Charge-switching, amphoteric glucose-responsive microgels with physiological swelling activity.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Developing smart materials for biomedical applications is crucial.
• Glucose-responsive systems are needed for advanced diabetes therapies.
• Existing systems often lack stability or responsiveness under physiological conditions.

Purpose of the Study:

• To create colloidally stable, glucose-responsive microgels.
• To investigate glucose-dependent swelling and deswelling behaviors.
• To explore the potential for glucose-triggered insulin delivery.

Main Methods:

• Functionalization of poly(N-isopropylacrylamide)-based microgels with aminophenylboronic acid (PBA).
• Characterization of microgel swelling responses at physiological conditions (temperature, pH, ionic strength).
• Assessment of microgel charge switching and insulin uptake/release capabilities.

Main Results:

• Achieved up to 2-fold volumetric swelling in response to physiological glucose concentrations.
• Demonstrated glucose-dependent swelling and deswelling modulated by pH and PBA concentration.
• Observed a charge switch from cationic to anionic with increasing glucose concentration.
• Showed high insulin uptake capacity and selective, glucose-triggered insulin release.

Conclusions:

• Amphoteric PBA-microgels offer a novel, stable platform for glucose sensing.
• These microgels exhibit tunable responses to glucose under physiological conditions.
• The developed system shows significant promise for developing advanced, "on-off" insulin delivery systems for diabetes management.