The focus of the program is to mimic advantageous surface properties or processes of living organisms for materials science and technology by utilising and combining state of the art nano- and microfabrication, soft lithography, molecular imprinting, chemical modification, self assembly, and organic- and bioorganic synthesis.
The research within the Biomimetic Materials Science program has a strong multidisciplinary flavour that requires input and skills from many academic fields. We are convinced that the newly formed crew of scientists with backgrounds in physics, materials science, spectroscopy, chemistry, biochemistry, and microbiology will be able to conduct front-line research in this highly competitive and challenging area.
The research will be undertaken in project groups each consisting of scientists/students from at least two universities. Four project areas have been identified
- Artificial Cells
- Research Team in Lipid functionalisation of nano- and microstructured materials
- Research Team in Integrated soft bioelectronic strucures
- Functional Materials and Coatings
- Research Team in Anti-Freeze materials
- Research Team in Low friction materials
- Supramolecular Materials
- Research Team in Electrically or optically contolled release of molecules
- Research Team in Synthetic peptides and biomolecular recognition
- Water in Confined Volumes
- Research Team
The aim of this project is to combine existing methodologies in nano-
and microfabrication with expertise in organic chemistry and
self-assembly for the generation of novel hybrid materials and devices
that enables detailed studies of cellular and transmembrane phenomena,
such as signal transduction. We intend to construct materials with
complex but controlled functions by making use of specific properties
and functions of various native as well as synthetic biopolymers, such
as lipids, oligosaccharides, nucleotides and proteins (enzymes). One
promising route to improve the function of inorganic materials is to
combine thiol- and silane-based surface modifications with lipid-based
surface modifications, ranging from lipid mono- and bilayers via
vesicles, liposomes to nanotube-connected networks of liposomes. Since
such functionalisation strategies can be steered and controlled by the
chemistry and topography of the underlying inorganic surface, the
combination with micro- and nanofabrication strategies will allow
construction of devices with extremely complex functions. Such devices,
mimicking cellular compartments, will be constructed and studied as a
function of external stimuli using a range of microanalytical tools.
Another interesting and somewhat visionary project involves recent
developments in liposome/nanotube networking and electroactive polymers
for the next generation of biosensors, bioelectronic devices and
biocomputers. The project will be focused on exploring the
possibilities of using lipid bilayer vesicles and lipid
nanotube-vesicle-networks (NVN) for encapsulation and support of
reconstituted biological functions such as receptors, synaptic
vesicles, and signal transduction systems/pathways. A second theme is
to integrate these structures into bioelectronic systems by use of soft
and porous polymer electrodes. These integrated biological functions
within lipid bilayer structures are very complex biomimetic systems,
approximating higher-order cellular structures. Such systems may be
designed to respond to complex stimuli, affecting multiple receptor
systems, and also to store, and process this information.
Functional Materials and Coatings
Our nano- and microfabrication-, organic chemistry- and self-assembly- expertise will also be gathered for the development of the next generation of new Functional Materials and Coatings. This project is divided in two parts: low friction materials and anti-freeze materials.
Shark skin is a prominent example of sophisticated low friction surfaces in water. A central issue with respect to the friction between a solid surface and a liquid flowing past the solid (as in a pipe line), or a solid body moving in the liquid (a ship or a shark) is the creation of dissipative structures called eddies, i.e. the onset of turbulence. Modern surface preparation techniques open up new opportunities both to study this phenomenon and to ultimately manufacture surfaces with low friction. We intend to mimic the low friction properties of shark skin by combining the existing knowledge about the topography of shark skin with our expertise in nano- and microfabrication and soft materials science.
The anti-freeze project relies on the structural properties of so-called anti-freeze proteins (AFPs) existing in the blood of certain arctic flounders. The APF protein is a 37-mer consisting of a repetitive amino acid sequence which has been identified as the critical domain leading to a lowering of the freezing point (about 1-2 °C). Two approaches will be examined during the development of novel anti-freeze materials: i) a minimum sequence approach where the 37-mer, or smaller segments thereof, are attached to surfaces; ii) a thin film approach where amino acids residues representing the active regions of the AFP are synthesized and assembled onto surfaces. The same approach will be adopted for studies of anti-freeze glyco proteins (AFGP). Our long term vision is to develop a biomimetic coating (paint) or surface process that can reduce ice nucleation on construction materials at sub-zero temperatures.
The research within this area can be divided into two subprojects, namely: Electrically or Optically Controlled Release of Molecules; and Synthetic Peptides and Molecular Recognition.
The aim of the Controlled Release project is to develop a material which on command can slowly release molecules, e.g., drugs. The command can for example be optical or electrical. Although the ultimate goal may be to marry molecularly imprinted polymers with porous materials the initial studies will be performed on flat surfaces. We plan also to use electroactive polymers and microrobotics for the preparation of sealable microvials. Another interesting aspect that will be addressed in parallel with the slow release work described above concerns fundamental interaction studies between ligands (drug candidates) and molecularly imprinted polymers. We will, for example, to use AFM to study the forces between 2D imprints developed on flat surfaces and complementary ligands attached to the cantilever of the AFM set-up.
Folded proteins are versatile scaffolds. Organised assemblies of amino acids form powerful enzymes and specific receptors, not because of the chemistry of their side chains but because of the cooperativity that comes from organisation. The understanding of how to make proteins fold opens daunting perspectives in biotechnology. We have designed non-natural sequences of 40-50 residues (synthetic peptides) that fold into helix-loop-helix motifs and dimerise to form four-helix and used them for purposes that are not observed in nature. One example of that is the introduction into the folded protein of the ability to site-selectively functionalise itself, but we have also constructed catalysts that follow saturation kinetics, the hallmark of native enzymes and protein receptors that recognise other proteins. Within the present research project the self functionalisation reaction is used in the development of biosensors.
Water in Confined Volumes
The basic features of confined water so called "Biological water" are of relevance to all of the above mentioned project areas. We recognise, for example, the possibility to use the structures identified within the lipid nanotube-vesicle-network project to study water structure within bilayers, in bilayer-water interfaces as well as in nanometer-water-columns. The understanding of the structural properties of water in hydrogels and at organic(biological) interfaces is also crucial for the development of synthetic protocols for the design of supported lipid bilayer membranes. In particular, we plan to investigate the influence of structured water on the folding and function of the intracellular loops of transmembrane proteins. The structural properties as well as the phase behaviour of water in porous materials are also of interest for our development of slow release materials. In addition, model systems such as vermiculate clays will be investigated. These clays has been shown to be very useful for such studies, because of the well defined 2D nm confinement and the readily controlled spacing and interaction through water vapour pressure and ionic concentrations. They constitute also a well-controlled model systems for porous materials and nanotube-interconnected liposomes, especially if the clay-based materials are mixed with the lipid-based preparations under planning. Moreover, the structure of water at subzero temperatures is of relevance for our anti-freeze work. intend, for example, to focus on studies of the nucleation and growth of ice on soft organic and biological model surfaces.
We are going to address this research project by combining the skills in advanced surface spectroscopy available at the participating centres, e.g. Surface Enhanced Raman Scattering (SERS), Raman imaging, infrared spectroscopy, Brillouin spectroscopy and ellipsometry. Furthermore, ultrafast time-resolved spectroscopies are under development, which will enable studies of water dynamics in the range fs-ns, as well as molecular orientation on surfaces.
Responsible for this page: Anna Maria Uhlin
Last updated: 05/22/06