Figure 4.
Cathodic writing onto a dual responsive (chitosan–agarose) medium induces the formation of an internal structure. (a) The dual responsive hydrogel is formed by cooling an acidic blend of chitosan and agarose. (b) The internal structure is created using a cathodic ‘pen’ to create regions of high pH that induce the localized self-assembly of chitosan chains within the agarose network. (c) The gradients in the structure induced by writing also yield gradients in mechanical, chemical and biological properties. Adapted with permission from [204]. John Wiley & Sons. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.