Direct stimulatory effect of low-intensity 670 nm laser irradiation on human endothelial cell proliferation.
BACKGROUND
Endothelial cell (EC) proliferation plays a key role in the process of tissue repair. Low-intensity laser irradiation has been demonstrated to accelerate wound healing and to improve microvascularization.


OBJECTIVE
The present study evaluated a possible stimulatory influence of low-intensity laser irradiation on human umbilical vein endothelial cell (HUVEC) proliferation in a systematic manner.


METHODS
Subconfluent cultures of HUVEC were irradiated every other day with a 670-nm diode laser (intensity: 10-65 mW cm(-2), dose: 2-8 J cm(-2)) during a period of 6 days. Cell proliferation was evaluated quantitatively by counting in a haemocytometer.


RESULTS
Our data demonstrate a dose-dependent and intensity-dependent stimulatory effect of laser irradiation on HUVEC cell proliferation. Doses of between 2 and 8 J cm(-2) induced statistically significant cell proliferation. Testing different intensities at a constant dose of 8 J cm(-2), 20 and 65 mW cm(-2) induced most pronounced cell proliferation.


CONCLUSIONS
Low-intensity laser irradiation influences EC proliferation and might thereby contribute to the increase in angiogenesis and the acceleration of wound healing in vivo.
Schindl
A
A
Department of Dermatology (Division of Special and Environmental Dermatology), University of Medical School, Währinger Gürtel 18-20, A-1090 Vienna, Austria. Andreas.Schindl@akh-wien.ac.at
Merwald
H
H
Schindl
L
L
Kaun
C
C
Wojta
J
J
D002455:Cell Division / Q000528:radiation effects*; D002478:Cells, Cultured; D004307:Dose-Response Relationship, Radiation; D004730:Endothelium, Vascular / Q000166:cytology / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D014471:Umbilical Veins / Q000166:cytology / Q000528:radiation effects