Preparation of polymer nanoparticle-based complex coacervate hydrogels using polymerisation-induced self-assembly
Ruiling Du1,2, Lee A Fielding1,2
1Department of Materials, School of Natural Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. lee.fielding@manchester.ac.uk.
Soft Matter
|March 1, 2023
Summary
This study introduces a novel method for creating polymer nanoparticle-complex coacervate (PNCC) hydrogels using pH-responsive nanogels synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization-induced self-assembly (PISA). The resulting hydrogels are injectable and exhibit rapid self-healing properties.
Area of Science:
- Polymer Chemistry
- Materials Science
- Biomaterials Engineering
Background:
- Complex coacervates are formed by the associative phase separation of oppositely charged polymers.
- Nanoparticle-based hydrogels offer tunable properties for various applications.
- Controlled polymerization techniques enable precise synthesis of functional polymer architectures.
Purpose of the Study:
- To develop a generic method for synthesizing polymer nanoparticle-complex coacervate (PNCC) hydrogels.
- To investigate the role of pH-responsive nanogels in PNCC hydrogel formation.
- To characterize the mechanical properties and injectability of the resulting PNCC hydrogels.
Main Methods:
- Synthesis of pH-responsive nanoparticles using RAFT polymerization-induced self-assembly (PISA).
- Incorporation of methacrylic acid (MAA) into the nanoparticle core for pH responsiveness.
- Formation of PNCC hydrogels by mixing nanogels with branched polyethyleneimine (bPEI).
- Characterization using dynamic light scattering (DLS) and oscillatory rheology.
Main Results:
- pH-responsive nanoparticles were successfully synthesized, exhibiting swelling behavior with increasing pH.
- PNCC hydrogel formation was dependent on the presence of MAA in the nanoparticle core.
- Optimized hydrogels (mass ratio 0.14, pH ~7) showed a storage modulus of ~2000 Pa.
- The hydrogels demonstrated shear-thinning behavior, injectability, and rapid self-healing capabilities.
Conclusions:
- A versatile method for preparing PNCC hydrogels using PISA-derived nanogels was established.
- The pH-responsive nature of the nanoparticles is crucial for hydrogel formation.
- The developed PNCC hydrogels possess desirable properties for potential applications requiring injectability and self-healing.
