银铁纳米复合材料的脑胶质瘤放射增敏作用

目的 研究银/四氧化三铁纳米复合材料(Ag/Fe3O4)对人源性脑胶质瘤U251细胞的放射敏感性的影响.方法 人源性脑胶质瘤U251细胞分为对照组、Ag/Fe3O4组、放疗组、Ag/Fe3O4复合放疗组.用集落形成实验检测Ag/Fe3O4对U251细胞放疗效果;流式细胞术检测银纳米颗粒(AgNPs)对细胞周期和凋亡率的影响.结果 Ag/Fe3O4能够引起U251细胞G2/M期阻滞,并使细胞放疗后凋亡率显著提高(P＜0.05).结论 可利用Ag/Fe3O4纳米颗粒提高脑胶质瘤放射敏感性.     

热、放射诱导的SHG-44细胞凋亡与Fas/FasL、Caspase-3表达关系

目的 了解热疗联合放射对SHG-44细胞凋亡的影响及凋亡相关基因Fas／FasL和Caspase-3的变化。方法 采用流式细胞仪(FCM)检测对照组、单纯放射(2Gy)组、放射(2Gy) 42℃加热(加热时问40分钟)组细胞凋亡的改变，并用RT-PCR法检测Fas／FasL和Caspase-3的表达。结果 空白对照组、单纯放射组、放射 热疗组凋亡比率分别为20．2％、29．3％和59．1％；Fas在三个实验组中均表达，但FasL和Caspase-3仅在单纯放射组、放射 热疗组中表达。结论 凋亡是热杀灭脑胶质瘤细胞SHG-44的主要方式，凋亡与Fas／FasL、Caspase-3有关。     

姜黄素-PLGA纳米粒的制备及诱导胶质瘤细胞凋亡的实验研究

目的制备姜黄素-PLGA纳米粒(Cur-PLGA-NPs),评价其对胶质瘤细胞的影响。方法 C6、U251细胞传代培养,随机分为对照组、姜黄素组和姜黄素-PLGA组。倒置荧光显微镜、透射电镜观察Cur-PLGA-NPs的形态;马尔文粒径电位仪检测Cur-PLGA-NPs的粒径;酶标仪检测Cur-PLGA-NPs的包封率和载药率;荧光显微镜观察C6、U251细胞对Cur-PLGA-NPs的摄取;CCK-8检测Cur-PLGA-NPs对C6、U251细胞活性的影响;流式细胞术检测Cur-PLGA-NPs对凋亡的影响;Hoechst染色检测凋亡。结果 Cur-PLGA-NPs的平均粒径为(284.6±9.0)nm,呈球形。其包封率为(70.712±2.615)%,载药率为(2.828±0.105)%。与对照组、姜黄素组相比,C6、U251细胞对Cur-PLGA-NPs的摄取均明显增加(P<0.05);与对照组、姜黄素组相比,姜黄素-PLGA组的C6、U251细胞活性均明显降低(P<0.05)。与对照组、姜黄素组相比,Cur-PLGA-NPs能更明显引起C6、U251细胞凋亡(P<0.05)。结论与姜黄素相比,Cur-PLGA-NPs能增强肿瘤细胞对药物的摄取,促进肿瘤细胞凋亡。     

Effects of nano ZnO powders coculture in vetro with HACaT cell lines under UVB radiation on the appoptosis

目的 研究纳米氧化锌(ZnO)颗粒对远紫外光(UVB)照射人皮肤HACaT细胞株凋亡的影响.方法 实验细胞分为对照(A)组、纳米ZnO共培养(B)组、UVB照射(C)组和UVB照射ZnO共培养(D)组.采用均匀沉淀法合成纳米ZnO颗粒并运用扫描电镜(SEM)和X-射线衍射(XRD)对其进行表征.使用310 nm UVB照射细胞,细胞计数试剂盒8(CCK-8)观察细胞增殖,流式细胞术观察细胞凋亡,Western blot观察细胞凋亡相关蛋白B细胞淋巴瘤-白血病2(Bcl-2)、Bcl相关X蛋白(Bax)表达.结果 经SEM表征,ZnO颗粒平均粒径为(40±6)nm.纳米ZnO孵育细胞不会影响细胞的增殖,也不会导致细胞发生显著的凋亡;UVB照射细胞能抑制细胞增殖并导致细胞发生大量早期凋亡,而纳米ZnO能显著降低UVB照射细胞抑制率及凋亡率(P＜0.05).结论 纳米ZnO能很好的保护HACaT细胞免受UVB的影响.     

热疗上调细胞间隙连接通讯对胶质瘤侵袭性的影响及其机制

目的探讨热疗降低胶质瘤侵袭性的作用与细胞间隙连接通讯(gap junctional intercellular communication,GJIC)的关系。方法热疗处理C6胶质瘤细胞后,免疫组织化学法和Western blot法动态检测HSP70和Cx43的表达水平;划痕标记染料示踪技术检测胶质瘤GJIC功能变化;结晶紫染色法检测胶质瘤侵袭性的改变。结果 C6细胞经热疗后,HSP70表达增加,于30 min时含量最多。C6细胞内Cx43的表达水平也在热疗后明显增加,并于热疗后的120 min达高峰,后逐渐减少。热疗后GJIC功能的恢复与C6细胞内Cx43的表达相一致,且GJIC功能越强,胶质瘤侵袭性越低。结论胶质瘤细胞经热疗后HSP70表达增加,增加的HSP70可能是通过其分子伴侣作用提高Cx43的表达水平,进而上调GJIC功能而引起胶质瘤侵袭性的下降。     

纳米ZnO颗粒共培养对UVB照射体外人皮肤HACaT细胞株凋亡的影响

目的研究纳米氧化锌(ZnO)颗粒对远紫外光(UVB)照射人皮肤HACaT细胞株凋亡的影响。方法实验细胞分为对照(A)组、纳米ZnO共培养(B)组、UVB照射(C)组和UVB照射ZnO共培养(D)组。采用均匀沉淀法合成纳米ZnO颗粒并运用扫描电镜(SEM)和X-射线衍射(XRD)对其进行表征。使用310nm UVB照射细胞,细胞计数试剂盒8(CCK-8)观察细胞增殖,流式细胞术观察细胞凋亡,Western blot观察细胞凋亡相关蛋白B细胞淋巴瘤-白血病2(Bcl-2)、Bcl相关X蛋白(Bax)表达。结果经SEM表征,ZnO颗粒平均粒径为(40±6)nm。纳米ZnO孵育细胞不会影响细胞的增殖,也不会导致细胞发生显著的凋亡;UVB照射细胞能抑制细胞增殖并导致细胞发生大量早期凋亡,而纳米ZnO能显著降低UVB照射细胞抑制率及凋亡率(P<0.05)。结论纳米ZnO能很好的保护HACaT细胞免受UVB的影响。     

槲皮素对热应激后神经胶质瘤细胞凋亡及热激蛋白表达的影响

目的探讨槲皮素对神经胶质瘤细胞(C6细胞)凋亡的影响及作用机制。方法 C6细胞加入槲皮素0~200μmol·L-1培养1 h后,于42℃水浴加热1 h,再正常培养12 h。MTT法检测C6细胞存活率,Hoechst/PI双染法,annexinⅤ-FITC/PI双染检测细胞凋亡率,Western印迹法检测热激蛋白70(HSP70)表达。结果与正常对照组相比,加热组细胞存活率和细胞凋亡率均无明显改变,但加热组HSP70表达水平从正常对照组的0.22±0.01升高到0.36±0.02(P<0.01)。槲皮素能明显抑制C6细胞增殖,槲皮素50,100,150和200μmol·L-1细胞存活率分别为103%,86%,77%和75%,呈浓度依赖性(r=0.94,P<0.05)。槲皮素50,100和200μmol·L-1显著诱导C6细胞凋亡(P<0.05)。与加热组相比,随着槲皮素浓度的增加,C6细胞早期和晚期凋亡率均明显增加,最高细胞凋亡率为59%,槲皮素200μmol·L-1处理后明显降低了加热导致的HSP70表达增加,降低了53%(P<0.01)。结论槲皮素可以抑制HSP70表达并诱导神经胶质瘤细胞凋亡。     

DMSA-Fe3O4纳米磁流体介导热疗对兔VX2肿瘤的影响

目的探讨交变磁场介导的二巯基丁二酸(DMSA)-Fe3O4纳米磁流体热疗治疗兔VX2肿瘤的疗效。方法建立20只兔后肢VX2软组织肿瘤模型,随机分为4组:A组(对照组)、B组(磁流体局部注射组+热疗)、C组(磁流体动脉灌注组+热疗)、D组(磁流体静脉注射组+热疗),每组5只。成瘤2周后CT测量肿瘤大小。结果 B组和C组的肿瘤中心区[(46.01±1.97)℃和(40.38±1.50)℃]和肿瘤边缘区[(40.35±1.36)℃和(42.57±1.80)℃]的温度显著高于正常肌肉组织[(35.73±1.32)℃和(35.37±1.55)℃]和直肠[(35.69±1.05)℃和(35.25±1.15)℃](P<0.05);A组及D组肿瘤区域温度无明显增高。治疗后14d,B组和C组肿瘤生长率分别为(441.04±29.61)%和(354.81±59.51)%,明显低于A组的(1119.90±179.40)%和D组的(1099.90±215.11)%(P<0.05)。结论交变磁场介导的DSMA-Fe3O4纳米磁流体热疗能明显抑制兔VX2肿瘤生长。     

Effect of DMSA-Fe3O4 nano-magnetic fluid-mediated thermotherapy on rabbit VX2 tumor

目的 探讨交变磁场介导的二巯基丁二酸(DMSA)-Fe3O4纳米磁流体热疗治疗兔VX2肿瘤的疗效.方法 建立20只兔后肢VX2软组织肿瘤模型,随机分为4组:A组(对照组)、B组(磁流体局部注射组十热疗)、C组(磁流体动脉灌注组十热疗)、D组(磁流体静脉注射组十热疗),每组5只.成瘤2周后CT测量肿瘤大小.结果 B组和C组的肿瘤中心区[(46.01±1.97)℃和(40.38±1.50)℃]和肿瘤边缘区[(40.35±1.36)℃和(42.57±1.80)℃]的温度显著高于正常肌肉组织[(35.73±1.32)℃和(35.37±1.55)℃]和直肠[(35.69±1.05)℃和(35.25±1.15)℃](P＜0.05);A组及D组肿瘤区域温度无明显增高.治疗后14 d,B组和C组肿瘤生长率分别为(441.04±29.61)％和(354.81±59.51)％,明显低于A组的(1119.90±179.40)％和D组的(1099.90±215.11)％ (P＜0.05).结论 交变磁场介导的DSMA-Fe3O4纳米磁流体热疗能明显抑制兔VX2肿瘤生长.     

槲皮素血浆代谢物抗大鼠C6脑胶质瘤细胞的作用

目的:考察槲皮素大鼠血浆中的代谢物对大鼠C6脑胶质瘤细胞增殖与凋亡的作用。方法:将槲皮素血浆代谢产物槲皮素、槲皮苷和异鼠李素分别与C6胶质瘤细胞共培养24 h后,LDH活性法检测代谢产物对C6脑胶质瘤细胞的毒性作用,流式细胞仪检测C6胶质瘤细胞凋亡与线粒体膜电位变化。结果:槲皮素和异鼠李素对大鼠C6胶质瘤细胞有显著的细胞毒性作用,均能显著诱导C6胶质瘤凋亡(P<0.05),槲皮素显著降低线粒体膜电位(P<0.05)。结论:槲皮素血浆中的槲皮素甲基化代谢产物是主要的抗肿瘤活性成分,而槲皮素苷类代谢产物抗肿瘤活性较弱,为槲皮素及其靶向制剂进一步应用于脑胶质瘤的治疗提供参考依据。     

Genotoxic effects of silver nanoparticles with/without coating in human liver HepG2 cells and in mice

With the rapid expansion of human exposure to silver nanoparticles (AgNPs), the genotoxicity screening is critical to the biosafety evaluation of nanosilver. This study assessed DNA damage and chromosomal aberration in the human hepatoma cell line (HepG2) as well as the effects on the micronucleus of bone marrow in mice induced by 20 nm polyvinylpyrrolidone‐coated nanosilver (PVP‐AgNPs) and 20 nm bare nanosilver (AgNPs). Our results showed that the two types of AgNPs, in doses of 20‐160 μg/mL, could cause genetic toxicological changes on HepG2 cells. The DNA damage degree of HepG2 cells in 20 nm AgNPs was higher than that in 20 nm PVP‐AgNPs, while the 20 nm PVP‐AgNPs caused more serious chromosomal aberration than 20 nm AgNPs. Both kinds of AgNPs caused genetic toxicity in a dose‐dependent manner in HepG2 cells. In the micronucleus test on mouse bone marrow cells, in doses of 10, 50 and 250 mg/kg body weight administered orally for 28 days once a day, the two kinds of AgNPs have no obvious inhibitory effect on the mouse bone marrow cells, and the effect of chromosome aberration could be documented at the high dose of 250 mg/kg. These results suggest that AgNPs have genotoxic effects in HepG2 cells and limited effects on bone marrow in mice; both in vitro and in vivo tests could be of great importance on the evaluation of genotoxicity of nanosilver. These findings can provide useful toxicological information that can help to assess genetic toxicity of nanosilver in vitro and in vivo.     

Persistence of silver nanoparticles in the rat lung: Influence of dose,size, and chemical composition

Abstract

Increasing silver nanoparticle (AgNP) use in sprays, consumer products, and medical devices has raised concerns about potential health effects. While previous studies have investigated AgNPs, most were limited to a single particle size or surface coating. In this study, we investigated the effect of size, surface coating, and dose on the persistence of silver in the lung following exposure to AgNP. Adult male rats were intratracheally instilled with four different AgNPs: 20 or 110?nm in size and coated with either citrate or polyvinylpyrrolidone (PVP) at 0.5 or 1.0?mg/kg doses. Silver retention was assessed in the lung at 1, 7, and 21?d post exposure. ICP-MS quantification demonstrated that citrate-coated AgNPs persisted in the lung to 21?d with retention greater than 90%, while PVP-coated AgNP had less than 30% retention. Localization of silver in lung tissue at 1 d post exposure demonstrated decreased silver in proximal airways exposed to 110?nm particles compared with 20?nm AgNPs. In terminal bronchioles 1 d post exposure, silver was localized to surface epithelium but was more prominent in the basement membrane at 7?d. Silver positive macrophages in bronchoalveolar lavage fluid decreased more quickly after exposure to particles coated with PVP. We conclude that PVP-coated AgNPs had less retention in the lung tissue over time and larger particles were more rapidly cleared from large airways than smaller particles. The 20?nm citrate particles showed the greatest effect, increasing lung macrophages even 21?d after exposure, and resulted in the greatest silver retention in lung tissue.     

Time‐dependent biodistribution and excretion of silver nanoparticles in male Wistar rats

Silver nanoparticles (AgNPs) are the most commonly used nanoparticles owing to their antimicrobial properties. The motivation of the present study was (1) to analyze the effect of silver particle size on rat tissue distribution at different time points, (2) to determine the accumulation of AgNPs in potential rat target organs, (3) to analyze the intracellular distribution of AgNPs and (4) to examine the excretion of AgNPs by urine and feces. AgNPs were characterized by dynamic light scattering (DLS), zeta potential measurements, BET surface area measurements, transmission and scanning electron microscopy. AgNPs (20 and 200 nm) were administered intravenously (i.v.) to male Wistar rats at a dose of 5 mg kg^–1 of body weight. Biological material was sampled 24 h, 7 and 28 days after injection. Using inductively coupled plasma‐mass spectrometry (ICP‐MS) and transmission electron microscopy (TEM) it was observed that AgNPs translocated from the blood to the main organs and the concentration of silver in tissues was significantly higher in rats treated with 20 nm AgNPs as compared with 200 nm AgNPs. The highest concentration of silver was found in the liver after 24 h. After 7 days, a high level of silver was observed in the lungs and spleen. The silver concentration in the kidneys and brain increased during the experiment and reached the highest concentration after 28 days. Moreover, the highest concentration of AgNPs was observed in the urine 1 day after the injection, maintained high for 14 days and then decreased. The fecal level of silver in rats was the highest within 2 days after AgNPs administration and then decreased. Copyright © 2012 John Wiley & Sons, Ltd.     

二巯基丁二酸修饰的Fe3O4纳米磁液联合碘油动脉栓塞热疗治疗兔VX2肝癌

目的评估二巯基丁二酸修饰的Fe3O4(DSMA-Fe3O4)纳米磁液联合碘油动脉栓塞热疗治疗兔VX2肝癌的疗效。方法 25只开腹肝左叶种植VX2瘤的实验兔,随机等分为五组:对照组(A组)、碘油栓塞组(B组)、DSMA-Fe3O4纳米磁液+碘油栓塞组(C组)、DSMA-Fe3O4纳米磁液+热疗组(D组)、DSMA-Fe3O4纳米磁液+碘油栓塞+热疗组(E组)。成瘤2周后各组行CT扫描并测量,随后行肝动脉栓塞,D、E组栓塞后诱导热疗。分别在术后7、14d行CT检查,计算肿瘤生长比率、肿瘤增长体积。14dCT扫描结束后每组处死部分实验兔,取完整的肝、肾、脾及肺作病理检查。各组分别在术前1d,术后1、3、7d经兔耳缘静脉采血测ALT和AST。结果所有肝癌模型均建立成功。五组术前肿瘤体积、术前1d、术后7dALT、AST水平均无统计学差异(P>0.05)。术后14d,E组肿瘤体积平均缩小26.7%,而B、C、D三组肿瘤体积分别平均增大了200.7%、209.4%和422.5%。结论 DSMA-Fe3O4纳米磁液联合碘油动脉栓塞热疗兔VX2肝癌有效、安全。     

Comparison of acute to chronic ratios between silver and gold nanoparticles,using Ceriodaphnia dubia

As integration of nanoparticles (NPs) into products becomes more common, the need to address the paucity of chronic hazard information for aquatic environments required to determine risk potential increases. This study generated acute and chronic toxicity reference values for Ceriodaphnia dubia exposed to 20 and 100?nm silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) to generate and evaluate potential differences in acute-to-chronic ratios (ACR) using two different feeding methods. A modified feeding procedure was employed alongside the standard procedures to investigate the influence of food on organism exposure. An 8-h period before food was added allowed direct organism exposure to NP dispersions (and associated ions) without food-to-NP interactions. The AgNPs [chronic lethal median concentrations (LC50) between 18.7 and 31.9?µg/L] were substantially more toxic than AuNPs (LC50?=?21 507 to >26 384?µg/L). The modified chronic testing method resulted in greater sensitivity in AgNPs exposures. However, the modified feeding ration had less of an effect in exposures to the larger (100?nm) AgNPs compared to smaller particles (20?nm). The ACRs for AgNPs using the standard feeding ration were 1.6 and 3.5 for 20?nm and 100?nm, respectively. The ACRs for AgNPs using the modified feeding ration were 3.4 and 7.6 for 20?nm and 100?nm NPs, respectively. This supports that the addition of the standard feeding ration decreases C. dubia chronic sensitivity to AgNPs, although it must also be recognized organisms may be sensitized due to less access to food. The ACRs for 20?nm and 100?nm AuNPs (standard ration only) were 4.0 and 3.0, respectively. It is important to also consider that dissolved Ag⁺ ions are more toxic than AgNPs, based on both acute toxicity values in the cited literature and chronic toxicity thresholds generated in this study that support existing thresholds that Ag⁺ are likely protective of AgNPs effects.     

Male- and female-derived somatic and germ cell-specific toxicity of silver nanoparticles in mouse

Silver nanoparticles (AgNPs) are widely used as an antibiotic agent in textiles, wound dressings, medical devices, and appliances such as refrigerators and washing machines. The increasing use of AgNPs has raised concerns about their potential risks to human health. Therefore, this study was aimed to determine the impact of AgNPs in germ cell specific complications in mice. The administration of AgNPs results in toxicity in mice; however, a more detailed understanding of the effects of AgNPs on germ cells remains poorly understood. Here, we demonstrate the effects of AgNPs (20?nm in diameter) in a mouse Sertoli and granulosa cells in vitro, and in male and female mice in vivo. Soluble silver ion (Ag⁺)-treated cells were used as a positive control. We found that excessive AgNP-treated cells exhibited cytotoxicity, the formation of autophagosomes and autolysosomes in Sertoli cells. Furthermore, an increase in mitochondrial-mediated apoptosis by cytochrome c release from mitochondria due to translocation of Bax to mitochondria was observed. In in vivo studies, the expression of pro-inflammatory cytokines, including tumor necrosis factor α, interferon-γ, ?6, ?1β, and monocyte chemoattractant protein-1 were significantly increased (p?<?0.05). Histopathological analysis of AgNP-treated mice shows that a significant loss of male and female germ cells. Taken together, these data suggest that AgNPs with an average size of 20?nm have negative impact on the reproduction.     

Inhibitory effects of 1-methyl-4-phenylpyridinium on glutamate uptake into cultured C6 glioma cells

INTRODUCTION Glutamate is a predominant excitatory neurotrans-mitter in the mammalian central neuron system[1]. En-hanced glutamatergic activity is implicated in the pa-thology of neurological diseases, such as Parkinson dis-ease (PD)[1]. PDis characterized by a progressive andselective loss of dopaminergic neurons in substantianigra pars compacta (SNpc) which is the site of a glialactivation in PD. Regulation of glutamate level in thesynaptic cleft by glutamate transporters loca…     

吗啡对增殖细胞核抗原(PCNA)基因表达的影响

目的 :研究吗啡对培养的大鼠胶质细胞瘤C6的增殖抑制作用及其机制。方法 :3H -TdR掺入法测定吗啡对细胞增殖的影响 ;RT -PCR方法观察吗啡对细胞PCNA基因表达的影响。免疫组织化学法观察吗啡对细胞PCNA蛋白质水平的影响。结果 :不同浓度吗啡 (0 0 0 1- 10 0mg·L- 1 )作用于培养C6细胞 2 4h后 ,3H -TdR掺入量剂量依赖性降低。不同浓度吗啡 (0 0 0 1- 10 0mg·L- 1 )作用于培养C6细胞 2 4h后 ,细胞PCNAmRNA的相对含量与对照组相比均明显减少 (P <0 0 1)。 10mg·L- 1 吗啡作用细胞 6 - 4 8h后 ,不同时间点吗啡组细胞的PCNAmRNA的相对含量与对照组相比均明显减少 (P <0 0 1)。10mg·L- 1 吗啡作用细胞 2 4h后 ,与相邻吗啡组比较细胞内PCNA蛋白质水平明显降低 (P <0 0 1)。结论 :吗啡对胶质细胞瘤C6的增殖具有抑制作用 ,其机理可能与吗啡使细胞中PCNA的基因表达水平降低有关。