Biotinylated Chlorin and Its Zinc and Indium Complexes: Synthesis and In Vitro Biological Evaluation for Photodynamic Therapy

Meden F Isaac-Lam; Dewana M Hammonds

doi:10.3390/ph10020041

Biotinylated Chlorin and Its Zinc and Indium Complexes: Synthesis and In Vitro Biological Evaluation for Photodynamic Therapy

Pharmaceuticals (Basel). 2017 Apr 15;10(2):41. doi: 10.3390/ph10020041.

Authors

Meden F Isaac-Lam¹, Dewana M Hammonds²

Affiliations

¹ Department of Chemistry and Physics, Purdue University Northwest, 1401 S US Hwy 421, Westville, IN 46391, USA. isaaclam@pnw.edu.
² Department of Chemistry and Physics, Purdue University Northwest, 1401 S US Hwy 421, Westville, IN 46391, USA. dhammon@pnw.edu.

Abstract

The synthesis and characterization of biotinylated chlorin photosensitizer and the corresponding zinc and indium complexes are described for potential applications in photodynamic therapy (PDT) for cancer. Phototoxicity of the biotin-chlorin conjugate and the metallated complexes was determined in colon carcinoma CT26 cell lines known to overexpress biotin (Vit B₇) receptors. Cell survival assay indicated that the biotinylated chlorin and indium complex showed increased cell growth inhibition than the zinc complex and the starting chlorin (methyl pheophorbide). Fluorescence microcopy studies revealed the generation of apoptotic cells upon light irradiation of colon cells treated with the indium complex. Targeting biotin receptors in cancer cells can improve specificity of photosensitizers for PDT applications.

Keywords: PDT; chlorin-biotin conjugate; indium chlorin-biotin complex; photodynamic therapy; vitamin-targeted cancer therapeutics; zinc chlorin-biotin complex.