Fig. 2

Double-layered N-S1 PNp on the maturation, uptake, and cytotoxicity of APCs were determined in vitro. A–D The expression of CD11c⁺, CD80⁺, and CD86⁺ surface markers on BMDCs. A, C Representative pseudocolor dots in different groups. B, D The percentages of CD11c⁺, CD80⁺, and CD11c⁺, CD86⁺ were measured using FCM. E, F In vitro APCs uptake assay. E Representative Immunofluorescent staining images of RAW264.7 (left) and DC2.4 (right) cells in different groups. From left to right, the panel showcases DAPI (blue) on the left, Alexa Fluor 488 labeled S1 (top) and N (bottom) (green), followed by a merged image of the two. The scale represents 100 μm. F The percentage statistics of internalized S1 (left) and N (right). Bars are presented as mean ± SD of triplicate technical replicates. Statistical significance was conducted by one-way ANOVA analysis followed by multiple comparisons post hoc tests (***p-value < 0.001, **p-value < 0.01, *p-value < 0.05, ^nsp-value > 0.05). G The cytotoxicity of N-S1 PNp to APCs in vitro