Dual-Responsive Material Based on Catechol-Modified Self-Immolative Poly(Disulfide) Backbones

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Functional materials that degrade on command are crucial for reducing environmental impact and for applications in sensing and medicine.
• Stimuli-responsive polymers offer tunable degradation pathways.
• Self-immolative polymer backbones enable controlled depolymerization.

Purpose of the Study:

• To engineer stimuli-responsive polymers and gels with controlled degradation capabilities.
• To utilize catechol units and metal-ion cross-links for pH-dependent gel formation and degradation.
• To investigate thiol-triggered depolymerization of a self-immolative polymer backbone.

Main Methods:

• Synthesis of a self-immolative poly(dithiothreitol) backbone functionalized with pendant catechol units.
• Formation of supramolecular gels via pH-dependent catecholato-metal ion cross-links.
• Stimulation of gel degradation using pH changes or thiol addition.

Main Results:

• Successfully prepared functional, stimuli-responsive gels capable of degrading under specific conditions.
• Demonstrated pH-dependent degradation by disrupting catecholato-metal ion complexes.
• Achieved complete backbone depolymerization triggered by thiol addition via thiol-disulfide exchange.
• Visualized gel degradation through the release of a model dye.

Conclusions:

• The developed polymer gels exhibit controlled degradation in response to distinct stimuli (pH and thiol).
• The combination of self-immolative backbones and dynamic cross-links provides a versatile platform for functional materials.
• These materials hold promise for environmentally benign applications, sensing, and advanced medical technologies.