IRDye 700DX-conjugated polymers inducing photochemical internalization

Photochemical internalization (PCI) is a promising technique to exert therapeutic potency of biopharmaceutics in a light-selective manner, and its endowment of selectivity to a specific molecule will broaden its application. This study reports αvβ3-targeted PCI of nucleic acids by the use of functional polymers modified with IRDye 700DX and cyclic RGD (cRGD) peptides. The functional polymers were constructed by conjugating multiple cRGD peptides with the side chains of poly(ethylene glycol)-poly(L-glutamic acid) and subsequent introduction of IRDye 700DX at the α-end. The functional polymers having multiple cRGD peptides exhibited specificity to αvβ3 integrins and selective accumulation within target tumors upon intravenous injection. Importantly, the polymer having the appropriate number of cRGD peptides induced efficient PCI. This study revealed that IRDye 700DX can be utilized for PCI and that the efficiency was critically affected by the delivery systems.