Resiquimod (R848) was purchased from Selleck (Houston, TX, USA). Poly(D, L-lactic-co-glycolic acid) (PLGA) (LA: GA = 50:50, 10–20 kDa) and cell counting kit-8 (CCK-8) were purchased from MedChenExpress (Monmouth Junction, NJ, USA). Poly(vinyl alcohol) (PVA), the heptamethine indocyanine dye IR-780 iodide, and 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) were obtained from Sigma-Aldrich Co. (St Louis, MO, USA). The anti-mouse TNFR2 (CD120b) antibody was purchased from Bio X Cell (West Lebanon, NH). Hoechst 33,342 and LysoTracker Red DND-99 were purchased from Yeasen Biotechnology (Shanghai, China). All other reagents used were of the highest commercially available grade.