Fluorescent Polymer Nanoparticles for Cell Barcoding In Vitro and In Vivo

Area of Science:

• Biotechnology
• Materials Science
• Cell Biology

Background:

• Accurate long-term tracking of living cells is crucial for understanding biological processes.
• Existing cell labeling methods often suffer from photobleaching, aggregation-caused quenching, and limited multicolor capabilities.

Purpose of the Study:

• To develop novel fluorescent polymer nanoparticles for robust, long-term, multicolor cell labeling and tracking.
• To demonstrate the utility of these nanoparticles in various biological applications, including in vitro and in vivo studies.

Main Methods:

• Synthesized biodegradable poly(lactic-co-glycolic acid) nanoparticles loaded with cyanine dyes.
• Utilized bulky fluorinated counterions to prevent aggregation-caused quenching and enhance brightness.
• Developed a method for creating multicolor cell barcodes using RGB mixing of nanoparticles.
• Validated cell barcoding across multiple cell lines and in vivo models.

Main Results:

• Developed ≈40 nm fluorescent nanoparticles that are ≈20-fold brighter than quantum dots.
• Achieved stable multicolor cell barcoding, transmitted through multiple cell generations.
• Enabled simultaneous tracking of co-cultured cells for over two weeks.
• Demonstrated successful in vivo imaging of cancer cells and zebrafish embryo development.

Conclusions:

• Fluorescent polymer nanoparticles provide a versatile and effective platform for multicolor cell labeling and tracking.
• This technology facilitates the study of cell competition, dynamics in complex biological systems, and in vivo processes.
• The approach offers potential for co-localizing multiple functions within cells using structurally similar nanoparticles.