Related Experiment Video
Updated: May 3, 2026
Preparation of Thermoresponsive Nanostructured Surfaces for Tissue Engineering
Published on: March 1, 2016
Anionic Oligo(ethylene glycol)-Based Molecular Brushes: Thermo- and pH-Responsive Properties
Alexey Sivokhin1, Dmitry Orekhov1, Oleg Kazantsev1
1Research Laboratory "New Polymeric Materials", Nizhny Novgorod State Technical University, n.a. R.E. Alekseev, 24 Minin Street, 603155 Nizhny Novgorod, Nizhegorodskaya Oblast, Russia.
Anionic copolymers responsive to temperature and pH were synthesized using photoiniferter reversible addition-fragmentation chain transfer polymerization (PI-RAFT). These polymers exhibit tunable properties for potential applications in drug delivery systems.
Area of Science:
- Polymer Chemistry
- Materials Science
- Nanotechnology
Background:
- Development of stimuli-responsive polymers is crucial for advanced applications.
- Anionic copolymers offer unique properties for tailored material design.
- Photoiniferter reversible addition-fragmentation chain transfer polymerization (PI-RAFT) enables controlled synthesis of complex polymer architectures.
Purpose of the Study:
- To synthesize anionic thermo- and pH-responsive copolymers using PI-RAFT.
- To investigate the influence of strong and weak acidic units on copolymer responsiveness.
- To evaluate the potential of these copolymers for drug delivery applications.
Main Methods:
- Synthesis of copolymers via photoiniferter reversible addition-fragmentation chain transfer polymerization (PI-RAFT) initiated by visible light.
- Incorporation of oligo(ethylene glycol)-based macromonomers for thermo-responsiveness and sulfonic or methacrylic acids for pH-responsiveness.
- Characterization using size exclusion chromatography, spectroscopy (IR, NMR), and differential scanning calorimetry; evaluation of pH-responsive behavior and micelle formation.
Main Results:
- High yields (94%) and controlled molecular weights (93-146 kDa) with low dispersities (1.18-1.45) were achieved.
- Strong acidic units (sulfonic acid) suppressed the Lower Critical Solution Temperature (LCST) in deionized water but maintained it in saline/buffer solutions.
- Weak acidic units (methacrylic acid) showed pronounced pH-dependent LCST behavior; micelles formed with high pyrene entrapment capacity.
Conclusions:
- Anionic copolymers with tunable thermo- and pH-responsiveness were successfully synthesized.
- The type and content of acidic monomers significantly impact the polymer's response to environmental stimuli.
- The synthesized anionic molecular brushes form small micelles with excellent drug-loading capabilities, indicating promise for targeted drug delivery.
More Related Videos
12:07Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning
Published on: April 16, 2018
08:39Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release
Published on: July 4, 2017
