Reversible meso-scale smart polymer--protein particles of controlled sizes

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Bioanalytical Chemistry

Background:

• Functionalized nanoparticles are increasingly used in bioanalysis.
• Controlling particle size and stability is crucial for bioanalytical applications.

Purpose of the Study:

• To synthesize and characterize temperature-responsive polymer-protein conjugates.
• To investigate the formation and stability of mesoscale particles from these conjugates.
• To explore the potential applications of these biohybrid particles in diagnostics and microfluidics.

Main Methods:

• Synthesis of streptavidin-poly(N-isopropylacrylamide) (PNIPAAm) conjugates using reversible addition-fragmentation chain transfer (RAFT) polymerization.
• Particle formation triggered by exceeding the lower critical solution temperature (LCST) of PNIPAAm.
• Control over particle size (250-900 nm) via conjugate concentration, polymer molecular weight, and temperature change rate.
• Stability assessment of formed particles over time (>16 h).

Main Results:

• Rapid formation of mesoscale polymer-protein particles above the LCST.
• Tunable particle sizes achieved through controlled synthesis and conditions.
• Biohybrid particles exhibited enhanced stability compared to free polymer aggregates.
• Demonstrated reversibility between particle and conjugate states.

Conclusions:

• Developed a method for creating stable, size-controllable biohybrid particles.
• These particles offer advantages in stability and tunability over existing materials.
• Potential applications in diagnostics, analyte concentration, and microfluidic separations.