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47404-SE
Nanostructured Fluorocarbons: Smart Modules for Self-Assembly, at the ACS National Meeting, August 2007, Boston, MA

Giuseppe Resnati, Politecnico di Milano and Pierangelo Metrangolo, Politecnico di Milano

During the 234^th ACS National Meeting (19-23 August 2007, Boston, MA) Pierangelo Metrangolo and Giuseppe Resnati (Politecnico di Milano, Italy) have organized the Symposium “Nanostructured Fluorocarbons: Smart Tectons for Self-Assembly” on behalf of the ACS Division of Fluorine Chemistry and with a co-sponsorship by the Division of Medicinal Chemistry. The Symposium was supported by different private and public foundations and industries, including “THE PETROLEUM RESEARCH FUND” (PRF). The subjects of the Symposium were the use of fluorinated materials in different technology applications and the development of new knowledge in the field of fluorinated compounds.
Two different aims have been pursued in this Symposium. The first aim was to consolidate the knowledge on the use of fluorinated materials in industrial applications, the second aim was to analyze the state of the art of the research in the field of fluorinated materials at its interface with Nanotechnology, Catalysis, Crystal Engineering, and Biology.
To reach these aims the scientific program of the symposium was patterned with 22 lectures provided by internationally recognized scientists coming from the most industrialized countries. The invited speakers were the international leaders in their respective areas and are working in academia, research institutes as well as industrial research centres. The speakers supported with PRF funds were Juerg Hulliger (Switzerland), Toshimasa Katagiri and Taizo Ono (Japan), Andre Laschewsky (Germany), Pierangelo Metrangolo (Italy), David O'Hagan (United Kingdom).
Lectures on industrial applications were focussed, among others, on fluoroelastomers and fluoroalkyl substituted copolymers. It has been presented how incorporation of semicrystalline perfluoropolymers in fluoroelastomers is a powerful way to improve and enlarge the functional properties, the size of the dispersed phase playing a key role. It has been shown that a fine dispersion has been obtained with an innovative mixing technology based on microemulsion polymerization. Those nano-blends combine the performing sealing and mechanical properties of fluoroelastomers with the exceptional thermal and chemical resistance, low permeability and low friction coefficient of semicrystalline perfluoropolymers. In order to match the high purity levels required by semiconductor and electronic applications, an innovative technology able to reduce impurities to ppb level has been described. As to copolymers containing fluoroalkyl groups, it has been described that ABA triblock-type fluoroalkylated oligomers and dendritic-type fluoroalkyl end-capped block copolymers can be prepared by the use of fluoroalkanoyl peroxide as a key intermediate. These fluorinated block co-polymers can form nanometer size-controlled self-assembled molecular aggregates with the aggregation of end-capped fluoroalkyl segments in aqueous and organic media. The fluorinated molecular aggregates thus obtained could interact with a variety of guest molecules such as organic dyes, low-molecular biocides, metal nanoparticles, calcium carbonates, fullerenes, single-walled carbon nanotubes, nanodiammonds and magnetites to afford stable fluorinated nanocomposites.
Lectures on the emerging new applications of fluorine chemistry allowed the second aim to be pursued. Some of the investigated topics are: Teflon substituted proteins, fluorinated amino acids, perfluorocarbon nanoemulsions for molecular imaging and therapy.
One lecture described the development of peptide based model systems, enabling to study of the effect, in native protein environments, of the introduction of fluorine in amino acid side chain. Particular attention was given to the proteolytic stability of fluorine substituted peptides.
Another lecture reported how the properties of a protein can be modified in a predictable manner by replacing hydrophobic amino acid residues with extensively fluorinated analogues. It was also shown that molecular imaging and targeted therapeutics with nanoparticulates represents a new approach for early diagnosis and drug delivery to various pathologies. It has been developed a liquid perfluorocarbon nanoemulsion combining flexible and multi/polyvalent targeting ligands with therapeutic agents against cancer and cardiovascular disease. Drugs such as doxorubicin, rapamycin, and fumagillan, and other agents such as siRNA and cytolytic peptides can be incorporated in a self-assembling particle that is approximately 200 nm diameter and contains a perfluorocarbon core. The unique spectral (19F) signature of the PFC core renders it especially interesting for magnetic resonance imaging (MRI). These targeted agents can be detected spectroscopically and imaged directly with no confounding background signal in vivo. The signal strength for useful PFC's such as perfluorooctylbromide or crown ethers render it a sensitive agent for molecular imaging of angiogenesis in cancer and atherosclerosis and for stem cell labelling and tracking in vivo.
The attendance at the symposium was very good. Scientists and researchers from academia and private companies have attended the event and very interesting discussions followed the lectures.

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