Directional transport by nonprocessive motor proteins on fascin-cross-linked actin arrays.

In this study, the unidirectional transport of heavy meromyosin (HMM)-coated beads is demonstrated on fascin-cross-linked actin arrays. The streptavidin-coated surface was properly blocked to prevent nonspecific binding of F-actin and, as a result, a high population of long gelsolin-actin complexes was suspended in the medium for subsequent processes. A flow field was utilized to lay down F-actin aligned along the direction of the flow and fascin cross-linked laid F-actin to prevent F-actin resuspension.

The movement of actin-myosin biomolecular linear motor under AC electric fields: an experimental study.

The role of actin-myosin as a biomolecular linear motor is considered a transport system at nanoscale because of their size, efficiency and functionality. To utilize the ability to transport, it is essential to control the random movement of actin filaments (F-actin) on myosin coated substrate. In the presence of an alternating current (AC) electric field, the direction of F-actin movement is regulated by electro-orientation torque and, as a result, its movement is perpendicularly toward the electrode edges.

A visualized observation of calcium-dependent gelsolin activity upon the surface coverage of fluorescent-tagged actin filaments.

Gelsolin regulates the dynamics of F-actin by binding to F-actin to sever and cap. In the present study, a novel approach is introduced to observe gelsolin activity through the coverage of surface-bound F-actin. Gelsolin was immobilized on streptavidin coated surface using biotinylation and, as a result, the interaction between gelsolin and F-actin was visualized.

Rapid and efficient sonochemical formation of gold nanoparticles under ambient conditions using functional alkoxysilane.

Gold nanoparticles (NPs) are rapidly and efficiently formed under ambient conditions with a novel and highly-efficient sonochemical promoter. Despite of the presence of free oxygen, 3-glycidoxypropyltrimethoxysilane (GPTMS) showed remarkable efficiency in promoting the reduction rate of Au (III) than that of conventional promoters (primary alcohols). This is likely attributed to the formation of a variety of radical scavengers, which are alcoholic products from sonochemical hydrolysis of the epoxide group and methoxysilane moieties of GPTMS under weakly acidic conditions.

Transport of single cells using an actin bundle-myosin bionanomotor transport system.

The potential of using actin bundles for the transport of liposomes and single cells across myosin-coated surfaces is investigated. Compared to that observed with filamentous actin, the liposome transport using actin bundles was more linear in nature and able to occur over longer distances. Bundles, but not filamentous actin, were capable of moving single cells.

Selective attachment of F-actin with controlled length for developing an intelligent nanodevice.

Development of the nanodevice that myosin-coated beads "walk" on actin filaments (F-actin) tracks for in vitro nanotransportation was hindered due to the difficulty of assembling large-area well-orientated F-actin tracks on the surface. In this work, we present a selective attachment of F-actin with controlled length on a patterned surface by employing biotinylated capped protein gelsolin as intermediate anchoring bridge. A patterned streptavidin layer was formed via coupling with a biotin layer that photo-actively attached to an amine-functionalized glass surface.

Application of capillary electrophoresis to predict crossover frequency of polystyrene particles in dielectrophoresis.

CE is used to calculate the zeta potential of polystyrene particles in order to estimate the surface conductivity of the particles. These values are used to predict the dielectrophoretic behavior, including the crossover frequency of particles under the influence of an AC electric field. Predictions for fluorescent polystyrene particles that are unmodified, carboxylate-modified, or streptavidin-modified are tested using miniaturized dielectrophoresis cells containing patterned gold quadrupole electrodes.