UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-22 2:27
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Conference: Bucharest University Faculty of Physics 2013 Meeting


Section: Biophysics; Medical Physics


Title:
Antibacterial activity and spectroscopic analysis of laser modified drugs


Authors:
A. Dinache (1,2), M. Boni(1,2), M. Martins (3), M. P. McCusker (3), V. Nastasa (1), S. Fanning (3), M.L. Pascu (1,2)


Affiliation:
(1)Laser Spectroscopy Group, Laser Department, National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG-36, Magurele, Ilfov, 077125, Romania

(2)Faculty of Physics, University of Bucharest, P.O. Box MG – 11, Magurele, Ilfov, 077125, Romania

3UCD School of Public Health, Physiotherapy and Population Science, UCD Centre for Food Safety, Veterinary Sciences Centre, University College Dublin, Belfield, Dublin 4, Ireland


E-mail
andra.dinache@inflpr.ro


Keywords:
laser irradiation, UV-Vis absorption spectroscopy, FTIR spectroscopy, LIF spectroscopy, phenothiazine derivatives, Vancomycin


Abstract:
A broad range of drugs, including antibiotics,antifungals, neuroleptic drugs, diuretics, etc., are sensitive to light, especially to UV radiation and if these drugs were exposed to white light and/or UV radiation their structure may be modified. The use of lasers has advantages over the use of the incoherent sources of light: the specific wavelength and the much higher energy. In this study, drugs belonging to two classes of medicines were investigated: Vancomycin, a glycopeptide antibiotic, and phenothiazine derivatives Chlorpromazine (CPZ), Thioridazine (TZ), Promazine (PZ) and Promethazine (PMZ. Drug solutions were exposed to laser radiation emitted by the fourth and second harmonic generation (FHG & SHG) of a Nd:YAG laser (wavelength = 266 nm & 532 nm). The laser induced fluorescence (LIF) emitted by the samples was collected in real time. Besides the LIF spectra, UV-Vis absorption and FT-IR spectra of the samples were recorded before and after exposure to laser radiation. The modifications of the spectra indicate alterations of the molecules.The main goal of exposing drug solutions to laser radiation is to modify the molecules and to generate new species active against some multi-drug resistant (MDR) bacteria. CPZ, TZ, PZ, PMZ and their laser modified derivatives were assessed for antibacterial activity against several Staphylococcus aureus, Listeria, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter aerogenes and Salmonella enterica serovar Typhimurium strains. Exposure of Vancomycin solutions in ultrapure water to laser radiation modifies the molecules, generating foams, most likely due to the tensile component of the laser induced photoacustic wave induced by the laser pulse. Acknowledgements: The authors from NILPRP acknowledge the financing of the research by Program LAPLAS 3, PN 09 39/2009 and CNCS – UEFISCDI by project number PN-II-ID-PCE-2011-3-0922 and PN-II-PT-PCCA-2011-3.1-1350. A. Dinache acknowledges the financial support of project POSDRU 107/1.5/S/80765.