(402g) Co-Assembly Of Biocomposite Materials From Live Cells And Inorganic Particles Using Dielectrophoresis On A Chip

The co-assembly of live cells and synthetic colloidal particles could be a route to making new hybrid biomaterials, in which the biological functionality of the cells is augmented by the physical functionality of the inorganic particles. We demonstrate how such biocomposite materials can be fabricated by rapid and controlled electric field driven assembly on a chip. The process is based on dielectrophoresis (DEP), mobility and interaction of particles in AC electric fields. Live cells such as baker's yeast and NIH/3T3 mouse fibroblasts were co-assembled with colloidal particles into freely suspended 1D "wires" and 2D membranes. Experimental observations of the DEP co-assembly dynamics showed that particles smaller in size than the cells were drawn and captured in-between the cell junctions by the electric field. The process could be modeled and understood by a combination of electrostatic field computation and MD-type of particle motion simulation. The effects of voltage, frequency, pH and electrolyte concentration will be discussed. Magnetic microparticles conjugated with lectins could be used to bind the cells irreversibly via bio-specific lectin-polysaccharide interactions. The formed membranes and wires could be manipulated by magnetic field and interfaced with on-chip electrodes. Such functional biomagnetic cell-particle assemblies may find application in sensors, microassays, microsurgery, or as responsive biomaterials.