Fig. 1: The design and operational mechanism of the hydrogel platform.

This diagram depicts the dual regulation capabilities of the hydrogel: intrinsic stress relaxation and responsive stress relaxation triggered by light exposure. The hydrogel is prepared through a Schiff base reaction, involving the dual dynamic crosslinkers and carboxymethyl-chitosan (CMCS, 30 kDa). The hydrogel’s ability to undergo intrinsic stress relaxation, with time reduction from 3400 s to 500 s, is facilitated by varying the aldehyde components which allow for imine metathesis. The TDS component within the hydrogel initiates a radical-induced disulfide metathesis upon light exposure, leading to a dose-dependent re-organization of the polymer network, thereby enabling controlled stress relaxation.