Ensuring activity in the long term

The researchers from Liège have now reached the third stage: ensuring activity in the long term. The active ingredient applied to the surface mustn’t denature under the effect of light, for instance. Peptides are biomolecules and to be efficient, they must have a certain structure which, of course, they retain. But here too, the tests were positive. Even better, they showed that cutting steel sheets (which would be the norm when it comes to constructing objects (furniture, tables, fridges, etc.) from coated steel!) doesn’t rip off the film and that the antimicrobial activity is maintained.

Finally, it should be noted that contrary to the other solutions proposed, the researchers from Liège approached the antibacterial problem in a multifunctional way: to prevent the adhesion of bacteria on the surface, kill the bacteria or prevent the formation of biofilm (once on the surface, the bacteria produce a polysaccharide film that allows them to adhere even better). “We’ve now developed a ‘ready-to-use’ solution”, Christophe Detrembleur points out, “that allows the functionalisation of substrates by biomolecules (antibiofilm enzymes, antibacterial peptides, etc.). We first studied these three functions separately; now, we have to unite them on the same surface film. The technology, the base and the platform are the same. Only the final layer of active film applied to the surface is different (Adv. Funct. Mater. 2012, DOI: 10.1002/adfm.201201106). Either an antibacterial molecule, or antibiofilm, or anti-adhesive. The three were validated separately; now we’d like to have the three functions together, on the same film.”

The creation of Symbiose Biomaterials

The Biocoat programme has now ended. At least the first version of it. It has now been reoriented towards broader applications. Cécile Van De Weerdt explains, “Mussels  stuck to all surfaces, including Teflon! We were therefore tempted to think that everything we developed with our biomimetic glue within the framework of the Biocoat project could be extended to other materials. The Walloon Region and the University thus decided to create a technological innovation platform called Symbiose Biomaterials, which will be hosted by MecaTech, the Walloon centre of competitive excellence in mechanical engineering. Its aim is to accelerate the marketing of developments resulting from the Biocoat research. Of course, other university laboratories, research centres and businesses will be associated with it.” To go in which direction? Those in charge of the project have defined three possibilities. The first one is obviously related to everything to do with antimicrobial coatings for hospitals, butchers, cold rooms, etc. But this time, regardless of the surface, whether it be steel, glass or something else: we simply change the biomolecule but we keep the active ingredient; this is one of the interests of the basic choice of DOPA as glue. The second direction chosen is still coating, but specific to the medical implants sector. The advances in medicine can be seen in the increasing use of implants, or 'spare parts', in our bodies. Covering these implants with an antimicrobial coating will undoubtedly help to prevent rejections and infections. The third direction selected is undoubtedly the most innovative, and even the most promising. Biocoat has allowed the researchers from Liège to familiarise themselves with GEPI technology (Genetically Engineered Polupeptide for Inorganics). In other words, engineering and constructing small made-to-measure peptides, and using proteins to create an assembly controlled on a nanomolecular level. As its name indicates, GEPI is a polypeptide designed through genetic engineering that specifically recognises an inorganic material. Just what you need for nanodetection, sorting and the manipulation of nano objects. A patent was registered for a peptide capable of fishing out nanopowders from the middle of a pile.  Or, another example, recovering rare earth elements from waste, whose value is continuously increasing. Or using them in filters to find a contaminant such as nanoparticles of TiO2 without filtering the water. Symbiose Biomaterials has an exciting future ahead of it!