Fig. 6

In vivo construction of immune cell-based nanomedicine carriers and initial PTT treatment enhance hitchhiking delivery into the tumor and improve antitumor immunotherapy. A E. coli OMVs are coated on both CD-GNPs and ADA-GNPs to prepare bacteria-mimetic nanoparticles. B Selective phagocytosis of bacteria-mimetic nanoparticles by phagocytic immune cells induces OMV degradation and subsequent intracellular aggregation of GNPs mediated by CD-ADA host–guest interactions, leading to photothermal property due to the plasmonic effects of GNP aggregates. The large size of intracellular GNP aggregates also inhibits the leakage during in vivo cell-hitchhiking delivery. Because of the inflammatory tropism to melanoma, immune cells achieve the targeted delivery of intracellular GNP aggregates to the tumor tissues. C Initial PTT treatment of GNP aggregates induces tumor damage that subsequently enhances inflammatory signals and provides positive feedback to recruit more immune cells (including the carriers) for enhanced antitumor therapy. Secondary photothermal treatment (PTT) of Mixture induces tumor cell immunogenic cell death (ICD) and activates antitumor immune response, further strengthened by immune checkpoint blockage (aPD-L1), reproduced with permission from [168], licensed under CC BY 4.0