Minimal Functionalization of Ruthenium Compounds with Enhanced Photoreactivity against Hard-to-Treat Cancer Cells and Resistant Bacteria

Inorg Chem. 2024 Aug 5;63(31):14673-14690. doi: 10.1021/acs.inorgchem.4c02235. Epub 2024 Jul 23.

Abstract

Metallocompounds have emerged as promising new anticancer agents, which can also exhibit properties to be used in photodynamic therapy. Here, we prepared two ruthenium-based compounds with a 2,2'-bipyridine ligand conjugated to an anthracenyl moiety. These compounds coded GRBA and GRPA contain 2,2'-bipyridine or 1,10-phenathroline as auxiliary ligands, respectively, which provide quite a distinct behavior. Notably, compound GRPA exhibited remarkably high photoproduction of singlet oxygen even in water (ϕΔ = 0.96), almost twice that of GRBAΔ = 0.52). On the other hand, this latter produced twice more superoxide and hydroxyl radical species than GRPA, which may be due to the modulation of their excited state. Interestingly, GRPA exhibited a modest binding to DNA (Kb = 4.51 × 104), while GRBA did not show a measurable interaction only noticed by circular dichroism measurements. Studies with bacteria showed a great antimicrobial effect, including a synergistic effect in combination with commercial antibiotics. Besides that, GRBA showed very low or no cytotoxicity against four mammalian cells, including a hard-to-treat MDA-MB-231, triple-negative human breast cancer. Potent activities were measured for GRBA upon blue light irradiation, where IC50 of 43 and 13 nmol L-1 were seen against hard-to-treat triple-negative human breast cancer (MDA-MB-231) and ovarian cancer cells (A2780), respectively. These promising results are an interesting case of a simple modification with expressive enhancement of biological activity that deserves further biological studies.

MeSH terms

  • Anti-Bacterial Agents* / chemical synthesis
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Antineoplastic Agents* / chemical synthesis
  • Antineoplastic Agents* / chemistry
  • Antineoplastic Agents* / pharmacology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Coordination Complexes / chemical synthesis
  • Coordination Complexes / chemistry
  • Coordination Complexes / pharmacology
  • Drug Resistance, Bacterial / drug effects
  • Drug Screening Assays, Antitumor
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Photochemical Processes
  • Photochemotherapy
  • Photosensitizing Agents / chemical synthesis
  • Photosensitizing Agents / chemistry
  • Photosensitizing Agents / pharmacology
  • Ruthenium / chemistry
  • Ruthenium / pharmacology
  • Ruthenium Compounds / chemistry
  • Ruthenium Compounds / pharmacology

Substances

  • Antineoplastic Agents
  • Anti-Bacterial Agents
  • Ruthenium Compounds
  • Coordination Complexes
  • Photosensitizing Agents
  • Ruthenium