Activatable MRI probes for the specific detection of bacteria

Area of Science:

• Biomedical research
• Molecular imaging
• Nanotechnology

Background:

• Fluorescent probes are valuable molecular tools but suffer from background signal interference and limited tissue penetration.
• These limitations hinder their clinical application for detecting molecular events.
• Activatable magnetic resonance probes offer a promising alternative to overcome these drawbacks.

Purpose of the Study:

• To develop and report the first oligonucleotide-based activatable probe for bacterial detection using magnetic resonance imaging (MRI).
• To design a probe capable of targeting specific bacterial components for signal activation.

Main Methods:

• An oligonucleotide sequence targeting micrococcal nuclease (MN) from Staphylococcus aureus was synthesized.
• The oligonucleotide was functionalized with a superparamagnetic iron oxide nanoparticle (SPION) and gadolinium complexes.
• The probe's activation and MRI signal detection were contingent upon recognition by the target bacteria.

Main Results:

• The developed probe demonstrates the capability to detect bacteria via MRI.
• Activation of the MRI signal occurs specifically upon interaction with the target bacteria.
• The probe design integrates nanoparticle and contrast agent functionalities.

Conclusions:

• This novel activatable MRI probe enables specific bacterial detection.
• The approach shows potential for clinical translation in diagnosing bacterial infections.
• This technology could be extended to detect other human conditions requiring sensitive imaging.