Poly(ethylene glycol) microparticles produced by precipitation polymerization in aqueous solution

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials Engineering

Background:

• Precipitation polymerization of polyethylene glycol diacrylate (PEG-diacrylate) typically requires comonomers.
• Stabilization of phase-separated colloids remains a challenge in microparticle synthesis.
• Developing novel methods for PEG-diacrylate microparticle formation is crucial for advanced applications.

Purpose of the Study:

• To develop a precipitation photopolymerization method for PEG-diacrylate microparticles without comonomers.
• To investigate the use of sodium sulfate to induce phase separation in PEG-diacrylate solutions.
• To explore the formation of PEG-diacrylate microparticles and their potential for scaffold fabrication.

Main Methods:

• Precipitation photopolymerization of PEG-diacrylate was induced by lowering the lower critical solution temperature (LCST) of PEG using sodium sulfate.
• Microparticles were also synthesized via copolymerization of PEG-diacrylate with acrylic acid or aminoethylmethacrylate.
• Scaffolds were constructed by activating carboxyl groups on acrylic acid-containing microparticles and mixing with amine-containing microparticles.

Main Results:

• The addition of sodium sulfate to PEG-diacrylate solutions resulted in microparticle or microsphere formation (1-5 microm) with low polydispersity.
• Aggregate formation was observed, indicating potential challenges in colloid stabilization.
• Copolymerization with acrylic acid or aminoethylmethacrylate influenced zeta potential but not particle size.
• Constructed scaffolds, though weak, supported excellent human hepatoma cell viability during cross-linking.

Conclusions:

• A novel precipitation photopolymerization method for PEG-diacrylate microparticles was established using sodium sulfate to lower PEG's LCST.
• Copolymerization offers a route to functionalize microparticles, impacting surface properties like zeta potential.
• The developed microparticles show promise for creating biocompatible scaffolds for cell culture applications.