Lanthanide-Loaded Nanoparticles as Potential Fluorescent and Mass Probes for High-Content Protein Analysis

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Current flow cytometry and imaging techniques are limited by the number of spectrally resolvable fluorochromes for multiparametric protein analysis.
• Mass cytometry offers higher signal resolution using lanthanide-tagged antibodies, but limited metal reporters per antibody reduce sensitivity for low-abundance proteins.

Purpose of the Study:

• To develop novel probes capable of carrying a higher number of lanthanide molecules per antibody to enhance sensitivity for protein detection.
• To create probes for improved mass cytometry applications, enabling sensitive and multiplexed analysis of cellular and tissue environments.

Main Methods:

• Development of mesoporous silica nanoparticles (MSNPs) functionalized with hydroxyl, amine, or phosphonate groups.
• Loading MSNPs with various lanthanide elements and a fluorescent dye for bimodal detection.
• Conjugation of antibodies to MSNPs for specific targeting of cell surface proteins.

Main Results:

• Phosphonated MSNPs demonstrated superior lanthanide loading capacity (up to 1.4 × 10⁶ molecules/particle) with diverse lanthanide elements.
• Modified MSNPs supported bimodal mass and fluorescence detection.
• Antibody-conjugated MSNPs showed specific targeting of cell surface proteins at 1.4 × 10³ antibodies per nanoparticle.

Conclusions:

• Novel MSNPs offer enhanced sensitivity for mass cytometry probes due to high lanthanide loading.
• These probes facilitate simultaneous monitoring of multiple factors in the tumor microenvironment.
• The technology holds potential for high-throughput proteomic analysis in personalized medicine.