*3.8. Biosafety Evaluation*

The evaluation of toxicity is important for each new drug. As such, we evaluated the safety of our hydrogels in vivo. We applied the hydrogels to the wounds of healthy mice, followed by NIR irradiation, and performed a routine histological analysis of the major organs (Figure 9). Compared with the controls, no significant organ damage, tissue edema, cell death, or inflammatory cell infiltration was observed in the examined organs after treatment with NIR irradiation, MoS2-Van-FITC@CS, and MoS2-Van-FITC@CS + NIR, indicating that MoS2-Van-FITC@CS + NIR was non-toxic in mice.

**Figure 8.** In vivo wound healing analysis. (**A**) The relative wound area curve shows the MoS2- Van-FITC@CS hydrogel had a significant positive effect on wound healing. (**B**) The body weights of different groups after treatment. (**C**) The thermal imaging of mice after treatment. The cells underwent NIR irradiation at 808 nm (1.5 W/cm2, 6 min). (**D**) The photographs of wounds were taken every 2 days after treatment. MoS2-Van-FITC@CS hydrogel + NIR (100 μg/mL), MoS2 NPs (100 μg/mL), MoS2 NPs + NIR (100 μg/mL) and MoS2-Van-FITC@CS hydrogel served as control groups. PBS + NIR served as a blank group. The cells underwent NIR irradiation at 808 nm (1.5 W/cm2, 6 min). Scale bar = 1 cm. Results shown are mean ± SD, *n* = 5–7.

**Figure 9.** In vivo toxicity evaluation. The hematoxylin–eosin-stained images of major organs following different treatments of normal mice. Group 1 was the no treatment group, group 2 was the NIR irradiation (1.5 W/cm2, 6 min) group, group 3 was the MoS2-Van-FITC@CS group and group 4 was the MoS2-Van-FITC@CS + NIR (1.5 W/cm2, 6 min) group.
