Active targeting of tumors through conformational epitope imprinting.

Inspired by the knowledge that most antibodies recognize a conformational epitope because of the epitope's specific three-dimensional shape rather than its linear structure, we combined scaffold-based peptide design and surface molecular imprinting to fabricate a novel nanocarrier harboring stable binding sites that captures a membrane protein. In this study, a disulfide-linked α-helix-containing peptide, apamin, was used to mimic the extracellular, structured N-terminal part of the protein p32 and then serve as an imprinting template for generating a sub-40 nm-sized polymeric nanoparticle that potently binds to the target protein, recognizes p32-positive tumor cells, and successfully mediates targeted photodynamic therapy in vivo. This could provide a promising alternative for currently used peptide-modified nanocarriers and may have a broad impact on the development of polymeric nanoparticle-based therapies for a wide range of human diseases.