11:15 AM–2:03 PM, Wednesday, March 7, 2007
Colorado Convention Center - 505
Sponsoring Unit:
DMP
Chair: Kalyanaraman Ramki, Washington University in St. Louis
Abstract ID: BAPS.2007.MAR.P42.1
11:15 AM–11:51 AM
C. Jeffrey Brinker
(Fellow, Sandia National Laboratories; Regents Professor of Chemical Engineering, the University of New Mexico, Albuquerque, NM.)
This talk describes our recent discovery of the ability of living cells to organize extended nanostructures and nano-objects in a manner that creates a unique, highly biocompatible nano//bio interface (\textit{Science} \textbf{313}, 337-340, 2006). We find that, using short chain phospholipids to direct the formation of thin film silica mesophases during evaporation-induced self-assembly, the introduction of cells (so far yeast and bacteria) alters profoundly the inorganic self-assembly pathway. Cells actively organize around themselves an ordered, multilayered lipid-membrane that interfaces coherently with a lipid-templated silica mesophase. This bio/nano interface is unique in that it withstands drying (even evacuation) without cracking or the development of tensile stresses -- yet it maintains accessibility to molecules, proteins/antibodies, plasmids, etc - introduced into the 3D silica host. Additionally cell viability is preserved for weeks to months in the absence of buffer, making these constructs useful as standalone cell-based sensors. The bio/nano interfaces we describe do not form `passively' -- rather they are a consequence of the cell's ability to sense and actively respond to external stimuli. During \textit{EISA}, solvent evaporation concentrates the extracellular environment in osmolytes. In response to this hyperosmotic stress, the cells release water, creating a gradient in pH, which is maintained within the adjoining nanostructured host and serves to localize lipids, proteins, plasmids, lipidized nanocrystals, and a variety of other components at the cellular surface. This active organization of the bio/nano interface can be accomplished during ink-jet printing or selective wetting -- processes allowing patterning of cellular arrays - and even spatially-defined genetic modification.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.P42.1