Fig. 2: Chemical properties and mechanical characterizations of hydrogel dressing.

A Infrared spectrum of OSA-GEL hydrogel and corresponding precursors OSA and gelatin. B Rheological measurement of OSA-GEL hydrogels at pH 8 and pH 5. C Time-programmable pH changes in OSA-GEL@G hydrogels with varying concentrations of glucose. n = 3 independent samples per concentration. D Time-programmable pH changes in OSA-GEL@G hydrogels with varying concentrations of GOx. n = 3 independent samples per concentration. E Rheological measurement showing three fuel-feedback cycles of OSA-GEL@G hydrogel upon adding alkaline buffer as the fuel. F Schematic diagram of the formation and dissociation of OSA-GEL@G hydrogel within a fuel-feedback loop. G SEM images of OSA-GEL@G hydrogel at different time intervals (0.6 g/L GOx and 4 g/L glucose, t = 0 min represents the starting point of the second cycle). Scale bar = 10 μm. H The pore size analysis of hydrogel samples (n = 3 independent samples). I Schematic illustration of adhesive behavior between hydrogels and skin tissue, and shear strength measurement. J Adhesion strength of hydrogels with varying OSA:GEL ratios (n = 3 independent samples per OSA:GEL ratio). K Images of hydrogels attached to mouse skin during shape changes, scale bar represents 1 cm. Data in (C, D, H and J) are presented as mean values +/- standard deviation. Source data are provided as a Source Data file.