持续性压力培养环境对兔骨髓基质干细胞增殖的影响

背景:骨髓基质干细胞来源的成骨细胞是骨髓腔内主要的受力细胞,在人工关节置换病例中,其生命活动状况与假体传导压力有密切关系.目的:观察持续性压力培养环境对兔骨髓基质干细胞增殖的影响.揭示持续压力致假体松动下沉进展及其置换后活动影响的生物学机制.设计、时间及地点:随机分组设计,细胞学体外观察,于2004-02/2007-10在解放军第四军医大学骨科研究所完成.材料:出生1个月的新西兰幼兔1只,体质量0.5 kg,取其骨髓基质干细胞用于实验.方法:传代培养兔骨髓基质干细胞,将生长良好的第3代骨髓基质干细胞按1×104个/孔随机接种于7块24孔培养板,14 h后细胞完全贴壁,换新鲜含体积分数为10%胎生血清的DMEM.实验随机将4块培养板分为4组:对照组不予加压,20 kPa持续压力组,60 kPa持续压力组,100 kPa持续压力组分别在规定的时间内每天施以20,60,100 kPa的持续3 h压力.主要观察指标:四甲基偶氮唑盐法检测培养1,3,5,7 d各组骨髓基质干细胞的吸光度值变化.结果:除培养第1天外,第3,5,7天各压力组骨髓基质干细胞的吸光度值均低于对照组(P<0.01).其中第3天20 kPa持续压力组与60 kPa持续压力组吸光度值差异无显著性意义(P>0.05),但均高于100 kPa持续压力组(P<0.05).第5天不同持续压力组吸光度值两两比较差异具有显著性意义(P<0.05),压力越高,吸光度值越低.第7天100 kPa持续压力组吸光度值低于压力20 kPa持续压力组(P<0.05).结论:关节置换后早期患者不宜过早下地,否则将产生持续性应力,可以引起骨髓腔内骨髓基质干细胞的抑止,从而不利于骨质愈合,容易产生假体下沉和松动.

Effect of continuous pressure on the proliferation of rabbit's bone marrow stem cells

BACKGROUND: Osteoblasts derived from bone marrow stromal stem cells are the main force of the cells In bone marrow cavity.In the artificial joint replacement cases, their life situation is closely related to conductive pressure of prosthesis.OBJECTIVE: To observe the continuous pressure on the proliferation of rabbit's bone marrow stromal stem cells, and to reveal the biomechanism of continuous pressure causing loosening and sinking of prosthesis and its activity after replacement.DESIGN, TIME AND SE'I-I'ING: A randomized study based on cytology was performed at the Institute of Othorpaedics, the Fourth Military Medical University of Chinese PLA from February 2004 to October 2007.MATERIALS: One New Zealand rabbit aging 1 month and weighing 0.5 kg was used to extract the bone marrow stromal calls.METHODS: The third-passaged bone marrow stromal stem cells were inoculated in seven 24-well culture plates at the density of 1 × 104 cells/well. After 14 hours, cells were adherent completely and cultured in DMEM culture media containing 10% fetal bovine serum. Thereafter, the four culture plates were randomly divided into 4 experimental groups, including control group without any pressure, and continuous pressure (20, 60, and 100 kPa) groups. The continuous pressure was performed for 3 hours every day.MAIN OUTCOME MEASURES: Absorbance was detected at day 1, 3, 5, and 7 after culture using MTT assay.RESULTS: Absorbance of the three pressure groups after 3, 5 and 7 days was significantly lower than the control group (P < 0.01). There was no significant difference in absorbance between 20 kPa continuous pressure group and 60 kPa continuous pressure group on the third day (P >0.05); but the absorbance was significantly higher than 100 kPa continuous pressure group (P < 0.05). On the fifth day, there was significant difference in absorbance between paired continuous pressure groups (P < 0.05),i.e., the higher the continuous pressure was, the lower the absorbance was. On the seventh day, the absorbance of the 100 kPa continuous pressure group was significantly lower than 20 kPa continuous pressure group (P < 0.05).CONCLUSION: Patients with eady post-joint replacement had better not stand on the ground; otherwise, a continuous stress will be caused so as to induce the restrain of bone marrow stromal stem calls in the bone marrow cavity, which is not helpful for bone healing and easily causes subsidence and loosening of prosthesis.