Additional file 1: Table S1. The BsAb-conjugation rate of αHER2/PEG-NPs. Table S2. The Characterization of BsAb/mPEG-NPs. Figure S1. Immunogenicity of humanized BsAbs. We cocultured dendritic cells differentiated from human PBMCs with autologous CD4+ T cells and stimulated with control medium (represented as DC+T), PHA (as positive control), PEG×HER2, PEG×DNS, respectively, for 5 days. Then, we detected the proliferation of CD4+ T cells by ATPlite assay. Bars, SD. CPM, counts per minute; PBMC, peripheral blood mononuclear cell; PHA, phytohemagglutinin.