Fig. 1: Strategy of using photothermal nanoparticle-adopted whole tumor cell vaccine (LN-TCV) for on-demand near-infrared (NIR) manipulation of immune responses against cancer and corresponding characterizations of the LN-TCV construction process.

a Schematic illustration of NIR laser irradiation-manipulated immune responses for antitumor immunotherapy. The on-demand immune responses manipulated by NIR laser irradiation based on the fluctuation of tumor growth rate (FTGR) can promote antitumor therapeutic effects after a single vaccination. b Schematic illustration of the preparation (left) and transmission electron microscopy (TEM) image (right) of photothermal nanoparticles (NPs). c Temperature change curves for NPs with different concentrations upon continuous NIR laser irradiation (808 nm, 0.65 W/cm², 1000 s). d Heating and cooling curves of NPs (10 μg/mL) after pulsed NIR laser irradiation (808 nm, 0.65 W/cm²). e Schematic illustration of LN-TC construction (left) and the confocal laser scanning microscopy (CLSM) image of N-TC (right). Red: Rhodamine-phalloidin-labeled-cell membrane; Cyan: P-F8-DPSB-labeled NPs. f NIR thermographic images of 4T1 tumor cells variously exposed to NPs and/or continuous NIR laser irradiation (808 nm, 0.65 W/cm², 40 min). The cells were incubated with NPs for 12 h, and the free NPs were washed off before irradiation. g Western blotting analysis for the expression of HSP 70, HSP 90, and HSP 105 proteins in 4T1 tumor cells variously exposed to NPs and/or NIR laser irradiation (808 nm, 0.65 W/cm², 40 min). h Schematic illustration of LN-TCV construction and CLSM images of LN-TCV for evaluating the cell membrane framework. Red: Rhodamine-phalloidin-labeled-cell membrane; Cyan: P-F8-DPSB-labeled NPs. i Live/dead analysis of LN-TCV before inactivation (before) and cultured (day 1, 2, and 4) after inactivation for demonstrating inactivated LN-TCV. Green: live cells; Red: dead cells. The images were presented with the same magnification. j NIR thermographic images of LN-TCV exposed to continuous NIR laser irradiation (808 nm, 0.65 W/cm², 15 min) (top). Photoacoustic (PA) images of LN-TCV with different concentrations (From left to right: 0, 2.5 × 10⁶, 5 × 10⁶, 7.5 × 10⁶, and 10⁷ cells/mL) (bottom). The experiments in (b–j) were repeated three times independently with similar results. Source data were provided in the Source data file.