Enhanced Molecular Imaging through a Versatile Peptide Nanofiber for Self-assembly and Precise Recognition.

Designing molecules for multivalent targeting of specific disease markers can enhance binding stability which is critical in molecular imaging and targeted therapy. Through rational molecular design, the nanostructures formed by self-assembly of targeting peptides are expected to achieve multivalent targeting by increasing the density of recognition ligands. However, the balance between targeting peptide self-assembly and molecular recognition remains elusive. In this study, we designed a targeting-peptide-based imaging probe system TAP which consist of the signal unit, the recognition motif, the assembly motif and a Pro-leverage. It is verified that TAP could specifically binds to PD-L1-positive tumor cells in a multivalent manner to produce biological effects, and could also be combined with imaging probes through unique self-assembly strategies. By the balance between the peptide self-assembly and targeting recognition, the specificity and stability can be improved while the accumulation capacity of the probes at the tumor site can be greatly enhanced compared with the conventional strategy, thus reducing side effects, providing an effective tool for diagnostic and therapeutic integration of tumors.