The principle of
peptide-drug conjugate (PDC) is to conjugate cell-targeting
peptides with drug molecules to enhance drug targeting and to
concentrate the drug in the target tissue, thus reducing its
relative concentration in other tissues, increasing effectiveness
and reducing adverse effects. The peptides used in PDCs include
cell-targeting peptides (CTPs) and cell-penetrating peptides
(CPPs). Various linkers have been used in PDCs development to
prevent unspecific release of the drug. Payloads available in the
PDCs include cytotoxic drugs and radionucleotides. PDC integrates
the advantages of peptides with low molecular weight and
biodegradability, while not causing immunogenic reactions.