Laser-induced inactivation of Plasmodium falciparum

Malaria Journal

Methodology

Robert Story¹  Danielle LeBlanc²  Eitan Gross² 

[1] Biomass Research Center, University of Arkansas, 72701, Fayetteville, AR, USA;Department of Physics, University of Arkansas, 72701, Fayetteville, AR, USA;

关键词: Dialysis;    Escherichia coli;    Haemozoin;    Plasmodium falciparum;    Pulsed laser;    Third harmonic generation;   

DOI  :  10.1186/1475-2875-11-267

 received in 2012-05-17, accepted in 2012-08-01,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundHaemozoin crystals, produced by Plasmodium during its intra-erythrocytic asexual reproduction cycle, can generate UV light via the laser-induced, non-linear optical process of third harmonic generation (THG). In the current study the feasibility of using haemozoin, constitutively stored in the parasite’s food vacuole, to kill the parasite by irradiation with a near IR laser was evaluated.MethodsCultured Plasmodium parasites at different stages of development were irradiated with a pulsed NIR laser and the viability of parasites at each stage was evaluated from their corresponding growth curves using the continuous culture method. Additional testing for germicidal effects of haemozoin and NIR laser was performed by adding synthetic haemozoin crystals to Escherichia coli in suspension. Cell suspensions were then irradiated with the laser and small aliquots taken and spread on agar plates containing selective agents to determine cell viability (CFU).ResultsParasites in the late-trophozoites form as well as trophozoites in early-stage of DNA synthesis were found to be the most sensitive to the treatment with ~4-log reduction in viability after six passes through the laser beam; followed by parasites in ring phase (~2-log reduction). A ~1-log reduction in E. coli viability was obtained following a 60 min irradiation regimen of the bacteria in the presence of 1 μM synthetic haemozoin and a ~2-log reduction in the presence of 10 μM haemozoin. Minimal (≤15%) cell kill was observed in the presence of 10 μM haemin.ConclusionsLaser-induced third-harmonic generation by haemozoin can be used to inactivate Plasmodium. This result may have clinical implications for treating severe malaria symptoms by irradiating the patient’s blood through the skin or through dialysis tubing with a NIR laser.

【 授权许可】

Unknown   
© LeBlanc et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.