2022-07-01 17:06


Conference: Bucharest University Faculty of Physics 2019 Meeting

Section: Optics, Spectroscopy, Plasma and Lasers

Interaction of laser irradiated phenothiazine droplets with Al surfaces under microgravity conditions: results of the Drop Tower Experiment Series 2018

Ágota SIMON (1,2), Bogdan-Ştefăniță CĂLIN (3,4), Dumitru-Cristian TRANCĂ (5), Ioana-Simona STROESCU (1,6), Ionuț Relu ANDREI (1), Thorben KÖNEMANN (7), Mihail-Lucian PASCU (1,2)

1) Laser Dept., National Institute for Laser, Plasma and Radiation Physics, Măgurele, Ilfov, Romania

2) Faculty of Physics, University of Bucharest, Măgurele, Ilfov, Romania

3) CETAL, National Institute for Laser, Plasma and Radiation Physics, Măgurele, Ilfov, Romania

4) Dept. of Physics, University Politehnica of Bucharest, Bucharest, Romania

5) Faculty of Automatic Control and Computers, University Politehnica of Bucharest, Bucharest

6) Faculty of Biology, University of Bucharest, Bucharest, Romania

7) ZARM, University of Bremen, Am Fallturm, 28359 Bremen, Germany

Corresponding address:

UV laser, medicine droplet, microgravity, wetting properties

The interaction of UV laser radiation with pendant medicine droplets and their wetting properties on target surfaces has been investigated under the aegis of the United Nations Office for Outer Space Affairs (UNOOSA) within the Drop Tower Experiment Series (DropTES) Fellowship Programme. Experiments were conducted in microgravity conditions at Bremen Drop Tower, sponsored by the German Aerospace Center (DLR) Space Administration and the Center of Applied Space Technology and Microgravity (ZARM). The DropTES 2018 experiment aimed to bring a new insight on the behaviour of medicine droplets in reduced gravitational environment. A novel aspect of the project represented droplets real time exposure and modification by UV laser beam, which then interacted with an Al surface in order to study the evolution of wetting phenomena under microgravity conditions. Since microorganisms can evolve into more virulent forms in space, astronauts and spacecraft surfaces may require treatment and decontamination, respectively, against onboard pathogens [1]. The alternative solution proposed for DropTES 2018 project consists in utilising a multifunctional drug and an unconventional method to make it acquire antimicrobial properties by exposure to UV laser radiation. The concept of optically induced structure modification of existing medicines regards the transformation of a single parent-compound into new and more efficient photoproducts that may have – either individually or in mixture – increased antimicrobial activity and better wetting properties, if compared to the corresponding unirradiated medicines [2-4].


[1] Wilson et al., Space flight alters bacterial gene expression and virulence and reveals a role for global regulator Hfq, Proc. Natl. Acad. Sci. USA 104, 16299-16304, 2007.

[2] Pascu et al., Direct modification of bioactive phenothiazines by exposure to laser radiation, Recent Pat. Antiinfect. Drug Discov. 6(2), 1-13, 2011.

[3] Pascu et al., Exposure of chlorpromazine to 266 nm laser beam generates new species with antibacterial properties: contributions to development of a new process for drug discovery, PLoS ONE 8(2), e55767(1-16), 2013.

[4] Simon et al., Interaction of solutions containing phenothiazines exposed to laser radiation with materials surfaces, in view of biomedical applications, Int. J. Pharm. 475, 270-281, 2014.

The DropTES project was supported by UNOOSA, DLR Space Administration and ZARM. The research was also financed by the Ministry of Education via LAPLAS VI project 16N/08.02.2019. The DropTES team was sponsored by APEL LASER SRL.