Fig. 1: Preparation and characterization of PIC.

a The preparation process of PIC. b Hydrodynamic size distribution of PIC. c Transmission electron microscopy image of PIC. Scale bar: 100 nm. d Zeta potentials of ION and PIC. (n = 3 independent samples). e CpG complexation abilities in different formulations, as measured by agarose gel electrophoresis. f The particle size stability of PIC during storage at 4 °C. (n = 3 independent samples). g The protein concentrations in B78 cell lysates after incubation with PIC (0.14 mg/mL) for 4 h. (n = 3 biologically independent samples). h Clonogenic assay of B78 melanoma cells after treatment with PIC (4.67 μg/mL) and indicated radiation doses. (n = 3 biologically independent samples). PIC was added to the cells 4 h before radiation, and fresh culture media was exchanged for this PIC treatment media 1 h after radiation. The colonies were counted at day 7. i The immunofluorescence images of B78 cells after indicated treatment (RT: 12 Gy; PIC: 4.67 μg/mL). j Quantification of foci of γH2AX as shown in i. 50 cells in each group were analyzed with ImageJ. PIC was added to the cells 4 h before radiation, and fresh culture media was exchanged for PIC treatment media 1 h after radiation. The immunofluorescence images were taken 1 h after radiation. Statistical significance was calculated via unpaired t-test in g, and one-way ANOVA test in h and j. Data in d, f, g, h and j are presented as mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001. A representative image of three independent samples from each group is shown in c, e and i. Source data are provided in Source Data file.