Preparation of chlorin e6–monoclonal antibody conjugate and its effect for photodynamic therapy

Chlorin e6 ( Ce 6) was conjugated with anti-tumor monoclonal antibody ( IgG 2 b ) to increase its binding affinity for tumors. The Ce 6 was activated by N -hydroxysuccinimide and directly conjugated with IgG 2 b ( IgG 2 b – Ce 6) via peptide bonds. An average of 11 Ce 6 molecules were coupled to each IgG2b molecule. IgG 2 b – Ce 6 showed high cellular uptake in tumor cells and high photocytotoxicity. These results indicate IgG 2 b – Ce 6 is a good photosensitizer with high binding affinity to tumor cells.