Self-Immolative Hydrogels with Stimulus-Mediated On-Off Degradation.

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Hydrogels are versatile materials for applications like drug delivery and tissue engineering.
• Self-immolative polymers offer cascade degradation and stimulus-tunable properties.
• Existing self-immolative hydrogels have limitations in stability and degradation speed.

Purpose of the Study:

• To prepare and characterize novel self-immolative polymer hydrogels.
• To investigate the stimulus-responsive degradation and drug release capabilities.
• To address limitations of previous self-immolative hydrogel systems.

Main Methods:

• Synthesis of hydrogels using self-immolative poly(ethyl glyoxylate) (PEtG) and poly(ethylene glycol) (PEG).
• Incorporation of a light-responsive linker end-cap for controlled degradation.
• Evaluation of hydrogel properties including gel content, water content, and compressive modulus.
• Assessment of repeated on/off degradation cycles and controlled drug release (celecoxib).

Main Results:

• Hydrogels exhibited high gel content (90%), equilibrium water content (89%), and a compressive modulus of 26 kPa.
• Degradation was repeatedly controlled by alternating light irradiation and dark storage.
• Controlled release of the anti-inflammatory drug celecoxib was achieved through light-triggered degradation cycles.

Conclusions:

• The developed self-immolative hydrogels demonstrate excellent stability and tunable degradation.
• These materials offer precise control over stimulus-response, suitable for advanced applications.
• The findings highlight the potential of self-immolative hydrogels in smart materials for drug delivery and sensing.