UCST-Type Thermoresponsive Sol-Gel Transition Triblock Copolymer Containing Zwitterionic Polymer Blocks
Akifumi Kawamura1,2, Ryogo Takahashi1, Takashi Miyata1,2
1Department of Chemistry and Materials Engineering, Kansai University, Suita 564-8680, Osaka, Japan.
Gels (Basel, Switzerland)
|May 24, 2024
Summary
Researchers developed a novel triblock copolymer exhibiting upper critical solution temperature (UCST)-type thermoresponsive sol-gel transitions. This smart biomaterial shows promise for advanced drug delivery systems and tissue engineering scaffolds.
Area of Science:
- Polymer Chemistry
- Materials Science
- Biomedical Engineering
Background:
- Thermoresponsive polymers are crucial for biomedical applications like drug delivery and tissue engineering.
- Most research focuses on lower critical solution temperature (LCST) polymers, with limited exploration of upper critical solution temperature (UCST) polymers.
- Designing UCST-type polymers is essential for developing novel smart biomaterials.
Purpose of the Study:
- To design and synthesize ABA-type triblock copolymers with UCST-type thermoresponsive properties.
- To investigate the sol-gel transition behavior of novel zwitterionic polymers.
- To explore the potential of these polymers as platforms for smart biomaterials.
Main Methods:
- Synthesized poly(sulfobetaine)-poly(ethylene glycol)-poly(sulfobetaine) (PSB-PEG-PSB) and poly(sulfabetaine)-poly(ethylene glycol)-poly(sulfabetaine) (PSaB-PEG-PSaB) triblock copolymers using reversible addition-fragmentation chain-transfer (RAFT) polymerization.
- Investigated the thermoresponsive phase transitions and sol-gel behavior of the synthesized copolymers in aqueous solutions and phosphate-buffered saline (PBS).
- Analyzed the structural and interaction differences between sulfobetaine (SB) and sulfabetaine (SaB) monomers.
Main Results:
- PSB-PEG-PSB copolymers showed increased viscosity upon cooling but no sol-to-gel transition.
- PSaB-PEG-PSaB copolymers exhibited a distinct UCST-type sol-to-gel transition upon cooling from 80 °C to 25 °C in PBS.
- The sulfate (-OSO3) groups in PSaB blocks facilitated stronger intermolecular dipole-dipole interactions, leading to gel network formation.
Conclusions:
- The PSaB-PEG-PSaB triblock copolymer demonstrates a unique UCST-type thermoresponsive sol-gel transition.
- The enhanced intermolecular interactions of PSaB blocks are key to forming the gel network.
- This copolymer offers a promising platform for developing advanced smart biomaterials for drug delivery and tissue engineering.
Keywords:
ammonium sulfate polymerammonium sulfonate polymerthermoresponsive sol–gel transitionupper critical solution temperature (UCST)zwitterionic polymerMore Related Videos
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