Pyridine-2,6-Dicarboxamide Proligands and their Cu(II)/Zn(II) Complexes Targeting Staphylococcus Aureus for the Attenuation of In Vivo Dental Biofilm

Adv Healthc Mater. 2024 Aug;13(20):e2400378. doi: 10.1002/adhm.202400378. Epub 2024 Apr 23.

Abstract

In the pursuit to combat stubborn bacterial infections, particularly those stemming from gram-positive bacteria, this study is an attempt to craft a precision-driven platform characterized by unparalleled selectivity, specificity, and synergistic antimicrobial mechanisms. Leveraging remarkable potential of metalloantibiotics in antimicrobial applications, herein, this work rationally designs, synthesizes, and characterizes a new library of Pyridine-2,6-dicarboxamide ligands and their corresponding transition metal Cu(II)/Zn(II) complexes. The lead compound L11 demonstrates robust antibacterial properties against Staphylococcus aureus (Minimum Inhibitory Concentration (MIC) = 2-16 µg mL-1), methicillin and vancomycin-resistant S. aureus (MIC = 2-4 µg mL-1) and exhibit superior antibacterial activity when compared to FDA-approved vancomycin, the drug of last resort. Additionally, the compound exhibits notable antimicrobial efficacy against resistant enterococcus strains (MIC = 2-8 µg mL-1). To unravel mechanistic profile, advanced imaging techniques including SEM and AFM are harnessed, collectively suggesting a mechanistic pathway involving cell wall disruption. Live/dead fluorescence studies further confirm efficacy of L11 and its complexes against S. aureus membranes. This translational exploration extends to a rat model, indicating promising in vivo therapeutic potential. Thus, this comprehensive research initiative has capabilities to transcends the confines of this laboratory, heralding a pivotal step toward combatting antibiotic-resistant pathogens and advancing the frontiers of metalloantibiotics-based therapy with a profound clinical implication.

Keywords: MRSA/VRSA; S. aureus; metalloantibiotics; resistant.

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Biofilms* / drug effects
  • Coordination Complexes / chemistry
  • Coordination Complexes / pharmacology
  • Copper* / chemistry
  • Copper* / pharmacology
  • Ligands
  • Microbial Sensitivity Tests*
  • Pyridines* / chemistry
  • Pyridines* / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Staphylococcal Infections / drug therapy
  • Staphylococcus aureus* / drug effects
  • Zinc* / chemistry
  • Zinc* / pharmacology

Substances

  • Anti-Bacterial Agents
  • Zinc
  • Copper
  • Pyridines
  • Coordination Complexes
  • Ligands