Fig. 5

Confocal microscopy images of various target cells treated by nanoparticles. Green fluorescent signals were generated by coumarin-6 (Cou6) loaded in the nanoparticles. The nuclei were stained blue with Hoechst. A PD-L1-expressing MDA-MB-231 cells or B PD-L1-negative A549 cells were treated with PBS, NP-Cou6, PDL1-NP-Cou6, or PD1-NP-PDL1-Cou6. C Activated PBMCs with high PD-1 expression or D Unactivated PBMCs with low PD-1 expression were treated with PBS, PD1-NP-Cou6, or PD1-NP-PDL1-Cou6. Scale bar represents 20 μm