title: Penetration of laser light through red blood cell ghosts.
abstract: Hemoglobin is the main absorber of visible light in blood and blood-perfused tissues. However, hemoglobin is released from a red blood cell (RBC) during hemolysis. Hemolysis may be caused by a large number of medical conditions, including photodynamic therapy (PDT) and this subsequently can affect passage of light through the treated biological structures. The purpose of the present study was to determine the penetration of a laser beam through a suspension of hemoglobin-free human red blood cells (RBCs) - ghosts. Although hemoglobin has been efficiently removed from the samples used in our experiments, our measurements show that the samples still effectively attenuate the radiant power of penetrating laser light. We established penetration depths of 12.6mm and 15.4mm for two different laser light wavelengths, 532nm and 630nm, respectively. The penetration depth of laser light was about one order of magnitude higher for hemoglobin-free RBC ghosts as compared to intact RBCs [8,10,12]. These results can be important in case of phototherapy or biostimulation, since all photons that penetrate in a biological object may interact with it and evoke biological response.
authors.affiliation: Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Computer Science, Comenius University, Mlynska dolina F1, 84248 Bratislava, Slovak Republic. sikuroval@gmail.com
authors.forename: L
authors.initials: L
authors.lastname: Sikurova
authors.forename: P
authors.initials: P
authors.lastname: Balis
authors.forename: M
authors.initials: M
authors.lastname: Zvarik
mesh_terms: D000328:Adult; D004910:Erythrocyte Membrane / Q000502:physiology / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D008875:Middle Aged; D010778:Photochemotherapy / Q000379:methods*; D013053:Spectrophotometry