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Jacek Czub, Miłosz Wieczór, Bartosz Prokopowicz, Helmut Grubmüller
F1-ATPase is a highly efficient molecular motor that can synthesize ATP driven by a mechanical torque. Its ability to function reversibly in either direction requires tight mechanochemical coupling between the catalytic domain and the rotating central shaft, as well as temporal control of substrate binding and product release. Despite great efforts and significant progress, the molecular details of this synchronized and fine-tuned energy conversion mechanism are not fully understood. Here, we use extensive molecular dynamics simulations to reconcile recent single-molecule experiments with structural data and provide a consistent thermodynamic, kinetic and mechanistic description of the main rotary substep in the synthetic cycle of mammalian ATP synthase...
March 9, 2017: Journal of the American Chemical Society
Carla Schmidt, Jamie A Macpherson, Andy M Lau, Ken Wei Tan, Franca Fraternali, Argyris Politis
Mass spectrometry (MS) has become an indispensable tool for investigating the architectures and dynamics of macromolecular assemblies. Here we show that covalent labeling of solvent accessible residues followed by their MS-based identification yields modeling restraints that allow mapping the location and orientation of subunits within protein assemblies. Together with complementary restraints derived from cross-linking and native MS, we built native-like models of four heterocomplexes with known subunit structures and compared them with available X-ray crystal structures...
February 7, 2017: Analytical Chemistry
Yingfeng Tu, Fei Peng, Alain A M André, Yongjun Men, Mangala Srinivas, Daniela A Wilson
We report the self-assembly of a biodegradable platinum nanoparticle-loaded stomatocyte nanomotor containing both PEG-b-PCL and PEG-b-PS as a potential candidate for anticancer drug delivery. Well-defined stomatocyte structures could be formed even after incorporation of 50% PEG-b-PCL polymer. Demixing of the two polymers was expected at high percentage of semicrystalline poly(ε-caprolactone) (PCL), resulting in PCL domain formation onto the membrane due to different properties of two polymers. The biodegradable motor system was further shown to move directionally with speeds up to 39 μm/s by converting chemical fuel, hydrogen peroxide, into mechanical motion as well as rapidly delivering the drug to the targeted cancer cell...
February 28, 2017: ACS Nano
Fabiana Arduini, Stefano Cinti, Viviana Scognamiglio, Danila Moscone, Giuseppe Palleschi
Through the years, scientists have developed cutting-edge technologies to make (bio)sensors more convenient for environmental analytical purposes. Technological advancements in the fields of material science, rational design, microfluidics, and sensor printing, have radically shaped biosensor technology, which is even more evident in the continuous development of sensing systems for the monitoring of hazardous chemicals. These efforts will be crucial in solving some of the problems constraining biosensors to reach real environmental applications, such as continuous analyses in field by means of multi-analyte portable devices...
March 22, 2017: Analytica Chimica Acta
Hong Wang, Martin Pumera
Self-propelled autonomous nano and micromotors are devices which in many aspects mimic living organisms: they take chemical energy from the environment and convert it to motion; they are capable of phototaxis, chemotaxis and magnetotaxis, following the gradient of fuel, a magnetic field or light. There is an immense spectrum of possible applications of these devices, ranging from environmental remediation to the biomedical field. All of these developments depend on the materials used and there has been intensive development of materials allowing more efficient propulsion, phototaxis, chemotaxis and enhanced applications of these devices...
February 1, 2017: Nanoscale
Ilya L Sokolov, Vladimir R Cherkasov, Andrey A Tregubov, Sveatoslav R Buiucli, Maxim P Nikitin
BACKGROUND: Theranostics, a fusion of two key parts of modern medicine - diagnostics and therapy of the organism's disorders, promises to bring the efficacy of medical treatment to a fundamentally new level and to become the basis of personalized medicine. Extrapolating today's progress in the field of smart materials to the long-run prospect, we can imagine future intelligent agents capable of performing complex analysis of different physiological factors inside the living organism and implementing a built-in program thereby triggering a series of therapeutic actions...
January 24, 2017: Biochimica et Biophysica Acta
Renfeng Dong, Yan Hu, Yefei Wu, Wei Gao, Biye Ren, Qinglong Wang, Yuepeng Cai
Light-driven synthetic micro-/nanomotors have attracted considerable attention due to their potential applications and unique performances such as remote motion control and adjustable velocity. Utilizing harmless and renewable visible light to supply energy for micro-/nanomotors in water represents a great challenge. In view of the outstanding photocatalytic performance of bismuth oxyiodide (BiOI), visible-light-driven BiOI-based Janus micromotors have been developed, which can be activated by a broad spectrum of light, including blue and green light...
January 30, 2017: Journal of the American Chemical Society
Fei Peng, Yingfeng Tu, Ashish Adhikari, Jordi C J Hintzen, Dennis W P M Löwik, Daniela A Wilson
A nanomotor based strategy for fast cellular entry and cargo delivery is presented. The concept focuses on integrating tat peptide, a basic domain of HIV-1 tat protein, with state of the art nanomotors which possess attractive autonomous properties, facilitating cellular penetration and uptake. The rapid cellular internalization process leads to higher delivery efficiency.
January 3, 2017: Chemical Communications: Chem Comm
Tailin Xu, Wei Gao, Li-Ping Xu, Xueji Zhang, Shutao Wang
Inspired by the swimming of natural microorganisms, synthetic micro-/nanomachines, which convert energy into movement, are able to mimic the function of these amazing natural systems and help humanity by completing environmental and biological tasks. While offering autonomous propulsion, conventional micro-/nanomachines usually rely on the decomposition of external chemical fuels (e.g., H2 O2 ), which greatly hinders their applications in biologically relevant media. Recent developments have resulted in various micro-/nanomotors that can be powered by biocompatible fuels...
December 27, 2016: Advanced Materials
Muhammad Safdar, Tam Do Minh, Niko Kinnunen, Janne Jänis
Manganese oxide (MnO2) has recently emerged as a promising alternate material for the fabrication of self-propelled micromotors. Platinum (Pt) has been traditionally used as a catalytic material for this purpose. However, the high cost associated with Pt restricts its widespread use toward practical applications where large amounts of material are required. MnO2 exists in different crystalline forms (polymorphs), which govern its catalytic behavior. In spite of this, the recent reports on MnO2 based micromotors have seldom reported on the polymorphic form involved...
November 30, 2016: ACS Applied Materials & Interfaces
Weiwei Qin, Tianhuan Peng, Yanjing Gao, Fei Wang, Xiaocai Hu, Kun Wang, Jiye Shi, Di Li, Jicun Ren, Chunhai Fan
It is highly demanding to design active nanomotors that can move in response to specific signals with controllable rate and direction. A catalysis-driven nanomotor was constructed by designing catalytically and plasmonically active Janus gold nanoparticles (Au NPs), which generate an asymmetric temperature gradient of local solvent surrounding NPs in catalytic reactions. The self-thermophoresis behavior of the Janus nanomotor is monitored from its inherent plasmonic response. The diffusion coefficient of the self-thermophoresis motion is linearly dependent on chemical reaction rate, as described by a stochastic model...
January 9, 2017: Angewandte Chemie
Dekai Zhou, Yuguang C Li, Pengtao Xu, Nicholas S McCool, Longqiu Li, Wei Wang, Thomas E Mallouk
Visible light driven Cu2O-Au micromotors exhibit rapid on/off switching and speed control. Electrochemical measurements confirm that the light-induced movement of the Cu2O-Au micromotors involves a self-electrophoresis mechanism modulated by the photoconductivity of Cu2O. This study extends the utilization of the electromagnetic spectrum for micro/nanomotors into the visible range.
January 7, 2017: Nanoscale
Fei Peng, Yingfeng Tu, Yongjun Men, Jan C M van Hest, Daniela A Wilson
With a convenient bottom-up approach, magnetic metallic nickel is grown in situ of a supramolecular nanomotor using the catalytic activities of preloaded platinum nanoparticles. After introducing magnetic segments, simultaneous guidance and steering of catalytically powered motors with additional magnetic fields are achieved. Guided motion in a tissue model is demonstrated.
November 28, 2016: Advanced Materials
Jiao Shi, Kun Cai, Qing-Hua Qin
A conceptual design is presented for a nanoengine governor based on the end interfacial effect of two rotary nanotubes. The governor contains a thermal-driven rotary nanomotor made from double-walled carbon nanotubes (DWCNTs) and a coaxially laid out rotary nanotube near one end of the nanomotor rotor. The rotation of the rotor in the nanomotor can be controlled by two features. One is the stator (the outer tube of DWCNTs) which has some end atoms with inward radial deviation (IRD) on the stator. The other is the relative rotation of the neighboring rotary tube of the rotor...
November 9, 2016: Nanotechnology
Deliang Yi, Qian Zhang, Yinghua Liu, Jiaying Song, Yi Tang, Frank Caruso, Yajun Wang
We report the synthesis of chemically asymmetric silica nanobottles (NBs) with a hydrophobic exterior surface (capped with 3-chloropropyl groups) and a hydrophilic interior surface for spatially selective cargo loading, and for application as nanoreactors and nanomotors. The silica NBs, which have a "flask bottle" shape with an average diameter of 350 nm and an opening of ca. 100 nm, are prepared by anisotropic sol-gel growth in a water/n-pentanol emulsion. Due to their chemically asymmetric properties, nanoparticles (NPs) with hydrophilic or hydrophobic surface properties can be selectively loaded inside the NBs or on the outside of the NBs, respectively...
November 14, 2016: Angewandte Chemie
Bumjin Jang, Wei Wang, Samuel Wiget, Andrew J Petruska, Xiangzhong Chen, Chengzhi Hu, Ayoung Hong, David Folio, Antoine Ferreira, Salvador Pané, Bradley J Nelson
We report Au/Ru core-shell nanowire motors. These nanowires are fabricated using our previously developed electrodeposition-based technique, and their catalytic locomotion in the presence of H2O2 is investigated. Unlike conventional bimetallic nanowires that are self-electroosmotically propelled, our open-ended Au/Ru core-shell nanowires show both a noticeable decrease in rotational diffusivity and increase in motor speed with increasing nanowire length. Numerical modeling based on self-electroosmosis attributes decreases in rotational diffusivity to the formation of toroidal vortices at the nanowire tail, but fails to explain the speed increase with length...
November 22, 2016: ACS Nano
Baohu Dai, Jizhuang Wang, Ze Xiong, Xiaojun Zhan, Wei Dai, Chien-Cheng Li, Shien-Ping Feng, Jinyao Tang
Phototaxis is commonly observed in motile photosynthetic microorganisms. For example, green algae are capable of swimming towards a light source (positive phototaxis) to receive more energy for photosynthesis, or away from a light source (negative phototaxis) to avoid radiation damage or to hide from predators. Recently, with the aim of applying nanoscale machinery to biomedical applications, various inorganic nanomotors based on different propulsion mechanisms have been demonstrated. The only method to control the direction of motion of these self-propelled micro/nanomotors is to incorporate a ferromagnetic material into their structure and use an external magnetic field for steering...
December 2016: Nature Nanotechnology
Fernando Soto, Gregory L Wagner, Victor Garcia-Gradilla, Kyle T Gillespie, Deepak R Lakshmipathy, Emil Karshalev, Chava Angell, Yi Chen, Joseph Wang
Herein we report a new design for acoustic nanoswimmers, making use of a nanoshell geometry that was synthesized using a sphere template process. Such shell-shaped nanomotors display highly efficient acoustic propulsion on the nanoscale by converting energy from the ambient acoustic field into motion. The propulsion mechanism of the nanoshell motors relies on acoustic streaming stress over the asymmetric surface to produce the driving force for motion. The shell-shaped nanomotors offer a high surface area to volume ratio, allow for efficient scalability and provide higher cargo towing capacity (in comparison to acoustically propelled nanowires)...
October 6, 2016: Nanoscale
Bahareh Kherzi, Martin Pumera
Self-propelled autonomous nano/micromotors are in the forefront of current materials science and technology research. These small machines convert chemical energy from the environment into propulsion, and they can move autonomously in the environment and are capable of chemotaxis or magnetotaxis. They can be used for drug delivery, microsurgeries or environmental remediation. It is of immense interest from a future biomedical application point of view to understand the motion of the nano/micromotors in microfluidic channels...
October 14, 2016: Nanoscale
Zhengyi Zhao, Hui Zhang, Dan Shu, Carlo Montemagno, Baoquan Ding, Jingyuan Li, Peixuan Guo
The significance of bionanomotors in nanotechnology is analogous to mechanical motors in daily life. Here the principle and approach for designing and constructing biomimetic nanomotors with continuous single-directional motion are reported. This bionanomotor is composed of a dodecameric protein channel, a six-pRNA ring, and an ATPase hexamer. Based on recent elucidations of the one-way revolving mechanisms of the phi29 double-stranded DNA (dsDNA) motor, various RNA and protein elements are designed and tested by single-molecule imaging and biochemical assays, with which the motor with active components has been constructed...
January 2017: Small
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