A Novel Approach to nanoscale materials assembly using bioengineered spider silk fusion proteins: a generic materials approach

In the present research proposal we will use a novel biomimetic approach to the synthesis of nanocomposites using silk fusion (chimeric) proteins. The experimental design for the project involves the design, cloning, expression, analysis and characterisation of the fusion proteins in a range of physical forms (David Kaplan, Tufts University, USA) and the use of these proteins in materials synthesis (Carole Perry, Nottingham Trent University, UK) with some of the materials being assessed for their mechanical and other properties as they arise(Rajesh Naik, Airforce research Laboratories, USA) . Our aims are (1) to evaluate silk protein chimeric designs to optimize materials 'assembly space' (structure, morphology), (2) to prepare silk nanocomposites with a range of metal/oxide functionality in a variety of different material forms (from solution, and as fibres and films) under environmentally benign reaction conditions (aqueous processing), (3) to investigate the possibility of making multifunctional silk-based nanocomposites, and (4) correlate mechanical properties with design chemistry. The hypothesis for the proposed study is that nanocomposite material features can be optimized (structure, morphology, etc) and controlled (on a range of length scales) through appropriate design of chimeric (fusion) proteins in which the self-assembling structural domains and the functional (mineral or metal forming) domains are linked at the molecular level. Our goal is to elucidate how alterations in the chemistry of the two domains will lead to predictable changes in composite materials properties including tensile strength. The outcome of the proposed studies will be an entirely new family of novel nanocomposite materials, embracing the self-assmbly and remarkable mechanical properties of silk proteins but with added functions due to the chimeric mineralizing domains encoded in the new bioengineered proteins. We anticipate an entirely new approach to polymer design to generate novel composite materials through the proposed three year programme. The range of potenital applications for these materials is vast and includes military, space, performance car racing, elite sports wear, functional filters and materials for wound dressing and medical applications.