共查询到19条相似文献,搜索用时 140 毫秒
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海马神经元的原子力显微成像 总被引:3,自引:0,他引:3
原子力显微镜(AFM)对完整的细胞成像并同时进行微细结构观察尚有一定困难。本实验改进了标本制备的过程.用原子力显微镜对戊二醛固定的海马神经元进行扫描,建立了方便、实用的完整海马神经元自完整胞体至超微结构的原子力显微镜成像技术,并用改进的方法获得了完整海马神经元及其超微结构的清晰的三维成像,并发现了一些其它显微技术所不能发现的微细结构。这些结构包括:①海马神经元胞体的亚细胞部分及这些亚细胞部分所具有的不同功能;②神经突触的完整形态;③损伤细胞膜表面出现的孔洞;④通过神经突触所形成的神经网络结构。 相似文献
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壳聚糖载药纳米微球对人肝癌细胞的杀伤作用及AFM探测 总被引:1,自引:1,他引:0
本文以5-氟尿嘧啶(5-Fu)为抗肿瘤药物模型,壳聚糖为载体,制备平均粒径约为250nm的5-氟尿嘧啶/壳聚糖(5-Fu/Cs)载药纳米微球。采用MTT法评价载药纳米微球在体外对人肝癌细胞BEL7402的杀伤率,并采用原子力显微镜探测用药处理前后的肿瘤细胞表面超微结构的变化。结果表明,载药纳米微球对肿瘤细胞的杀伤率在量效和时效上明显比同剂量单独5-Fu作用的杀伤率高;AFM结果显示5-Fu与载药纳米微球对人肝癌细胞BEL7402作用后的细胞膜表面超微结构的变化存在较大差异,载药纳米微球在肿瘤细胞表面的吸附作用或内吞作用,导致载药纳米微球在细胞表面的释药机制不同于单独药物的扩散模型。 相似文献
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利用原子力显微镜分别对在I-型胶原和bFGF表面改性的p(HEMA-MMA)及未改性的p(HEMA-MMA)材料表面对于角膜基质细胞的膜表面结构进行了分析。将角膜基质细胞接种于改性前后的材料表面,用原子力显微镜对不同表面生长的角膜细胞的三维形态和超微结构等方面进行了研究。结果表明,改性后材料表面细胞宽度更大,高度更低,并且铺展较为完全,与正常条件下培养的细胞形态相似。膜超微结构参数分析显示在改性后材料表面生长的细胞膜微区的平均粗糙度(Ra)、均方粗糙度(Rq)、平均高度(MeanHt)、中值高度(MedianHt)明显较高于改性前材料表面的细胞。 相似文献
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石墨烯及其衍生物纳米材料因具有独特的物理化学性质,被广泛应用于生物医学领域,常被用作抗肿瘤药物的载体。本研究旨在探索氧化石墨烯对非小细胞肺癌细胞A549的生长和迁移的影响及机制。主要实验方法包括live/dead染色、Transwell实验、免疫印迹及原子力显微镜、激光共聚焦显微镜、透射电子显微镜、扫描电子显微镜等显微成像技术。结果显示GO能够穿透细胞膜切入细胞,导致细胞骨架肌动蛋白丝的形态结构发生显著改变;GO能够大量吸附细胞裂解物中F-actin蛋白。这些结果提示GO进入细胞后,可能通过吸附F-actin,破坏细胞骨架的结构,进而影响A549细胞的生长和转移。这些发现为未来以GO为载体的抗肿瘤药物设计提供了新的理论依据。 相似文献
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利用原子力显微镜(AFM)观察稳恒磁场(SMF)处理后,悬浮生长细胞(K562人白血病细胞)、贴壁生长细胞(人结肠癌SW480细胞)、小鼠肝癌细胞Hepal-6和原代小鼠肝细胞表面精细结构的变化,以了解SMF杀伤肿瘤细胞的可能机制.观察结果显示:随曝磁时间延长,SMF可在肿瘤细胞表面造成不同程度损伤,主要表现为细胞膜上出现许多大小不一的凹陷,且凹陷数量和直径随着曝磁时间延长而增加.与MTT检测相比,AFM观察到的各类细胞表面损伤远早于细胞的生长抑制.实验观察显示,悬浮生长细胞比贴壁生长细胞对磁场处理更为敏感,小鼠肝癌细胞比肝细胞对磁处理更敏感.实验结果显示,AFM能够及早观察到细胞表面因SMF作用而产生的精细结构方面的变化. 相似文献
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利用近场光学显微镜(SNOM)和原子力显微镜(AFM)研究细胞的超微结构。SNOM对传统的光学分辨极限产生了革命性的突破,能够在纳米距离内探测光与样品物质之间的相互作用,在超高光学分辨率下对细胞成像,这种技术无侵入性和破坏性,能在细胞的自然状态下进行观测 相似文献
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Iu I Kudriavets 《Eksperimental?nai?a onkologii?a》1990,12(1):43-47
Cells of the Lewis lung carcinoma (3LL), B16 melanoma and Ehrlich carcinoma pre-treated in vitro by a recombinant tumour necrosis factor (rTNF) were studied for their spontaneous and experimental metastatic spreading. The rTNF (1000 u/ml) was determined to stimulate a metastatic potential of the Lewis carcinoma cells after their treatment with the factor for 6 h and, vice versa, to inhibit it after 96 h prolonged treatment. The efficacy of the stimulating effect of rTNF on a metastatic spreading depends on the peculiarities of the studied cells. 相似文献
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Virions of vaccinia and orf viruses were examined by ultrahigh-resolution scanning electron microscopy using a non-coating method. Intracellular mature particles of vaccinia virus appeared to be covered with a net and ultrastructurally their surface consists of many fine ridges and globules, while the surfaces of orf virus mature particles recovered from infected cells consist of spirally running protrusions. The ridge-like structures of vaccinia virus were presumed to correspond to surface tubules shown by negative staining of this virus, while the spiral protrusions of orf virus were presumed to correspond to spiral threads having a criss-cross appearance by the same staining. Using scanning electron microscopy in which the samples were prepared by the conventional method, we observed: (i) many virions, i.e. one or two hundreds, or occasionally more reaching about one thousand particles, of the IHD strain of vaccinia virus, (ii) many or a moderate number of virions, i.e. about one hundred or fewer particles, of the 58 strain of cowpox virus and (iii) rather few virions, i.e. several tens or fewer particles, of the Iwate strain of orf virus on the free surface of each cell infected with these viruses. It must be noted that the number of virions detected considerably differed in respective cells examined. Virus budding was frequently observed at the cell surface of monolayer cells infected with vaccinia virus but it was never detected with cowpox or orf virus, indicating a difference in the mechanism of virus release between vaccinia and the other two viruses. When whole cells infected with vaccinia virus were examined by a combination of high-voltage and scanning electron microscopies, virions on the cell surface and those inside the cells were clearly differentiated. All virions on the cell surface had an envelope, and some of the envelopes had a slack and/or one or more bulges. 相似文献
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纳米金棒(AuNRs)具有众多独特的属性,已广泛运用于生物医学领域,但其是否具有潜在的生物危害尚有争议.作者运用了激光扫描共聚焦显微镜技术、western blotting技术和其他分子生物学方法从细胞氧化应激的角度探讨了AuNRs诱导A549细胞产生自噬的分子机制.研究结果表明,4μg·mL-1的AuNRs处理6 h能够诱导A549细胞自噬标志蛋白LC3-Ⅱ表达增加,LC3蛋白从细胞核转移至细胞质并形成自噬小泡.进一步研究发现,AuNRs能够降低A549细胞线粒体膜电位、ATP含量、UCP2蛋白表达水平以及细胞抗氧化能力并导致活性氧蓄积,后者可能最终引起细胞产生自噬.而10 mmol·L-1抗氧化剂NAC能够逆转上述线粒体及细胞功能的改变,并抑制自噬的发生.这一研究为深入认识其生物危害及可能机制提供了有力的实验证据. 相似文献
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So-Jung Kim Hae-Bin Park Eun-Koung An Hee-Yun Eom Wei Zhang Jihoe Kim Inho Choi Minseok Kwak Peter C. W. Lee Jun-O Jin 《Advanced functional materials》2023,33(31):2302825
Anticancer drug-mediated induction of immunogenic cell death (ICD) blocks metastasis or recurrence in cancer cells by promoting specific immune activity against cancer antigens. However, this strategy has failed to afford adequate treatment efficiency. Overcoming the failure of ICD-mediated cancer therapy, lipid nanoparticles (LNPs) containing cancer cell surface proteins are synthesized using sonication and extrusion without microfluidics. In addition, these LNPs are decorated with high-mobility group box 1 protein and calreticulin, indicators of ICD, and named artificial ICD LNPs (AiLNPs). Administration of AiLNPs effectively targets dendritic cells (DCs) and induces DC activation in mice. Moreover, treating CT-26 tumor-bearing mice with AiLNPs inhibits tumor growth by inducing CT-26 antigen-specific T-cell immunity. Furthermore, AiLNPs containing Lewis lung carcinoma (LLC1) membrane proteins can prevent metastatic LLC1 tumor growth in the lung via LLC1 antigen-specific T-cell activation. Finally, AiLNPs synthesized with human breast cancer membrane proteins activate DC-mediated antigen-specific T-cell immunity, effectively killing tumor cells. Therefore, AiLNPs are expected to be developed as a patient-specific cancer treatment to prevent cancer recurrence and metastasis. 相似文献
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A G Zolotareva V P Nikolin T N Subkhankulova V I Kaledin E V Gruntenko 《Eksperimental?nai?a onkologii?a》1986,8(6):28-32
The fragments of cell plasma membranes of two lines of metastatic tumour of A/He mice (lung adenocarcinoma--LA-cells and hepatoma HA-1--HA-cells) were used to prepare "hybrid" vesicles (LA- and HA-liposomes). Incorporation of the fragments of LA-cells into the bilayer vesicle increased the binding of LA-liposomes with lung almost by an order of magnitude, their trapping by liver being noticeably decreased. HA-liposomes were retained in the liver in larger amounts than the model phospholipid liposomes. It is assumed that the specificity of metastatic spreading into an organ is associated with the interaction of the plasma membrane of the tumour cells with the apical membrane of the target organ endothelium. 相似文献
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O A Khomutovski? O V Peredere? M D Lutsik N Kh Pogorelaia O V Iurchenko 《Eksperimental?nai?a onkologii?a》1987,9(3):59-62
Statistical procedures were used to estimate lectin receptor distribution on the surface of ascite lymphoma cells, neuroblastoma C-1300 cells and of transformed human T- and B-derived lymphoid cell lines. Relationships between the arithmetic means and mean square variances for sample populations from each cell and ferritin- or colloidal gold-lectin combination were used to define four types of topographical distributions: uniform-ordered, uniform-random, random and clustered. 相似文献
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Although the intracellular toxic sites of paraquat, a herbicide toxic to human bodies, have remained unclear for a long time, we recently demonstrated paraquat-induced mitochondrial injury in rat lung and liver in vivo. In the present study, cultured human lung cells (A549 adenocarcinoma cell line) which received 0.15 mM paraquat (equivalent to 40 mg/kg i.v.) showed selective mitochondrial breakage at 6-24 hr and died at 36-48 hr. These results suggest that mitochondria are the initial toxic site of paraquat in vitro as well as in vivo in contrast to the previously proposed microsome theory. 相似文献
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Serum protein transcobalamin II (TC-II) is responsible for transport of cobalamins into mammalian cells. A method of quantitative estimation of plasma membrane receptors of hemopoietic cells to TC-II cobalamin complex is suggested. Analysis of mouse leukemia L1210 cells includes the saturation of radiolabelled ligand-receptor complex with papain. The number of receptors and 57CoCNCbl content in one cell is determined by differentiated radioactivity count of solubilized protein complexes and of cytoplasm. 相似文献