ABA-type triblock copolymer micellar system with lower critical solution temperature-type sol-gel transition

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Amphiphilic copolymers are extensively studied for their self-assembly properties and temperature-sensitive sol-gel transitions.
• Applications in various industries, including drug delivery, drive research in this area.

Purpose of the Study:

• To synthesize and characterize a novel ABA-type amphiphilic copolymer using reversible addition-fragmentation chain transfer (RAFT) polymerization.
• To investigate the temperature-sensitive sol-gel transition and micellar behavior of the synthesized copolymer.
• To evaluate the potential of the copolymer for drug loading and controlled release.

Main Methods:

• Two-step RAFT polymerization to synthesize PDMAA-b-PDAAM-b-PDMAA copolymer.
• Dynamic light scattering (DLS), transmission electron microscopy (TEM), rheology, 1H NMR, and FTIR for characterization.
• Temperature-dependent studies to monitor sol-gel transition and drug release kinetics.

Main Results:

• The ABA copolymer exhibits a lower critical solution temperature (LCST)-type sol-gel transition.
• An abnormal sphere-to-worm micellar transition was observed at the LCST.
• The transition behavior is influenced by block lengths, distribution, and copolymer concentration.
• Successful loading and sustained release of paracetamol were demonstrated.

Conclusions:

• The synthesized ABA copolymer displays a tunable, temperature-sensitive sol-gel transition with potential for drug delivery.
• The observed micellar transition and controlled release characteristics highlight its utility in smart material applications.
• Further studies can optimize copolymer design for enhanced drug loading and release profiles.