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Guangxue Feng, Bin Liu
Theranostic nanolights refer to luminescent nanoparticles possessing both imaging and therapeutic functions. Their shape, size, surface functions, and optical properties can be precisely manipulated through integrated efforts of chemistry, materials, and nanotechnology for customized applications. When localized photons are used to activate both imaging and therapeutic functions such as photodynamic or photothermal therapy, these theranostic nanolights increase treatment efficacy with minimized damage to surrounding healthy tissues, which represents a promising noninvasive nanomedicine as compared to conventional theranostic approaches...
May 7, 2018: Accounts of Chemical Research
Sheng Wang, Xuanze Chen, Lei Chang, Miao Ding, Ruiying Xue, Haifeng Duan, Yujie Sun
Fluorescent probes with multimodal and multilevel imaging capabilities are highly valuable as imaging with such probes not only can obtain new layers of information but also enable cross-validation of results under different experimental conditions. In recent years, the development of genetically-encoded reversibly photoswitchable fluorescent proteins (RSFPs) has greatly promoted the application of various kinds of live-cell nanoscopy approaches, including reversible saturable optical fluorescence transitions (RESOLFT) and stochastic optical fluctuation imaging (SOFI)...
May 3, 2018: Analytical Chemistry
Chuankang Li, Cuifang Kuang, Xu Liu
Overcoming Abbe's diffraction limit has been a challenging task and one of great interest for biological investigations. The emergence of fluorescence nanoscopy circumvents the diffraction barrier with nearly limitless power for optical microscopy, which enables investigations of the microscopic world in the 1-100 nm range. Proposed variants, such as expansion microscopy (ExM), stimulated emission depletion microscopy (STED), and Airyscan, are innovative in three aspects: sampling, illumination, and detection...
April 30, 2018: ACS Nano
Shuai Ye, Wei Yan, Mengjie Zhao, Xiao Peng, Jun Song, Junle Qu
Stimulated emission depletion (STED) nanoscopy is one of the most promising super-resolution imaging techniques for microstructure imaging. Commercial CdSe@ZnS quantum dots are used as STED probes and ≈50 nm lateral resolution is obtained. Compared with other quantum dots, perovskite CsPbBr3 nanoparticles (NPs) possess higher photoluminescence quantum yield and larger absorption cross-section, making them a more effective probe for STED nanoscopy. In this study, CsPbBr3 NPs are used as probes for STED nanoscopy imaging...
April 24, 2018: Advanced Materials
Stefan Stoldt, Dirk Wenzel, Kirsten Kehrein, Dietmar Riedel, Martin Ott, Stefan Jakobs
Oxidative phosphorylation (OXPHOS) is vital for the regeneration of the vast majority of ATP in eukaryotic cells 1 . OXPHOS is carried out by large multi-subunit protein complexes in the cristae membranes, which are invaginations of the mitochondrial inner membrane. The OXPHOS complexes are a mix of subunits encoded in the nuclear and mitochondrial genomes. Thus, the assembly of these dual-origin complexes is an enormous logistical challenge for the cell. Using super-resolution microscopy (nanoscopy) and quantitative cryo-immunogold electron microscopy, we determined where specific transcripts are translated and where distinct assembly steps of the dual-origin complexes in the yeast Saccharomyces cerevisiae occur...
April 16, 2018: Nature Cell Biology
Denny Lang, Jonathan Döring, Tobias Nörenberg, Ádám Butykai, István Kézsmárki, Harald Schneider, Stephan Winnerl, Manfred Helm, Susanne C Kehr, Lukas M Eng
We introduce a scattering-type scanning near-field infrared microscope (s-SNIM) for the local scale near-field sample analysis and spectroscopy from room temperature down to liquid helium (LHe) temperature. The extension of s-SNIM down to T = 5 K is in particular crucial for low-temperature phase transitions, e.g., for the examination of superconductors, as well as low energy excitations. The low temperature (LT) s-SNIM performance is tested with CO2 -IR excitation at T = 7 K using a bare Au reference and a structured Si/SiO2 -sample...
March 2018: Review of Scientific Instruments
Sergey Alexandrov, James McGrat, Colin J R Sheppard, Francesca Boccafoschi, Cinzia Giannini, Teresa Sibillano, Hrebesh Subhash, Josh Hogan, Martin Leahy
For both fundamental study of biological processes and early diagnosis of diseases, information about nanoscale changes in tissue and cell structure is crucial. Nowadays almost all currently known nanoscopy methods rely upon the contrast created by fluorescent stains attached to the object or molecule of interest. This causes limitations due to the impact of the label on the object and its environment, as well as its applicability in vivo, particularly in humans. In this paper, a new label-free approach to visualize small structure with nano-sensitivity to structural alterations is introduced...
March 23, 2018: Journal of Biophotonics
Yiting Yu, Wenli Li, Haoyong Li, Muyuan Li, Weizheng Yuan
Planar super-oscillation lenses (SOLs) can fulfill super-resolution focusing and nanoscopic imaging in the far field without the contribution of evanescent waves. Nevertheless, the existing deviations between the design and experimental results have been seldomly investigated, leaving the practical applications of SOLs unpredictable and uncontrollable. In this paper, some application-oriented issues are taken into consideration, such as the inevitable fabrication errors and the size effect of the designed SOLs, with the aim of providing an engineering reference to elaborately customize the demanded focusing light field...
March 22, 2018: Nanomaterials
Mehran Kianinia, Carlo Bradac, Bernd Sontheimer, Fan Wang, Toan Trong Tran, Minh Nguyen, Sejeong Kim, Zai-Quan Xu, Dayong Jin, Andreas W Schell, Charlene J Lobo, Igor Aharonovich, Milos Toth
Layered van der Waals materials are emerging as compelling two-dimensional platforms for nanophotonics, polaritonics, valleytronics and spintronics, and have the potential to transform applications in sensing, imaging and quantum information processing. Among these, hexagonal boron nitride (hBN) is known to host ultra-bright, room-temperature quantum emitters, whose nature is yet to be fully understood. Here we present a set of measurements that give unique insight into the photophysical properties and level structure of hBN quantum emitters...
February 28, 2018: Nature Communications
Diego Grassi, Shannon Howard, Minghai Zhou, Natalia Diaz-Perez, Nicolai T Urban, Debbie Guerrero-Given, Naomi Kamasawa, Laura A Volpicelli-Daley, Philip LoGrasso, Corinne Ida Lasmézas
Exposure of cultured primary neurons to preformed α-synuclein fibrils (PFFs) leads to the recruitment of endogenous α-synuclein and its templated conversion into fibrillar phosphorylated α-synuclein (pα-synF) aggregates resembling those involved in Parkinson's disease (PD) pathogenesis. Pα-synF was described previously as inclusions morphologically similar to Lewy bodies and Lewy neurites in PD patients. We discovered the existence of a conformationally distinct, nonfibrillar, phosphorylated α-syn species that we named "pα-syn*...
March 13, 2018: Proceedings of the National Academy of Sciences of the United States of America
Rifka Vlijm, Xue Li, Marko Panic, Diana Rüthnick, Shoji Hata, Frank Herrmannsdörfer, Thomas Kuner, Mike Heilemann, Johann Engelhardt, Stefan W Hell, Elmar Schiebel
The centrosome linker proteins C-Nap1, rootletin, and CEP68 connect the two centrosomes of a cell during interphase into one microtubule-organizing center. This coupling is important for cell migration, cilia formation, and timing of mitotic spindle formation. Very little is known about the structure of the centrosome linker. Here, we used stimulated emission depletion (STED) microscopy to show that each C-Nap1 ring at the proximal end of the two centrioles organizes a rootletin ring and, in addition, multiple rootletin/CEP68 fibers...
March 6, 2018: Proceedings of the National Academy of Sciences of the United States of America
S Roy Chowdhury, Jin Cao, Yufan He, H Peter Lu
Manipulating protein conformations for exploring protein structure-function relationship has shown great promise. Although protein conformational changes under pulling force manipulation have been extensively studied, protein conformation changes under a compressive force have not been explored quantitatively. The latter is even more biologically significant and relevant in revealing protein functions in living cells associated with protein crowdedness, distribution fluctuations, and cell osmotic stress. Here we report our experimental observations on abrupt ruptures of protein native structures under compressive force, demonstrated and studied by single-molecule AFM-FRET spectroscopic nanoscopy...
March 27, 2018: ACS Nano
Thibault Lagache, Alexandre Grassart, Stéphane Dallongeville, Orestis Faklaris, Nathalie Sauvonnet, Alexandre Dufour, Lydia Danglot, Jean-Christophe Olivo-Marin
Elucidating protein functions and molecular organisation requires to localise precisely single or aggregated molecules and analyse their spatial distributions. We develop a statistical method SODA (Statistical Object Distance Analysis) that uses either micro- or nanoscopy to significantly improve on standard co-localisation techniques. Our method considers cellular geometry and densities of molecules to provide statistical maps of isolated and associated (coupled) molecules. We use SODA with three-colour structured-illumination microscopy (SIM) images of hippocampal neurons, and statistically characterise spatial organisation of thousands of synapses...
February 15, 2018: Nature Communications
Anna M Chizhik, Carina Wollnik, Daja Ruhlandt, Narain Karedla, Alexey I Chizhik, Lara Hauke, Dirk Hähnel, Ingo Gregor, Jörg Enderlein, Florian Rehfeldt
We report a novel method, dual color axial nanometric localization by Metal Induced Energy Transfer (dcMIET), and combine it with Förster Resonant Energy Transfer (FRET) for resolving structural details in cells on the molecular level. We demonstrate the capability of this method on cytoskeletal elements and adhesions in human mesenchymal stem cells (hMSCs). Our approach is based on Fluorescence-Lifetime-Imaging Microscopy (FLIM), and allows for precise determination of the 3D architecture of stress fibers anchoring at focal adhesions, thus yielding crucial information to understand cell-matrix mechanics...
February 14, 2018: Molecular Biology of the Cell
Carola Gregor, Sven C Sidenstein, Martin Andresen, Steffen J Sahl, Johann G Danzl, Stefan W Hell
The reversibly switchable fluorescent proteins (RSFPs) commonly used for RESOLFT nanoscopy have been developed from fluorescent proteins of the GFP superfamily. These proteins are bright, but exhibit several drawbacks such as relatively large size, oxygen-dependence, sensitivity to low pH, and limited switching speed. Therefore, RSFPs from other origins with improved properties need to be explored. Here, we report the development of two RSFPs based on the LOV domain of the photoreceptor protein YtvA from Bacillus subtilis...
February 9, 2018: Scientific Reports
Xiaohe Tian, Hui Wang, Qiong Zhang, Mingzhu Zhang, Yingzhong Zhu, Yan Chen, Jieying Wu, Yupeng Tian
Probe for dual-site target distinct subcellular compartments from cytosol and nucleus is an attractive approach, however, which was scarcely reported. Herein, a series of small-molecular thiophene pyridium salt derivatives (MitoNuc1-4) possessing water-soluble, high quantum yield and two-photon activity were rationally designed, and their structures were crystallographic confirmed. Systematic photophysical and biological imaging property investigations were carried out for them. It was found that MitoNuc1-4 exhibit two-photon absorption properties in the near infrared region, and MitoNuc1 has membrane permeability and cationic nature, rendering it to be double labelling of mitochondria and nucleolus in living cells with superb photo-stability and non-invasiveness...
May 30, 2018: Analytica Chimica Acta
Waja Wegner, Alexander C Mott, Seth G N Grant, Heinz Steffens, Katrin I Willig
The post-synaptic density (PSD) is an electron dense region consisting of ~1000 proteins, found at the postsynaptic membrane of excitatory synapses, which varies in size depending upon synaptic strength. PSD95 is an abundant scaffolding protein in the PSD and assembles a family of supercomplexes comprised of neurotransmitter receptors, ion channels, as well as signalling and structural proteins. We use superresolution STED (STimulated Emission Depletion) nanoscopy to determine the size and shape of PSD95 in the anaesthetised mouse visual cortex...
January 9, 2018: Scientific Reports
Michael Abadier, Akula Bala Pramod, Sara McArdle, Alex Marki, Zhichao Fan, Edgar Gutierrez, Alex Groisman, Klaus Ley
The adaptive immune response involves T cell differentiation and migration to sites of inflammation. T cell trafficking is initiated by rolling on inflamed endothelium. Tethers and slings, discovered in neutrophils, facilitate cell rolling at high shear stress. Here, we demonstrate that the ability to form tethers and slings during rolling is highly inducible in T helper 1 (Th1), Th17, and regulatory T (Treg) cells but less in Th2 cells. In vivo, endogenous Treg cells rolled stably in cremaster venules at physiological shear stress...
December 26, 2017: Cell Reports
Roderick P Tas, Anaël Chazeau, Bas M C Cloin, Maaike L A Lambers, Casper C Hoogenraad, Lukas C Kapitein
Microtubules are essential for polarized transport in neurons, but how their organization guides motor proteins to axons or dendrites is unclear. Because different motors recognize distinct microtubule properties, we used optical nanoscopy to examine the relationship between microtubule orientations, stability, and modifications. Nanometric tracking of motors to super-resolve microtubules and determine their polarity revealed that in dendrites, stable and acetylated microtubules are mostly oriented minus-end out, while dynamic and tyrosinated microtubules are oriented oppositely...
December 20, 2017: Neuron
Federico M Barabas, Luciano A Masullo, Martín D Bordenave, Sebastián A Giusti, Nicolás Unsain, Damián Refojo, Alfredo Cáceres, Fernando D Stefani
Fluorescence nanoscopy imaging permits the observation of periodic supramolecular protein structures in their natural environment, as well as the unveiling of previously unknown protein periodic structures. Deciphering the biological functions of such protein nanostructures requires systematic and quantitative analysis of large number of images under different experimental conditions and specific stimuli. Here we present a method and an open source software for the automated quantification of protein periodic structures in super-resolved images...
November 22, 2017: Scientific Reports
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