Dual Nanoparticle Conjugates for Highly Sensitive and Versatile Sensing Using ¹⁹ F Magnetic Resonance Imaging

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Molecular Biology

Background:

• Conventional ¹ H MRI faces limitations due to background signal.
• ¹⁹ F MRI offers enhanced specificity due to a negligible endogenous signal.
• Developing sensitive and specific probes is crucial for advanced molecular imaging.

Purpose of the Study:

• To develop a versatile aptamer-based sensor for ¹⁹ F MRI.
• To create a dual nanoparticle conjugate (DNC) platform for enhanced sensitivity.
• To demonstrate the efficacy of the DNC probe for detecting specific biomarkers in vitro and in vivo.

Main Methods:

• Fabrication of core-shell nanoparticles with a perfluorocarbon core and mesoporous silica shell (¹⁹ F-MSNs).
• Integration of superparamagnetic iron oxide nanoparticles (SPIONs) as magnetic quenchers.
• Incorporation of target-specific DNA aptamers for a 'turn-on' sensing mechanism.

Main Results:

• The DNC platform demonstrated high sensitivity due to SPION-mediated magnetic quenching.
• A proof-of-concept DNC probe (DNC_Thr) showed a significant increase in ¹⁹ F MR signal upon binding to human α-thrombin.
• The DNC probe successfully generated a detectable ¹⁹ F MRI 'hot-spot' signal in live mice in response to thrombin.

Conclusions:

• The DNC platform is a sensitive and versatile tool for ¹⁹ F MRI.
• This aptamer-based sensor technology can be adapted for detecting various biomarkers.
• The DNC probe represents a practical and biologically relevant molecular imaging solution.