Robust DNA Cross-Linked Polymeric Lighting-Up Nanogel Facilitates Sensitive Live Cell MicroRNA Imaging

Area of Science:

• Biomedical Engineering
• Molecular Imaging
• Nanotechnology

Background:

• Accurate imaging of intracellular microRNAs (miRNAs) is vital for understanding cellular processes and diagnosing diseases.
• Existing nucleic acid amplification technologies face challenges in live cell imaging due to probe instability and slow reaction kinetics.

Purpose of the Study:

• To develop a novel nanogel platform for sensitive and specific live cell imaging of low-abundance intracellular miRNAs.
• To overcome the limitations of probe stability and reaction kinetics in current miRNA detection methods.

Main Methods:

• Synthesis of DNA-cross-linked polymeric lighting-up nanogels (DPLNs) utilizing DNA hairpin-based hybridization chain reaction.
• Confined catalytic hairpin assembly within nanogels triggered by target miRNA for amplified fluorescence signals.
• Evaluation of DPLNs' performance in live cell imaging, including sensitivity, specificity, cytotoxicity, and nuclease resistance.

Main Results:

• DPLNs demonstrated high sensitivity and specificity for imaging miRNA-21 in live cells.
• The nanogel platform exhibited accelerated reaction kinetics and enhanced fluorescence resonance energy transfer (FRET) signals.
• DPLNs showed low cytotoxicity and improved nuclease resistance, enabling successful intracellular delivery and imaging.

Conclusions:

• DPLNs provide a robust and efficient platform for sensitive live cell imaging of miRNAs.
• This technology has potential for monitoring various molecular targets in live cells for biological and biomedical applications.
• The tunable nature of DPLN probes allows for broad applicability in diagnostics and research.