Nanotubes

纳米管
  • 文章类型: Journal Article
    通过水热合成开发了ZnO纳米棒无纺布(ZNRN),以促进预防呼吸道病原体的传播。通过响应面法提高了ZNRN的超疏水性和抗菌性能。合成的材料表现出显著的防水性,水接触角为163.9°,因此对大肠杆菌的抗菌率为91.8%(E.大肠杆菌)和79.75%的金黄色葡萄球菌(S.金黄色葡萄球菌)。这表明具有较薄肽聚糖的大肠杆菌可能比金黄色葡萄球菌更容易被杀死。这项研究确定了合成条件对抗菌效果的显着影响,全面的多变量分析阐明了潜在的相关性。此外,通过SEM和XRD分析对ZNRN的ZnO纳米棒结构进行了表征。它赋予超疏水性(从而防止细菌粘附到ZNRN表面)和抗菌能力(从而通过刺穿这些纳米棒破坏细胞)的性质。因此,希望将两个这样的特征对齐,以帮助支持个人防护设备的开发,这有助于避免呼吸道感染的传播。
    ZnO nanorod nonwoven fabrics (ZNRN) were developed through hydrothermal synthesis to facilitate the prevention of the transmission of respiratory pathogens. The superhydrophobicity and antibacterial properties of ZNRN were improved through the response surface methodology. The synthesized material exhibited significant water repellency, indicated by a water contact angle of 163.9°, and thus demonstrated antibacterial rates of 91.8% for Escherichia coli (E. coli) and 79.75% for Staphylococcus aureus (S. aureus). This indicated that E. coli with thinner peptidoglycan may be more easily killed than S. aureus. This study identified significant effects of synthesis conditions on the antibacterial effectiveness, with comprehensive multivariate analyses elucidating the underlying correlations. In addition, the ZnO nanorod structure of ZNRN was characterized through SEM and XRD analyses. It endows the properties of superhydrophobicity (thus preventing bacteria from adhering to the ZNRN surface) and antibacterial capacity (thus damaging cells through the puncturing of these nanorods). Consequently, the alignment of two such features is desired to help support the development of personal protective equipment, which assists in avoiding the spread of respiratory infections.
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  • 文章类型: Journal Article
    胰岛素和C肽作为糖尿病和某些肝病的临床指标起着至关重要的作用。然而,关于同时检测微量血清中胰岛素和C肽的研究有限。有必要开发一种具有高灵敏度和特异性的新方法来同时检测胰岛素和C肽。
    使用简单的湿化学方法制造了核-壳-卫星分层结构的纳米复合材料作为SERS生物传感器,采用4-MBA和DTNB进行识别,抗体进行特异性捕获。金纳米棒(AuNRs)用拉曼报道分子和银纳米粒子(AgNP)修饰,建立高灵敏度的SERS标签,用于检测胰岛素和C肽。抗体修饰的商业羧化磁珠@抗体用作捕获探针。通过探针捕获目标材料并结合SERS标签,形成“三明治”复合结构,用于后续检测。
    在优化条件下,制备的纳米复合材料可用于同时检测胰岛素和C肽,检出限为4.29×10-5pM和1.76×10-10nM。胰岛素浓度(4.29×10-5-4.29pM)与1075cm-1处的SERS强度呈强线性相关,在检测人血清样品中具有高回收率(96.4-105.3%)和低RSD(0.8%-10.0%)。同时,C肽浓度(1.76×10-10-1.76×10-3nM)也与1333cm-1处的SERS强度呈特定的线性相关,回收率为85.4%-105.0%,RSD为1.7%-10.8%。
    这一突破提供了一种小说,敏感,方便,稳定的方法,用于糖尿病和某些肝病的临床诊断。总的来说,我们的发现为生物医学研究领域做出了重大贡献,为改善糖尿病和肝病的诊断和监测开辟了新的可能性。
    UNASSIGNED: Insulin and C-peptide played crucial roles as clinical indicators for diabetes and certain liver diseases. However, there has been limited research on the simultaneous detection of insulin and C-peptide in trace serum. It is necessary to develop a novel method with high sensitivity and specificity for detecting insulin and C-peptide simultaneously.
    UNASSIGNED: A core-shell-satellites hierarchical structured nanocomposite was fabricated as SERS biosensor using a simple wet-chemical method, employing 4-MBA and DTNB for recognition and antibodies for specific capture. Gold nanorods (Au NRs) were modified with Raman reporter molecules and silver nanoparticles (Ag NPs), creating SERS tags with high sensitivity for detecting insulin and C-peptide. Antibody-modified commercial carboxylated magnetic bead@antibody served as the capture probes. Target materials were captured by probes and combined with SERS tags, forming a \"sandwich\" composite structure for subsequent detection.
    UNASSIGNED: Under optimized conditions, the nanocomposite fabricated could be used to detect simultaneously for insulin and C-peptide with the detection limit of 4.29 × 10-5 pM and 1.76 × 10-10 nM in serum. The insulin concentration (4.29 × 10-5-4.29 pM) showed a strong linear correlation with the SERS intensity at 1075 cm-1, with high recoveries (96.4-105.3%) and low RSD (0.8%-10.0%) in detecting human serum samples. Meanwhile, the C-peptide concentration (1.76 × 10-10-1.76 × 10-3 nM) also showed a specific linear correlation with the SERS intensity at 1333 cm-1, with recoveries 85.4%-105.0% and RSD 1.7%-10.8%.
    UNASSIGNED: This breakthrough provided a novel, sensitive, convenient and stable approach for clinical diagnosis of diabetes and certain liver diseases. Overall, our findings presented a significant contribution to the field of biomedical research, opening up new possibilities for improved diagnosis and monitoring of diabetes and liver diseases.
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  • 文章类型: Journal Article
    细胞膜表现出许多高度弯曲的形态,例如芽,纳米管,定义细胞器轮廓的池状薄片。这里,我们使用包裹在巨大囊泡中的葡聚糖和聚(乙二醇)的双水相系统模拟细胞分隔。在渗透放气时,囊泡膜形成纳米管,在囊泡内部的液-液界面发生令人惊讶的形态转变。在这些接口上,纳米管转化为通过短膜颈与母囊泡连接的类似水箱的双膜片(DMS)。使用超分辨率(受激发射损耗)显微镜和理论考虑,我们构建了一个形态学图,预测管到板的转变,这是由自由能的减少驱动的。纳米管结可以通过阻止水流入管中而阻止管到板的转变。因为纳米管和DMS通常都是由细胞膜形成的,了解这些膜形态之间的形成和转化,可以深入了解细胞器的起源和进化。
    Cellular membranes exhibit a multitude of highly curved morphologies such as buds, nanotubes, cisterna-like sheets defining the outlines of organelles. Here, we mimic cell compartmentation using an aqueous two-phase system of dextran and poly(ethylene glycol) encapsulated in giant vesicles. Upon osmotic deflation, the vesicle membrane forms nanotubes, which undergo surprising morphological transformations at the liquid-liquid interfaces inside the vesicles. At these interfaces, the nanotubes transform into cisterna-like double-membrane sheets (DMS) connected to the mother vesicle via short membrane necks. Using super-resolution (stimulated emission depletion) microscopy and theoretical considerations, we construct a morphology diagram predicting the tube-to-sheet transformation, which is driven by a decrease in the free energy. Nanotube knots can prohibit the tube-to-sheet transformation by blocking water influx into the tubes. Because both nanotubes and DMSs are frequently formed by cellular membranes, understanding the formation and transformation between these membrane morphologies provides insight into the origin and evolution of cellular organelles.
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  • 文章类型: Journal Article
    背景:正确设计的具有响应性的肿瘤微环境的第二近红外(NIR-II)纳米平台可以智能地区分正常组织和癌组织,以实现更好的靶向效率。传统的光声纳米探针总是“开启”,和肿瘤微环境响应型纳米探针可以最大程度地减少内源性发色团背景信号的影响。因此,能够响应肿瘤内部微环境和外界刺激的纳米探针的开发在肿瘤的光声诊断中显示出巨大的应用潜力。
    结果:在这项工作中,构建了低pH触发的热响应体积相变纳米凝胶金纳米棒@聚(正异丙基丙烯酰胺)-乙烯基乙酸(AuNR@PNIPAM-VAA),用于肿瘤的光声检测。通过外部近红外光热开关,AuNR@PNIPAM-VAA纳米凝胶在肿瘤微环境中的吸收可以动态调节,因此AuNR@PNIPAM-VAA纳米凝胶在NIR-II窗口中产生可切换的光声信号用于肿瘤特异性增强光声成像。体外实验结果表明,在pH5.8时,经过光热调节后,AuNR@PNIPAM-VAA纳米凝胶在NIR-II中的吸收和光声信号幅度明显增加,而它们在pH7.4时保持轻微变化。定量计算表明,在模拟肿瘤微环境中,随着温度从37.5°C升高到45°C,AuNR@PNIPAM-VAA纳米凝胶在1064nm处的光声信号幅度增强了〜1.6倍。体内实验结果表明,制备的AuNR@PNIPAM-VAA纳米凝胶可以通过动态响应热场实现增强的NIR-II光声成像,用于选择性肿瘤检测。可以通过外部光线精确控制。
    结论:这项工作将为使用NIR光调节热场和靶向低pH肿瘤微环境的肿瘤特异性光声成像提供可行的策略,有望实现肿瘤诊断和治疗的准确、动态监测。
    BACKGROUND: Properly designed second near-infrared (NIR-II) nanoplatform that is responsive tumor microenvironment can intelligently distinguish between normal and cancerous tissues to achieve better targeting efficiency. Conventional photoacoustic nanoprobes are always \"on\", and tumor microenvironment-responsive nanoprobe can minimize the influence of endogenous chromophore background signals. Therefore, the development of nanoprobe that can respond to internal tumor microenvironment and external stimulus shows great application potential for the photoacoustic diagnosis of tumor.
    RESULTS: In this work, a low-pH-triggered thermal-responsive volume phase transition nanogel gold nanorod@poly(n-isopropylacrylamide)-vinyl acetic acid (AuNR@PNIPAM-VAA) was constructed for photoacoustic detection of tumor. Via an external near-infrared photothermal switch, the absorption of AuNR@PNIPAM-VAA nanogel in the tumor microenvironment can be dynamically regulated, so that AuNR@PNIPAM-VAA nanogel produces switchable photoacoustic signals in the NIR-II window for tumor-specific enhanced photoacoustic imaging. In vitro results show that at pH 5.8, the absorption and photoacoustic signal amplitude of AuNR@PNIPAM-VAA nanogel in NIR-II increases up obviously after photothermal modulating, while they remain slightly change at pH 7.4. Quantitative calculation presents that photoacoustic signal amplitude of AuNR@PNIPAM-VAA nanogel at 1064 nm has ~ 1.6 folds enhancement as temperature increases from 37.5 °C to 45 °C in simulative tumor microenvironment. In vivo results show that the prepared AuNR@PNIPAM-VAA nanogel can achieve enhanced NIR-II photoacoustic imaging for selective tumor detection through dynamically responding to thermal field, which can be precisely controlled by external light.
    CONCLUSIONS: This work will offer a viable strategy for the tumor-specific photoacoustic imaging using NIR light to regulate the thermal field and target the low pH tumor microenvironment, which is expected to realize accurate and dynamic monitoring of tumor diagnosis and treatment.
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  • 文章类型: Journal Article
    纯有机磷光共振能量转移是一个研究热点。在这里,由客体分子烷基桥联甲氧基-四苯基乙烯-苯基吡啶衍生物构建了具有367nm大斯托克斯位移和近红外发射的单分子磷光共振能量转移系统,葫芦[n]脲(n=7,8)和β-环糊精修饰的透明质酸。葫芦脲以各种化学计量比与客体分子的高结合亲和力不仅调节了超分子组装的拓扑形态,而且还诱导了不同的磷光发射。从二元组装的球形纳米粒子和纳米棒不同,通过客体与葫芦[7]脲/葫芦[8]脲的三元共组装获得三维纳米板,伴随增强的磷光在540nm。不常见,β-环糊精修饰透明质酸的二次组装和三元组装激活了苯基吡啶单元向甲氧基-四苯基乙烯官能团的单分子内磷光共振能量转移过程,使近红外延迟荧光在700纳米,最终应用于癌细胞的线粒体靶向成像。
    Pure organic phosphorescence resonance energy transfer is a research hotspot. Herein, a single-molecule phosphorescence resonance energy transfer system with a large Stokes shift of 367 nm and near-infrared emission is constructed by guest molecule alkyl-bridged methoxy-tetraphenylethylene-phenylpyridines derivative, cucurbit[n]uril (n = 7, 8) and β-cyclodextrin modified hyaluronic acid. The high binding affinity of cucurbituril to guest molecules in various stoichiometric ratios not only regulates the topological morphology of supramolecular assembly but also induces different phosphorescence emissions. Varying from the spherical nanoparticles and nanorods for binary assemblies, three-dimensional nanoplate is obtained by the ternary co-assembly of guest with cucurbit[7]uril/cucurbit[8]uril, accompanying enhanced phosphorescence at 540 nm. Uncommonly, the secondary assembly of β-cyclodextrin modified hyaluronic acid and ternary assembly activates a single intramolecular phosphorescence resonance energy transfer process derived from phenyl pyridines unit to methoxy-tetraphenylethylene function group, enabling a near-infrared delayed fluorescence at 700 nm, which ultimately applied to mitochondrial targeted imaging for cancer cells.
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  • 文章类型: Journal Article
    甘露糖结合凝集素(MBL)激活补体系统凝集素途径和随后的炎症机制。许多人类疾病的发病率和结果,如脑缺血和感染,与体液中MBL的活性和血清浓度有关并受其影响。为了量化MBL水平,使用基于ELISA的测试,需要几个孵化和洗涤步骤和漫长的周转时间。这里,我们的目的是开发一种用于在护理点直接检测人血清中MBL的纳米等离子体激元测定法。我们的测定基于通过两亲性接头用甘露糖(Man-GNR)官能化的金纳米棒(GNR)。我们通过实验确定了连接到纳米棒表面的糖的有效量,导致每nm2约4个分子的接枝密度,以及与单个纳米颗粒结合的11至13个MBL分子的平均数。在MBL检测中实现最高灵敏度的最佳Man-GNRs浓度为15μg·mL-1。证实了在简单缓冲液和复杂的混合人血清中用于MBL检测的测定的特异性。我们的无标记生物传感器能够通过一步反应并使用酶标仪在15分钟内直接在人血清中检测低至160ng·mL-1的MBL浓度。因此,它构成了禁食的基础,非侵入性,用于诊断适应症和监测疾病和治疗的即时检测。
    Mannose-binding lectin (MBL) activates the complement system lectin pathway and subsequent inflammatory mechanisms. The incidence and outcome of many human diseases, such as brain ischemia and infections, are associated with and influenced by the activity and serum concentrations of MBL in body fluids. To quantify MBL levels, tests based on ELISA are used, requiring several incubation and washing steps and lengthy turnaround times. Here, we aimed to develop a nanoplasmonic assay for direct MBL detection in human serum at the point of care. Our assay is based on gold nanorods (GNRs) functionalized with mannose (Man-GNRs) via an amphiphilic linker. We experimentally determined the effective amount of sugar linked to the nanorods\' surface, resulting in an approximate grafting density of 4 molecules per nm2, and an average number of 11 to 13 MBL molecules binding to a single nanoparticle. The optimal Man-GNRs concentration to achieve the highest sensitivity in MBL detection was 15 μg·mL-1. The specificity of the assay for MBL detection both in simple buffer and in complex pooled human sera was confirmed. Our label-free biosensor is able to detect MBL concentrations as low as 160 ng·mL-1 within 15 min directly in human serum via a one-step reaction and by using a microplate reader. Hence, it forms the basis for a fast, noninvasive, point-of-care assay for diagnostic indications and monitoring of disease and therapy.
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  • 文章类型: Journal Article
    在现存的生物学中,大型和复杂的酶使用低分子量的辅因子,如二氢烟酰胺作为有效的氢化物转移剂和电子载体,用于调节关键的代谢过程。在没有复杂的当代酶的情况下,这些分子辅因子通常不能促进任何反应。在这里,我们报道了短的基于肽的淀粉样蛋白纳米管,其特征是阳离子和疏水残基的暴露阵列,可以结合小分子弱氢化物转移剂(NaBH4),以促进水中酯底物的有效还原。此外,负载有硼氢化物的顺晶淀粉样蛋白相表现出可回收性,底物选择性和受控还原,超过标准还原剂如LiAlH4的能力。淀粉样蛋白微相及其与小分子辅因子的合作预示了基于短肽的组装体可能在益生元地球中原代谢和生物聚合物进化的出现中发挥的重要作用。
    In extant biology, large and complex enzymes employ low molecular weight cofactors such as dihydronicotinamides as efficient hydride transfer agents and electron carriers for the regulation of critical metabolic processes. In absence of complex contemporary enzymes, these molecular cofactors are generally inefficient to facilitate any reactions on their own. Herein, we report short peptide-based amyloid nanotubes featuring exposed arrays of cationic and hydrophobic residues that can bind small molecular weak hydride transfer agents (NaBH4) to facilitate efficient reduction of ester substrates in water. In addition, the paracrystalline amyloid phases loaded with borohydrides demonstrate recyclability, substrate selectivity and controlled reduction and surpass the capabilities of standard reducing agent such as LiAlH4. The amyloid microphases and their collaboration with small molecular cofactors foreshadow the important roles that short peptide-based assemblies might have played in the emergence of protometabolism and biopolymer evolution in prebiotic earth.
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  • 文章类型: Journal Article
    最近,纳米材料由于其独特的表面和尺寸特性,在癌症靶向治疗和药物递送载体中引起了广泛的关注。随着研究人员旨在全面了解纳米材料的特性,纳米材料的多功能组合已成为研究热点。在这项研究中,合成了金属-有机框架覆盖的金纳米棒杂化物。我们的研究探索了它们通过光热结论局部升高温度来杀死肿瘤细胞的能力。特定的过氧化物酶样活性赋予杂种在体外破坏氧化平衡的能力。同时,化疗药物通过装载和运输来施用和递送,以实现有效的组合癌症治疗,从而提高疗效,减少大剂量化疗药物不可预知的毒副作用。这些研究可以改善组合癌症治疗并增强癌症治疗。
    Recently, nanomaterials have attracted extensive attention in cancer-targeting therapy and as drug delivery vehicles owing to their unique surface and size properties. Multifunctional combinations of nanomaterials have become a research hotspot as researchers aim to provide a full understanding of their nanomaterial characteristics. In this study, metal-organic framework-capped gold nanorod hybrids were synthesized. Our research explored their ability to kill tumor cells by locally increasing the temperature via photothermal conclusion. The specific peroxidase-like activity endows the hybrids with the ability to disrupt the oxidative balance in vitro. Simultaneously, chemotherapeutic drugs are administered and delivered by loading and transportation for effective combinatorial cancer treatment, thereby enhancing the curative effect and reducing the unpredictable toxicity and side effects of large doses of chemotherapeutic drugs. These studies can improve combinatorial cancer therapy and enhance cancer treatment.
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  • 文章类型: Journal Article
    最近,荧光传感器由于其高灵敏度而获得了相当大的关注,低成本和非侵入性。在可用于此目的的不同材料中,碳点(CD)代表有价值的候选应用在传感。这些,的确,很容易合成,显示高量子产率和高度生物相容性。然而,有人指出,这些纳米材料的光致发光特性严格依赖于所采用的合成和纯化方法。埃洛石纳米管(HNTs)的存在,一个自然的,低成本和生物相容性粘土矿物,已发现可有效地获得小且高度单分散的CD,而无需冗长而繁琐的纯化技术。在这里,我们报告了获得可用于生物传感的埃洛石-N-掺杂的CD(HNTs-NCDs)的合成途径的比较。一种是基于通过MW热解过程在HNTs表面上通过自下而上的方法合成N掺杂的CD;另一种是基于用埃洛石衍生物对原始N掺杂的CD进行的后改性。通过不同的物理化学技术进行最佳合成路线的评估。发现自下而上的方法导致在HNTs表面上形成具有不同官能团的N掺杂CD。该证据也转化为不同的荧光量子产率,并且通过电位滴定法研究了所获得材料中几个官能团的存在。此外,通过光谱测量评估了合成的纳米材料作为Fe3离子检测传感器的能力,细胞摄取也通过共聚焦/荧光显微镜进行了验证。
    Recently, fluorescent sensors have gained considerable attention due to their high sensitivity, low cost and noninvasiveness. Among the different materials that can be used for this purpose, carbon dots (CDs) represent valuable candidates for applications in sensing. These, indeed, are easily synthesized, show high quantum yield and are highly biocompatible. However, it was pointed out that the photoluminescence properties of these nanomaterials are strictly dependent on the synthetic and purification methods adopted. The presence of halloysite nanotubes (HNTs), a natural, low cost and biocompatible clay mineral, has been found to be efficient in obtaining small and highly monodispersed CDs without long and tedious purification techniques. Herein, we report the comparison of synthetic pathways for obtaining halloysite-N-doped CDs (HNTs-NCDs) that could be used in biological sensing. One was based on the synthesis of N-doped CDs by a bottom-up approach on HNTs\' surface by a MW pyrolysis process; the other one was based on the post-modification of pristine N-doped CDs with halloysite derivatives. The evaluation of the best synthetic route was performed by different physico-chemical techniques. It was found that the bottom-up approach led to the formation of N-doped CDs with different functional groups onto the HNTs\' surface. This evidence was also translated in the different fluorescence quantum yields and the existence of several functional groups in the obtained materials was investigated by potentiometric titrations. Furthermore, the ability of the synthesized nanomaterials as sensors for Fe3+ ions detection was assessed by spectroscopic measurements, and the cellular uptake was verified by confocal/fluorescence microscopies as well.
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  • 文章类型: Journal Article
    微生物的结合和相互作用驱动和调节海洋中的营养通量。然而,到目前为止,还没有研究海洋蓝藻细胞之间的物理接触。这里,我们展示了海洋蓝细菌Prochlolococus和Synechococcus之间直接相互作用的机制,细胞间膜纳米管。我们提供了由纳米管介导的蓝细菌的相邻和远处细胞之间的细胞质物质的属间和属内交换的证据。我们在激素和无菌培养物以及天然样品中可视化并测量了这些结构。我们发现纳米管是在活细胞之间产生的,这表明这是体内物质交换的相关系统。在海洋中最丰富的光合生物中,纳米管作为交换桥梁的发现可能对它们与其他生物的相互作用及其种群动态具有重要意义。
    Microbial associations and interactions drive and regulate nutrient fluxes in the ocean. However, physical contact between cells of marine cyanobacteria has not been studied thus far. Here, we show a mechanism of direct interaction between the marine cyanobacteria Prochlorococcus and Synechococcus, the intercellular membrane nanotubes. We present evidence of inter- and intra-genus exchange of cytoplasmic material between neighboring and distant cells of cyanobacteria mediated by nanotubes. We visualized and measured these structures in xenic and axenic cultures and in natural samples. We show that nanotubes are produced between living cells, suggesting that this is a relevant system of exchange material in vivo. The discovery of nanotubes acting as exchange bridges in the most abundant photosynthetic organisms in the ocean may have important implications for their interactions with other organisms and their population dynamics.
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