Design of Inorganic Polymers with Stimuli Responsive Cleavage and/or Degradation in Biological Environments

Description

Herein, we describe our work on degradable polymers, in particular polymers which are designed to be stable but spontaneously and quickly disintegrate upon exposure to certain triggers. Firstly, a photolabile ruthenium-based complex is incorporated into polyurea hydrogels to give supramolecular photosensitive materials1. The gels were shown to undergo rapid photocleavage at wavelengths of 400–500 nm, as well as via a two-photon process in the NIR region (800 nm). The rapid de-gelation of the supramolecular gels also enabled spatiotemporal micropatterning by photomasking or pulsed NIR-laser irradiation. The long-wavelengths required for cleavage of the metallopolymers mean that they could have significant potential for biological applications, where materials which respond to mild, tissue penetrating irradiation are of particular importance. Furthermore, these supramolecular metallogels are also shown to be thermally reversible, thus opening opportunities in self-healing materials. We also present a second set of materials based on the polyphosphazene backbone2. The backbone phosphorus atoms are quite prone to hydrolytic attack but can be “protected” by substitution with organic substituents. Hence, we designed hydrolyticially unstable polymers but with cleavable protecting groups along the phosphorus backbone. This allows us to create stable high molecular weight polymers, which can be rapidly degraded upon cleavage of the protecting group. Through the choice of protecting groups, macromolecules were also designed to respond to visible light, as well as to biologically relevant oxidative triggers.3 1.Theis, S. et al., Angew. Chem. Int. Ed., 10.1002/anie.201707321 2.Rothemund, S.; Teasdale, I., Chem. Soc. Rev. 2016, 45 (19), 5200. 3.Iturmendi et al., ACS Macro Lett. 2017, 150.

Period	22 Mar 2018
Event title	PDFA - Polymers: Design, Function and Application
Event type	Conference
Location	SpainShow on map