Fig. 5: LIA induced reduced systemic toxicity and enhanced immune responses in vivo.

a Fluorescence images of the 4T1 tumour-bearing mice at 3, 6, 9, 12, 24 h post intravenous administration of free Ce6 and LIA (Ce6 3 mg/kg), 2 mice per group. b Fluorescence images of major organs (heart, liver, spleen, lung, kidney) and tumour tissues were collected at 24 h post injection, 2 mice per group. c, d ELISA analysis of TNF-α (c) and IL-6 (d) concentrations in serum collected from mice 24 h after different treatments (PBS, LIA, LIA+L, CpG and LPS). e, f Images of spleens (e) and weight of spleens (f) from each group 14 days after treatment with different formulations. g, h The tumour-bearing mice were i.v. injected with PBS, free Ce6, DP-Ce6 and LIA at an equivalent Ce6 dose of 3 mg/kg, then NIR light was used to irradiate (665 nm, 0.15 W/cm², for 30 min) the tumour site at 4 h post injection. The treatments were performed in triplicates every other day. DC maturation was analysed 72 h after the final treatment (gated on CD11C⁺ cells). Representative flow cytometry (g) and statistical analysis (h) of CD80⁺ CD86⁺ DCs in LNs of mice after different treatments. i, j Representative flow cytometry (g) and statistical analysis (h) of CD8⁺ T cells in spleens of mice 7 days after different treatments. Data in c, d, f, h, j are presented as mean ± s.d. (n = 3). Statistically significant differences between groups were identified by one-way ANOVA. ****P < 0.0001, ***P < 0.001, **P < 0.01, *P < 0.05.