A new nano-structured antibiotic to treat traditional antibiotic-resistant bacterial infections synthesized for the first time by an international team coordinated by Debora Berti and Costanza Montis of the Department of Chemistry of the University of Florence in collaboration with the Schools of Pharmacy and Medicine of the University of East Anglia (Norwich, UK), Procarta Biosystems Ltd (Norwich, UK). The work is part of the European project IAPP (Marie Curie Industry-Academia Partnerships & Pathways) DNA TRAP (Delivery of Nucleic Acid-Based Therapeutics for the Treatment of Antibiotic-Resistant Pathogens).
The study appeared in Nature Scientific Reports (Antimicrobial Nanoplexes meet Model Bacterial Membranes: the key role of Cardiolipin DOI: 10.1038/srep41242).
“One of the major challenges of present day medicine is the treatment of bacterial infections, comments Debora Berti. Traditional antibiotics are progressively less active and numerous bacterial strands have developed resistance mechanisms towards them. In spite of this, the discovery of new molecules with antibiotic properties has also diminished over time and their availability on the market is inadequate. It is therefore of key importance to develop new antibiotics with innovative formulas and able to overcome bacterial resistance mechanisms. In this case the experimentation pathway is still long, warns Berti, but the efficacy of the nano-antibiotic in the treatment of infections of Clostridium difficile has already been demonstrated on animal models.”
The new nano-structured antibiotic is made up by two components: one (a cationic molecule, i.e. formed by an ion with a positive charge) interacts with the membrane of bacteria by destabilizing it and the other (an oligonucleotide, i.e. a small fragment of a nucleic acid) interferes with the transcription mechanisms of DNA. The two components combine to form a nano-particle called “nanoplex”, measuring about 160 nanometers in diameter.
“The advantages of this system compared to traditional antibiotics, Berti explains, are essentially twofold: resistance mechanisms that the bacterium can develop are ineffective against the oligonucleotides and secondly the oligonucleotides can be easily modified to be active against different targets inside the same bacterium or over different bacteria. The new antibiotic can be modified to be used as a general antibiotic or for the treatment of Gram-negative or Gram-positive bacteria, simply by changing the oligonucleotide accordingly.”