Fig. 1

Synthesis of Gel-H.P and Gel-H.P.Cur. a Schematic and b Original materials representation. HA was incubated at basic pH, and the interaction of epoxide groups with the HA hydroxyl groups leads to ether bond formation. This cross-linking reaction created the HA-PDMS 3D hydrogel network. By adsorbing and penetrating curcumin in the Gel-H.P (at appropriate pH condition) the color completely converted to yellow even in the inner parts of Gel-H.P.Cur