Self-assembly building blocks

A number of routes have been explored in enzymatic activation of precursors to self-assembly building blocks, either exploring bond cleavage (hydrolysis) or bond formation (Fig. 3). 

Hogberg, B., et al. (2006), Study of DNA coated nanoparticles as possible programmable self-assembly building blocks, Appl. Surf. Sci., 252(15), 5538-5541. 

Self-assembly building blocks can be divided into natural and synthetic molecules but each can encompass a wide range of molecules. These building... 

The inherent ability of block copolymers to self-assemble into various well-ordered supramolecular structures makes them attractive for numerous technological applications. For instance, thin films self-assembled from block copolymers have been used as building blocks in nanotechnology and materials science [89-91 ]. Block copolymers have been employed directly without further manipulation as nanomaterials [92], or used as self-organized templates for the creation of nanos-tructured materials [92, 93]. Block copolymer blends demonstrated their applicability as patterning templates for the fabrication of well-ordered arrays [94], as well as for nanoscale manufacturing of more complex patterns [95]. The use of amphiphilic block copolymers for templating applications has been reviewed by FOrster [96]. 

The first examples of porphyrin coordination polymers that have been characterized according to our definition in Sect. 3.1 were reported in 1991 by Fleischer and Shachter [72]. Upon metalation of 5-pyridyl-10,15,20-triphenyl-porphyrin with a Zn " ion, a self-complementary building block was obtained which readily assembles to polymer 19 as confirmed by concentration dependent UV/vis spectroscopy and NMR studies. The structure of the polymer 19 in the solid state was established by X-ray analysis. Recent reinvestigations of this system suggest that in solution tetrameric squares prevail, and polymer formation may take place at higher concentration (> 1 M) as predicted by computer simulation [12]. 

The work reviewed here demonstrates the tremendous versatility, promise and importance of peptides as building blocks in molecular self-assembly. However, in order to fully harness their potential in nanotechnology, more systematic work... 

The importance of surface characterization in molecular architecture chemistry and engineering is obvious. Solid surfaces are becoming essential building blocks for constructing molecular architectures, as demonstrated in self-assembled monolayer formation [6] and alternate layer-by-layer adsorption [7]. Surface-induced structuring of liqnids is also well-known [8,9], which has implications for micro- and nano-technologies (i.e., liqnid crystal displays and micromachines). The virtue of the force measurement has been demonstrated, for example, in our report on novel molecular architectures (alcohol clusters) at solid-liquid interfaces [10]. 

In this chapter we describe the basic principles involved in the controlled production and modification of two-dimensional protein crystals. These are synthesized in nature as the outermost cell surface layer (S-layer) of prokaryotic organisms and have been successfully applied as basic building blocks in a biomolecular construction kit. Most importantly, the constituent subunits of the S-layer lattices have the capability to recrystallize into iso-porous closed monolayers in suspension, at liquid-surface interfaces, on lipid films, on liposomes, and on solid supports (e.g., silicon wafers, metals, and polymers). The self-assembled monomolecular lattices have been utilized for the immobilization of functional biomolecules in an ordered fashion and for their controlled confinement in defined areas of nanometer dimension. Thus, S-layers fulfill key requirements for the development of new supramolecular materials and enable the design of a broad spectrum of nanoscale devices, as required in molecular nanotechnology, nanobiotechnology, and biomimetics [1-3]. 

The nanostructured molecular arrangements from DNA developed by Seeman may find applications as biological encapsulation and drug-delivery systems, as artificial multienzymes, or as scaffolds for the self-assembling nanoscale fabrication of technical elements. Moreover, DNA-protein conjugates may be anticipated as versatile building blocks in the fabrication of multifunctional supramolecular devices and also as highly functional-... 

Due to its unique chemical composition and structure, DNA can interact with a plethora of chemical structures via numerous types of bonds. This property ultimately defines the ability of DNA fragments to serve as the building blocks in the complex three-dimensional self-assembled structures. Following we Ust four major types of polymer/DNA interactions that can lead to formation of supramolecular structures ... 

Examples representing the very wide range of self-assembled protein structures obtained as just described are presented in Figure 1. These examples demonstrate that the size and shape of self-assembled nanostructures made of proteins primarily depend on the molecular mechanism effecting self-assembly and are not merely an amplified reflection of the shape and size of the starting building block. ... 

FIG. 1 Examples of shape, geometry and size of self-assembled protein made structures demonstrating that the size and shape of in vitro obtained nanostructures depend on the mechanism of self-assembly rather than on the size and shape of the building block. Note that the scale of the building blocks (left-hand side) is in nanometers, while the scale of the structures obtained (right-hand side) is in microns. 

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