Folic Acid-Functionalized Water-Soluble Calixarene for Accurate Identification of Human Breast Cancer Cells.

Recently, a great interest in the synthesis of various macrocyclic compounds that have the potential to selectively bind to a variety of targets and have the biomedical applications, such as supramolecular biomedical materials, supramolecular diagnostics and self-assembled precursor drugs appear. In this paper, the water-soluble anthracenyl-modified oxacalix[4]arene(AO3) was synthesized by converting four imine groups and ester groups of anthracenyl-modified oxacalix[4]arene (AO1) to amine groups and hydrophilic carboxyl groups respectively via reduction and alkaline hydrolysis reactions. Afterwards, the folic acid was bonded to the AO3 via amidation reaction, and the folic acid-functionalized water-soluble anthracenyl-modified oxacalix[4]arene (FA-AO3) with targeting recognition of cancer cells MCF-7 was prepared. The modification of folic acid made FA-AO3 have an obvious redshift phenomenon by 30 nm and significant increase in fluorescence intensity. When normal cells (HUVEC cells) and cancer cells (MCF-7 cells) were cultured with FA-AO3 respectively, obvious green fluorescence could be observed in cancer cells, while fluorescence phenomenon didn't happen in normal cells, indicating that FA-AO3 had a good specificity to recognize human breast cancer cells. FA-AO3 would have potentially valuable application in early cancer diagnosis and can also be as a drug carrier for specific targeted therapy in the future.