The chemical basis of cytotoxicity of silicon-phthalocyanine-based near infrared photoimmunotherapy (NIR-PIT) and its implications for treatment monitoring

Near infrared photoimmunotherapy (NIR-PIT) is a new cancer therapy based on the photo-induced ligand release reaction of a silicon???phthalocyanine derivative, IRDye700DX (IR700), that causes rapid cell death. Following exposure to an anti-body-IR700-conjugate, cells exposed to NIR light within mi-nutes undergo rapid swelling, blebbing, and finally, bursting. The photo-induced ligand release reaction also induces im-mediate loss of IR700 fluorescence due to dimerization or aggregation of the antibody-IR700 conjugate allowing for real time monitoring of NIR-PIT therapy.

Automated summary

Near infrared photoimmunotherapy (NIR-PIT) is a new cancer therapy that utilizes the photo-induced ligand release reaction of a silicon-phthalocyanine derivative, IRDye700DX (IR700), to cause rapid cell death. When exposed to NIR light, cells conjugated with an anti-body-IR700 compound undergo swelling, blebbing, and bursting within minutes. The ligand release reaction also leads to immediate loss of IR700 fluorescence, enabling real time monitoring of NIR-PIT therapy.