Assembly of Fluorescent Polymer Nanoparticles Using Different Microfluidic Mixers

Area of Science:

• Materials Science
• Biomedical Engineering
• Nanotechnology

Background:

• Nanoprecipitation is a key method for creating polymer nanoparticles (NPs) for bioimaging and drug delivery.
• Clinical applications necessitate reproducible and scalable NP synthesis, making microfluidics a promising technique.
• Efficient mixing is crucial for controlling NP formation during nanoprecipitation.

Purpose of the Study:

• To evaluate and compare five microfluidic mixer designs for synthesizing loaded polymer nanoparticles.
• To assess the impact of different microfluidic mixers on nanoparticle size and fluorescence properties.
• To provide guidance on selecting optimal microfluidic setups for nanomaterial production.

Main Methods:

• Synthesized poly(d-l-lactide-co-glycolide) (PLGA) and poly(methyl methacrylate) NPs loaded with a fluorescent dye using five microfluidic mixers (cross-shaped, multilamination, split and recombine, herringbone, impact jet) and manual methods.
• Evaluated NP size and fluorescence properties (including quantum yield) for each mixer type.
• Investigated the effect of flow speed on NP characteristics, particularly for impact jet mixers.

Main Results:

• All tested microfluidic mixers, except the cross-shaped design, produced NPs comparable or superior in size and fluorescence to manual methods.
• Impact jet mixers, especially at high flow speeds, achieved significant NP size reduction (<20 nm).
• Fluorescence quantum yield of PLGA NPs increased substantially with flow speed in impact jet mixers, from 30% to over 70%.

Conclusions:

• Microfluidic mixing offers a controllable and scalable approach for producing polymer nanoparticles for biomedical applications.
• Impact jet mixers demonstrate superior performance in reducing NP size and enhancing fluorescence.
• Precise control over microfluidic assembly conditions is critical for optimizing loaded polymer NP properties.