Figure 1.

Schematic representation of recent CPP-based strategies. The hydrophilic nature of cargos such as nucleic acids, small drugs, proteins, or peptides, can hinder their cellular uptake and subsequent intracellular localization. Conjugating the cargos to a CPP via noncovalent interactions or covalent bonds facilitates the CPP-conjugated therapeutic to cross the cell membrane and reach intracellular areas which are otherwise challenging to access, thus improving the therapeutic efficacy.