Fig. 2.

Characterizations of APTP NPs. a Illustration of the structure of the amphiphilic PEG-polyphenol. b Transmission electron microscope (TEM) image of aPD-L1-functionalized APTP NPs. The inserted picture illustrates the enlarged morphology of APTP NPs. c,d Energy-dispersive X-ray spectroscopy (EDX) elemental mapping and spectra of APTP NPs. e Dynamic light scattering (DLS) of PTP and APTP NPs. f ζ potential analyses of aPD-L1, PTP, and APTP NPs. g SDS–PAGE image of aPD-L1 and APTP NPs under the different pH. ‘HC’ represents high chains, ‘LC’ represents light chains. h The pH-responsive release profile of APTP NPs using fluorochrome Nile red as a model drug.