Bionanocomposites for Multidimensional Brain Cell Signaling - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 92

We anticipate that engineered environments for cell patterning to combine RBM-
VECs, astrocytes, and neurons will provide a better model and experimental testbed
for multidimensional analysis of brain cell signaling dynamics.
Finally, as shown in Figure 5, and as we have recently described (Xing et al.,
2010), biocomposites may be used in three dimensional matrices to grow brain cells
over extended periods of time.
Figure 5. Confocal microscopy images of brain tumor cells grown in 3D matrices of gelatin-cellulose
nanocomposites from wood fibers. Left panel shows the white light phase image of the 3D matrix
with nanocomposite fibers and cells visible. Right panel shows fluorescent image of the same field
with cells stained with the vital dye calcein. Scale bar indicates 20.55 microns.
Thus far we have utilized CRL-2020 brain tumor cells to test these 3D matrices,
since they have intrinsic invasive behavior and high growth potential (Sehgal et al.,
1999). In their own right, these 3D matrices may provide important growth environ-
ments for modeling brain tumor growth and for testing the efficacy of drug delivery
and diffusion in all dimensions. We chose cellulose-derived fibers from wood as an
important component of our developed 3D matrices due to their intrinsic aspect ratio
that includes diameters in the 1020 micron range, which may be ideal for binding
and guiding brain cell growth. Furthermore, although we have not tested the idea,
these cellulose fibers do have intrinsic lumen structures which might help retain
nutrients permissive for developing cells in three dimensions.
CoNClusioN
Putting together the different dimensions of engineered growth environments with
[Ca 2+ ] i dynamics experiments and modeling has benefitted from bionanocomposites
such as gelatin-cellulose matrices shown in Figure 5, and from printed nanofilms as
shown in Figure 2. By controlling the growth environments of cells of the brain and
by varying which cells are present, we may better understand and model brain cell
communication in both health and disease. For example, the release of glutamate from