Hawkins Denise H, Abrahamse Heidi
Laser Research Group, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, Johannesburg 2028, South Africa.
J Photochem Photobiol B. 2007 Sep 25;88(2-3):147-55. doi: 10.1016/j.jphotobiol.2007.07.003. Epub 2007 Jul 28.
The penetration and distribution of laser light in target tissue is dependent on the wavelength of the light. One problem with most of the published data on laser irradiation is that most studies do not record the duration between the exposure and the evaluation. This study aimed to establish if the dose, wavelength or duration of effect (1h or 24h) influences the biological responses of irradiated fibroblasts.
The study established cellular responses of normal and wounded human skin fibroblasts to helium-neon (632.8 nm), diode (830 nm) and Nd:YAG (1064 nm) laser irradiation using one exposure of 5 J/cm(2) or 16 J/cm(2) on day 1 and again on day 4. Cellular responses to laser irradiation were evaluated by measuring changes in cell viability (ATP viability and caspase 3/7 activity) and cell proliferation (ALP enzyme activity and bFGF expression), 1h and 24h post irradiation.
Wounded cells exposed to 5 J/cm(2) using 632.8 nm showed an increase in ATP viability after 1h, a decrease in caspase 3/7 activity after 24h and an increase in cell proliferation after 24h. The results suggest that changes in parameters such as ATP viability should be observed directly after laser irradiation (1h) whereas other parameters such as caspase 3/7 activity, bFGF expression and ALP enzyme activity should be measured at least 24h after the final exposure.
This study confirms that the duration of effect should be included as one of the main laser parameters when reporting on the effects of laser irradiation. It is important to establish time-dependent responses as the results may provide an understanding of the cellular responses following laser irradiation.
激光在靶组织中的穿透和分布取决于光的波长。大多数已发表的激光照射数据存在的一个问题是，大多数研究没有记录照射与评估之间的时间间隔。本研究旨在确定剂量、波长或效应持续时间（1小时或24小时）是否会影响照射后成纤维细胞的生物学反应。
本研究通过在第1天和第4天对正常和创伤的人皮肤成纤维细胞进行一次5 J/cm²或16 J/cm²的照射，来确定其对氦氖（632.8 nm）、二极管（830 nm）和Nd:YAG（1064 nm）激光照射的细胞反应。在照射后1小时和24小时，通过测量细胞活力（ATP活力和半胱天冬酶3/7活性）和细胞增殖（碱性磷酸酶活性和bFGF表达）的变化来评估细胞对激光照射的反应。
使用632.8 nm波长、5 J/cm²照射的创伤细胞在照射后1小时ATP活力增加，24小时后半胱天冬酶3/7活性降低，24小时后细胞增殖增加。结果表明，如ATP活力等参数的变化应在激光照射后立即观察（1小时），而其他参数如半胱天冬酶3/7活性、bFGF表达和碱性磷酸酶活性应在最后一次照射后至少24小时测量。
本研究证实，在报告激光照射的效果时，效应持续时间应作为主要激光参数之一。确定时间依赖性反应很重要，因为结果可能有助于理解激光照射后的细胞反应。
