Kinetically Controlled Star Copolymer Self-Assembly for Rapid Fabrication of Nanoparticles with High Encapsulation...

Area of Science:

• Polymer Chemistry
• Materials Science
• Nanotechnology

Background:

• Amphiphilic star copolymers, like polystyrene-block-polyethylene glycol)21 [(PS-b-PEG)21], are promising for nanoparticle fabrication.
• Controlling self-assembly kinetics is crucial for achieving desired nanoparticle properties such as size and loading capacity.

Purpose of the Study:

• To investigate a rapid and scalable self-assembly method for (PS-b-PEG)21 star copolymers in aqueous solution.
• To understand the kinetic mechanism governing nanoparticle formation and its relation to copolymer architecture.
• To evaluate the encapsulation efficiency of hydrophobic cargo within the self-assembled nanoparticles.

Main Methods:

• Reverse solvent exchange procedure for self-assembly of (PS-b-PEG)21.
• Transmission electron microscopy (TEM) for nanoparticle morphology analysis.
• Nanoparticle tracking analysis (NTA) for size distribution determination.

Main Results:

• Formation of nanoparticles with a narrow size distribution was confirmed by TEM and NTA.
• A kinetically controlled self-assembly mechanism was identified, driven by intrachain contraction facilitated by star topology and rapid solvent exchange.
• Nanoparticles demonstrated a high encapsulation capacity for hydrophobic cargo, reaching up to 19.84%.

Conclusions:

• The study presents a rapid and scalable method for fabricating nanoparticles from amphiphilic star copolymers.
• The kinetically controlled self-assembly process allows for the formation of nanoparticles with low aggregation numbers and high drug loading capacity.
• These nanoparticles offer a promising platform for applications in drug delivery and nanopesticide formulations.