Ratiometric pH-Responsive and Biomimetic Microparticles for Quantitative Monitoring of Phagosomal Acidification.

Area of Science:

• Biomimetic sensing platforms
• Cellular microbiology
• Immunology

Background:

• Phagocytosis is crucial for pathogen destruction and immune signaling.
• Phagosomal acidification is a key step in phagosome maturation.
• Current methods lack the precision to study phagosomal acidification mechanisms influenced by particle properties and receptor engagement.

Purpose of the Study:

• To develop a modular biomimetic fluorescent sensing platform for precise interrogation of phagosomal acidification.
• To create cell-mimicking microparticulate sensors with controlled composition and mechanical properties.
• To couple receptor-specific uptake with quantitative intracellular pH measurements.

Main Methods:

• Development of soft, deformable microparticulate fluorescent pH sensors.
• Integration of cell-mimicking properties and fluid interfaces.
• Utilizing ratiometric pH-responsive fluorescence for quantitative measurements.
• Employing receptor-specific uptake mechanisms for targeted sensing.

Main Results:

• The platform successfully mimics cell-like properties and allows for receptor-specific uptake.
• Ratiometric fluorescence enables quantitative monitoring of phagosomal acidification onset and progression.
• The sensors provide a direct link between interfacial recognition and intracellular pH dynamics.

Conclusions:

• The presented biomimetic sensing platform offers a novel approach to study phagosomal physiology.
• This tool can unravel the physicochemical mechanisms governing phagosomal acidification.
• It opens new avenues for understanding immune signaling and pathogen degradation pathways.