title: Bio-inspired Dynamic Gradients Regulated by Supramolecular Bindings in Receptor-Embedded Hydrogel Matrices.
abstract: The kinetics of supramolecular bindings are fundamentally important for molecular motions and spatial-temporal distributions in biological systems, but have rarely been employed in preparing artificial materials. This report proposes a bio-inspired concept to regulate dynamic gradients through the coupled supramolecular binding and diffusion process in receptor-embedded hydrogel matrices. A new type of hydrogel that uses cyclodextrin (CD) as both the gelling moiety and the receptors is prepared as the diffusion matrices. The diffusible guest, 4-aminoazobenzene, quickly and reversibly binds to matrices-bound CD during diffusion and generates steeper gradients than regular diffusion. Weakened bindings induced through UV irradiation extend the gradients. Combined with numerical simulation, these results indicate that the coupled binding-diffusion could be viewed as slowed diffusion, regulated jointly by the binding constant and the equilibrium receptor concentrations, and gradients within a bio-relevant extent of 4 mm are preserved up to 90 h. This report should inspire design strategies of biomedical or cell-culturing materials.
authors.affiliation: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral Materials School of Materials Science and Technology China University of Geosciences Beijing 100083 P. R. China.
authors.forename: Xinglong
authors.initials: X
authors.lastname: Luan
authors.affiliation: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral Materials School of Materials Science and Technology China University of Geosciences Beijing 100083 P. R. China.
authors.forename: Yihe
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Science China University of Geosciences Beijing 100083 P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Molecular Nanofabrication Group MESA+Institute of Nanotechnology University of Twente, 7500 AE Enschede The Netherlands.
authors.forename: Pascal
authors.initials: P
authors.lastname: Jonkheijm
authors.affiliation: Department of Chemistry Tsinghua University Beijing 100084 P. R. China.
authors.forename: Guangtao
authors.initials: G
authors.lastname: Li
authors.affiliation: Institute of Chemistry Chinese Academy of Sciences Beijing 100084 P. R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Molecular Nanofabrication Group MESA+Institute of Nanotechnology University of Twente, 7500 AE Enschede The Netherlands.
authors.forename: Jurriaan
authors.initials: J
authors.lastname: Huskens
authors.affiliation: Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral Materials School of Materials Science and Technology China University of Geosciences Beijing 100083 P. R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: An
keywords: cyclodextrin; diffusion; dynamic gradients; hydrogels; supramolecular binding