photoimmunotherapy is anew form of cancer therapy involving near-infrared light. photoimmunotherapy usesan antibody to which a photoabsorbingchemical is attached. the antibodyâ€“photoabsorberconjugate is injected into a patient. it will travel through thebloodstream and eventually reach the site of the tumor. the conjugate will then leakout of permeable vessels
near the tumor. it will bind to specialreceptors on the surface of cancer cells. once the conjugate isbound to cancer cells, the photoabsorbing chemicalcan be specifically activated by near-infrared light. when the chemicalhas been activated, it causes immediate damageto the cell membrane. water that is outside ofthe cell rushes into it,
causing the cell to swell. nearby cells without thethe special receptors will not be affected. increased pressure withinthe swollen cell causes the membrane to burst, releasingintracellular contents such as proteins, dna and rna. the cell then becomes smallerand shrunken in shape, a process known as necrosis. after treatment, the cellnecrosis causes the tumor
to shrink, creatingspaces between the cells. the tumor will die and normal tissue will regrow in its place. photoimmunotherapy is a newform of cancer therapy that is highly specific for cancercells and does not damage nearby normal cells. it is currently in clinicaltrials in patients with inoperable tumors.