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Dynamic assembly of polymer nanotube networks via kinesin powered microtubule filaments

Nanoscale

Paxton, Walter F.; Bachand, George B.; Gomez, Andrew G.; Henderson, Ian M.; Bouxsein, Nathan F.

In this study, we describe for the first time how biological nanomotors may be used to actively self-assemble mesoscale networks composed of diblock copolymer nanotubes. The collective force generated by multiple kinesin nanomotors acting on a microtubule filament is large enough to overcome the energy barrier required to extract nanotubes from polymer vesicles comprised of poly(ethylene oxide-b-butadiene) in spite of the higher force requirements relative to extracting nanotubes from lipid vesicles. Nevertheless, large-scale polymer networks were dynamically assembled by the motors. These networks displayed enhanced robustness, persisting more than 24 h post-assembly (compared to 4–5 h for corresponding lipid networks). The transport of materials in and on the polymer membranes differs substantially from the transport on analogous lipid networks. Specifically, our data suggest that polymer mobility in nanotubular structures is considerably different from planar or 3D structures, and is stunted by 1D confinement of the polymer subunits. Moreover, quantum dots adsorbed onto polymer nanotubes are completely immobile, which is related to this 1D confinement effect and is in stark contrast to the highly fluid transport observed on lipid tubules.

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Microtubule-based nanomaterials: Exploiting nature's dynamic biopolymers

Biotechnology and Bioengineering

Bachand, George B.; Stevens, Mark J.; Spoerke, Erik D.

ABSTRACT

For more than a decade now, biomolecular systems have served as an inspiration for the development of synthetic nanomaterials and systems that are capable of reproducing many of unique and emergent behaviors of living systems. One intriguing element of such systems may be found in a specialized class of proteins known as biomolecular motors that are capable of performing useful work across multiple length scales through the efficient conversion of chemical energy. Microtubule (MT) filaments may be considered within this context as their dynamic assembly and disassembly dissipate energy, and perform work within the cell. MTs are one of three cytoskeletal filaments in eukaryotic cells, and play critical roles in a range of cellular processes including mitosis and vesicular trafficking. Based on their function, physical attributes, and unique dynamics, MTs also serve as a powerful archetype of a supramolecular filament that underlies and drives multiscale emergent behaviors. In this review, we briefly summarize recent efforts to generate hybrid and composite nanomaterials using MTs as biomolecular scaffolds, as well as computational and synthetic approaches to develop synthetic one‐dimensional nanostructures that display the enviable attributes of the natural filaments. Biotechnol. Bioeng. 2015;112: 1065–1073. © 2015 Wiley Periodicals, Inc.

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Simple, Benign, Aqueous-Based Amination of Polycarbonate Surfaces

ACS Applied Materials and Interfaces

Bachand, George B.; Vandelinder, Virginia A.; Wheeler, David R.; Small, Leo J.; Henderson, Ian M.; Spoerke, Erik D.

Polycarbonate is a desirable material for many applications due to its favorable mechanical and optical properties. Here, we report a simple, safe, environmentally friendly aqueous method that uses diamines to functionalize a polycarbonate surface with amino groups. The use of water as the solvent for the functionalization ensures that solvent induced swelling does not affect the optical or mechanical properties of the polycarbonate. We characterize the efficacy of the surface amination using X-ray photo spectroscopy, Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and contact angle measurements. Furthermore, we demonstrate the ability of this facile method to serve as a foundation upon which other functionalities may be attached, including antifouling coatings and oriented membrane proteins. (Chemical Presented).

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Biomolecular motors in nanoscale materials, devices, and systems

Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology

Bachand, George B.; Bouxsein, Nathan F.; Vandelinder, Virginia A.; Bachand, Marlene B.

Biomolecular motors are a unique class of intracellular proteins that are fundamental to a considerable number of physiological functions such as DNA replication, organelle trafficking, and cell division. The efficient transformation of chemical energy into useful work by these proteins provides strong motivation for their utilization as nanoscale actuators in ex vivo, meso- and macro-scale hybrid systems. Biomolecular motors involved in cytoskeletal transport are quite attractive models within this context due to their ability to direct the transport of nano-/micro-scale objects at rates significantly greater than diffusion, and in the absence of bulk fluid flow. As in living organisms, biomolecular motors involved in cytoskeletal transport (i.e., kinesin, dynein, and myosin) function outside of their native environment to dissipatively self-assemble biological, biomimetic, and hybrid nanostructures that exhibit nonequilibrium behaviors such as self-healing. These systems also provide nanofluidic transport function in hybrid nanodevices where target analytes are actively captured, sorted, and transported for autonomous sensing and analytical applications. Moving forward, the implementation of biomolecular motors will continue to enable a wide range of unique functionalities that are presently limited to living systems, and support the development of nanoscale systems for addressing critical engineering challenges. © 2013 Wiley Periodicals, Inc.

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Results 76–100 of 167
Results 76–100 of 167