title: Biocatalytic Feedback-Driven Temporal Programming of Self-Regulating Peptide Hydrogels.
abstract: Switchable self-assemblies respond to external stimuli with a transition between near-equilibrium states. Although being a key to present-day advanced materials, these systems respond rather passively, and do not display autonomous dynamics. For autonomous behavior, approaches must be found to orchestrate the time domain of self-assemblies, which would lead to new generations of dynamic and self-regulating materials. Herein, we demonstrate catalytic control of the time domain of pH-responsive peptide hydrogelators in a closed system. We program transient acidic pH states by combining a fast acidic activator with the slow, enzymatic, feedback-driven generation of a base (dormant deactivator). This transient state can be programmed over orders of magnitude in time. It is coupled to dipeptides to create autonomously self-regulating, dynamic gels with programmed lifetimes, which are used for fluidic guidance, burst release, and self-erasing rapid prototyping.
authors.affiliation: DWI-Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, 52056 Aachen (Germany) http://www.dwi.rwth-aachen.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Heuser
authors.affiliation: DWI-Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, 52056 Aachen (Germany) http://www.dwi.rwth-aachen.de.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Weyandt
authors.affiliation: DWI-Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, 52056 Aachen (Germany) http://www.dwi.rwth-aachen.de. walther@dwi.rwth-aachen.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Walther
mesh_terms: D055162:Biocatalysis; D004151:Dipeptides / Q000737:chemistry / Q000378:metabolism*; D025461:Feedback, Physiological; D020100:Hydrogels / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013997:Time Factors; D014510:Urease / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004151:Dipeptides; D020100:Hydrogels; D014510:Urease
keywords: dynamic materials; hydrogels; materials science; peptides; self-regulation