Diffraction-Unlimited Photomanipulation at the Plasma Membrane via Specifically Targeted Upconversion Nanoparticles

Area of Science:

• Nanotechnology
• Cell Biology
• Biophotonics

Background:

• Upconversion nanoparticles (UCNPs) offer unique optical properties for biological imaging.
• Photoconversion of fluorescent proteins like Dendra2 is crucial for tracking cellular dynamics.
• Precise spatial control of photochemical reactions in cells remains a challenge.

Purpose of the Study:

• To develop UCNPs for rapid, high-resolution photoconversion of Dendra2 in mammalian cells.
• To demonstrate targeted delivery and specific activation of UCNPs for bioanalytical applications.
• To establish UCNP-controlled photomanipulation for studying cellular processes.

Main Methods:

• Engineered core-shell UCNPs with high thulium doping for intense emission.
• Biocompatible surface coating and functionalization for targeted cell surface binding.
• Utilized UCNP-mediated photoconversion of Dendra2 for detecting cytokine receptor dimerization.

Main Results:

• Achieved <10 nm resolution photoconversion of Dendra2 using UCNPs.
• Demonstrated highly specific UCNP targeting to anti-GFP fusion proteins on cell surfaces.
• Successfully detected cytokine receptor dimerization in plasma membranes and endosomes.
• Showcased UCNP ability to manipulate intracellular Dendra2 across the plasma membrane.

Conclusions:

• UCNP-controlled photomanipulation enables nanoscale precision in biological studies.
• This technology opens new avenues for sensitive bioanalytical applications in cell biology.
• UCNPs provide a versatile tool for precise optical control within living cells.