间歇式轴向压应力对组织工程骨种子细胞的黏附增殖与成骨分化促进作用的研究

目的探究间歇式轴向压应力对组织工程骨种子细胞黏附、增殖与成骨分化能力的影响。方法构建表达绿色荧光蛋白的兔骨髓间充质干细胞(rBMSCs)作为示踪种子细胞,运用旋转细胞培养仪将松质骨支架和种子细胞共培养7 d获得组织工程骨(TEB),实验组在第7～14天施加大小10 N、频率1 Hz、4 h/d的间歇式轴向压应力刺激,对照组常规培养,14 d后胰酶消化法获取两组种子细胞并比较其黏附、增殖和成骨分化能力。采用两组独立样本t检验进行统计学分析。结果 (1)流式细胞术显示rBMSCs被成功提取分离。(2)倒置荧光显微镜及扫描电镜显示TEB中种子细胞与支架相容性良好。(3)活体荧光成像系统及扫描电镜显示应力刺激组种子细胞的生长状况要优于非应力刺激组,前者平均荧光密度及细胞数/500倍视野均大于后者,差异均具有统计学意义(平均荧光密度:(3.75±0.34)×108 vs(2.91±0.22)×108,t=2.90,P=0.04;细胞数/500倍视野:30.50±4.43 vs 21.00±5.13,t=3.14,P=0.01)。(4)细胞黏附实验显示,应力刺激组种子细胞的75﹪细胞贴壁时间短于非应力刺激组,两组时间分别为(3.00±0.41) h、(13.33±1.70)h,差异具有统计学意义(t=8.20,P <0.01),前者的最终细胞贴壁率高于后者(99.97﹪±0.34﹪vs 85.83﹪±1.18﹪),差异具有统计学意义(t=11.31,P <0.01)。(5) CCK-8检测显示,在培养第48～96 h,应力刺激组种子细胞的增殖能力优于非应力刺激组,将两者的450 nm吸光度值在第48小时(0.49±0.02、0.40±0.02)、72 h(0.76±0.07、0.64±0.04)和96 h(1.58±0.07、1.34±0.13)分别进行比较,差异均具有统计学意义(t=5.15、2.57、2.86,P均<0.01)。(6)在成骨诱导14 d后,应力刺激组种子细胞的ALP和Ca结节染色阳性率要强于非应力刺激组:两组ALP染色阳性率分别为26.73﹪±4.56﹪、16.68﹪±3.89﹪,差异具有统计学意义(t=3.33,P=0.03);两组Ca结节染色阳性率分别为41.81﹪±3.56﹪、27.40﹪±2.35﹪,差异具有统计学意义(t=3.68,P=0.02)。结论间歇性轴向压应力可促进组织工程骨种子细胞的黏附、增殖与成骨分化

SDF-1α/CXCR4信号通路对轴向应力刺激促进骨再生中影响的实验研究

目的 通过轴向应力刺激促进骨再生,观察基质细胞衍生因子1α/趋化因子CXC亚族受体4(stromal cell-derived-factor-1α/cysteine X cysteine receptor 4,SDF-1α/CXCR4)信号通路变化,探讨轴向应力刺激促进骨再生的机制。方法 取72只雄性新西兰大白兔,于右后肢胫骨近端内侧制备直径8 mm圆形皮质骨缺损并脱蛋白松质骨支架修复模型后,随机分为3组(n=24)。A组腹腔注射PBS,B组术肢给予应力刺激治疗+腹腔注射PBS,C组术肢给予应力刺激治疗+腹腔注射CXCR4拮抗剂(AMD3100)。术后2、4、8、12周,摄X线片并采用Lane-SandhuX线评分标准评价骨愈合情况,取标本行HE染色观察新生骨组织及支架降解,免疫组织化学染色观察VEGF、CXCR4表达水平;4、8周取标本Western blot检测SDF-1α及CXCR4蛋白表达水平。12周行Micro-CT检查,计算新生骨体积及新生骨密度。结果 X线片检查示,除术后2周各组骨缺损区及支架无明显变化外,4、8及12周时B组骨愈合评分均优于A、C组(P<0.05)。12周时Micro-CT扫描可见B组骨缺损修复、髓腔再通,新生骨体积及骨密度均高于A、C组(P<0.05)。HE染色显示,术后4周开始B组骨再生及支架降解均明显快于A、C组。免疫组织化学染色示,各组VEGF及CXCR4阳性表达均在4周时达峰值;各时间点B组VEGF及CXCR4表达量均显著高于A、C组(P<0.05)。Western blot检测显示,4、8周时B组SDF-1α与CXCR4表达量均显著高于A、C组(P<0.05)。结论 轴向应力刺激促进骨再生可能与其促进骨缺损区组织高表达SDF-1α,激活与其下游调控BMSCs募集的CXCR4信号有关

SDF-1α/CXCR4信号通路在轴向应力刺激促进骨再生中的作用研究

目的通过轴向应力刺激促进骨再生,观察基质细胞衍生因子1α/趋化因子CXC亚族受体4(stromal cell-derived factor 1α/cysteine X cysteine receptor 4,SDF-1α/CXCR4)信号通路变化,探讨轴向应力刺激促进骨再生的机制。方法取72只雄性新西兰大白兔,于右后肢胫骨近端内侧制备直径8 mm圆形皮质骨缺损并脱蛋白松质骨支架修复模型,随机分为3组(n=24)。A组腹腔注射PBS,B组术肢给予应力刺激治疗+腹腔注射PBS,C组术肢给予应力刺激治疗+腹腔注射CXCR4拮抗剂(AMD3100)。术后2、4、8、12周,摄X线片并采用Lane-Sandhu X线评分标准评价骨愈合情况,取标本行HE染色观察新生骨组织及支架降解,免疫组织化学染色观察VEGF、CXCR4表达水平;4、8周取标本Western blot检测SDF-1α及CXCR4蛋白表达水平;12周行Micro-CT检查,计算新生骨体积及新生骨密度。结果 X线片检查示,除术后2周各组骨缺损区及支架无明显变化外,4、8及12周时B组骨愈合评分均高于A、C组(P<0.05)。12周时Micro-CT扫描可见B组骨缺损修复、髓腔再通,新生骨体积及骨密度均高于A、C组(P<0.05)。HE染色显示,术后4周开始B组骨再生及支架降解均明显快于A、C组。免疫组织化学染色示,各组VEGF及CXCR4阳性表达均在4周达峰值;各时间点B组VEGF及CXCR4表达量均显著高于A、C组(P<0.05)。Western blot检测显示,4、8周时B组SDF-1α与CXCR4表达量均显著高于A、C组(P<0.05)。结论轴向应力刺激促进骨再生可能与其促进骨缺损区组织高表达SDF-1α,激活与其下游调控BMSCs募集的CXCR4信号有关。国家自然科学基金资助项目(81401783);;\n福建省自然科学基金资助项目(2016J05208);;\n军队后勤科研项目基金(CNJ16C013);;\n军队青年医学科技培育项目(19QNP046)~

SDF-1α/CXCR4信号通路在轴向应力刺激促进骨再生中的作用研究

目的 通过轴向应力刺激促进骨再生,观察基质细胞衍生因子1α/趋化因子CXC亚族受体4(stromal cell-derived-factor-1α/cysteine X cysteine receptor 4,SDF-1α/CXCR4)信号通路变化,探讨轴向应力刺激促进骨再生的机制..

低能铁离子注入氨基酸分子改性和质量沉积

用110keV Fe+注入L（+）-半胱氨酸薄膜样品,经盐酸溶解后通过缓慢蒸发育成纯物质单晶,并对其中一粒单晶用四圆衍射仪进行了X射线衍射分析.晶体属单斜晶系,空间群为C2,晶体学参数a=1.8534（4）nm,b=0.5234（1）nm,c=0.7212（1）nM,β=103.72（3）°,V=0.67965（3）nm3,Z=4,F（000）=144.0,Dclac=1.763 g·cm-3,μ（MoKα）=1.06mm-1,T=293（2）K.最终一致性因子R=0.0379,wR=0.0835.晶体化合物的化学式为[CH2CH（NH2）NO2]ClFe（Mr=180.38）.提纯了重离子束改性分子并直接证实注入铁离子在新分子中的质量沉积.相同注量的110 keV Fe+离子注入L（+）-半胱氨酸盐酸盐单晶水合物薄膜样品后的Fourier变换红外光谱分析表明,样品分子受到严重损伤,产生了很大变化

低能铁离子束对原卟啉IX二钠盐的辐照效应研究

110 ke V Fe+ 离子注入原卟啉 IX二钠盐薄膜样品后的一些谱学分析结果表明 ,低能铁离子束辐照可以导致生物分子的损伤和化学改性 ,并且初步证实注入铁离子在样品分子中慢化沉积后能形成含铁的金属络合物 ,即注入铁离子的质量沉积

Effects of the Decomposition of Chaetomorpha sp. on Nitrogen and Phosphorus Levels in Water from Swan Lake

Macroalgal blooms,which can dramatically modify nitrogen (N) and phosphorus (P) cycle in water column and sediments, have frequently occurred in coastal areas in recent decades. Rongcheng Swan Lake,a natural coastal lagoon in the eastern Shandong Peninsula in China,has suffered from extensive macroalgal blooms dominated by Chaetomorpha sp. over the past ten years. In the present study,Chaetomorpha sp. and the sediments from different areas of Swan Lake were collected to study the influence of algal decomposition on N and P levels in the overlying water. In addition,the changes of physio-chemical parameters in water were detected during the algal decomposition,and the release potential of N and P from sediments in different lake areas was estimated. The results showed that the concentrations of total nitrogen (TN) and NH_4 ~+ -N in water increased obviously during the first 16 days due to the decomposition of Chaetomorpha sp.,and reached 12.40 mg /L and 7.98 mg /L,respectively. However,the concentrations of total phosphorous (TP) and soluble reactive phosphorous (SRP) changed slightly at the early stage,and increased significantly after 19 days. During the experiment, the concentrations of TP and SRP ranged from 0.02-1.14 mg /L and 0.01-0.40 mg /L, respectively. After 16 days of the incubation experiment,N and P concentrations in water at different sediment treatments both followed the order of: treatment with sediments and algae > treatment with only algae > treatment with only sediments. There were great differences in the release ability of N and P from the sediments among different lake regions. Under the condition of algal decomposition,the order of the release amount of N and P from the sediments was: center > northwest > south and northwest > center > south. During the degradation phase of green tide,the concentrations of TN,NH_4 ~+ -N,TP and SRP in water all increased significantly due to the nutrient release from the decomposing Chaetomorpha sp. and the indirect effect on promoting nutrient release from the sediments,which aggravated the level of water eutrophication in Swan Lake,China. Therefore,the massive decomposing Chaetomorpha sp. should be salvaged quickly to avoid the deterioration of water quality in Swan Lake