A novel flow-cytometry-based assay for cellular uptake studies of polyelectrolyte microcapsules

Area of Science:

• Biotechnology
• Cell Biology
• Materials Science

Background:

• Quantifying cellular uptake of nanoparticles is crucial for drug delivery and toxicology.
• Distinguishing between particle adhesion and internalization is a key challenge in nanoparticle research.

Purpose of the Study:

• To develop a flow cytometry-based assay for quantifying polyelectrolyte capsule uptake.
• To differentiate between adherent and internalized polyelectrolyte capsules using a pH-sensitive dye.

Main Methods:

• Utilized flow cytometry for particle uptake analysis.
• Loaded polyelectrolyte capsules with the pH-sensitive dye SNARF.
• Quantified red and green fluorescence to determine capsule localization relative to cells.

Main Results:

• Developed a quantitative assay for polyelectrolyte capsule uptake.
• Successfully distinguished between cell-surface adherent and internalized capsules.
• Demonstrated that adherent capsules fluoresce red (alkaline pH) and internalized capsules fluoresce green (acidic pH).

Conclusions:

• The developed assay provides a detailed quantitative analysis of particle uptake.
• This method allows for the discrimination of adherent versus ingested particles.
• The SNARF dye-loaded capsules offer a robust tool for studying cellular interactions.