (s-FLAME) offer high 19F MRI sensitivity and improved biodistribution.
• Size and surface chemistry tuning of silica nanoprobes enables controlled in vivo behavior.
• These s-FLAME nanoprobes represent a promising platform for advanced molecular imaging applications.