Generation and identification of antimicrobial species from medicines exposed to laser radiation in view of fighting multiple drug resistance acquired by bacteria
Project code: PN-III-P1-1.1-PD-2016-1072
Contract number: 68PD/2018
Founded by: MCI, UEFISCDI
Program: Postdoctoral research projects
Contractor:(CO): National Institute for Laser, Plasma and Radiation Physics
Project Leader: Dr. Tatiana Tozar
Start Date: 02.05.2018
End Date: 30.04.2020
Summary:
One of the most important current drawbacks that have to be addressed in fighting infections with multiple drug resistant bacteria is the ineffectiveness of current antibiotics to destroy them and the lack of new antibiotic molecules and of new treatment schemes. At the same time, a fast and cheap approach for drug development is needed such as exposure of existing drugs to laser beams. Then, identification of new drugs must be made, which implies in most cases HPLC systems. A better solution is the high-performance thin layer chromatography (HPTLC), an offline method that is superior to other analytical techniques in terms of total costs and time for analysis. Development of a HPTLC single track scanner to identify new photoproducts is proposed in this project, for which low-intensity monochromatic light generated by picosecond lasers is used. The signal obtained from the HPTLC plates is analyzed with a spectrograph equipped with a CCD camera for fluorescence spectra monitoring and a photomultiplier coupled to an oscilloscope for fluorescence lifetime evaluation. The overall objective of the proposal is to photo-generate antimicrobial species by exposing current drugs to UV laser beam and to characterize and identify the new species by performing qualitative and quantitative analysis using an improved HPTLC densitometry system. The results concerning the new species will be correlated with mass spectrometry measurements performed by LC-TOF/MS and the molecular structures of the antimicrobial compounds will be validated with Gaussian09 software.
Expected results:
The objective of the project is to generate antimicrobial agents by exposing aqueous solutions of thioridazine and ciprofloxacin to 266 nm laser radiation for time intervals ranging from 1 minute to 240 minutes. For unirradiated and irradiated medicine solutions, the antimicrobial activity will be determined against ciprofloxacin sensitive and resistant Gram-positive/-negative bacteria. The optimal irradiation time for the best antimicrobial activity will be established. Samples will be investigated using the HPTLC densitometry system in order to determine laser induced fluorescence and fluorescence lifetime for the separated photoproducts. The results will be correlated with mass spectrometry measurements. The photoproducts molecular structure will be validated with the Gaussian09 software.
The estimated results are *optical characterization and antimicrobial activity determination of thioridazine and ciprofloxacin solutions before and after their exposure to laser radiation; *characterization by HPTLC densitometry of thioridazine and ciprofloxacin solutions before and after exposure to laser radiation; *characterization by LC-TOF/MS of thioridazine and ciprofloxacin solutions before and after exposure to laser radiation; *the identification of photoproducts molecular structure, the photoproducts resulted from the irradiation of thioridazine and ciprofloxacin solutions.
