Figure 4. Dose- and time-dependent nitric oxide (NO) generation of human umbilical vein endothelial cells (HUVECs) and neuronal cells induced by NIR-II exposure.

(A-C) We irradiated cultured human umbilical vein endothelial cells (HUVECs) with 808, 1064, or 1270 nm laser at an irradiance of 0.1-100 mW/cm² for 1-5 min. We determined NO generation upon laser irradiation using NO-sensitive fluorophore 4,5-diaminofluorescein diacetate (DAF-2 DA). The fold change in the fluorescent signals at each time point over the no-laser control group was calculated for each group. (A-C, top) Representative fluorescence images of DAF-2T signal loaded in HUVECs in each experimental group and (A-C, bottom) the fold changes of the fluorescence signal of (A), 1064 (B), 1270 and (C), 808 nm laser-treated group. Adapted from Yokomizo et al. 2022 [80] with permission from John Wiley and Sons.