Fig. 2
Sol–gel transition properties and in vitro stability test of I-5 hydrogel. a Temperature-dependent sol–gel transition and changes in viscosity measured by a viscometer. Each black dot represents the average value from four replicated measurements. Error bars represent standard deviation. b, c Visualization of the rapid gelation process. I-5 polymer solution was injected into a glass vial containing distilled water at either 4 °C (b) or 37 °C (c). After being injected into the water at 37 °C, the polymer solution rapidly turned into a rod-like gel material (yellow dotted circle). Gel-like materials accumulated at the bottom of the vial (white dotted rectangle, c). In comparison, there was no visible opaque gel-like material in the vial containing water at 4 °C (white dotted rectangle, c). Images in the white dotted rectangles in b, c were magnified in bʹ, cʹ. d Changes in viscosity as a function of time elapsed after the temperature is set as 37 °C. Each bar is the average of three replicate measurements. Error bars represent standard deviation. e In vitro stability test. Three independent I-5 gels were monitored until 7 days in vitro at 37 °C
