核壳结构CdS-TiO_2纳米颗粒体外光催化灭活白血病HL60细胞实验研究

本文研究了核壳结构CdS-TiO_2纳米颗粒光对HL60细胞光催化灭活作用,并初步探讨了CdS量子点增强TiO_2光催化灭活效率的作用机理。实验利用超声法制备了核壳结构CdS-TiO_2纳米颗粒,使用CCK-8法检测了其对白血病HL60细胞的光催化灭活效果,并采用活性氧分析和荧光发光光谱等分析手段对CdS量子点增强TiO_2光催化灭活效率的作用机理进行了分析。细胞实验结果表明,在暗室条件下,随着CdS包裹的TiO_2外壳的增厚,细胞的暗室存活率从28.5%逐渐上升至80%;在可见光照下,细胞的存活率显著下降。CdS-TiO_2纳米颗粒对HL60细胞的光催化灭活率均超过60%,其中CdS-TiO_2样品0.6对HL60细胞的光催化灭活效率最高,达到95%。根据荧光光谱和活性氧含量分析的结果推测,这可能是由于核壳结构的CdS内核与TiO_2外壳之间产生了有效的电子转移,抑制了TiO_2的空穴电子的复合,增强了TiO_2外壳的光催化活性,最终增加了TiO_2对HL60细胞的PDT灭活效果。     

叶酸修饰增强CdS-TiO_2光动力体外灭活HL60细胞效果探究

本文研究了叶酸修饰硫化镉掺杂二氧化钛(FA-CdS-TiO_2)纳米颗粒体外光动力(PDT)灭活HL60细胞的作用效果,探讨了叶酸修饰增强CdS-TiO_2体外PDT效果的作用机理。采用表面修饰的方法制备FA-CdSTiO_2;通过透射电镜(TEM)、傅里叶红外光谱(FTIR)、荧光激发光谱(FS)方法,对纳米颗粒进行结构和光学性质的表征;采用CCK-8法检测细胞活性;利用荧光探针标记技术分析细胞内活性氧水平和细胞对纳米颗粒的摄取效率。实验结果表明:叶酸修饰后,纳米颗粒粒径大小和光学性质符合光敏剂要求,且不会引起新的细胞毒性;通过叶酸修饰,细胞对纳米颗粒的摄取效率提升,细胞内活性氧产量提高,FA-CdS-TiO_2纳米颗粒的PDT效率明显增强,在FA-CdS-TiO_2浓度为20μg/m L时,暗室细胞存活率约为85%,可见光下对HL60细胞的灭活率达78%,实现了较低暗毒性下的较高PDT灭活效率。     

弱稳恒磁场环境下基于BiFeO_3@TiO_2复合纳米颗粒体外光动力疗法灭活HL60细胞试验研究

本文通过溶胶-凝胶法制备了BiFeO_3@TiO_2复合纳米颗粒,利用透射电镜(TEM)、X射线衍射(XRD)、荧光发光光谱等对纳米颗粒进行表征。研究采用Cell Counting Kit-8(CCK-8)法分别检测了在暗室条件、光照条件以及不同强度的弱稳恒磁场作用下,用终值质量浓度为50μg/mL纳米颗粒处理HL60细胞活性,试验结果表明:在暗室条件下,药物质量浓度为50μg/mL,与HL60细胞共同孵育12 h后,BiFeO_3@TiO_2复合纳米颗粒随着TiO_2外壳厚度增加,细胞的暗室相对存活率从78%增加到85%;在光照条件下,有弱稳恒磁场作用的BiFeO_3与TiO_2质量比为1∶2的BiFeO_3@TiO_2复合纳米颗粒对HL60细胞的PDT灭活效率最高达到78%,弱稳恒磁场环境增强了对HL60细胞的PDT灭活效率,这为对弱稳恒磁场环境下的光动力疗法治疗白血病肿瘤细胞的临床应用提供了参考。     

基于5-ALA-TS-FA体外光动力疗法灭活HL60细胞实验研究

本文通过癌症靶向性分子叶酸(FA),硅壳包裹的TiO_2(TS)纳米颗粒和5-氨基乙酰丙酸(5-ALA)进行结合形成新型光敏剂5-ALA-TS-FA,并研究其在光动力疗法(photodynamic therapy,PDT)治疗白血病肿瘤细胞HL60中的灭活效果。实验采用表面修饰的方法成功制备了5-ALA-TS-FA纳米颗粒,表征样品通过透射电镜(TEM)、傅里叶红外光谱(FTIR)、紫外-可见光吸收光谱(UV-Vis)等测试方法,通过加入不同浓度的复合纳米颗粒5-ALA-TS-FA与HL60细胞共育12 h,分别测量纳米颗粒的暗毒性和PDT灭活效应,其中PDT灭活效应采用Cell Counting Kit-8(CCK-8)法检测。实验结果表明,5-ALA-TS-FA复合纳米颗粒分散性良好;当药物浓度为100μg/m L与HL60细胞共育12 h后,5-ALA-TS-FA对HL60细胞的暗毒性较低,在光动力疗法中5-ALA-TS-FA灭活效率可达到74.65%,显著高于TiO_2和TS-FA的灭活效率。因此5-ALA-TS-FA作为一种潜在的光敏剂具备良好的应用前景。     

基于CdSe掺杂锐钛矿TiO_2的可见光体外灭活HL60细胞实验研究

用超声驱动方法合成了CdSe/TiO_2复合纳米粒子,并通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、紫外可见光(UV-Vis)吸收光谱和荧光(FS)光谱对CdSe/TiO_2复合纳米粒子进行表征。使用CCK-8法测定CdSe/TiO_2对白血病细胞的可见光光催化活性并通过SEM研究HL60细胞的表面超微结构形态。实验结果表明,用CdSe/TiO_2复合纳米粒子处理的组中观察到明显的HL60细胞生长抑制,并且HL60细胞在CdSe掺杂TiO_2复合纳米粒子作用下的PDT效率显著高于TiO_2,表明可以通过CdSe的修饰有效增强TiO_2的可见光光催化活性。此外,CdSe/TiO_2在可见光辐照下在4μg/m L的终值浓度下显示非常高的光动力效率,达76%。荧光光谱分析表明,CdSe/TiO_2复合纳米粒子可能通过分离光生空穴电子对提高此复合纳米粒子的光催化活性,从而提高CdSe/TiO_2对HL60细胞的PDT灭活效率。     

弱恒定电场对铁氮共掺二氧化钛纳米颗粒光催化灭活HL60细胞实验的影响研究

文章主要探讨弱恒定电场对铁氮共掺二氧化钛纳米颗粒光催化灭活HL60细胞实验的影响以及其机理。利用细胞计数法、CCK-8法检测、倒置显微镜、活性氧检测和荧光光谱等手段进行了分析研究,结果表明,在无电场作用下,此纳米颗粒光催化灭活HL60细胞的效率达到75.07%,然而在弱恒定电场的作用下,其效率将提高,在场强为600 m V/mm的电场作用下,其效率可达到80.13%,同时,对细胞膜的损伤程度也更大,产生的活性氧类物质也更多;荧光光谱分析推测,电场可能通过分离光生空穴电子对和提供能量给价带电子跃迁来使更多空穴和电子被利用,进而提高此纳米颗粒的光催化活性。     

可见光响应的CdTe/TiO2复合纳米颗粒体外PDT灭活HL60细胞的研究

文章采用溶胶凝胶法制备核壳CdTe/TiO_2复合纳米颗粒,探讨了该复合纳米颗粒体外PDT对HL60细胞的灭活作用。通过扫描电镜(TEM)、X射线光电子衍射仪(XPS)对CdTe/TiO_2进行表征。文中,用紫外可见光吸收光谱(UV-vis)测得尺寸为2-5 nm的CdTe QDs吸收峰为460 nm。研究表明,CdTe/TiO_2复合纳米颗粒尺寸在80 nm左右,其吸收光谱相较于TiO_2的光响应区拓展至可见光区。将CdTe/TiO_2与HL60细胞进行共同孵育,采用CCK-8法研究了其在暗室条件下细胞的生长情况和浓度对细胞相对存活率的影响以及在不同浓度的CdTe/TiO_2复合纳米颗粒PDT后的细胞活性。实验结果表明:在共同孵育16 h后CdTe/TiO_2对HL60细胞的毒性最强,10~320μg/mL浓度的CdTe/TiO_2样品对HL60细胞均具有较强的灭活作用。当添加CdTe/TiO_2样品浓度为320μg/mL时,光照1 h后PDT灭活效率达到87.7%。     

5-ALA表面修饰TiO2诱导的光动力疗法体外灭活HL60细胞实验研究

利用表面修饰的方法制备了5-ALA表面修饰的TiO2（5-ALA／TiO2）,并利用傅里叶红外光谱,拉曼光谱以及紫外-可见光吸收光谱（uV—Vis）对样品进行了表征。利用CellCountingKit-8（CCK-8）法检测研究5-ALA／TiO2对HL60细胞的灭活效应。结果显示,5-ALA／TiO2能够显著地抑制HL60细胞的生长,5-ALA／TiO2对HL60细胞的灭活效率要明显高于5-ALA以及TiO2,实验中5-ALA／TiO2的灭活效率达到77．9％,相衬显微镜细胞形态学无损观察表明,细胞凋亡开始于细胞膜的破裂。同时,激光显微拉曼光谱检测显示,TiO2纳米粒子能够进入细胞内部,与细胞发生相互作用。     

基于HA修饰的CoFe2O4-TiO2纳米颗粒体外PDT灭活HL60细胞的试验研究

通过水热法和表面修饰法制备了以Co Fe₂O₄为内核、Ti O₂为外壳、用透明质酸修饰的HA@Co Fe₂O₄-Ti O₂。利用场发射扫描电子显微镜(SEM)成像、能谱分析(EDS)、X射线衍射(XRD)、X射线光电子谱(XPS)、紫外-可见吸收光谱(UV-Vis)以及傅里叶变换红外光谱(FTIR)对复合纳米颗粒的理化性质进行表征。用细胞计数试剂(CCK-8)法研究HA@Co Fe₂O₄-Ti O₂复合纳米颗粒在暗室条件下对白血病HL60细胞的毒性，以及在光照条件下的光动力疗法(PDT)灭活效果。结合复合纳米颗粒的荧光光谱(FS)、细胞内活性氧(ROS)产量和摄取纳米颗粒水平分析，初步探究Co Fe₂O₄和透明质酸与Ti O₂结合影响PDT灭活HL60细胞的作用机制。试验结果表明，HA@Co Fe₂O     

基于Fe-TiO_2和Ni-TiO_2的PDT体外灭活HL60细胞的试验研究

本文通过溶胶-凝胶法制备了Fe-TiO_2和Ni-TiO_2纳米颗粒,并研究这两种纳米颗粒体外光动力疗法(PDT)对HL60细胞的灭活效果。通过透射电镜(TEM)、能谱仪(EDS)、X射线衍射(XRD)、紫外-可见光(UVVis)吸收光谱等方法对纳米颗粒进行表征。使用CCK-8法分别测定Fe-TiO_2和Ni-TiO_2对HL60细胞的灭活效果。结果表明,不同终值浓度及掺杂量的Fe-TiO_2和Ni-TiO_2纳米颗粒对HL60细胞的暗毒性较低,但是PDT效率均显著高于未掺杂的TiO_2。在各自的最佳作用参数下,PDT灭活效率分别达到72. 5%±1. 6%和56. 4%±1. 2%。此外,还对这两种纳米颗粒灭活效果的差异进行了探讨。     

Differential responses of proliferative and non-proliferative leukemia cells to oxidative stress

The response of three human leukemia cell lines, the proliferative promonocyte THP-1 and the promyeloid HL60 cells and the non-proliferative phorbol ester-treated HL60 cells (HL60/PMA), to oxidative stress induced by tert-butylhydroperoxide (t-BHP) treatment was analyzed by fluorescence microplate assay, anti-oxidant enzyme activity measurements, high performance liquid chromatography, yopro-1/PI incorporation, poly (ADP-ribose) polymerase and caspase 3 cleavages. After t-BHP treatment, the non-proliferative HL60/PMA cells exhibited a weak increase in reactive oxygen species (ROS) production, a better preservation of thiol content, a decrease of glutathione peroxidase activity and a high ability to undergo necrosis rather than apoptosis. Submitted to the same treatment, the proliferative HL60 and THP-1 cells exhibited a high increase of ROS production, a moderate thiol depletion and a high percentage of apoptosis. Under thiol depleting conditions, the oxidative treatment of the HL60/PMA cells resulted in a high ROS production that reached levels similar to those of the two other cell lines and in cell death mainly by necrosis. In conclusion, these results that show proliferative phenotype is essential for cell response towards oxidative stress, are of particular interest in chemotherapy involving an oxidative mechanism.     

Inhibition of free radical-mediated oxidation of cellular biomolecules by carboxylated chitooligosaccharides

The objective of this study was to identify the cellular antioxidant effects of carboxylated chitooligosaccharides (CCOS), a chemically modified derivative of chitooligosaccharides (COS), by assessing oxidation inhibition potential on cellular biomolecules such as lipids, proteins, and direct scavenging of reactive oxygen species (ROS). Radical-mediated oxidation of cell membrane lipids and proteins was dose-dependently inhibited by CCOS, assessed by amount of lipid hydroperoxides and carbonyl carbon content in mouse macrophages, RAW264.7 cells. Further, CCOS inhibited myeloperoxidase (MPO) activity in human myeloid cells (HL60) suggesting indirect possibility of inhibiting generation of reactive oxygen species (ROS) such as superoxide radicals, H(2)O(2) and HOCl. Direct radical scavenging studies carried out with DCFH-DA fluorescence probe concluded that CCOS can act as a potent radical scavenger in cells.     

纳米二氧化铈对神经细胞PC12及SH-SY5Y活力的影响

目的:探究纳米二氧化铈(CeO₂)对神经细胞PC12与SH-SY5Y活力的影响。方法:合成纳米CeO₂材料,并对其结构进行表征,性能进行评估。用不同终浓度(1、2.5、5、10、25、50、75、100、150 μg/ml)的纳米CeO₂分别处理PC12细胞与SH-SY5Y细胞24 h,使用MTT法检测其细胞活力。然后使用活性氧清除剂NAC与纳米CeO₂共孵育处理PC12细胞与SH-SY5Y细胞,并用DCFH-DA探针染色,在荧光倒置显微镜下观察各组细胞的数量及其荧光强度。对实验数据采用单因素方差(one-way ANOVA)分析。结果:纳米CeO₂处理后,PC12细胞(P＜0.01)与SH-SY5Y细胞(P＜0.01)的活力都明显下降,与对照组差异明显。DCFH-DA探针染色后,发现纳米CeO₂的浓度越高,荧光强度越强,表明有活性氧(ROS)的产生。活性氧清除剂NAC与纳米CeO₂(100 μg/ml)共同处理PC12后,荧光强度明显减弱。与25 μg/ml (P＜0.01)、50 μg/ml(P＜0.01)、75 μg/ml(P＜0.01)、100 μg/ml(P＜0.01)纳米CeO₂处理组相比,共同处理组细胞活力明显增加。结论:纳米CeO₂对神经细胞PC12与SH-SY5Y的活力有明显的抑制作用,其机制可能与ROS有关。     

Silver nanoparticles induce apoptotic cell death in Candida albicans through the increase of hydroxyl radicals

Silver nanoparticles have been shown to be detrimental to fungal cells although the mechanism(s) of action have not been clearly established. In this study, we used Candida albicans cells to show that silver nanoparticles exert their antifungal effect through apoptosis. Many studies have shown that the accumulation of reactive oxygen species induces and regulates the induction of apoptosis. Furthermore, hydroxyl radicals are considered an important component of cell death. Therefore, we assumed that hydroxyl radicals were related to apoptosis and the effect of thiourea as a hydroxyl radical scavenger was investigated. We measured the production of reactive oxygen species and investigated whether silver nanoparticles induced the accumulation of hydroxyl radicals. A reduction in the mitochondrial membrane potential shown by flow cytometry analysis and the release of cytochrome c from mitochondria were also verified. In addition, the apoptotic effects of silver nanoparticles were detected by fluorescence microscopy using other confirmed diagnostic markers of yeast apoptosis including phosphatidylserine externalization, DNA and nuclear fragmentation, and the activation of metacaspases. Cells exposed to silver nanoparticles showed increased reactive oxygen species and hydroxyl radical production. All other phenomena of mitochondrial dysfunction and apoptotic features also appeared. The results indicate that silver nanoparticles possess antifungal effects with apoptotic features and we suggest that the hydroxyl radicals generated by silver nanoparticles have a significant role in mitochondrial dysfunctional apoptosis.     

绞股蓝总皂苷对光老化人皮肤成纤维细胞凋亡及Caspase-3信号通路的影响

目的:探讨绞股蓝总皂苷(Gyp)对光老化人皮肤成纤维细胞(HSF细胞)凋亡以及Caspase-3信号通路的影响。方法:分别以80、160、320 mg/d剂量的Gyp生理盐水溶液灌胃大鼠7d后取血并分离血清,长波紫外线(UVA)照射方法(照射剂量36 J/cm3)构建光老化HSF细胞模型以得到低剂量组、中剂量组、高剂量组,同时以空白对照组(未照射细胞)、UVA模型组、正常组为对照。UVA诱导的细胞活性氧表达采用二氯荧光素(DCF)法测定,细胞凋亡情况采用TUNEL法测定,HSF细胞活性采用四甲基偶氮唑盐微量酶反应比色法(MTT法)测定,Bax、Bcl-2、Caspase-3基因和蛋白表达分别采用反转录-聚合酶链反应(RT-PCR)和Western-blotting方法进行测定。结果:与空白对照组比较,其余5组的OD值、HSF细胞凋亡数、活性氧(平均荧光强度)、活性氧水平、Bax、Bcl-2、Caspase-3 mRNA及蛋白表达水平差异具有统计学意义(P0.05);与UVA模型组和正常组比较,低、中、高剂量组OD值、HSF细胞凋亡数、活性氧(平均荧光强度)、活性氧水平、Bax、Bcl-2、Caspase-3 mRNA及蛋白表达水平差异具有统计学意义(P0.05);低、中、高剂量组随着剂量增加OD值、Bcl-2mRNA和蛋白表达水平逐渐升高,细胞凋亡数、活性氧(平均荧光强度)、活性氧水平、Bax、Caspase-3 mRNA和蛋白表达水平逐渐降低(P0.05)。结论:Gyp通过抑制细胞内活性氧的产生以及Bax的表达,以及激活Bcl-2、Caspase-3信号通路而逆转UVA诱导的HSF细胞凋亡,进而延缓HSF细胞的光老化现象。     

Induction of phospholipid hydroperoxide glutathione peroxidase in human polymorphonuclear neutrophils and HL60 cells stimulated with TNF-alpha

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is characterized as an important enzyme for protecting cells from oxidative stress-induced apoptosis and regulating the production of leukotrienes and prostanoids in cells overexpressing PHGPx. We studied whether the expression level of PHGPx fluctuates in polymorphonuclear leukocytes (PMNs) which were exposed to reactive oxygen species (ROS) and inflammatory cytokines at an inflammation site. Human peripheral PMNs up-regulated the expression level of PHGPx following culture with TNF-alpha, but not with IL-1beta, IL-8, and GRO. The up-regulated PHGPx expression was also observed in neutrophil-like cells that differentiated from the human leukemia cell line HL60 only after stimulation with TNF-alpha. However, macrophage-like differentiated HL60 cells and other cell lines, A498, ECV304, HeLa, U937, and HEK293, showed no increase in the PHGPx expression. This up-regulation of PHGPx was inhibited by treatment with the anti-oxidants, pyrrolidine dithiocarbamate, and N-acetyl-L-cysteine, and by inhibitors of NFkappaB and Src kinases. The stimulation of neutrophil-like differentiated HL60 cells with TNF-alpha induced activation of NFkappaB and c-Src kinase, and the activation was attenuated by treatment with the anti-oxidants. Up-regulation in neutrophil-like HL60 cells was also observed following exposure to H(2)O(2). These results indicate that activation of NFkappaB and/or Src kinases through ROS signaling may be involved in the up-regulation of the PHGPx in human PMNs stimulated by TNF-alpha.