Self-Assembly of Synthetic and Biological Polymeric Systems of ...

and the available configurations of the polymeric backbone´s building blocks. The ability of
polymer chains to establish a sufficient high number of dipole-dipole interactions, hydrogen
bonding, or van der Waals interactions, amongst others, is also a key factor in promoting and
controlling the molecular aggregation process in spite of the energy involved in this kind of
intermolecular forces is very weak (0.5-10 kcal/mol) if compared with covalent bonds (50-100
kcal/mol)
1.4.- Molecular self-assembly.
Molecular self-assembly is a spontaneous process by which molecules interact with each other
to form well-ordered supramolecular structures. The self-association between molecular
building blocks is mediated through non-covalent association of molecules (molecular
recognition processes). In this way, extraordinarily complex assemblies are formed in various
natural systems, and synthetic preformed molecular building blocks are assembled together by
keeping a delicate balance between non-covalent repulsive and attractive interaction by using
forces such as van der Waals and ionic interactions, metal coordination, H-bonding, π-π
interactions or hydrophobic forces. This process has motivated many different studies in the
fields of nanotechnology and materials science based on the design of new functional
nanostructures (6)(7). The only requirement for self-assembly is that the building block should
contain moieties able to establish non-covalent interactions in specific environments (6)(7).
Thus, advanced self-assembled nanomaterials have already been prepared from many
different types of molecules such as lipids, synthetic peptides, nucleic acids, low molecular
weight surfactants, dendrons, transition metals, inorganic nanoparticles or polymers (8)(9).
The latter have recently received great attention due to their increasingly scientific importance
and vast utility in a wide range of technological applications by their ability to spontaneously
self-organize into well-ordered aggregates, either in the solid state or in semidilute and dilute
solutions (9)(10).
Nowadays, the self-organization of molecular building blocks is probably one of the most
prominent topics of modern sciences. Indeed, supramolecular self-assembly is the key strategy
of Nature for fabricating multifunctional structures such as enzymes, ribosomes, membranes
channel or transport proteins from rather simple molecules such peptides, sugars and lipids.
For instance, Nature produces complex intermolecular structures with biomolecules, through
the control of biomolecular primary, secondary, tertiary and quaternary structure. The
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