We report on the generation of nanometer-wide, non-topographical patterns of proteins on planar surfaces. In particular, we used the regular lattice of reconstituted microtubules as template structures to specifically bind and transfer kinesin-1 and nonclaret disjunctional motor proteins. The generated tracks, which comprise dense and structurally oriented arrays of functional motor proteins, proved to be highly efficient for the guiding of microtubule transporters.

Isopolar arrays of aligned cytoskeletal filaments are components in a number of designs of hybrid nanodevices incorporating biomolecular motors. For example, a combination of filament arrays and motor arrays can form an actuator or a molecular engine resembling an artificial muscle. Here, isopolar arrays of microtubules are fabricated by flow alignment, and their quality is characterized by their degree of alignment. We find, in agreement with our analytical models, that the degree of alignment is ultimately limited by thermal forces, while the kinetics of the alignment process are influenced by the flow strength, the microtubule stiffness, the gliding velocity, and the tip length. Strong flows remove microtubules from the surface and reduce the filament density, suggesting that there is an optimal flow strength for the fabrication of ordered arrays.

A challenge for nanotechnology is the dynamic and specific control of nanomachines by the user. Molecular shuttles, consisting of cargobinding microtubules propelled by surface-immobilized kinesin motor proteins, are an example of a nanoscale system that ideally can be selectively activated at programmable locations and times. Here we discuss a biomimetic solution where activating molecules are delivered locally via photolysis of a caged compound and subsequently sequestered in an enzymatic network. The controlled sequestration of the activator not only creates a rapid deactivation when the stimulus is removed but also sharpens the concentration profile of the rapidly diffusing activator. This improvement comes at the expense of a reduced efficiency in the utilization of the activator molecules, suggesting that these nanosystems are most efficiently addressed as a swarm rather than as individuals. Our work represents a step toward transferring the cellular control strategies of molecular activation to bionanotechnology.Bionanotechnology is concerned with the utilization of biological components in nanotechnology, 1 which to a varying degree necessitates the use of biological engineering approaches in a wider sense, for example, in the use of selfassembly to create extended structures. However, a striking accomplishment of nature is not only to create nanomachines and weave them into larger structures, but also to control their spatial and temporal activation via specific signals. This controlled activation is often achieved through the delivery of small molecules, whose spatial and temporal distribution is shaped by the actions of multiple enzymes releasing or sequestering the activating species. Examples include intracellular signaling via calcium, 2,3 NAD(P)H, 4 or cAMP. 5In contrast, the dynamic and controlled activation of specific nanomachines has been addressed in a technological context primarily by making light-activation an integral part of the design as in the light-driven synthetic motors based on rotaxanes or catenanes 6 or by designing devices that can be individually activated with a highly specific fuel molecule. 7 A new, chemical approach is to exploit reactiondiffusion systems to locally change buffer conditions and activate enzymes. 8 Here, we present a biomimetic approach to dynamically control motor protein-driven bionanodevices 9 in particular kinesin-driven molecular shuttles. 10 Molecular shuttles consist of a surface patterned with stationary kinesin motors and cargo-binding microtubules transported by the motors. Localized release and enzymatic sequestration of the substrate ATP creates a spatially and temporally well-defined concentration profile, which in turn leads to controlled activation of a small number of molecular shuttles, as shown in Figure 1. This approach significantly expands the scope of previous work, 11 which demonstrated that repeated, stepwise activation of kinesin-driven molecular shuttles can be achieved by A nearly cylindrical cone of UV light is produced ...

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The simple and quick patterning of functional proteins on engineered surfaces affords an opportunity to fabricate protein microarrays in lab-on-chip systems. We report on the programmable patterning of proteins as well as the local activation of enzymes by visible light. We successfully generated functional protein patterns with different geometries in situ and demonstrated the specific patterning of multiple kinds of proteins side-by-side without the need for specific linker molecules or elaborate surface preparation.

A biomimetic strategy to stabilize the activity of kinesin motors – a key component of molecular shuttles – against temperature changes is investigated but proves unsuccessful for this enzyme because the Km of Drosophila kinesin‐1 and Thermomyces kinesin‐3 is independent of temperature in the range of 19–34 °C (see image).

The absolute brightness of fluorescent particles, such as dye-containing nano- and microspheres or quantum dots, is a critical design parameter for many applications relying on fluorescence detection. The absolute brightness, defined as the ratio of radiant intensity of emission to illumination intensity of excitation, of nile-red fluorescent microspheres with a 1 micrometre diameter is measured to be 4.2 +/- 1 x 10(-16) m(2)/sr, and the implications for the design of kinesin motor protein-powered "smart dust" devices and the remote detection of fluorescence are discussed.

Developing combination drug delivery systems (CDDS) is a challenging but necessary task to meet the needs of complex therapy regimes for patients. As the number of multi-drug regimens being administered increases, so does the difficulty of characterizing the CDDS as a whole. We present a single-step method for quantifying three model therapeutics released from a model hydrogel scaffold using high-performance liquid chromatography (HPLC). Poly(ethylene glycol) dimethacrylate (PEGDMA) hydrogel tablets were fabricated via photoinitiated crosslinking and subsequently loaded with model active pharmaceutical ingredients (APIs), namely, porcine insulin (PI), fluorescein isothiocyanate-labeled bovine serum albumin (FBSA), prednisone (PSE), or a combination of all three. The hydrogel tablets were placed into release chambers and sampled over 21 days, and APIs were quantified using the method described herein. Six compounds were isolated and quantified in total. Release kinetics based on chemical properties of the APIs did not give systematic relationships; however, PSE was found to have improved device loading versus PI and FBSA. Rapid analysis of three model APIs released from a PEGDMA CDDS was achieved with a direct, single-injection HPLC method. Development of CDDS platforms is posited to benefit from such analytical approaches, potentially affording innovative solutions to complex disease states.