described herein are modifications and adaptations of iron storage proteins for a novel photo - initiated approach to cancer therapy whereby cells are killed via production of iron - generated hydroxyl radicals . the iron is photo - released from a protein scaffold that includes tumor - targeting peptides and / or proteins fused to the exterior surface of the protein scaffold . one or more photosensitizers are coupled to the protein shell . the multiple tumor - targeting peptides and / or proteins will bind to specific hyperexpressed receptors on the cancer cells . after binding of the photosensitizer - iron - loaded protein to the cancer cells , photochemical excitation of the photosensitizers with tissue - penetrating near - infrared light triggers release of “ free ” ferrous iron , which in oxic or mildly hypoxic intracellular environments generates toxic hydroxyl radicals via fenton chemistry . this light - triggered release of “ free ” iron overwhelms the cancer cells &# 39 ; defenses against free radicals . the combination of tumor - targeting peptides and photo - triggered release of iron ensures that non - cancerous cells are not bombarded with iron .