Fig. 7.

The illustration of zwitterionic nDDS to achieve lymphatic and spleen targeting. (A) Intravascular distribution of zwitterionic and PEGylated nDDS is depicted schematically. NIR fluorescence pictures of (B) skin-removed ventral left hind leg muscle tissue and (C) the sciatic LNs at 180 min after subcutaneous foot injection of native L-ASP, PEG-ASP, and PCB-ASP conjugates. (D) The relative abundance of ASP in sciatic LNs was measured against the total flux of fluorescent signal. Mice were given native ASP, PEG-ASP, and PCB-ASP conjugates through subcutaneous injection once weekly for three weeks. Non-draining axillary LNs (E and draining popliteal LNs (F) from mice were obtained at various time intervals after the third injection for lymph PK investigation. (G) The bioavailability of each sample after third dosage in axillary and popliteal LNs. (H) Antibody titers were discovered in the popliteal LNs 72 h following the third injection. (**P<0.01; ***P<0.001). (Reproduced with permission from [137]. Copyright 2020 American Chemical Society).