Self-assembled D-arginine derivatives based on click chemical reactions for intracellular codelivery of antigens and adjuvants for potential immunotherapy

Self-assembled amino acid derivatives could form well-defined nanostructures which have great application value for drug delivery systems. In particular, D-amino acid derivatives possess tremendous advantages including anti-degradation and good lysosome escape compared with L-amino acid derivatives. In this work, 9-fluorenylmethyloxycarbonyl (Fmoc) neighboring D-arginine derivatives were replaced by dibenzocyclooctyne (DBCO) to extend the class of functional D-arginine derivatives, which were further reacted with various cross-linkers including azide to construct a library of self-assembled supramolecular nanovehicles and strengthen the stability of nanostructures for disease immunotherapy. Moreover, in vitro studies demonstrated that the combination of DBCO modified D-arginine derivative DR3 and cross-linker C1 not only reinforced the cellular uptake efficiency of ovalbumin (OVA) which was chosen as the model antigen, but also promoted the cytokine TNF-α release of RAW 264.7 cells after the introduction of adjuvant unmethylated cytosine-phosphate-guanine dinucleotides (CpG). Furthermore, the nanovaccine based on DR3C1 could enhance the antigen OVA and adjuvant cytosolic delivery of marrow derived dendritic cells (BMDCs), which improved the antigen-presentation cross efficiency and induced the maturation of BMDCs. Taken together, we believe that D-arginine derivatives functionalized by DBCO provide an effective strategy for disease immunotherapy and act as a great potential delivery tool.