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(24.5 ± 2.0 nmol), bovine serum albumin (42.1 ± 0.7 nmol), papain (22.9 ± 1.0 nmol),
trypsin (16.2 ± 2.6 nmol), and protein-free (10.2 ± 1.3 nmol) experiments. These
data clearly indicated that the capacity to synthesize silica was not generalizable to
all proteins but that a native silicatein structure was required in order observe this
phenomenon in an efficient manner.
Attempts to gain an understanding of how diatoms processed silicic acid dis-
solved in water into ornate physical structures served as a starting point for forays
into silicon biotechnology (Sect. 1.3, Chaps. 3, 5, and 6).
1.3
Drawing Inspiration from Nature
Given the natural interaction between certain silicon compounds with biological
systems, it is perhaps not surprising that a great deal of research is concerned with
incorporating and/or applying silicon-based compounds to biological systems in a
controlled manner. There have been a great number of silicon-based compounds de-
veloped for applications in biologically relevant systems. To fully review the com-
plete gamut of silicon compounds developed for biological systems is beyond the
scope of this chapter. This chapter will provide only a very brief introduction into
the application of silicon-based compounds to the biomedical and agricultural fields.
1.3.1
Applications in Agriculture
Aside from conferring resistance to pests (Sect 1.2.1), silicon-based compounds
have been used as delivery vehicles in agricultural spray applications as a means
of increasing the efficacy of the compound being applied [
44
]. These so called “su-
perwetters”, which include compounds that fall under the Silwet® brand, have a
tendency to undergo spontaneous spreading when applied to surfaces such as foli-
age (Fig.
1.3
) [
45
]. Organosilicone-based surfactants typically have low surface
tensions at equilibrium, which have been reported as low as 20 mN m
− 1
[
44
].
The silicone superwetters facilitate leaf wetting by any solutions being applied
to the foliage. This phenomenon permits herbicides to travel to the underside of
leaves, which allows the spray solution to enter open stomata, which improves the
uptake, and performance of herbicides [
44
]. It has been postulated that the silicone
alkylenoxides commonly used as superwetters create a surface tension gradient
which ultimately facilitates its spreading [
45
].
1.3.2
Silicon in Human Health and Medicine
Given the natural abundance of silicon on the planet (silicon makes up approximately
28 % of the Earth's crust [
46
,
47
]), it stands to reason that Nature has evolved to
