Nanotechnology 22 (2011) 245101 (8pp) Transport of single cells using an actin bundle–myosin bionanomotor transport system Hideyo Takatsuki, Hideyuki Tanaka, Kevin M Rice, Madhukar B Kolli, Siva K Nalabotu, Kazuhiro Kohama, Parviz Famouri and Eric R Blough Marshall University, Huntington, USA Gunma University Graduate School of Medicine, Japan West Virginia University, Morgantown, USA

Introduction Actin are muscle protein localized in the myofibrils; acting along with myosin, it is responsible for contraction and relaxation of muscle. It occurs in globular (G-actin) and fibrous (F-actin) forms. Individual subunits of microfilaments are known as globular actin (G-actin). G-actin subunits assemble into long filamentous polymers called F-actin

Nitro-benzoxadiazole -NBD Green fluorescent protein - GFP Biotinylated liposome (labeled with NBD; green) (a) and E. coli cell (expressing GFP; green) (b) that have been bound to biotin-labeled actin bundle (red) via neutravidin linker (blue).

Morphology 150 nm 300 nm microne TEM -ve Staining

Motility of liposome on actin filament Image series (a) U-turn Overlay image(b) Video

Motility of liposome on actin bundle Image series (a) Arrows and arrowheads point to liposomes and bundles Actin bundle Overlay image(b) Video

Motility of cell on actin bundle Arrows and arrowheads point to E.coli cell and bundles. Video

Velocity 3.9± 0.2 3.0± 0.2 4.0± 0.2 3.8± 0.2 3.4± 0.1 2.4± 0.1 2.3± 0.1 1.8± 0.1 2.1± 0.1 1.7± 0.1

Linearity of translocation, 87± 2 85± 4 77± 4 53± 4 56± 5 39± 3 39± 2 27± 4 48± 4 40± 11

Unloading UV reactive chemical linkages in catalytic motors DNA tethers alone Combination of liposome with MT-Kinesin system Triton X-100 added

Conclusion F-actin and actin bundles can be used to transport liposomes over a myosin motor-patterned surface while actin bundles can only have the capacity to transport E. coli cells. Actin bundles have advantageous over F-actin systems for the nanotransport of cargo given that the bundles exhibit greater efficiency of translational movement, higher velocity of translocation and the ability to move larger loads over a greater distance. Triton X-100 could be used as a means of introducing liposome rupture and presumably cargo unloading following the transport of liposomes by the actin–myosin motor platform. thank you