Photodynamic and Antibiotic Therapy in Combination to Fight Biofilms and Resistant Surface Bacterial Infections

International Journal of Molecular Sciences

Federica Barra¹  Emanuela Roscetto¹  Amata A. Soriano¹  Adriana Vollaro¹  Ilaria Postiglione¹  Giovanna Maria Pierantoni¹  Giuseppe Palumbo¹  Maria Rosaria Catania¹  Michael R. Hamblin² 

[1] Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples 80131, Italy; E-Mails:Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples 80131, Italy;

关键词: photodynamic therapy;    5-aminolevulinic acid;    Gentamicin;    combination therapy;   

DOI  :  10.3390/ijms160920417

来源: mdpi

【 摘 要 】

Although photodynamic therapy (PDT), a therapeutic approach that involves a photosensitizer, light and O₂, has been principally considered for the treatment of specific types of cancers, other applications exist, including the treatment of infections. Unfortunately, PDT does not always guarantee full success since it exerts lethal effects only in cells that have taken up a sufficient amount of photosensitizer and have been exposed to adequate light doses, conditions that are not always achieved. Based on our previous experience on the combination PDT/chemotherapy, we have explored the possibility of fighting bacteria that commonly crowd infected surfaces by combining PDT with an antibiotic, which normally does not harm the strain at low concentrations. To this purpose, we employed 5-aminolevulinic acid (5-ALA), a pro-drug that, once absorbed by proliferating bacteria, is converted into the natural photosensitizer Protoporphyrin IX (PpIX), followed by Gentamicin. Photoactivation generates reactive oxygen species (ROS) which damage or kill the cell, while Gentamicin, even at low doses, ends the work. Our experiments, in combination, have been highly successful against biofilms produced by several Gram positive bacteria (i.e., Staphylococcus aureus, Staphylococcus epidermidis, etc.). This original approach points to potentially new and wide applications in the therapy of infections of superficial wounds and sores.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.