self-assembly

 Nanofiber scaffolds demonstrate new features in the behavior of stem and cancer cells

A discovery in the field of biomaterials may open new frontiers in stem and cancer cell manipulation and associated advanced therapy development. Novel scaffolds are shown enabling cells to behave in a different but controlled way in vitro due to the presence of aligned, self-assembled ceramic nanofibers of an ultra-high anisotropy ratio augmented into graphene shells.

“This unique hybrid nano-network allows for an exceptional combination of selective guidance stimuli for stem cell development, variations in immune reactions, and behavior of cancer cells”, says Professor Michael Gasik from Aalto University.

These scaffolds, for example, were shown to be able to direct the preferential orientation of human mesenchymal stem cells, similarly to neurogenic lineage, to suppress of major inflammatory factors expression and to immobilize cancer cells.

The results of the study were published in Nature Scientific Reports

Caption: Fluorescent images of breast carcinoma cell line showing the morphological changes of cells grown on vertical GAIN scaffolds. Credit: Aalto University / Michael Gasik

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Silicon Origami Folds From Flat To 3-D With A Drop Of Water

Scientists in the Netherlands have created flat shapes that open and close with a droplet of water into tiny cubes, pyramids and other three-dimensional structures.

With more research, the self-assembling, silicon-based shapes could lead to microscopic packages of drugs that release their therapeutic cargo directly where it is needed. The 3-D structures, about the size of a sand grain, could also open and close at specific locations, allowing for noninvasive microbiopsies from deep within the body.

“Possible shapes are in principle limitless as long as they can first be made on a flat surface,” said University of Twente graduate student Antoine Legrain.

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VIDEO: Researchers create self assembling carbon nanotubes - Many potential applications

Carbon nanotubes in a dish assemble themselves into a nanowire in seconds under the influence of a custom-built Tesla coil created by scientists at Rice University.

But the scientists don’t limit their aspirations for the phenomenon they call Teslaphoresis to simple nanowires.

The team led by Rice research scientist Paul Cherukuri sees its invention as setting a path toward the assembly of matter from the bottom up on nano and macro scales.

READ MORE ON RICE UNIVERSITY

Ref: Teslaphoresis of Carbon Nanotubes. ACS NANO (13 April 2016) | DOI: 10.1021/acsnano.6b02313

ABSTRACT

This paper introduces Teslaphoresis, the directed motion and self-assembly of matter by a Tesla coil, and studies this electrokinetic phenomenon using single-walled carbon nanotubes (CNTs). Conventional directed self-assembly of matter using electric fields has been restricted to small scale structures, but with Teslaphoresis, we exceed this limitation by using the Tesla coil’s antenna to create a gradient high-voltage force field that projects into free space. CNTs placed within the Teslaphoretic (TEP) field polarize and self-assemble into wires that span from the nanoscale to the macroscale, the longest thus far being 15 cm. We show that the TEP field not only directs the self-assembly of long nanotube wires at remote distances (>30 cm) but can also wirelessly power nanotube-based LED circuits. Furthermore, individualized CNTs self-organize to form long parallel arrays with high fidelity alignment to the TEP field. Thus, Teslaphoresis is effective for directed self-assembly from the bottom-up to the macroscale.

Microtubules, assemble!

What bones are to bodies, the cytoskeleton is to cells. The cytoskeleton maintains cellular structure, builds appendages like flagella and, together with motor proteins, powers cellular movement, transport, and division. Microtubules are a critical component of the cytoskeleton, vital for cell division and, because of that, an excellent target for chemotherapy drugs.

Microtubules can spontaneously self-organize, transforming from many singular components into one large cellular structure capable of performing specific tasks. Think Transformers. How they do that, however, has remained unclear.

Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have observed how microtubules and motor proteins assemble into macroscopic networks. Their observation provides a better understanding of cytoskeletal self-organization in general, which may in turn lead to better drug design and new materials that can mimic cellular behaviors.

The research was recently published in the journal eLife.

Peter J Foster, Sebastian Fürthauer, Michael J Shelley, Daniel J Needleman. Active contraction of microtubule networks. eLife, 2015; 4 DOI: 10.7554/eLife.10837

The white spindles in the center of the cell separate the chromosomes and pull the duplicated DNA from the mother cell into the daughter cell 

Self-assembling printable robotic components | KurzweilAI
Printable robotic components that, when heated, automatically self-assemble into prescribed three-dimensional configurations have been developed by MIT researchers.

Printable robots that can be assembled from parts produced by 3-D printers have long been a topic of research in the lab of Daniela Rus, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science at MIT.

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[1] Self assembling articles created by scientists in 2012, 1/100th the diameter of a human hair, they spontaneously assemble themselves into structures resembling molecules made from atoms.  Illustration courtesy of Yufeng Wang and Yu Wang.

[2] Previously, scientists had succeeded in building rudimentary structures from colloids. Electron microscope images of “colloidal atoms,” micrometer-sized particles with patches that allow bonding only along particular directions. From left to right: particle with one patch (analogous to a hydrogen atom), two, three, four (analogous to a carbon atom), five, six, and seven patches.
Image courtesy of Vinothan N. Manoharan and David J. Pine.

SOURCE: PhysOrg

New artificial cells mimic nature’s tiny reactors

Artificial cells that mimic their natural counterparts help scientists learn the secrets of complex processes, such as how plant cells turn sunlight, water, and carbon dioxide into fuel. Today’s artificial cells often become unstable when materials transit the membrane. Scientists have developed a new artificial cell where lipid vesicles (small pools of fatty molecules) self-assemble around treated water droplets. The result is an artificial cell or microscopic bioreactor.

On the lDaniel C. Dewey, Christopher A. Strulson, David N. Cacace, Philip C. Bevilacqua, Christine D. Keating. Bioreactor droplets from liposome-stabilized all-aqueous emulsions. Nature Communications, 2014; 5: 4670 DOI: 10.1038/ncomms5670

eft: Fluorescent microscope image shows artificial bioreactors composed of sugar-based dextran polymer solution (blue) encapsulated within a shell of lipid vesicles (red). On the right: schematic illustration of what the vesicles look like at the aqueous/aqueous interface. Blue and yellow shading indicate the interior and exterior solutions.        Credit: Christine Keating

Shape-changing ‘smart’ material: Heat, light stimulate self-assembly

Washington State University researchers have developed a unique, multifunctional smart material that can change shape from heat or light and assemble and disassemble itself. They have filed a provisional patent on the work.

This is the first time researchers have been able to combine several smart abilities, including shape memory behavior, light-activated movement and self-healing behavior, into one material. They have published their work inACS Applied Materials & Interfaces.

The work is led by Michael Kessler, professor and Berry Family director and in the WSU School of Mechanical and Materials Engineering (MME), and Yuzhan Li, MME staff scientist, in collaboration with Orlando Rios, a researcher at Oak Ridge National Laboratory.

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Self assembling superconductor research provides new mechanisms for superconducting structures and composite materials with novel properties

Building on nearly two decades’ worth of research, a multidisciplinary team at Cornell has blazed a new trail by creating a self-assembled, three-dimensional gyroidal superconductor.

Ulrich Wiesner, the Spencer T. Olin Professor of Engineering, led the group, which included researchers in engineering, chemistry and physics.

READ MORE ON CORNELL CHRONICLE

Ref: Block copolymer self-assembly–directed synthesis of mesoporous gyroidal superconductors. Science Advances (29 January 2016) | DOI: 10.1126/sciadv.1501119 | PDF (Open Access)

ABSTRACT

Superconductors with periodically ordered mesoporous structures are expected to have properties very different from those of their bulk counterparts. Systematic studies of such phenomena to date are sparse, however, because of a lack of versatile synthetic approaches to such materials. We demonstrate the formation of three-dimensionally continuous gyroidal mesoporous niobium nitride (NbN) superconductors from chiral ABC triblock terpolymer self-assembly–directed sol-gel–derived niobium oxide with subsequent thermal processing in air and ammonia gas. Superconducting materials exhibit a critical temperature (Tc) of about 7 to 8 K, a flux exclusion of about 5% compared to a dense NbN solid, and an estimated critical current density (Jc) of 440 A cm−2 at 100 Oe and 2.5 K. We expect block copolymer self-assembly–directed mesoporous superconductors to provide interesting subjects for mesostructure-superconductivity correlation studies.

Title: Fluid Crystallization

Category: #selfassembly

Author: Skylar Tibbits

Year: 2013

Url: http://sjet.us/MIT_FLUID%20CRYSTALLIZATION.html

Description : This installation investigates hierarchical and non-deterministic self-assembly with large numbers of parts in a fluid medium. 350 hollow spheres have been submerged in a 200 gallon glass water-filled tank. Armatures, modeled after carbon atoms, follow intramolecular covalent bonding geometries within atoms. Intermolecular structures are formed as spheres interact with one another in 1, 2, or 3-Dimensional patterns. The highly dynamic self-assembly characteristic of the system offers a glimpse at material phase change between crystalline solid, liquid, and gaseous states. Turbulence in the water introduces stochastic energy into the system, increasing the entropy and allowing structures to self-assemble; thus, transitioning between gas, liquid, and solid phases. Polymorphism may be observed where the same intramolecular structures can solidify in more than one crystalline form, demonstrating the versatile nature of carbon as a building block for life.

New model for how twisted bundles take shape

Team unravels rules of twisted bundle morphology

In the current issue of Nature Materials, polymer scientists Greg Grason, Douglas Hall and Isaac Bruss at the University of Massachusetts Amherst, with Justin Barone at Virginia Tech, identify for the first time the factors that govern the final morphology of self-assembling chiral filament bundles. They also report experimental results supporting their new model.

At the molecular level, Grason explains, chiral filament bundles are many-stranded, self-twisting, yarn-like structures. One example are amyloid fibers, assemblies of misfolded proteins linked to diseases like Alzheimer’s and Parkinson’s. Many other proteins take this shape, including collagen, the most abundant protein in the body, and sickle-hemoglobin proteins found in sickle-cell anemia. But how they attain their final size and shape has not been well understood.

Previous work by Bruss and Grason described the formation of cable-like filament bundles. When Grason presented this at Virginia Tech, Justin Barone, a biological systems engineer, approached him with a question about the geometric structure of amyloid fibers he had been studying. Barone asked why the shapes he was observing were in some cases flat and tape-like, while under other conditions they were cylindrical.

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vimeo

Benjamin Vermeulen’s furniture is even easier to assemble than Ikea.

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The weight of their history hangs in the words left unsaid, and standing so close to the empty distance of space beyond the window gives Ezri a touch of vertigo… It’s like they’re at the edge of an airlock, the vast unknown looming beyond, willing themselves not to jump.

Ezri / Lenara, Regrets Collect Like Old Friends