Biomedical Engineering Reference
In-Depth Information
recently initiated an NSF funded collaboration to advance nanoscale manufacturing. In gen-
eral, the goals of the collaboration are to create novel high-rate/high-volume nanomanufac-
turing processes. Some of the nanoscale technical issues that must be solved include
robustness, reliability/testing, tooling and interconnects, registration and nanosite identifica-
tion, and nanoscale reading of the signal. One proof-of-principle outcome of this project will
be to create a nanoscale patterned polymeric surface, suitable for attachment of biological
elements such as antibodies to form a nanoscale biosensor array. The nanoscale patterned sur-
face will be created in an injection molding device. During cooling of the polymer melt, pat-
terning will result from phase separation and solidification of each of two component
polymers possessing different surface energies at energetically compatible regions upon a
solid nanotemplate surface. The follow-on biosensor proof-of-principle will evolve upon this
platform into an antibody-based biosensor diagnostic for different clinical indications. Part of
the development of this biosensor will involve creating more sensitive and nanoscale resolu-
tion detection methodologies that would be capable of subsequently quantitating indication-
specific biomarker analytes binding to nanoscale spot sizes.
Many investigators are taking highly creative approaches to incorporating novel syn-
thetic molecules and engineered biological macromolecules into structures that could be
incorporated into the future design of biosensors. A few notable examples are worth men-
tioning. As we briefly mentioned earlier, a prime mover in the field of DNA nanoscale
topological structures has been the Seeman lab (146,147). They developed an approach
involving the design of appropriately positioned base complementary regions within mul-
tiple short DNA sequences that could be transformed by hybridization-coupled self-
assembly to form regular 3-D geometric structures. Their efforts have yielded examples
such as the formation of a DNA cube, truncated octahedron, and dimorphic switchable
linear structures. In Figure 1.56, an example of the self-assembled DNA structure forming
a truncated octahedron is presented (189). Structures like these, appropriately modified,
FIGURE 1.56
(See color insert) A schematic diagram of the top of a truncated DNA octahedron. The molecule contains 14
cyclic strands of DNA with each face of the octahedron comprising squares and hexagons, corresponding to a
different cyclic strand. This view is looking down the fourfold axis of one of the squares comprising the octahe-
dron. The approximate molecular weight of the DNA octahedron is about 790,000 Da. Reprinted with permis-
sion from Zhang, Y., Seeman, N.C. (1994). Construction of a DNA-Truncated Octahedron. J. Am. Chem. Soc.
116:1661-1669 and Dr. Ned Seeman. Copyright (1994) American Chemical Society.
Search WWH ::




Custom Search