Fluorochrome-functionalized nanoparticles for imaging DNA in biological systems

Area of Science:

• Nanotechnology
• Molecular Imaging
• Biomedical Engineering

Background:

• Nanoparticles (NPs) functionalized with DNA-binding fluorochromes enable DNA detection via fluorochrome-mediated interactions.
• Developing targeted NPs for biological systems is crucial for advanced diagnostics.

Purpose of the Study:

• To create a nanoparticle (NP) capable of binding to DNA in biological systems.
• To functionalize Feraheme (FH) NPs with the DNA-binding fluorochrome TO-PRO 1 (TO).

Main Methods:

• Attaching TO to FH NPs to create TO-FH NPs.
• Characterizing DNA/TO-FH microaggregate formation using fluorescence, light scattering, T2 changes, and AFM.
• Assessing TO-FH binding to normal and necrotic cells in culture.
• Evaluating TO-FH uptake in HT-29 xenografts using fluorescence and MRI.

Main Results:

• TO-FH formed DNA microaggregates in vitro (median size 200 nm) composed of DNA and multiple TO-FH NPs (25-35 nm).
• TO-FH did not bind normal cells but bound necrotic cells similarly to vital fluorochromes.
• TO-FH uptake was observed in chemotherapy-treated HT-29 xenografts via fluorescence and MRI.

Conclusions:

• Fluorochrome-functionalized NPs are multimodal (magnetic and fluorescent) nanomaterials.
• These NPs enable DNA detection through microaggregate formation.
• They are useful for imaging necrotic cells and chemotherapy-treated tumors.