INTERACTIONS BETWEEN ORGANIC AND INORGANIC MATTER: FROM BASIC SCIENCE TO APPLICATIONS

Several natural processes are mediated by the interactions between organic and inorganic materials. The immune response towards an implant is mediated by proteins. Composite materials are formed by the interactions of organic materials (usually proteins) and minerals. Biofouling, the process in which organisms attached to surfaces, is also mediated by organic molecules. Understanding the nature of interactions between organic and inorganic materials will bring to the development of improved implants, new composites and antifouling material.

Using single-molecule force spectroscopy with AFM, we study the underlying forces between organic and inorganic matter. Specifically, we investigate the interactions between individual biomolecules (either amino acid residues or short peptides) and inorganic surfaces in aqueous solution. Using this method, we were able to measure low adhesion forces and could clearly determine the strength of interactions between individual amino acid residues and inorganic substrates. Our results with peptides also shade light on the factors that control the interactions at the organic-inorganic interface.

Based on our knowledge from single molecule experiments, we designed a short peptide (tripeptide) that can spontaneously form a coating that resists biofilm formation. Our results demonstrate the formation of a coating on various surfaces (glass, titanium, silicon oxide, metals and polymers). In addition, we showed that this coating prevents the first step of antifouling, which involves the adsorption of bioorganic molecules to the substrate. Moreover, the coating significantly reduced the attachment of various organisms to surfaces. This includes pathogenic bacteria and fungi.