Fantastic plastic – developing biomedical technologies in the microscopic world
Much of the health and comfort associated with modern life is due to the discovery and development of polymers, otherwise known as plastics and rubbers. Polymers are long-chain molecules made from many identical links called monomers, and are the central focus of an £800,000 EPSRC-funded Platform Grant based in the Department of Chemistry at the University of Sheffield.
Led by Professors Steve Armes and Tony Ryan, a team of researchers are pursuing various research themes in both basic and applied polymer science. This work is expected to lead to exciting new breakthroughs that will impact on biomedical research, as well as encapsulation/release technologies for both consumer products and improved crop yields. Each of these areas is of strategic importance to UK industry and will help to maintain our international competitiveness.
Professors Armes and Ryan have a wide range of expertise of designing polymer molecules to form specific shapes. A main strand of their research involves taking two chemically different polymers which do not mix, and tying them together to form a 'block copolymer'. The new chains can self-assemble in water to form micelles, which are microscopic spherical particles up to 10,000 times smaller than the width of a human hair. These micelles are then coated with an outer layer of silica (which is chemically the same as sand) and the silica-coated micelles are deposited as an ultrathin layer onto glass and heated up to 500oC to burn off the polymer. The remaining nano-structured silica coating is highly anti-reflective. A University patent application was sold to a global speciality chemicals company in 2007, which has recently captured a substantial share of the global market for high-quality glass frames in the fine art world.
Another strand of the project, involving Mr Adam Blanazs, is developing block copolymers that self-assemble in solution to form hollow capsules, or vesicles, which are about one-tenth the size of biological cells. Recently, in collaboration with Dr Beppe Battaglia's group, it has been shown that the surface of these hollow capsules dictates whether these microscopic particles are toxic or biocompatible.
In a related theme, Dr Steve Edmondson and Andrew Morse have grown biocompatible polymer chains from various model surfaces. These polymers bind strongly to water, which has obvious applications for skin care products. In collaboration with Professor Graham Leggett's group, also in the Department of Chemistry, these polymer-coated surfaces have been shown to have very low frictional coefficients compared to bare surfaces, which suggests possible aqueous lubrication applications.
Also being conducted under this EPSRC Platform Grant is a project by Dr Linge Wang in collaboration with Professor Sheila MacNeil, of the Department of Engineering Materials. This work involves the spinning of tiny fibres, 50-100 times thinner than human hair, to be used as scaffolding to grow new skin and bone and also for the repair of bladders by a process called 'tissue engineering'.
Professor Steve Armes comments: "This EPSRC Platform Grant has provided vital underpinning funding to enable myself and Professor Ryan to collaborate over a wide range of topics that are of central importance to our independent research programmes. We have been able to conduct exciting 'value-added' science that could not have been achieved by either of us independently".
For further information, please contact Ian Kingsbury:
tel: 0114 222 1456
email : i.r.kingsbury@sheffield.ac.uk
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