A chemically labeled cytotoxic agent: two-photon fluorophore for optical tracking of cellular pathway in chemotherapy.

Chemotherapy is commonly used in the treatment of cancers. However, the mechanism of action of many of these agents is not well understood. We present the synthesis of a two-photon fluorophore (C625) and its biological application when chemically linked to a chemotherapeutic agent (AN-152). By using two-photon laser-scanning microscopy, the drug:fluorophore conjugate can be observed directly as it interacts with receptor-positive cell lines. The results of this project visually show the receptor-mediated entry of AN-152 into the cell cytoplasm and subsequently into the nucleus. These observations will allow for better understanding of the drug's therapeutic mechanism, which is a subject of ongoing research aimed at improving present methods for cancer therapy.