From their comfortable "home," the empowered cells can also direct their own landscaping. They can organize metallic nanocrystals added at the cell surface. These may enhance the sensitivity of Raman spectroscopy for monitoring the onset of infection or the course of therapy. The cells also localize proteins at the cellular interface.
Assistant Professor Graham Timmins of UNM's College of Pharmacy notes that the encapsulated cells' unusual longevity may serve as a model for persistent infections such as tuberculosis, which has a long latency period. TB bacteria can remain dormant in vivo for 30-50 years and then re-activate to cause disease. Presently the state of the dormant bacterium is not understood. Timmins and Brinker are discussing further experiments to validate the model.
Finally, building the cells into a coating with a high enough density might elicit from them a defensive, multi-cellular signal of an unpleasant nature that discourages unwanted biofilm formation on the coated surface - important for avoiding infections that could be carried by implants and catheters.
The cell's ability to sense and respond to its environment is what forms these unique nanostructures, says Brinker. During spin-coating, the cells react to the increasing concentrations of materials in the developing silica nanostructure by expelling water and developing a gradient in the local pH. This in turn influences lipid organization and the form of the silica nanostructure, reduces stress, and ultimately improves the living conditions of the ensconced cellular tenants.
The work was initially funded by Sandia's Laboratory Directed Research and Development (LDRD) office, and then by DOE's Basic Energy Sciences group for its fundamental implications, and then (through UNM) by the Department of Defense (Air Force) for its practical possibilities.
Along with Baca, the
Source:DOE/Sandia National Laboratories