[Synthesis and characterization of thermosensitive hydrogel based on PEG-PCL-PEG block copolymers]

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Thermosensitive polymers offer potential for controlled drug release.
• Injectable hydrogels are desirable for minimally invasive drug delivery systems.
• PEG-PCL-PEG triblock copolymers are known for their tunable properties.

Purpose of the Study:

• To synthesize and characterize low-molecular-weight PEG-PCL-PEG triblock copolymers.
• To investigate the thermosensitive gel-sol transition behavior of these copolymers in aqueous solutions.
• To explore the potential of these copolymers as injectable drug delivery systems.

Main Methods:

• Synthesis via ring-opening polymerization.
• Characterization using 1H-NMR and FTIR spectroscopy.
• Gel-sol transition analysis using the test tube-inverting method.

Main Results:

• Successful synthesis of PEG-PCL-PEG triblock copolymers.
• Demonstration of a thermosensitive gel-sol transition above a critical gel concentration (CGC).
• Development of a gel-sol phase diagram influenced by hydrophilic/hydrophobic balance and heating history.
• Tunable gel-sol transition temperature range observed.

Conclusions:

• PEG-PCL-PEG triblock copolymers exhibit tunable thermosensitive properties.
• The observed gel-sol transition is suitable for injectable drug delivery applications.
• Control over hydrophilic/hydrophobic balance and heating history allows for tailored material performance.