Name: designing a bio-responsive robot from dna origami
Uploaded: 2013-07-08T12:00:00
Description: Watch this Scientific Journal Video about Designing a Bio-responsive Robot from DNA Origami at JoVE.com

Gli autori desiderano ringraziare S. Douglas per il grande valore discussioni e consigli, e tutti i membri del laboratorio Bachelet per utili discussioni e lavoro. Questo lavoro è supportato da finanziamenti della Facoltà di Scienze della Vita e Istituto di nanotecnologia e materiali avanzati a Bar-Ilan University.

Il robot verrà costruito in questo documento risponde ad una proteina P facendo un carico C disponibili per legarsi ai recettori sulla superficie di una cellula bersaglio prescelto. Il robot è mostrato in Figura 1 C può essere un farmaco recettore-bloccaggio;. Un fattore di crescita, ecc, e un modo per collegare chimicamente ad un oligonucleotide DNA deve essere disponibile che non distrugge la sua funzione. Il robot dispone di due stati. Quando, cancelli DNA inattivo sul d...

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	<li>Watson, J. D., Crick, F. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetical+implications+of+the+structure+of+deoxyribonucleic+acid.">Genetical implications of the structure of deoxyribonucleic acid.</a> Nature. 171, 964-967 (1953).</li><li>Adleman, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+computation+of+solutions+to+combinatorial+problems.">Molecular computation of solutions to combinatorial problems.</a> Science. 266, 1021-1024 (1994).</li><li>Qian, L., Winfree, E., Bruck, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+network+computation+with+DNA+strand+displacement+cascades.">Neural network computation with DNA strand displacement cascades.</a> Nature. 475, 368-372 (2011).</li><li>Ellington, A. D., Szostak, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+selection+of+RNA+molecules+that+bind+specific+ligands.">In vitro selection of RNA molecules that bind specific ligands.</a> Nature. 346, 818-822 (1990).</li><li>Tang, Z., Parekh, P., Turner, P., Moyer, R. W., Tan, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generating+aptamers+for+recognition+of+virus-infected+cells.">Generating aptamers for recognition of virus-infected cells.</a> Clin. Chem. 55, 813-822 (2009).</li><li>Baskerville, S., Bartel, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+ribozyme+that+ligates+RNA+to+protein.">A ribozyme that ligates RNA to protein.</a> Proc. Natl. Acad. Sci. U.S.A. 99, 9154-9159 (2002).</li><li>Bartel, D. P., Szostak, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+new+ribozymes+from+a+large+pool+of+random+sequences+[see+comment].">Isolation of new ribozymes from a large pool of random sequences [see comment].</a> Science. 261, 1411-1418 (1993).</li><li>Benenson, Y., Gil, B., Ben-Dor, U., Adar, R., Shapiro, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+autonomous+molecular+computer+for+logical+control+of+gene+expression.">An autonomous molecular computer for logical control of gene expression.</a> Nature. 429, 423-429 (2004).</li><li>Xie, Z., Wroblewska, L., Prochazka, L., Weiss, R., Benenson, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-input+RNAi-based+logic+circuit+for+identification+of+specific+cancer+cells.">Multi-input RNAi-based logic circuit for identification of specific cancer cells.</a> Science. 333, 1307-1311 (2011).</li><li>Rothemund, P. W., Papadakis, N., Winfree, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Algorithmic+self-assembly+of+DNA+Sierpinski+triangles.">Algorithmic self-assembly of DNA Sierpinski triangles.</a> PLoS Biol. 2, e424 (2004).</li><li>Chen, J. H., Seeman, N. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+from+DNA+of+a+molecule+with+the+connectivity+of+a+cube.">Synthesis from DNA of a molecule with the connectivity of a cube.</a> Nature. 350, 631-633 (1991).</li><li>He, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hierarchical+self-assembly+of+DNA+into+symmetric+supramolecular+polyhedra.">Hierarchical self-assembly of DNA into symmetric supramolecular polyhedra.</a> Nature. 452, 198-201 (2008).</li><li>Seeman, N. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nucleic+acid+junctions+and+lattices.">Nucleic acid junctions and lattices.</a> J. Theor. Biol. 99, 237-247 (1982).</li><li>Wei, B., Dai, M., Yin, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complex+shapes+self-assembled+from+single-stranded+DNA+tiles.">Complex shapes self-assembled from single-stranded DNA tiles.</a> Nature. 485, 623-626 (2012).</li><li>Yin, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Programming+DNA+tube+circumferences.">Programming DNA tube circumferences.</a> Science. 321, 824-826 (2008).</li><li>Rothemund, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Folding+DNA+to+create+nanoscale+shapes+and+patterns.">Folding DNA to create nanoscale shapes and patterns.</a> Nature. 440, 297-302 (2006).</li><li>Dietz, H., Douglas, S. M., Shih, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Folding+DNA+into+twisted+and+curved+nanoscale+shapes.">Folding DNA into twisted and curved nanoscale shapes.</a> Science. 325, 725-730 (2009).</li><li>Douglas, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-assembly+of+DNA+into+nanoscale+three-dimensional+shapes.">Self-assembly of DNA into nanoscale three-dimensional shapes.</a> Nature. 459, 414-418 (2009).</li><li>Douglas, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+prototyping+of+3D+DNA-origami+shapes+with+caDNAno.">Rapid prototyping of 3D DNA-origami shapes with caDNAno.</a> Nucleic Acids Res. 37, 5001-5006 (2009).</li><li>Douglas, S. M., Bachelet, I., Church, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+logic-gated+nanorobot+for+targeted+transport+of+molecular+payloads.">A logic-gated nanorobot for targeted transport of molecular payloads.</a> Science. 335, 831-834 (2012).</li><li>Castro, C. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+primer+to+scaffolded+DNA+origami.">A primer to scaffolded DNA origami.</a> Nature Methods. 8, 221-229 (1038).</li><li>Ke, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multilayer+DNA+origami+packed+on+a+square+lattice.">Multilayer DNA origami packed on a square lattice.</a> Journal of the American Chemical Society. 131, 15903-15908 (2009).</li><li>Mallikaratchy, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+aptamers+evolved+from+cell-SELEX+to+engineer+a+molecular+delivery+platform.">Using aptamers evolved from cell-SELEX to engineer a molecular delivery platform.</a> Chem. Commun. (Camb). , 3056-3058 (2009).</li><li>Hamad-Schifferli, K., Schwartz, J. J., Santos, A. T., Zhang, S., Jacobson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remote+electronic+control+of+DNA+hybridization+through+inductive+coupling+to+an+attached+metal+nanocrystal+antenna.">Remote electronic control of DNA hybridization through inductive coupling to an attached metal nanocrystal antenna.</a> Nature. 415, 152-155 (2002).</li></ol>

Origami di DNA ci permette di fabbricare oggetti accuratamente definiti funzioni arbitrarie su scala nanometrica. Un importante passo successivo sarà l&#39;integrazione della funzione in questi disegni. Mentre molte applicazioni e le sfide possono essere affrontate con questa tecnologia, vi è un particolare interesse per la fabbricazione di robot terapeutici e scientifici da origami di DNA, in quanto questi rappresentano un ambiente naturale di DNA. DNA si interfaccia già con macchine molecolari in cellule come una i...

<table border="1">
 <tbody>
 <tr>
 <td>Name of Reagent/Material</td>
 <td>Company</td>
 <td>Catalog Number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Autodesk Maya 2012</td>
 <td>Autodesk</td>
 <td></td>
 <td>A student/academic account needs to be created first (see platform-specific instructions in <a href="http://cadnano.org" target="_blank">http://cadnano.org</a>)</td>
 </tr>
 <tr>
 <td>caDNAno 2.0 (software)</td>
 <td>(Open source)</td>
 <td></td>
 <td>Software for the design of DNA origami structures <a href="http://cadnano.org/" target="_blank">http://cadnano.org</a></td>
 </tr>
 <tr>
 <td>Cando (webpage)</td>
 <td>(Open source)</td>
 <td></td>
 <td>Webpage running a simulator of DNA origami shapes <a href="http://cando-dna-origami.org" target="_blank">http://cando-dna-origami.org</a></td>
 </tr>
 </tbody>
</table>

designing a bio-responsive robot from dna origami

Gli acidi nucleici sono sorprendentemente versatile. Oltre al loro ruolo naturale come supporto di memorizzazione per informazioni biologiche 1, possono essere utilizzati in parallelo computazione 2,3, riconoscono e si legano bersagli molecolari o cellulari 4,5, 6,7 catalizzano reazioni chimiche, e generano risposte calcolate in biologico Sistema di 8,9. Soprattutto, gli acidi nucleici possono essere programmate per auto-assemblano in strutture 2D e 3D 10-12, consentendo l&#39;integrazione di tutte queste caratteristiche notevoli in un unico robot che collegano il rilevamento di segnali biologici per una risposta predeterminata per esercitare un effetto desiderato. Creare forme di acidi nucleici è stata proposta da Seeman 13, e diverse variazioni sul tema sono stati da allora realizzati con varie tecniche 11,12,14,15. Tuttavia, il più significativo è forse quello proposto da Rothemund, definito scaffolded DNA origami16. In questa tecnica, la piegatura di una lunga (&gt; 7000 basi) a singolo filamento di DNA &#39;scaffold&#39; è diretta ad una forma desiderata da centinaia di corti filamenti complementari denominati &#39;graffette&#39;. Piegatura viene effettuata da temperatura rampa ricottura. Questa tecnica è stata dimostrata con successo nella creazione di una gamma di forme 2D con notevole precisione e robustezza. Origami di DNA è stato successivamente esteso al 3D e 17,18. Il documento attuale si concentrerà sul software caDNAno 2.0 19 sviluppato da Douglas e colleghi. caDNAno è un robusto, facile da usare strumento CAD che consente la progettazione di forme 2D e 3D origami di DNA con caratteristiche versatili. Il processo di configurazione si basa su uno schema di astrazione sistematica e accurata per strutture del DNA, che rende relativamente semplice ed efficiente. In questo lavoro abbiamo dimostrato la progettazione di un origami di DNA ndnorobot che è stata recentemente descritta 20. Questo robot è &#39;robotica&#39;, nel senso che ci è concesso di rilevamento di attuazione, al fine di eseguire un compito. Vi spieghiamo come vari sistemi di rilevamento possono essere integrati nella struttura, e come questo può essere inoltrato a un effetto desiderato. Infine usiamo Cando 21 per simulare le proprietà meccaniche della forma progettata. Il concetto discutiamo può essere adattato a molteplici compiti e le impostazioni.

<html> Figure 1-25 sono schermate dell&#39;interfaccia caDNAno 2.0 che mostra il processo di progettazione passo-passo. La sezione trasversale della forma è stato illustrato (figura 3), seguito da aggiunta automatica di scaffold frammenti filamento e completamento dell&#39;intero percorso ponteggio (Figura 7). Filoni Staple vengono aggiunti automaticamente (Figura 12), suddivisi in base a parametri definiti dall&#39;utente (Figura 14), ...

Watch this Scientific Journal Video about Designing a Bio-responsive Robot from DNA Origami at JoVE.com

Designing a Bio-responsive Robot from DNA Origami

Origami di DNA è un potente metodo per la realizzazione di oggetti in nanoscala precise programmando l&#39;auto-assemblaggio di molecole di DNA. Qui, descriviamo come origami di DNA può essere utilizzato per progettare un robot in grado di rilevare segnali biologici e rispondenti, per il cambiamento di forma, successivamente trasmesso ad un effetto desiderato.

Progettazione di un robot bio-sensibile da DNA Origami

Nucleic acids are astonishingly versatile. In addition to their natural role as storage medium for biological information1, they can be utilized in ...

designing-a-bio-responsive-robot-from-dna-origami

Research

JoVE Journal

Bioengineering

Haptic/Graphic Rehabilitation: Integrating a Robot into a Virtual Environment Library and Applying it to Stroke Therapy

Recent research that tests interactive devices for prolonged therapy practice has revealed new prospects for robotics combined with graphical and other forms of biofeedback. Previous human-robot interactive systems have required different software commands to be implemented for each robot leading to unnecessary developmental overhead time each time a new system becomes available. For example, when a haptic/graphic virtual reality environment has been coded for one specific robot to provide haptic feedback, that specific robot would not be able to be traded for another robot without recoding the program. However, recent efforts in the open source community have proposed a wrapper class approach that can elicit nearly identical responses regardless of the robot used. The result can lead researchers across the globe to perform similar experiments using shared code. Therefore modular "switching out"of one robot for another would not affect development time. In this paper, we outline the successful creation and implementation of a wrapper class for one robot into the open-source H3DAPI, which integrates the software commands most commonly used by all robots.

Recently, a vast amount of prospects have come available for human-robot interactive systems. In this paper we outline the integration of a new robotic device with open source software that can rapidly make possible a library of interactive functionality. We then outline a clinical application for a neurorehabilitation application.

Haptic / grafica di riabilitazione: integrazione di un robot in un ambiente di biblioteca virtuale e sua applicazione alla terapia Corsa

Recent research that tests interactive devices for prolonged therapy practice has revealed new prospects for robotics combined with graphical and other ...

Ricerca

Bioingegneria

Adaptation of a Haptic Robot in a 3T fMRI

Functional magnetic resonance imaging (fMRI) provides excellent functional brain imaging via the BOLD signal 1 with advantages including non-ionizing radiation, millimeter spatial accuracy of anatomical and functional data 2, and nearly real-time analyses 3. Haptic robots provide precise measurement and control of position and force of a cursor in a reasonably confined space. Here we combine these two technologies to allow precision experiments involving motor control with haptic/tactile environment interaction such as reaching or grasping. The basic idea is to attach an 8 foot end effecter supported in the center to the robot 4 allowing the subject to use the robot, but shielding it and keeping it out of the most extreme part of the magnetic field from the fMRI machine (Figure 1).
The Phantom Premium 3.0, 6DoF, high-force robot (SensAble Technologies, Inc.) is an excellent choice for providing force-feedback in virtual reality experiments 5, 6, but it is inherently non-MR safe, introduces significant noise to the sensitive fMRI equipment, and its electric motors may be affected by the fMRI's strongly varying magnetic field. We have constructed a table and shielding system that allows the robot to be safely introduced into the fMRI environment and limits both the degradation of the fMRI signal by the electrically noisy motors and the degradation of the electric motor performance by the strongly varying magnetic field of the fMRI. With the shield, the signal to noise ratio (SNR: mean signal/noise standard deviation) of the fMRI goes from a baseline of &tilde;380 to &tilde;330, and &tilde;250 without the shielding. The remaining noise appears to be uncorrelated and does not add artifacts to the fMRI of a test sphere (Figure 2). The long, stiff handle allows placement of the robot out of range of the most strongly varying parts of the magnetic field so there is no significant effect of the fMRI on the robot. The effect of the handle on the robot's kinematics is minimal since it is lightweight (&tilde;2.6 lbs) but extremely stiff 3/4" graphite and well balanced on the 3DoF joint in the middle. The end result is an fMRI compatible, haptic system with about 1 cubic foot of working space, and, when combined with virtual reality, it allows for a new set of experiments to be performed in the fMRI environment including naturalistic reaching, passive displacement of the limb and haptic perception, adaptation learning in varying force fields, or texture identification 5, 6.

The adaptation and use of a haptic robot in a 3T fMRI is described.

Adattamento di un robot tattile in un fMRI 3T

Functional magnetic resonance imaging (fMRI) provides excellent functional brain imaging via the BOLD signal 1 with advantages including non-ionizing ...

Designing Silk-silk Protein Alloy Materials for Biomedical Applications

Fibrous proteins display different sequences and structures that have been used for various applications in biomedical fields such as biosensors, nanomedicine, tissue regeneration, and drug delivery. Designing materials based on the molecular-scale interactions between these proteins will help generate new multifunctional protein alloy biomaterials with tunable properties. Such alloy material systems also provide advantages in comparison to traditional synthetic polymers due to the materials biodegradability, biocompatibility, and tenability in the body. This article used the protein blends of wild tussah silk (Antheraea pernyi) and domestic mulberry silk (Bombyx mori) as an example to provide useful protocols regarding these topics, including how to predict protein-protein interactions by computational methods, how to produce protein alloy solutions, how to verify alloy systems by thermal analysis, and how to fabricate variable alloy materials including optical materials with diffraction gratings, electric materials with circuits coatings, and pharmaceutical materials for drug release and delivery. These methods can provide important information for designing the next generation multifunctional biomaterials based on different protein alloys.

Blending is an efficient approach to generate biomaterials with a broad range of properties and combined features. By predicting the molecular interactions between different natural silk proteins, new silk-silk protein alloy platforms with tunable mechanical resiliency, electrical response, optical transparency, chemical processability, biodegradability, or thermal stability can be designed.

Progettazione di materiali in lega di proteine ​​della seta-seta per le applicazioni biomediche

Fibrous proteins display different sequences and structures that have been used for various applications in biomedical fields such as biosensors, ...

Medical-grade Sterilizable Target for Fluid-immersed Fetoscope Optical Distortion Calibration

We have developed a calibration target for use with fluid-immersed endoscopes within the context of the GIFT-Surg (Guided Instrumentation for Fetal Therapy and Surgery) project. One of the aims of this project is to engineer novel, real-time image processing methods for intra-operative use in the treatment of congenital birth defects, such as spina bifida and the twin-to-twin transfusion syndrome. The developed target allows for the sterility-preserving optical distortion calibration of endoscopes within a few minutes. Good optical distortion calibration and compensation are important for mitigating undesirable effects like radial distortions, which not only hamper accurate imaging using existing endoscopic technology during fetal surgery, but also make acquired images less suitable for potentially very useful image computing applications, like real-time mosaicing. In this paper proposes a novel fabrication method to create an affordable, sterilizable calibration target suitable for use in a clinical setup. This method involves etching a calibration pattern by laser cutting a sandblasted stainless steel sheet. This target was validated using the camera calibration module provided by OpenCV, a state-of-the-art software library popular in the computer vision community.

This article describes the design and development of a sterilizable custom camera optical distortion calibration target for the peri-operative, fluid-immersed calibration of endoscopes during endoscopic interventions.

Medico-grade di destinazione sterilizzabile per fetoscope ottico Distortion calibrazione Fluid-immersi

We have developed a calibration target for use with fluid-immersed endoscopes within the context of the GIFT-Surg (Guided Instrumentation for Fetal ...

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers

Mechanical properties of complex, polymer-based soft matter, such as cells or biopolymer networks, can be understood in neither the classical frame of flexible polymers nor of rigid rods. Underlying filaments remain outstretched due to their non-vanishing backbone stiffness, which is quantified via the persistence length (lp), but they are also subject to strong thermal fluctuations. Their finite bending stiffness leads to unique, non-trivial collective mechanics of bulk networks, enabling the formation of stable scaffolds at low volume fractions while providing large mesh sizes. This underlying principle is prevalent in nature (e.g., in cells or tissues), minimizing the high molecular content and thereby facilitating diffusive or active transport. Due to their biological implications and potential technological applications in biocompatible hydrogels, semiflexible polymers have been subject to considerable study. However, comprehensible investigations remained challenging since they relied on natural polymers, such as actin filaments, which are not freely tunable. Despite these limitations and due to the lack of synthetic, mechanically tunable, and semiflexible polymers, actin filaments were established as the common model system. A major limitation is that the central quantity lp cannot be freely tuned to study its impact on macroscopic bulk structures. This limitation was resolved by employing structurally programmable DNA nanotubes, enabling controlled alteration of the filament stiffness. They are formed through tile-based designs, where a discrete set of partially complementary strands hybridize in a ring structure with a discrete circumference. These rings feature sticky ends, enabling the effective polymerization into filaments several microns in length, and display similar polymerization kinetics as natural biopolymers. Due to their programmable mechanics, these tubes are versatile, novel tools to study the impact of lp on the single-molecule as well as the bulk scale. In contrast to actin filaments, they remain stable over weeks, without notable degeneration, and their handling is comparably straightforward.

Semiflexible polymers display unique mechanical properties that are extensively applied by living systems. However, systematic studies on biopolymers are limited since properties such as polymer rigidity are inaccessible. This manuscript describes how this limitation is circumvented by programmable DNA nanotubes, enabling experimental studies on the impact of filament rigidity.

Nanotubi di DNA come un Versatile strumento per lo studio di polimeri semiflessibili

Mechanical properties of complex, polymer-based soft matter, such as cells or biopolymer networks, can be understood in neither the classical frame of ...

Optimizing the Use of a Liquid Handling Robot to Conduct a High Throughput Forward Chemical Genetics Screen of Arabidopsis thaliana

Chemical genetics is increasingly being employed to decode traits in plants that may be recalcitrant to traditional genetics due to gene redundancy or lethality. However, the probability of a synthetic small molecule being bioactive is low; therefore, thousands of molecules must be tested in order to find those of interest. Liquid handling robotics systems are designed to handle large numbers of samples, increasing the speed with which a chemical library can be screened in addition to minimizing/standardizing error. To achieve a high-throughput forward chemical genetics screen of a library of 50,000 small molecules on Arabidopsis thaliana (Arabidopsis), protocols using a bench-top multichannel liquid handling robot were developed that require minimal technician involvement. With these protocols, 3,271 small molecules were discovered that caused visible phenotypic alterations. 1,563 compounds induced short roots, 1,148 compounds altered coloration, 383 compounds caused root hair and other, non-categorized, alterations, and 177 compounds inhibited germination.

Optimizing the Use of a Liquid Handling Robot to Conduct a High Throughput Forward Chemical Genetics Screen of Arabidopsis thaliana

A high throughput screen of synthetic small molecules was conducted on the model plant species, Arabidopsis thaliana. This protocol, developed for a liquid handling robot, increases the speed of forward chemical genetics screens, accelerating the discovery of novel small molecules affecting plant physiology.

Ottimizzare l'utilizzo di un Robot di manipolazione liquido per condurre un alto Throughput avanti chimica genetica schermo di Arabidopsis thaliana

Chemical genetics is increasingly being employed to decode traits in plants that may be recalcitrant to traditional genetics due to gene redundancy or ...

Design and Synthesis of a Reconfigurable DNA Accordion Rack

DNA nanostructure-based mechanical systems or DNA nanomachines, which produce complex nanoscale motion in 2D and 3D in the nanometer to &#229;ngstr&#246;m resolution, show great potential in various fields of nanotechnology such as the molecular reactors, drug delivery, and nanoplasmonic systems. The reconfigurable DNA accordion rack, which can collectively manipulate a 2D or 3D nanoscale network of elements, in multiple stages in response to the DNA inputs, is described. The platform has potential to increase the number of elements that DNA nanomachines can control from a few elements to a network scale with multiple stages of reconfiguration.
In this protocol, we describe the entire experimental process of the reconfigurable DNA accordion rack of 6 by 6 meshes. The protocol includes a design rule and simulation procedure of the structures and a wet-lab experiment for synthesis and reconfiguration. In addition, analysis of the structure using TEM (transmission electron microscopy) and FRET (fluorescence resonance energy transfer) is included in the protocol. The novel design and simulation methods covered in this protocol will assist researchers to use the DNA accordion rack for further applications.

We describe the detailed protocol for design, simulation, wet-lab experiments, and analysis for a reconfigurable DNA accordion rack of 6 by 6 meshes.

Progettazione e sintesi di un Rack di fisarmonica di DNA riconfigurabile

DNA nanostructure-based mechanical systems or DNA nanomachines, which produce complex nanoscale motion in 2D and 3D in the nanometer to &#229;ngstr&#246;m ...

Designing Porous Silicon Films as Carriers of Nerve Growth Factor

Despite the great potential of NGF for treating neurodegenerative diseases, its therapeutic administration represents a significant challenge as the protein does not cross the blood-brain barrier, owing to its chemical properties, and thus requires long-term delivery to the brain to have a biological effect. This work describes fabrication of nanostructured PSi films as degradable carriers of NGF for sustained delivery of this sensitive protein. The PSi carriers are specifically tailored to obtain high loading efficacy and continuous release of NGF for a period of four weeks, while preserving its biological activity. The behavior of the NGF-PSi carriers as a NGF delivery system is investigated in vitro by examining their capability to induce neuronal differentiation and outgrowth of PC12 cells and dissociated DRG neurons. Cell viability in the presence of neat and NGF-loaded PSi carriers is evaluated. The bioactivity of NGF released from the PSi carriers is compared to the conventional treatment of repetitive free NGF administrations. PC12 cell differentiation is analyzed and characterized by the measurement of three different morphological parameters of differentiated cells; (i) the number of neurites extracting from the soma (ii) the total neurites' length and (iii) the number of branching points. PC12 cells treated with the NGF-PSi carriers demonstrate a profound differentiation throughout the release period. Furthermore, DRG neuronal cells cultured with the NGF-PSi carriers show an extensive neurite initiation, similar to neurons treated with repetitive free NGF administrations. The studied tunable carriers demonstrate the long-term implants for NGF release with a therapeutic potential for neurodegenerative diseases.

Here, we present a protocol to design and fabricate nanostructured porous silicon (PSi) films as degradable carriers for the nerve growth factor (NGF). Neuronal differentiation and outgrowth of PC12 cells and mice dorsal root ganglion (DRG) neurons are characterized upon treatment with the NGF-loaded PSi carriers.

Progettazione di film di silicio poroso come elementi portanti del fattore di crescita del nervo

Despite the great potential of NGF for treating neurodegenerative diseases, its therapeutic administration represents a significant challenge as the ...

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity

Measuring spasticity is important in treatment planning and determining efficacy after treatment. However, the current tool used in clinical settings has been shown to be limited in inter-rater reliability. One factor in this poor inter-rater reliability is the variability of passive motion while measuring the angle of catch (AoC) measurements. Therefore, an isokinetic device has been proposed to standardize the manual joint motion; however, the benefits of isokinetic motion for AoC measurements has not been tested in a standardized manner. This protocol investigates whether isokinetic motion itself can improve inter-rater reliability for AoC measurements. For this purpose, a robotic isokinetic device was developed that is combined with surface electromyography (EMG). Two conditions, manual and isokinetic motions, are compared with the standardized method to measure the angle and subjective feeling of catch. It is shown that in 17 stroke patients with mild elbow flexor spasticity, isokinetic motion improved the intraclass correlation coefficient (ICC) for inter-rater reliability of AoC measurements to 0.890 [95% confidence interval (CI): 0.685&#8211;0.961] by the EMG criteria, and 0.931 (95% CI: 0.791&#8211;0.978) by the torque criteria, from 0.788 (95% CI: 0.493&#8211;0.920) by manual motion. In conclusion, isokinetic motion itself can improve inter-rater reliability of AoC measurements in stroke patients with mild spasticity. Given that this system may provide greater standardized angle measurements and catch of feeling, it may be a good option for the evaluation of spasticity in a clinical setting.

Using a robotic isokinetic device with electromyography (EMG) measurements, this protocol illustrates that isokinetic motion itself can improve inter-rater reliability for the angle of catch measurements in stroke patients with mild elbow flexor spasticity.

Dispositivo robotico isokinetico per migliorare l'affidabilità di Test-Retest e Inter-Rater per misurazioni Stretch Reflex nei pazienti colpiti da corsa con spasticità

Measuring spasticity is important in treatment planning and determining efficacy after treatment. However, the current tool used in clinical settings has ...

Bioinspired Soft Robot with Incorporated Microelectrodes

Bioinspired soft robotic systems that mimic living organisms using engineered muscle tissue and biomaterials are revolutionizing the current biorobotics paradigm, especially in biomedical research. Recreating artificial life-like actuation dynamics is crucial for a soft-robotic system. However, the precise control and tuning of actuation behavior still represents one of the main challenges of modern soft robotic systems. This method describes a low-cost, highly scalable, and easy-to-use procedure to fabricate an electrically controllable soft robot with life-like movements that is activated and controlled by the contraction of cardiac muscle tissue on a micropatterned sting ray-like hydrogel scaffold. The use of soft photolithography methods makes it possible to successfully integrate multiple components in the soft robotic system, including micropatterned hydrogel-based scaffolds with carbon nanotubes (CNTs) embedded gelatin methacryloyl (CNT-GelMA), poly(ethylene glycol) diacrylate (PEGDA), flexible gold (Au) microelectrodes, and cardiac muscle tissue. In particular, the hydrogels alignment and micropattern are designed to mimic the muscle and cartilage structure of the sting ray. The electrically conductive CNT-GelMA hydrogel acts as a cell scaffold that improves the maturation and contraction behavior of cardiomyocytes, while the mechanically robust PEGDA hydrogel provides structural cartilage-like support to the whole soft robot. To overcome the hard and brittle nature of metal-based microelectrodes, we designed a serpentine pattern that has high flexibility and can avoid hampering the beating dynamics of cardiomyocytes. The incorporated flexible Au microelectrodes provide electrical stimulation across the soft robot, making it easier to control the contraction behavior of cardiac tissue.

A bioinspired scaffold is fabricated by a soft photolithography technique using mechanically robust and electrically conductive hydrogels. The micropatterned hydrogels provide directional cardiomyocyte cell alignment, resulting in a tailored direction of actuation. Flexible microelectrodes are also integrated into the scaffold to bring electrical controllability for a self-actuating cardiac tissue.

Robot morbido bioispirato con microelettrodi incorporati

Bioinspired soft robotic systems that mimic living organisms using engineered muscle tissue and biomaterials are revolutionizing the current biorobotics ...