Revealing the dynamic mechanism of cell-penetrating peptides across cell membranes at the single-molecule level

Cell-penetrating peptides (CPPs) have gained prominence in cellular drug delivery due to their extremely low toxicity and rapid cell internalization properties. Understanding the effect of CPPs' physicochemical properties on trans-membrane behavior will provide a better screening scheme for designing effective CPP-conjugated nano-drugs. Herein, the efficiency of the CPPs interacting with the cell membrane and the subsequent trans-membrane is revealed at the single-molecule level using single-molecule force spectroscopy (SMFS) and force tracing technique based on atomic force spectroscopy (AFM). The dynamic force spectroscopy (DFS) analysis indicates that cationic TAT