尼莫地平对体外培养成骨细胞的影响

目的 观察尼莫地平对体外培养成骨细胞的作用.方法 在新生SD大鼠头颅骨第2继代成骨细胞(OB2)培养液中分别加入不同浓度(10-1～10 9g/L)尼莫地平,分别观察OB2的增殖功能(用波长570nm处OD值表示),分化功能(用碱性磷酸酶ALP活性表示)和矿化功能(用矿化结节数量/视野表示).结果 增殖功能OD值为0.12±0.01～0.41±0.04;ALP活性为0.09±0.01U/mg蛋白质;矿化结节数量/视野为1.3±0.9个.结论 与对照组比较,尼莫地平各浓度对OB2的增殖、分化和矿化功能作用各异.当尼莫地平浓度为10 6g/L时,对OB2的增殖和分化功能具有刺激作用,对OB2的矿化功能具有显著的抑制作用;当浓度升高(10-2g/L)时,对OB2的增殖功能具有明显的抑制作用;当浓度降低(10 8g/L)时,对OB2的增殖功能失去作用.     

降钙素对体外培养成骨细胞的影响

目的观察破骨细胞抑制剂--降钙素(密钙息)对体外培养成骨细胞的作用.方法在新生SD大鼠头颅骨第二继代成骨细胞(OB\-2)培养液中分别加入不同浓度(10-4～10-12g/ml)的密钙息,分别观察OB\-2的增殖功能(用波长570nm处OD值表示),分化功能[用碱性磷酸酶(ALP)活性表示]和矿化功能(用矿化结节数量/视野表示).结果OD值(均值+标准差)为0.323±0.101～0.523±0.158;ALP活性(均数±标准差)为(0.104±0.012)U/mg蛋白质;矿化结节数量/视野(均数±标准差)为5.75±0.957个.结论与对照组比较,适当浓度(10-8～10-12)的密钙息对OB\-2的增殖,分化和矿化功能均具有促进作用,10-10g/ml浓度密钙息作用尤其显著,它们的作用显著性差异为促进OB2增殖功能P＜0.05;促进OB2分化功能P＜0.01和促进OB2矿化功能P＜0.001.     

骨折愈合刺激素对体外培养成骨细胞的影响

目的　观察骨折愈合刺激素对体外培养成骨细胞的作用。方法　在新生SD大鼠头颅骨次代成骨细胞 (OB2 )培养液中分别加入不同浓度 (2× 10 2 U/L～ 2× 10 4U/L)骨折愈合刺激素 ,观察OB2的增殖功能 (用波长 5 70nm处OD值表示 ) ,取药物敏感浓度 (2× 10 2 U/L)分别观察分化功能〔用碱性磷酸酶 (ALP)活性表示〕和矿化功能 (用矿化结节数量 /视野表示 )。结果　OB2 增殖功能 (OD值 )实验组为 0 336± 0 0 73～ 0 35 9± 0 0 5 1,对照组为 0 347± 0 0 35 ;OB2 分化功能〔ALP(U/g蛋白质 )活性〕实验组为 83± 9,对照组为 81± 4 ;OB2 矿化结节数量 /视野 (个 )实验组为 6 0± 1 82 6 ,对照组为1 5± 1 0。结论　骨折愈合刺激素各浓度对OB2 的增殖和分化功能均无明显作用 (P >0 0 5 ) ,而对其矿化功能具有明显的刺激作用 (P <0 0 1)。     

长春新碱对体外培养成骨细胞的影响

目的　观察抗癌药物长春新碱对体外培养成骨细胞的作用。方法　在新生SD大鼠头颅骨次代成骨细胞 (OB2 )培养液中分别加入不同浓度 (10 -1～ 10 -9g/L)长春新碱 ,分别观察OB2 的增殖功能 (用波长 5 70nm处OD值表示 )、分化功能 [用碱性磷酸酶 (ALP)活性表示 ]和矿化功能 (用矿化结节数 /视野表示 )。结果　OD值实验组为 0 0 91± 0 0 0 5～ 0 2 97± 0 0 44 ,对照组为 0 34 7± 0 0 35 ;ALP(U/g蛋白质 )活性实验组为 77± 12 ,对照组为 81± 4;矿化结节数 /视野 (个 )实验组为 1 0±0 816,对照组为 1 5± 1 0。结论　从绝对数来看 ,各浓度长春新碱对OB2 的增殖、分化和矿化功能均具抑制作用。与对照组比较 ,长春新碱对OB2 增殖功能的抑制作用具有极显著性意义 (P <0 0 1)。     

生物陶瓷对体外培养大鼠成骨细胞的影响

生物陶瓷是近20年来研究的热点之一,作为无机生物医学材料,其良好的生物相容性,在医学领域广阔的应用前景,越来越受到学者们的重视。而大鼠成骨细胞的体外复合培养,常被应用于评估材料与成骨细胞间的相互作用,特别是材料对细胞增殖、功能、黏附的影响,其结果往往成为材料体内植入实验的基地。随着相关文献的增多,结合近年来有关文献就生物陶瓷对大鼠成骨细胞增殖、功能、黏附的影响作一回顾和分析。     

成骨细胞移植促进老龄鼠骨质疏松性骨折愈合过程中VEGF的动态变化

目的：动态观察在幼龄成骨细胞移植促进骨质疏松性骨折愈合过程中，VEGF在不同时相的表达及其生物学意义。方法：通过建立老龄骨质疏松SD大鼠骨折的动物模型，并将体外培养的SD雄性乳鼠成骨细胞移动到SD雌性鼠老年骨质疏松性骨缺损部位，利用免疫组化及原位杂交检测骨折愈合过程中不同时间相的移植标本VEGF、VEGFmRNA的表达，并作图像分析、绘出其动态变化图。结果：实验组VEGF、VEGFmRNA均在7d左右可见有阳性表达的细胞，14d有分泌,高峰其中以软骨细胞中阳性最强，21 d分泌量开始下降，56d后基本消失。而对照且未见明显分泌高峰。结论；成骨细胞细胞促进老龄鼠骨质疏松性骨折愈合，其机制可能是通过促进VEGF的转录和表达，从而促进骨折部位建立良好的血液循环，加速骨形成。     

高能震波对体外培养的大鼠成骨细胞和成纤维细胞的影响

目的 探讨高能震波(HESW)对成骨细胞和成纤维细胞的直接作用效应及其促进骨折愈合的机理。方法 对体外培养的上述两种细胞悬液分别施以不同剂量HESW，检测细胞的存活率、贴壁率及增殖能力，结果随着HESW剂量的增加，各实验组细胞的存活率、贴壁率及增殖能力逐渐降低。在相同的剂量，成纤维细胞组的上述各项指标均明显低于成骨细胞组(P＜0.05）。结论 HESW对成纤维细胞和成骨细胞均有杀伤和抑制生长怍用，日成纤维细胞对HESE的损伤更为敏感。这种敏感性不同可能使敏感性较差的成骨细胞在体内可获得更好的生长条件，而有利于骨折愈合。     

生骨注射液对大鼠成骨细胞VEGF mRNA表达的影响

目的: 研究生骨注射液对体外培养的大鼠成骨细胞VEGFmRNA表达的影响, 探讨其促进骨折愈合的分子机制。方法: 体外培养大鼠成骨细胞, 分别予不同浓度和时间的生骨注射液干预实验, 然后用RT PCR技术检测各组细胞的VEGFmRNA表达, 并行定量分析。结果: 不同浓度的生骨注射液连续干预至第 5d, 以 1mg/ml浓度条件下, VEGFmRNA表达最强, 干预 1 ~5d, VEGFmRNA的表达随时间逐渐增强。结论: 适当浓度的生骨注射液对体外培养的大鼠成骨细胞VEGFmRNA表达有明显促进作用, 其作用强度与时间有关。     

含药血清对体外培养成骨细胞的影响

目的 研究中药骨康吸收后不同浓度血清对离体大鼠成骨细胞增殖的影响及其对成骨细胞分泌IL-6的影响。方法 采用胶原-胰蛋白酶消化法获得新生大鼠的成骨细胞，然后以中药骨康吸收后血清，加入体外培养成骨细胞中进行培养，MTT法测成骨细胞增殖，ELISA法测培养上清中IL-6含量。结果 发现中药吸收后血清能促进成骨细胞的增殖和分化，各种浓度中以正常剂量药物灌胃后5h取血清含10％药物浓度最佳。同时，新生大鼠体外培养成骨细胞能够分泌IL-6，体外培养成骨细胞在培养后9d左右，IL-6的分泌达到高峰值，随后分泌IL-6的能力逐步下降，中药骨康含药血清可作用于成骨细胞，使其分泌IL-6的能力下降。结论 中药骨康含药血清能够促进成骨细胞的增殖与分化，从而促进骨形成同时可抑制成骨细胞分泌IL-6，这可能是中药骨康抑理骨吸收的机制之一。     

The effects of clindamycin on human osteoblasts in vitro

Introduction Clindamycin is an antibiotic frequently used in different local application forms for the treatment of prosthetic joint infections, chronic osteomyelitis or as infection prophylaxis in bone cement. No information is available regarding its direct effects on bone cells, although very high local effective antibiotic concentrations can be achieved. Materials and methods We cultured pooled osteoblasts, previously derived from human trabecular bone specimens of four healthy donors, with different concentrations of clindamycin (0–500 μg/ml) for 24, 48 and 72 h. Cell proliferation (MTT), cytotoxicity [lactate dehydrogenase (LDH)-activity], cell metabolism [alkaline phosphatase (ALP)-activity] and extracellular matrix calcification (Alizarin staining) were assessed after antibiotic treatment. Results Proliferation significantly decreased in a dose-dependent manner and reached 3.5% of control samples at 500 μg/ml at 72 h. LDH-activity was unaffected at lower concentrations but significantly increased at 500 μg/ml at 48 and 72 h. ALP-activity significantly increased at 10 μg/ml at 24 and 48 h and then decreased in a time- and dose-dependent manner. Calcification increased at 10 and 25 μg/ml, while it decreased or no calcification was found at concentrations of 50 μg/ml and above. Conclusion We could demonstrate that clindamycin at lower concentrations stimulated the cell metabolism of human osteoblasts and that higher clindamycin levels of 500 μg/ml had cytotoxic effects. The observed effects of high clindamycin levels on human osteoblasts highlight a potential alteration of bone metabolism in vivo and have to be taken into account in local antibiotic administration, e.g., in clindamycin-impregnated bone cement, where such high antibiotic concentrations can be achieved.     

Effect of near-infrared light on in vitro cellular ATP production of osteoblasts and fibroblasts and on fracture healing with intramedullary fixation

ObjectiveEvaluate the effect of near-infrared light (NIR) on immediate production of ATP by osteoblasts and fibroblasts in vitro, and the healing process of rat femur fractures with intramedullary fixation.BackgroundNIR is one potential treatment option for complications of fracture healing, which has shown to stimulate cellular proliferation and to enhance the healing process.MethodsCell culture – MC3T3-E1 and 3T3-A31 cells were subjected to NIR at 660 nm, 830 nm, or both combined. ATP was assayed at 5, 10, 20, and 45 min after exposure. Animal study – 18 rats had surgery with retrograde intramedullary pins inserted into their femurs, which then underwent closed, transverse femur fracture. Rats were randomly divided into 3 study groups of 6 each: nonirradiated controls, 660 nm, and 830 nm NIR. Healing process was assessed by a blinded radiologist, assigning a healing score of 1–6 for radiographs taken on days 0, 7, 14, and 21.ResultsCell culture – All groups gave significant increase in ATP within 5–10 min, with decay to baseline by 45 min. 660 nm NIR was significantly more effective than 830 nm with fibroblasts or either wavelength with osteoblasts. Animal study – A significant increase in the fracture healing grade in the 660 nm group at day 14, but with no differences at day 21.ConclusionThe study demonstrated an immediate increase in ATP production in vitro and an initial acceleration of callus formation in the fracture healing process, in the presence of NIR.     

The non-steroidal anti-inflammatory drug diclofenac reduces appearance of osteoblasts in bone defect healing in rats

Introduction

Non-steroidal anti-inflammatory drug (NSAID) is well known to significantly delay fracture healing. Results from in vitro studies implicate an impairment of osteoblast proliferation due to NSAIDs during the initial stages of healing. We studied whether diclofenac, a non-selective NSAID, also impairs appearance of osteoblasts in vivo during the early phase of healing (at 10 days).

Materials and methods

Two defects (Ø 1.1 mm) were drilled within distal femurs of 20 male Wistar rats. Ten rats received diclofenac continuously; the other obtained a placebo until sacrificing at 10 days. Osteoblast proliferation was assessed by cell counting using light microscopy, and bone mineral density (BMD) was measured using pQCT.

Results

Osteoblast counts from the centre of bone defect were significantly reduced in the diclofenac group (median 73.5 ± 8.4 cells/grid) compared to animals fed with placebo (median 171.5 ± 13.9 cells/grid). BMD within the defect showed a significant reduction after diclofenac administration (median 111.5 ± 9.3 mg/cm³) compared to the placebo group (median 177 ± 45.4 mg/cm³).

Conclusion

The reduced appearance of osteoblasts in vivo implicates an inhibiting effect of diclofenac on osteoblasts at a very early level of bone healing. The inhibition of proliferation and migration of osteoblasts, or differentiation from progenitor cells, is implicated in the delay of fracture healing after NSAID application.

     

Cell viability, osteoblast differentiation, and gene expression are altered in human osteoblasts from hypertrophic fracture non-unions

Recent studies have provided evidence that the number and proliferation capacity of bone marrow-derived mesenchymal stem cells, as well as the number of osteoprogenitor cells are reduced in patients with fracture non-unions. For fracture non-unions that do not heal after appropriate surgical intervention, the question arises as to what extent systemic cellular dysfunctions should be considered as being pathogenetic factors. For this purpose, we have examined the hypothesis that the cell function of osteoblasts isolated from patients with fracture non-unions may differ from those of normal control individuals in an identical and controlled in vitro situation. We analyzed the osteoblast cell viability, formation of alkaline phosphatase-positive (CFU-ALP) and mineralization-positive (CFU-M) colony forming units, as well as global differences of gene expression in osteoblasts from patients with fracture non-unions and from control individuals. We found that cell viability and CFU-M-formation were significantly reduced in non-union osteoblasts. This was accompanied by significant differences in osteoblast gene expression as revealed by Affymetrix-microarray analysis and RT-PCR. We identified a set of significantly down-regulated factors in non-union osteoblasts that are involved in regulation of osteoblast proliferation and differentiation processes (canonical Wnt-, IGF-, TGF-β-, and FGF-signaling pathways). The results of the present study strongly support the hypothesis that cell viability, differentiation, and gene expression of osteoblasts may be altered in patients who develop recurrent and recalcitrant fracture non-unions. Proteins involved in Wnt-, IGF, TGF-β-, and FGF-signaling pathways may be of particular interest and may unveil new potential therapies.     

肌肉活动方式对骨痂骨密度及X线片灰度值的影响

目的 探讨有利于骨折愈合的肌肉活动方式。方法 应用兔实验性骨折复位固定器对１８只兔一侧小腿胫腓骨中段骨折进行复位固定,以不同强度的电信号,刺激坐骨神经获得不同肌力的肌肉收缩活动。     

Correlations between mechanical stress history and tissue differentiation in initial fracture healing

A general theory for the role of intermittently imposed stresses in the differentiation of mesenchymal tissue is presented and then applied to the process of fracture healing. Two-dimensional finite element models of a healing osteotomy in a long bone were generated and the stress distributions were calculated throughout the early callus tissue under various loading conditions. These calculations were used in formulating theoretical predictions of tissue differentiation that were consistent with the biochemical and morphological observations of previous investigators. The results suggest that intermittent hydrostatic (dilatational) stresses may play an important role in influencing revascularization and tissue differentiation and determining the morphological patterns of initial fracture healing.