(579b) Nano-Pipette Directed Motion of Bio-Inspired Transmembrane Channel

Via Dissipative Particle Dynamics (DPD) approach, we study the
directed motion of a transmembrane end-functionalized nanotube using a
suitably functionalized nano-pipette. In our earlier work (Nanoscale
2011), we demonstrated the design and creation of biomaterials which
promote controlled release by integrating end-functionalized nanotubes
into lipid bilayers. Each nanotube encompasses an ABA architecture,
with a hydrophobic shaft (B) and two hydrophilic ends (A). To allow
controlled transport through the nanotube, we also introduce
hydrophilic tethers at one end of the tube. We showed that nanotubes
initially located in the outer solvent spontaneously penetrate the
membrane and assume a trans-membrane position, with the hydrophilic
tethers extending from the surface of the bilayer. The hydrophilic
tethers can also serve as anchors for directing the motion of the
inserted nanotube across the membrane. We demonstrate this process by
locating a suitably functionalized nano-pipette near such an
end-functionalized nanotube. The nanotube diffuses in the membrane
until the tethers are close to the nano-pipette. Due to favorable
interactions, the tethers anchor onto the nano-pipette. We also show
that the nanotube motion can be controlled through the
nano-pipette. This system can provide design guidelines for
lab-on-chip applications for drug delivery.