The Biology of Integration of Cells into Microscale and Nanoscale Systems - Cellular Computing - page 156

Figure 8.5 Salicylate induction of unencapsulated and Rovace SF-091 encapsulated
P. fluorescens 5RL cells.
of a 24-well microtiter plate. Luria-Bertani medium supplemented with sodium
salicylate at a concentration of 100 ppm and tetracycline was added to each well.
The plate was placed in a Wallac Luminometer, and bioluminescence readings
were recorded every 30 min for 7 h.
In the presence of salicylate and no latex, P. fluorescens 5RL exhibited its
classical response with a sharp increase in light production in the first 90 min,
followed by a gradual reduction over 90-240 min and then another increase in
light production (Figure 8.5). In the presence of latex, bioluminescence was not
observed until 90 min, followed by a plateau at 180-240 min. After 240 min,
there was a steady increase in bioluminescence. The cause of the lag phase is
not clear. It may be due to diffusion of the inducer through the latex matrix or
an unidentified physiological effect on the cells themselves.
Although the physiological effect of latex on bioluminescence bioreporter
responses requires more study, the use of latex as an immobilization agent
has many advantages for the encapsulation of cells deployed in microscale or
nanoscale systems. Because of the burden of maintaining cell viability, cell
encapsulation will remain an important topic in the device science of cells.
NANOSCALE SYSTEMS
Interfacing with cells on the microscale is sufficient for interaction with single
genetic regulatory systems through reporter genes or the stimulation and record-
ing of action potentials. However, broadly interfacing with genetic circuits and
networks with the goal of fully using the functional complexity of these sys-
tems in engineered devices requires an interface on the same size scale as the
biomolecular machines that carry out these functions. Synthetic nanostructures