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首先介绍了超声作用的物理机理和血卟啉及其衍生物的化学结构及物理化学性质,对超声激活血卟啉抗肿瘤疗法(声动力学疗法)近15年国内外的试验进展情况进行了总结,对比了不同参数超声系统对不同细胞系肿瘤的作用效果。重点探讨了超声激活血卟啉抑制肿瘤增殖的物理、化学和生物学机理,着重介绍了单线态氧机制和自由基理论,并对今后的基础研究和临床实践进行了展望。 相似文献
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文章主要研究纳米金溶胶的细胞毒性。通过[3H]-TdR掺入法,研究粒径在15—20nm的纳米金溶胶,溶胶中含有的柠檬酸钠溶液以及溶胶中含有的柠檬酸钠与PVP混合溶液对正常细胞(人体表皮细胞、人体皮肤成纤维细胞)和癌细胞(HeLa细胞、K562细胞)活性的影响,实验结果表明,纳米金溶胶中含有的柠檬酸钠与PVP对这四种细胞的活性基本没有影响,可以在一定浓度范围内促进人体正常皮肤细胞的增殖,并具有剂量(以50μmol/L浓度为临界点)和时间依赖性;对于癌细胞则需高于一定浓度(50μmol/L)才有显著的抑制作用。 相似文献
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在333K、pH=3.5~4.5、频率为40kHz的超声波条件下通过改变电流密度和电解液浓度,得到超声电解法制备超细钴金属粉体粒度的变化规律。研究了在电解过程中加入明胶和十二烷基硫酸钠分散剂对钴粉粒度的影响。在0.08mol/L CoCl2电解液,电流密度160mA,1v01%十二烷基硫酸钠分散剂,电解时间1h实验条件下得到了D50粒度为0.72μm的钴超细粉体。 相似文献
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以钛酸丁酯为原料,采用超声法制备了纳米TiO2,以该TiO2作为光催化剂,对模拟氯苯废水进行超声光催化降解研究,考察了TiO2的加入量、氯苯的初始浓度、溶液pH值、过氧化氢的浓度等对氯苯降解率的影响。结果表明,pH值对氯苯的超声光催化影响较小,H2O2的浓度、氯苯的初始浓度影响较大。在TiO2质量浓度为200mg/L、氯苯质量浓度为110.6mg/L、pH为7.0、反应时间为90min的条件下,氯苯降解率可达92.94%。探讨了氯苯TiO2光催化降解的机理,氯苯超声光催化降解的中间产物主要是邻氯苯酚和间氯苯酚。 相似文献
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将PMMA、PVAc和碳纳米管在四氢呋喃中混合,通过超声分散及溶液浇铸工艺制备了碳纳米管/PMMA/PVAc复合膜。研究了在低浓度四氢呋喃气氛下,碳纳米管/PMMA/PVAc复合膜电阻与气氛浓度的变化关系。研究表明:在浓度为0.6~6.0ppt的四氢呋喃气氛下,复合膜电阻随着气氛浓度的增大而增大,复合膜具有较优的敏感性:当四氢呋喃的气氛浓度为6.0ppt时,复合膜敏感率为16%。 相似文献
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采用MTT法、细胞形态学观察和流式细胞术检测纳米雌黄对白血病K562细胞生长的影响;通过免疫组化、RT-PCR方法检测雌黄纳米粒处理K562细胞后凋亡相关基因的表达变化.结果表明,雌黄纳米粒能强烈抑制K562细胞增殖并诱导其凋亡,效果明显优于普通雌黄;雌黄纳米粒对K562细胞的bcl-2蛋白、bcl-2mRNA、survivin蛋白以及survivin mRNA表达均有抑制作用,对bax蛋白与mRNA表达均有促进作用,提示其抗肿瘤作用可能与凋亡抑制基因bcl-2、survivin表达减少、促凋亡基因bax表达增强有关,并从mRNA水平上发挥作用, 相似文献
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Jian You Ruping Shao Xin Wei Sanjay Gupta Chun Li 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(9):1022-1031
Despite advances in controlled drug delivery, reliable methods for activatable, high‐resolution control of drug release are needed. The hypothesis that the photothermal effect mediated by a near‐infrared (NIR) laser and hollow gold nanospheres (HAuNSs) could modulate the release of anticancer agents is tested with biodegradable and biocompatible microspheres (1–15 µm) containing the antitumor drug paclitaxel (PTX) and HAuNSs (≈35 nm in diameter), which display surface plasmon absorbance in the NIR region. HAuNS‐containing microspheres exhibit a NIR‐induced thermal effect similar to that of plain HAuNSs. Rapid, repetitive PTX release from the PTX/HAuNS‐containing microspheres is observed upon irradiation with NIR light (808 nm), whereas PTX release is insignificant when the NIR light is switched off. The release of PTX from the microspheres is readily controlled by the output power of the NIR laser, duration of irradiation, treatment frequency, and concentration of HAuNSs embedded inside the microspheres. In vitro, cancer cells incubated with PTX/HAuNS‐loaded microspheres and irradiated with NIR light display significantly greater cytotoxic effects than cells incubated with the microspheres alone or cells irradiated with NIR light alone, owing to NIR‐light‐triggered drug release. Treatment of human U87 gliomas and MDA‐MB‐231 mammary tumor xenografts in nude mice with intratumoral injections of PTX/HAuNS‐loaded microspheres followed by NIR irradiation results in significant tumor‐growth delay compared to tumors treated with HAuNS‐loaded microspheres (no PTX) and NIR irradiation or with PTX/HAuNS‐loaded microspheres alone. The data support the feasibility of a therapeutic approach in which NIR light is used for simultaneous modulation of drug release and induction of photothermal cell killing. 相似文献
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Low-energy ultrasound (LEUS) shows distinct potential as a safe therapeutic strategy for cancer treatment. Herein, mesoporous silica nanoparticles with closed-end cavities as sensitive nanoagents are prepared for effective cancer cell killing, when synergistically combined with mild LEUS (1 MHz, ≤1.0 W cm?2). The closed-end cavities can entrap gas bubbles, and provide a large number of cavitation nucleation sites, which could lead to drastically amplify ultrasonic cavitation effect by responding to the mild LEUS (1 MHz, ≤1.0 W cm?2). Significant killing effect against cancer cells is observed, when cells are treated by synergetic combination of mild LEUS and the nanoagents with closed-end cavities, showing distinct dose dependency on the nanoagents and irradiation intensity. Nevertheless, the killing effect is disappeared when the closed-end cavities are destructed. Moreover, no obvious cytotoxicity is observed when either the nanoagents or the LEUS is applied alone. The research may open up application opportunities of mild low-energy ultrasound for cancer therapy. 相似文献
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以大肠杆菌078、沙门氏菌C-79和金黄色葡萄球菌C58000为指示菌,研究不同超声波频率处理及超声波与温度协同作用的杀菌效果。结果表明,室温下采用超声波处理时,大肠杆菌078对超声波最敏感,而28kHz、33kHz和38kHz3种频率对同一菌株的致死率差异不显著。超声波与温度协同作用对革兰氏阴性的078和C-79致死增效作用显著,但对革兰氏阳性的金黄色葡萄球菌无明显效果;对细菌超显微结构观察表明,杀菌效果的差异可能与细菌细胞壁成分和结构有关。 相似文献
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《材料科学技术学报》2016,(8)
To combine localized drug release with multimodal therapy for malignant tumor, a composite hydrogel as an integrative drug delivery system was facilely prepared. The system contains spinach extract(SE),reduced graphene oxide(r GO) and gold nanocages(Au NCs). SE conduces to the formation of hydrogel,and also serves as a green material for improving the biocompatibility of hydrogel, and a natural photosensitizer for killing tumor cells under laser radiation(660 nm). Au NCs show obvious photothermy and can enhance the generation of cytotoxic singlet oxygen(1O2). The composite hydrogel shell on tumor cells exhibits several competitive advantages including enhanced antitumor effect by retaining the high concentration of drugs around cancer cell, excellent PDT/PTT compatibility as well as high loading and controllable release of fluorouracil(5-FU) for synergetic multimodal treatment. The survival rate of He La cells incubated with 5-FU loaded hydrogel under NIR radiation for 10 min sharply decreases to 1.2%, indicating remarkably improved antitumor effects. These results demonstrate that the hydrogel is an excellent delivery carrier for localizable, NIR-responsive and combined PTT/PDT/Chemo synergetic antitumor. 相似文献
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The ability of engineered cerium oxide nanoparticles to confer radioprotection was examined. Human normal and tumor cells were treated with nanoceria and irradiated, and cell survival was measured. Treatment of normal cells conferred almost 99% protection from radiation-induced cell death, whereas the same concentration showed almost no protection of tumor cells. For the first time, nanoceria is shown to confer radioprotection to a normal human breast line but not to a human breast tumor line, MCF-7. 相似文献
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Vascular targeted single-walled carbon nanotubes for near-infrared light therapy of cancer 总被引:1,自引:0,他引:1
A new approach for targeting carbon nanotubes to the tumor vasculature was tested using human endothelial cells and MCF-7 breast cancer cells in vitro. Single-walled carbon nanotubes were functionalized with the F3 peptide using a polyethylene glycol linker to target nucleolin, a protein found on the surface of endothelial cells in the vasculature of solid tumors. Confocal microscopy and Raman analysis confirmed that the conjugate was internalized by actively dividing endothelial cells. Dividing endothelial cells were used to mimic these cells in the tumor vasculature. Incubation with the conjugate for 8?h or more caused significant cell death in both actively dividing endothelial cells and MCF-7 breast cancer cells, an effect that is hypothesized to be due to the massive uptake of the conjugate. This targeted cell killing was further enhanced when coupled with near-infrared laser treatment. For confluent (non-dividing) endothelial cells, no cytotoxic effect was seen for incubation alone or incubation coupled with laser treatment. These results are promising and warrant further studies using this conjugate for cancer treatment in vivo. 相似文献
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Zhang C Huang P Bao L He M Luo T Gao G Cui D 《Journal of nanoscience and nanotechnology》2011,11(11):9528-9535
We explored the biocompatible gold nanoparticles (GNPs) with surface modified by chitosan in the applications of cell's response to X-ray irradiation. Substantial amounts of chitosan modified gold nanoparticles (CS-GNPs) were found to be internalized in cell cytoplasm revealed by transmission electron microscopy. Their in vitro cytotoxicity effects on MGC-803 cells and GES-1 cells were observed at 24, 48 and 72 h. The MTT results showed that CS-GNPs own excellent biocompatibility. The dose enhancement based on CS-GNPs induced the damage of MGC-803 cells under X-ray irradiation, monitored by clonogenic cell survival assay. We also investigated their effects on the survival rates of MGC-803 cells during irradiation for a dose up to 10 Gy using a radio-oncology linear accelerator (6 MeV). The survival fraction of cells incubated with different concentration of CS-GNPs was obviously reduced in comparison with that irradiation alone. The result also revealed an increase of cell inhibition with increasing the concentration of CS-GNPs. In conclusion, CS-GNPs can enhance the cell radiation therapeutic sensitivity, and have potential application in tumor irradiation therapy in near future. 相似文献
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Reversal effect of low‐intensity ultrasound on adriamycin‐resistant human hepatoma cells in vitro and in vivo 下载免费PDF全文
Wenfei Xia Xiaopeng Ma Xingrui Li Chao Lu Xiaowei Yang Zhi Zhu Jilin Yi 《International journal of imaging systems and technology》2014,24(1):23-28
The aim of this study was to determine whether the ultrasound, with a dosage that did not lead to acute and delayed inhibition, could potentiate the cytotoxicity of adriamycin to human hepatoma resistant cell line HepG2 both in vitro and in vivo. In order to determine whether low‐intensity ultrasound could reverse resistance in adriamycin‐resistant human hepatoma cell line HepG2/ADM in vitro, cells were subjected to a variable level of ultrasound. The results showed that survival rates were decreased in groups in which ultrasound and adriamycin were exerted. The same effect of low‐intensity ultrasound was also observed in the xenograft tumor experiment. Furthermore, transmission electron microscope revealed the cavitation effects play the determining role in accelerating transmembrane transportation, suggesting that low‐intensity ultrasound altered the cell membrane thus resulting in change in adriamycin uptake into HepG2/ADM cells. Further investigation of the underlying mechanisms showed that the reversal effect of low‐intensity ultrasound on adriamycin‐resistant human hepatoma cells was attributed to the downregulation of the multidrug resistant genes, MDR1 and MRP1, in both mRNA and protein expression. In addition, downregulation of MDR1 and MRP1 was detected in HepG2/ADM xenograft tumor treated with adriamycin and ultrasound. These observations suggest the use of ultrasound could increase cytotoxicity attributable to adriamycin in chemoresistant human hepatoma cancer cells. Ultrasound is a promising therapeutic modality for refractory hepatoma patients. 相似文献
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There is now a significant body of data that indicate that the effects of ionising radiation may extend to more than those cells that directly suffer damage to DNA in the cell nucleus. Cells neighbouring those cells that are irradiated, or even well separated from those that are irradiated demonstrate several responses that are recorded in hit cells as a function of absorbed dose. That is, the responding non-hit cells are bystanders of hit cells. A protocol has been devised which allows for examination of one means of eliciting bystander responses, specifically, effects on non-contacting cells. Cell culture chambers are set up such that a population of cells is physically separate from the energy depositions of track segment charged particles. Absorption of energy in sub-millimetre distances in the cell culture medium ensures that one population of cells can only respond to factors generated in the irradiated medium or in another population of irradiated co-cultured cells, which may be of similar or dissimilar origin. For irradiation of medium alone, enhanced levels of micronuclei, and of delays in cell cycle progression occur in normal human fibroblasts, but not epithelial cells. This procedure allows for a defining of the factors responsible for initiating bystander effects and for determining their quantitative relevance. 相似文献