Synthesis and Biological Evaluation of New Fluorescent Probe BPN-01: A Model Molecule for Fluorescence Image-guided Surgery

J Fluoresc. 2023 Sep;33(5):1827-1839. doi: 10.1007/s10895-023-03166-7. Epub 2023 Feb 27.

Abstract

Fluorescence image-guided surgery (FIGS) can serve as a tool to achieve successful resection of tumour tissues during surgery, serving as a surgical navigator for surgeons. FIGS relies on the use of fluorescent molecules that can specifically interact with cancer cells. In this work, we developed a new model of fluorescent probe based on benzothiazole-phenylamide moiety featuring the visible fluorophore nitrobenzoxadiazole (NBD), namely BPN-01. This compound was designed and synthesised for potential applications in the tissue biopsy examination and ex-vivo imaging during FIGS of solid cancers. The probe BPN-01 exhibited favourable spectroscopic properties, particularly in nonpolar and alkaline solvents. Moreover, in vitro fluorescence imaging revealed that the probe appeared to recognise and be internalised in the prostate (DU-145) and melanoma (B16-F10) cancer cells, but not in the normal cells (myoblast C2C12). The cytotoxicity studies revealed that probe BPN-01 was not toxic to the B16 cells, suggesting excellent biocompatibility. Furthermore, the computational analysis showed that the calculated binding affinity of the probe to both translocator protein 18 kDa (TSPO) and human epidermal growth factor receptor 2 (HER2) was considerably high. Hence, probe BPN-01 displays promising properties and may be valuable for visualising cancer cells in vitro. Furthermore, ligand 5 can potentially be labelled with NIR fluorophore and radionuclide, and serves as a dual imaging agent for in vivo applications.

Keywords: Benzothiazole-phenylamide; Cancer imaging; Fluorescence image-guided surgery; Fluorescent probe BPN-01; Nitrobenzoxadiazole (NBD).

MeSH terms

  • Cell Line
  • Fluorescent Dyes / chemistry
  • Humans
  • Male
  • Neoplasms*
  • Optical Imaging / methods
  • Receptors, GABA
  • Surgery, Computer-Assisted* / methods

Substances

  • Fluorescent Dyes
  • TSPO protein, human
  • Receptors, GABA