Ebert D W, Bertone A L, Roberts C
Biomedical Engineering Center, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA.
Am J Vet Res. 1998 Dec;59(12):1613-8.
To determine whether irradiation with a low-intensity diode laser, which produces radiation at a wavelength of 810 nm, will induce nonthermal enhancement of chondrocyte metabolism.
144 grossly normal articular cartilage explants aseptically harvested from the femoral condyles of 6 adult horses.
Treated cartilage explants were irradiated with a diode laser at 1 of 7 fluence levels that ranged from 8 to 1,600 J/cm2. Explants were incubated for 24 or 72 hours, labeled for 24 hours with [35S]Na2SO4, and assayed for newly synthesized sulfated glycosaminoglycan (GAG; measured incorporation of 35SO4) and endogenous GAG, chondroitin 6-sulfate (CS), and keratan sulfate (KS) content, using a dimethylmethylene blue assay. Laser-induced temperature changes were measured during irradiation with a diode laser and a neodymium:yttrium aluminum garnet (Nd:YAG) laser, which produces radiation at a wavelength of 1,064 nm, using conditions that were reported in previous studies to increase explant metabolism.
After incubation for 24 or 72 hours, rate of 33SO4 uptake or endogenous GAG, CS, or KS content in irradiated explants was not significantly different than in nonirradiated explants. Cartilage temperature increased < 4.75 C during diode laser application. Cartilage temperature increased 5 to 12 C during Nd:YAG laser application.
Minimal thermal increases in cartilage explants with use of a low-intensity diode laser resulted in no change in proteoglycan metabolism of chondrocytes. An increase in tissue temperature over a narrow range with use of a Nd:YAG laser may have contributed to the metabolic alteration of chondrocytes reported in previous studies.
确定发射波长为810nm辐射的低强度二极管激光照射是否会诱导软骨细胞代谢的非热增强。
从6匹成年马的股骨髁无菌采集的144个大体正常的关节软骨外植体。
将处理过的软骨外植体用二极管激光以7种不同的能量密度水平之一进行照射，能量密度范围为8至1600J/cm²。外植体孵育24或72小时，用[³⁵S]Na₂SO₄标记24小时，并使用二甲基亚甲蓝测定法检测新合成的硫酸化糖胺聚糖（GAG；³⁵SO₄的测量掺入量）以及内源性GAG、硫酸软骨素6-硫酸酯（CS）和硫酸角质素（KS）的含量。在使用二极管激光和钕：钇铝石榴石（Nd:YAG）激光照射期间测量激光诱导的温度变化，Nd:YAG激光发射波长为1064nm，采用先前研究中报道的可增加外植体代谢的条件。
孵育24或72小时后，照射外植体中³⁵SO₄摄取率或内源性GAG、CS或KS含量与未照射外植体相比无显著差异。在二极管激光照射期间，软骨温度升高<4.75℃。在Nd:YAG激光照射期间，软骨温度升高5至12℃。
使用低强度二极管激光时软骨外植体的热增量极小，软骨细胞蛋白聚糖代谢未发生变化。使用Nd:YAG激光在窄温度范围内组织温度升高可能导致了先前研究中报道的软骨细胞代谢改变。
