Fig. 1: The general mechanism of complexation-induced hydrogel shrinking.
From: Complexation-induced resolution enhancement of 3D-printed hydrogel constructs
a Schematics showing the shrinking effect based on charge compensation. b Photograph showing size change of fabricated HAMA hydrogel (1.0 w/v%) before (lower) and after (upper) shrinking in 2.0 w/v% MMw chitosan dissolved in 1.0 v/v% acetic acid aqueous solution. c Schematic representation of a HAMA hydrogel disc together with the dimensions and corresponding quantitative analyses showing the dimensions and volume changes before and after shrinking in 2.0 w/v% MMw chitosan dissolved in 1.0 v/v% acetic acid aqueous solution. d Corresponding quantitative analyses showing the shrinking of HAMA hydrogels in perchloric acid solution (pH = 1.0) or in 1.0 v/v% acetic acid aqueous solutions (pH = 4.7) with 2.0 w/v% of chitosan of different molecular weights and types. e Confocal images showing the diffusion of FITC-Q. chitosan solution in PBS into a 2.0 w/v% HAMA hydrogel at 3 and 24 h of shrinking. The bright-field image at 0 h serves as the size reference of the initial hydrogel. f Photograph showing size change of HMw chitosan hydrogels (2.0 w/v%), where the lower one was swollen in 1.0 v/v% acetic acid aqueous solution and the upper one was shrunken in 2.0 w/v% alginate in 1.0 v/v% acetic acid aqueous solution. **P < 0.01; one-way ANOVA (c, d, compared with the values of corresponding as-prepared samples); mean ± s.d, (n = 3).
