Targeted Optical Imaging Agents in Cancer: Focus on Clinical Applications

Figure 1

Nonspecific optical imaging agents. (a) Chemical structure of 5-ALA. (b) 5-ALA is taken up by tumor cells and used for synthesis of PpIX (abs = 405 nm, em = 635 nm). (c) Chemical structure of ICG (abs = 783 nm, em = 813 nm). (d) ICG binds to albumin and forms a complex that accumulates in tumor cells to enhance image contrast.

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