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Effect of low-power laser irradiation on bone formation

低功率激光照射对骨形成的影响

基本信息

批准号：
06454586
负责人：
IWASAWA Tadamasa
金额：
$ 2.37万
依托单位：
Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06454586/
关键词：
Low-power laser Bone nodul Rat calvarial cell Differentiation bone formation osteoblast bone nodule

项目摘要

Effects of low-power laser irradiation on bone nodule formation in vitro were assessed. Osteoblast-like cells isolated from rat calvariae of rat fetuses were cultured and were irradiated with a low-power laser for 10 min per day. Both every day and pulsed laser irradiation significantly increased the number of bone nodules formed in a dish. When pulsed irradiation was performed within 1 to 13 d after subculture, bone nodule formation significantly increased. However, irradiation had no effects on bone nodule formation when laser was irradiated after 14 d of subculture. Furthermore, irradiation was performed in the earlier period (within 13 d) after subculture to the cells resulting in larger average size of bone nodules. It is most likely that laser irradiation stimulated differentiation and proliferation of the cells in the earlier period and these cells formed a larger number and size of bone nodules. Therefore, laser irradiation to immature osteoblasts, but not mature osteoblasts ma … More y effective to stimulate bone nodule formation.The extra-cellular collagen level and alkaline phosphatase (ALP) activity were increased by laser irradiation and increased rates were 20 to 30% suggesting that osteoblasts function may be also stimulated by laser irradiation. When Ca and P contents in mineralized nodules were assessed by JEOL JED-2000 energy-dispersive X-ray microanalyzer, net intensities of Ca and P were significantly higher (Ca : 1.3 fold ; P : 1.3 fold) in laser group than in control group. However, the mean values of Ca/P mole ratio were similar in both groups. It may show that laser irradiation stimulated mineralization of bone nodules.Effects of pulsed laser irradiation (10min) on gene expression of type 1 collagen and ALP were investigated using RT-PCR method. Gene expression of both collagen and ALP increased 24 h after laser irradiation compared to those in the controls. These data suggest that laser irradiation may directly affect cells and stimulate differentiation and function of rat calvarial cells resulting a large number and size of bone nodule formation. Less

观察低强度激光照射对体外骨结节形成的影响。从胎鼠颅骨分离培养成骨样细胞，每天用低功率激光照射10分钟。每天和脉冲激光照射都显著增加了培养皿中形成的骨结节的数量。在继代培养后1 ~ 13 d内进行脉冲照射，骨结节形成明显增加。传代培养14 d后激光照射对骨结节形成无影响。此外，在细胞传代后的早期（13 d内）进行照射，导致骨结节的平均大小较大。这很可能是因为激光照射刺激了早期细胞的分化和增殖，这些细胞形成了更多数量和尺寸的骨结节。因此，激光照射未成熟的成骨细胞，而不是成熟的成骨细胞， ...更多信息激光照射可使成骨细胞外胶原含量和碱性磷酸酶（ALP）活性增加，增幅达20 ~ 30%，提示激光照射对成骨细胞的功能也有促进作用。用JEOL JED-2000型能量色散X射线显微分析仪测定矿化结节中Ca和P的含量时，激光组Ca和P的净强度显著高于对照组（Ca：1.3倍; P：1.3倍）。然而，两组的Ca/P摩尔比的平均值相似。采用RT-PCR方法研究脉冲激光照射（10 min）对骨组织中Ⅰ型胶原和碱性磷酸酶基因表达的影响。与对照组相比，激光照射后24 h胶原和ALP的基因表达均增加。这些数据表明，激光照射可能直接影响细胞，刺激大鼠颅骨细胞的分化和功能，导致大量和大小的骨结节形成。少