New hydrolysis-dependent thermosensitive polymer for an injectable degradable system.

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Thermosensitive polymers are crucial for controlled release applications.
• Bioerodible polymers offer tunable degradation profiles.
• Combining these properties can lead to advanced drug delivery systems.

Purpose of the Study:

• To synthesize and characterize novel bioerodible, thermosensitive copolymers.
• To investigate the hydrolysis-dependent thermosensitivity of poly(NIPAAm-co-dimethyl-gamma-butyrolactone acrylate).
• To explore the potential of these copolymers for biomedical applications.

Main Methods:

• Radical polymerization to synthesize poly(NIPAAm-co-dimethyl-gamma-butyrolactone acrylate) with varying dimethyl-gamma-butyrolactone acrylate (DBA) content.
• Characterization using differential scanning calorimetry, gel permeation chromatography with static light scattering, FTIR, and NMR.
• Acid titration to analyze hydrolysis and its effect on polymer properties.

Main Results:

• Successful synthesis of copolymers with tunable lower critical solution temperature (LCST) based on DBA content.
• LCST decreases with increasing DBA content and increases after DBA side group hydrolysis.
• FTIR and NMR confirmed copolymerization and hydrolysis-dependent ring-opening of DBA.
• Polymers dissolve at 37°C without low-molecular-weight byproducts.

Conclusions:

• The synthesized copolymers exhibit tunable, hydrolysis-dependent thermosensitivity.
• The ring-opening hydrolysis of DBA is self-catalytic, increasing hydrophilicity and charge.
• These novel polymers show promise for applications requiring controlled degradation and temperature-triggered behavior, such as drug delivery.