Fig. 2: Characterization of TIOs.

a Representative SEM images of TIOs and its precursor UCNPs engineered Raw 264.7 cells (scale bar = 2 μm). The blue arrows indicate the pores on the surface of TIO. b TEM images of TIOs. Scale bars, 5 μm, 1 μm. c The Dil labelled TIOs were imaged in phosphate buffer saline at 37 °C. d, e The average size and zeta-potential of TIOs and its precursor UCNPs engineered Raw 264.7 cells. d The average particle size. e The zeta-potential. Data are shown as mean ± s.d. (n = 3 independent experiments, two-tailed unpaired Student’s t-test, P < 0.0001). f The stability of TIOs in phosphate-buffered saline (37 °C). The quantity variation of TIOs was determined by cell counter assay (10⁵ units / tube). Data are shown as mean ± s.d. (n = 3 independent experiments). g The stress of Raw 264.7 cells, LNT Raw 264.7 cells (liquid nitrogen treated Raw 264.7 cells), the precursors of TIOs and TIOs were determined by cytokine release assay, with or without NIR light (980 nm, 1.0 W cm⁻²). Data shown as mean ± s.d. (n = 3 independent experiments, two-tailed unpaired Student’s t-test). In the living cell system (precursors of TIOs), RSL3@azo-Ce6-mSiO₂-UCNPs themselves interacted with living macrophages, resulting in the release of many inflammatory factors (black columns). In our study, RSL3@azo-Ce6-mSiO₂-UCNPs were designed as NIR light controlled nanoparticles, which produced ROS under NIR irradiation (Fig. 2h, i and Supplementary Fig. 1h record the relationship between ROS generation and irradiation time). In the case of with NIR (red columns), precursors of TIOs produced more inflammatory factors than other groups, indicating an obvious ROS-related stress responses in living macrophages. h, i The NIR light controlled ROS generation of TIOs. The TIOs were pre-treated with SOSG. h The image of TIOs after NIR light treatment. Scale bar, 20 μm. i Flow cytometry analysis of ROS generation from TIOs by NIR light (980 nm, 1.0 W cm⁻², 5 min). j A HPLC-MS assay for RSL3 release from TIOs. For a–d, h-j, experiment was repeated three times independently with similar results. Source data (d–g) are provided as a Source Data file. Source data (j) are provided in Supplementary Information.