Dual‐Responsive Material Based on Catechol‐Modified Self‐Immolative Poly(Disulfide) Backbones. Issue 39 (31st August 2021)

• Record Type: Journal Article
• Authors: Agergaard, Asger Holm; Sommerfeldt, Andreas; Pedersen, Steen Uttrup; Birkedal, Henrik; Daasbjerg, Kim
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 39(2021)
• Page Start: 21543
• Page End: 21549
• Publication Date: 2021-08-31
• Subjects: catechol -- hydrogel -- polymers -- self-immolative -- stimuli-responsive; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202108698
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Functional materials engineered to degrade upon triggering are in high demand due their potentially lower impact on the environment as well as their use in sensing and in medical applications. Here, stimuli‐responsive polymers are prepared by decorating a self‐immolative poly(dithiothreitol) backbone with pendant catechol units. The highly functional polymer is fashioned into stimuli‐responsive gels, formed through pH‐dependent catecholato–metal ion cross‐links. The gels degrade in response to specific environmental changes, either by addressing the pH responsive, non‐covalent, catecholato–metal complexes, or by addition of a thiol. The latter stimulus triggers end‐to‐end depolymerization of the entire self‐immolative backbone through end‐cap replacement via thiol–disufide exchanges. Gel degradation is visualized by release of a dye from the supramolecular gel as it itself is converted into smaller molecules. Abstract : Catechol‐functionalized self‐immolative poly(disulfides) are synthesized and fashioned into dual‐responsive gels through formation of catecholato–Al 3+ cross‐links. Two distinct pathways to cargo release are engineered, namely the depolymerization in a self‐immolative fashion, or breaking catecholato–Al 3+ cross‐links at low pH. Both gel degradation pathways lead to release of bound dye molecules on demand.