pH- and temperature-responsive hydrogels from crosslinked triblock copolymers prepared via consecutive atom transfer
Fu-Jian Xu1, En-Tang Kang, Koon-Gee Neoh
1Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Singapore.
Biomaterials
|January 31, 2006
Summary
Smart hydrogels synthesized from novel triblock copolymers exhibit both temperature and pH sensitivity. These responsive materials show potential for biomedical applications like tissue engineering and drug delivery.
Area of Science:
- Polymer Chemistry
- Materials Science
- Biomedical Engineering
Background:
- Stimuli-responsive hydrogels are crucial for advanced biomedical applications.
- Developing materials with tunable responses to environmental changes is an ongoing challenge.
Purpose of the Study:
- To synthesize and characterize novel triblock copolymers for smart hydrogel formation.
- To investigate the temperature and pH-responsive behavior of the resulting hydrogels.
Main Methods:
- Consecutive atom transfer radical polymerizations (ATRPs) were used to synthesize P(DMAEMA-co-HEMA)-b-P(NIPAAm)-b-P(DMAEMA-co-HEMA) triblock copolymers.
- Hydrogels were prepared utilizing the hydroxyl groups of HEMA units as crosslinking sites.
- Characterization involved techniques such as GPC, XPS, FTIR, 1H NMR, and DSC.
Main Results:
- The synthesized hydrogels demonstrated independent temperature and pH sensitivity due to P(NIPAAm) and P(DMAEMA) components.
- A lower critical solution temperature (LCST) between 31-32°C was observed in aqueous media (pH 1-7).
- Swelling ratios and kinetics were significantly influenced by the pH and temperature of the surrounding medium.
Conclusions:
- Well-defined, stimuli-responsive hydrogels were successfully synthesized.
- The dual temperature and pH-responsive nature makes these hydrogels promising for biomedical applications.
- Potential applications include advanced drug delivery systems and tissue engineering scaffolds.
