PEPTIDE SELF-ASSEMBLY BIOMATERIALS DESIGN AND APPLICATION - Biologically-Responsive Hybrid Biomaterials - page 72

assembly are chemical complementarity and structural compatibility through
numerous noncovalent weak interactions.
Molecular self-assembly is a rather broad and fast-moving field; it is
impossible to fully cover the entire spectrum, so here we will only focus on the
self-assembling peptide systems from our own laboratories.
Several self-assembling peptide systems have been developed, ranging from
models for studying protein folding and protein conformational diseases, to
molecular materials that produce peptide nanofibers, peptide scaffolds, peptide
surfactants and peptide ink. These self-assembling peptide systems are rather
simple, versatile, economically affordable and easy to produce on a large-scale to
spur new industries. These self-assembling peptide systems represent a
significant advance in molecular design and engineering for diverse
technological innovations. Those who are interested in a broad view are
encouraged to consult earlier reviews.
Molecular self-assembly is facilitated through numerous weak, noncovalent
bonds—especially hydrogen bonds, ionic bonds (also called electrostatic
interactions, or salt bridges as commonly referred to in biology), hydrophobic
interactions, van der Waals interactions, and water-mediated hydrogen bonds.
Although these weak bonds are rather insignificant in isolation, when combined
they not only govern the 3-D structural conformations of all proteins, nucleic
acids and other molecules, but also dictate their interaction with other molecules.
The water-mediated hydrogen bond is particularly important for living systems
since all biological molecules interact with water.
These weak interactions promote the assembly of molecules into units of
well-defined and stable hierarchical macroscopic structures. Although each of the
bonds or interactions is rather weak, the collective interactions can result in very
stable structures and materials. Like hands and gloves, both the size/shape and
the correct orientation, i.e. chirality, are important in order to have a
complementary and compatible fit.
Molecular self-assembly is ubiquitous in Nature and has recently emerged as
a new approach in chemical synthesis, nanotechnology, polymer science,
materials and engineering. Molecular self-assembly systems lie at the interface
between molecular biology, protein science, biochemistry, polymer science,
materials science and engineering. Many self-assembling systems have been
developed, and they represent a significant advance in the molecular engineering
of simple molecular building blocks useful for a wide range of applications
(Figure 1). This field is growing at an accelerating pace, riding on the tide of
biotechnology and nanotechnology.