Tunable Upper Critical Solution Temperatures for Acrylamide Copolymers with Bile Acid Pendants

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Bile acids are biocompatible hydrophobic molecules.
• Developing smart polymers with tunable properties is crucial for advanced applications.
• Thermoresponsive polymers offer unique solutions for controlled release and separation.

Purpose of the Study:

• To synthesize and characterize novel copolymers of acrylamide and bile acid derivatives.
• To investigate the temperature-dependent solubility of these copolymers.
• To explore their potential for biomedical applications.

Main Methods:

• Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to create P(AAm-co-CAA) copolymers.
• The upper critical solution temperature (UCST) behavior and mixing temperature (Tmix) were studied.
• Dynamic light scattering and transmission electron microscopy were employed for characterization.

Main Results:

• Copolymers exhibited sharp, reversible insoluble-to-soluble transitions in water upon heating.
• The mixing temperature (Tmix) was tunable around 37 °C by adjusting copolymer composition and concentration.
• Addition of beta-cyclodextrin decreased the Tmix, and the transition was confirmed by DLS and TEM.

Conclusions:

• Bile acid-based acrylamide copolymers demonstrate tunable thermoresponsive behavior.
• Their biocompatibility and tunable Tmix make them promising for biomedical applications.
• These materials offer a new platform for smart hydrogel development.