A Polyanionic Tartrate-containing Temperature-responsive Hydrogel

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials Engineering

Background:

• Thermogels are soft biomaterials that undergo sol-gel transitions upon warming.
• Most existing thermogelling polymers are uncharged, limiting understanding of charge effects on thermogelation.
• The influence of ionizable groups on thermogel properties remains largely unexplored.

Purpose of the Study:

• To report the first polyanionic amphiphilic multi-block copolymer capable of forming thermogels.
• To investigate the impact of negative charges on micelle and thermogel properties.
• To explore the modulation of thermogel rheology and drug release using polyanionic character.

Main Methods:

• Synthesis of a polyanionic amphiphilic multi-block copolymer with pendant carboxylate groups.
• Characterization of thermogel formation and properties upon warming to physiological temperatures.
• Evaluation of rheological properties (stiffness, gelation temperature) via electrostatic interactions with cations.
• Assessment of drug release profiles for cationic and anionic model compounds.

Main Results:

• Successful formation of transparent thermogels from the polyanionic copolymer at physiological temperatures.
• Demonstration that negative charges significantly alter micelle and thermogel characteristics.
• Tunable rheological properties (stiffness, gelation temperature) achieved through cation interactions.
• Slower sustained release of a cationic drug observed compared to an anionic drug over two weeks.

Conclusions:

• Introduced a novel polyanionic thermogelling polymer with tunable properties.
• Highlighted the significant impact of polymer charge on thermogel behavior and drug delivery.
• Showcased potential for advanced biomedical applications of charged polyelectrolyte thermogels.