Projects

Projects

Design of a versatile and fast colloidal sensor based on virus modified particles (VIROMA)

Duration 4 years

 

Viroma is an EU-funded research project in the framework of FP7–PEOPLE-2013-IAPP (Industry-Academia Partnerships and Pathways)

Viroma project aims to fabricate multiplexed bead-based arrays as sensing devices on the basis of virus capsid and virosome Layer by Layer assisted assembly on colloidal carriers. The virosome based platform technology will be suitable for the detection of several analytes ranging from comparatively small molecules, of the size of dioxins to larger biomolecules such as small proteins. Such systems are fast and sensitive, and require due to multiplexing and single particle based fluorometric read-outs only a very small amount of sample for analysis and is, suitable for high throughput analysis. The uniqueness of the approach developed in VIROMA is that the virus particles will retain their specific recognition properties provided by the virus capsides and transfer this specificity to the colloidal carrier. Moreover, the possibility of assembling different virus nanoparticles and virosomes on top of the colloids will result in particles with multiple recognition capabilities, going a step ahead nature. Depending on the analytes size two different detection mechanisms will be employed. If the analyte is a larger peptide or protein, a sandwich immunoassay can be employed with the capture antibody integrated into the virosome and transferred to the bead by means of virosome-membrane fusion. The fluorescence will be recorded with a flowcytometry using a colloidal dispersion of the beads or a laser scanning microscope if the beads are immobilized on a chip. As an example, we will assemble beads capable of detecting troponin, a standard marker for myocardial infarction. For small molecules specific receptor molecules will be designed for a competitive assay. The project involves a synergic collaboration between two academic institutions: CIC biomaGUNE and the University of Leipzig with the company SURFLAY.

 

Collaborations:

Dr. Sergio Moya, CICbiomaGUNE, Spain

Dr. habil. Lars Dähne, SURFLAY (Germany)

Regenerable active polyelectrolyte nanofiltration membranes for water reuse and metal/acid recovery - LbLBRANE.

LbLBRANE is an EU-funded research project carried out by a consortium of 12 European partners comprising research institutes and universities as well as industrial partners. For more information, please click here

 

 

 

 

Health Impact of Engineered Metal and Metal Oxide Nanoparticles: Response Bioimaging and Distribution at Cellular and Body Level, HINAMOX

 Health Impact of Engineered Metal and Metal Oxide Nanoparticles: Response Bioimaging and Distribution at Cellular and Body Level

Our part of this project focuses on the interaction of metallic and metal oxidic nanoparticles with culture cells with the aim of estimating the potential health risk caused by nanoparticle exposure. In particular, we study the cellular uptake and toxicity of nanoparticles in culture cells.

The project is supervised by Dr. Irina Estrela-Lopis.
 
(Supported by The European Community, EU Nanosafety Cluster)    

Fabrication and Characterization of Colloidal Biocomposites Employing Viral Building Blocks

This research project aimed at transferring authentic protein and peptide functions onto colloidal carriers and arrays. The structure, functionality and stability of the composites was studied.  Diagnostic and immunological applications could be envisaged. The inherent fusion competence of enveloped viruses was employed to integrate viruses or virus-like particles into a lipid layer formed on a polyelectrolyte support. This approach ensured the correct orientation of the proteins of the viral envelope. The fusion process itself was controlled by decreasing the pH to values typical for the endosomal interior. Molecular biology techniques could be used to incorporate nonnative functions into viral envelope proteins. In principle, this platform technology permitted the transfer of arbitrary peptide-based functions onto mesoscopic carriers, provided the particular sequence did not block the self-assembly process of the viral shell itself. It was not necessary to use intact viruses only, as for a variety of viruses it is possible to produce empty capsids by means of transfecting culture cells with the respective plasmids encoding for capsid and envelope proteins.  

BEAD ARRAY for the simultaneous detection of virus antibodies. Colloids carrying different antigens are encoded by fluorescent PE-layers. For a presentation on this topic click the dotplot graph on the left.

The project was supported by the EU.

Polyelectrolyte-Lipid Interaction

The project focuses on understanding the interaction of cationic polyelectrolytes with lipid membranes. A deeper knowledge of the mechanism of binding is essential for the design of optimal interfaces between nonbiologic and biologic matter. Polyelectrolytes and lipids play a key role as building elements for various devices, such as carriers and sensors. 

On the one hand the electrostatic interaction certainly plays a role, at least in the case of anionic lipids such as POPS, but on the other hand hydrogen bonds formed between amino groups and phosphate or caroxyl groups may considerably contribute to binding interactions. By means of vibration spectroscopy (IR and Raman spectroscopy) we could show that, for example, poly(allyl amine hydrochloride) (PAH) displaces water molecules from the immediate vicinity of the respective groups. Instead of hydrogen bonds between lipids and water new hydrogen bonds with the primary amino groups are formed. 

Molecular force spectroscopy permits studying the binding in great detail. PAH is conjugated to the tip of an Atomic Force Microscopy device. The binding energy per monomer can be extracted from the respective force curves.  The kinetics of binding are especially interesting. 

Mechanical Properties of Viral Shells - Relevance for Fusion Processes

Force microscopy is employed to measure the mechanical properties and the stability viral of capsids and viruses. During the course of infection the genetic material of the virus has to be released. This requires a controlled destabilization of the capsid. Very little is known about this nanomechanic aspect of virus infection. So far, we have investigated the mechanics of Rubella virus capsids as an example of an enveloped virus and norovirus capsids as an example of a non-enveloped virus. In the case of noroviruses the mechanical response of the capsid depends on pH. At  basic pH values the shell becomes more susceptible while at acidic pH the capsid is stable. Interestingly, this correlates with the pH changes and the place of infection in the gastro-intestinal tract. 

letzte Änderung: 14.06.2017