PhD Defense: Simon Poly, on 17.06.2013 at 10:00

CIC nanoGUNE Seminars

Speaker

Simon Poly

When

2013/06/17
12:00

Place

Auditorium of the Centro de Fisica de Materiales, Paseo Manuel de Lardizabal 5, Donostia-San Sebastián

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Nanomaterials have attracted widespread attention due to their peculiar properties, originating from their nanometre-scale dimension. The unusual optical, mechanical, and magnetic properties of nanomaterials allow their application in the development of more efficient biomedical devices. However, recent studies have proved that due to the materials used in their preparation and to their nanometre-scale dimensions, nanomaterials present possible risks for human health. Indeed, it was demonstrated that some nanomaterials could induce cellular toxicity _in vitro_ because of the seeding of toxic ions and to the generation of toxic free radicals at the nanomaterial surface. These direct and indirect cellular toxicity mechanisms of nanomaterials have been thoroughly studied and are currently well-known but another level of toxicity has been recently discovered, namely the molecular toxicity of nanomaterials. It has been demonstrated that the presence of nanomaterials in biological fluids could create instabilities in the structure of biomolecules. Various studies have shown such effects of nanomaterials on different biomolecules. Within this study we have demonstrated that the effect of nanomaterials on protein structure stability is due to the charge present at the surface of nanomaterials. We showed that different proteins will react differently with the same charge at the surface of nanomaterials. Interestingly, we demonstrated that the effect of nanomaterials on protein structure was dependent not only on the charge present at the surface of nanomaterials but more importantly on the distribution of charge at the surface. On the basis of these data, we were able to develop a new type of therapeutic agent based on controlled charge distribution at the surface of nanomaterials allowing specific interaction of nanomaterials and target protein without the need for coupled recognition molecules. This new agent is able to specifically interact with pathological proteins and aggregate them in a safe way in order to ease their removal from living organisms. Furthermore this discovery opens the way to a better understanding of nanomaterial toxicity and to new nanomaterial with increased _in vivo_ stability __ for biomedical applications e.g. drug- delivery, biomedical implants, and tagging agents.