Year/Course: 2014-2015, Easter 2015

Contact: Dr. Tuomas Knowles, Xizhou Liu, Chemistry

The research team led by Dr Knowles has developed substantial expertise in understanding and controlling the structures formed by functional protein molecules, enabling them to create nanoscale filaments and complete microcapsules formed solely from proteins.

While microcapsules are already used widely in a range of applications, from cosmetics to washing products to glues, these are typically formed using synthetic polymers or polysaccharides. The advantages of using proteins instead are that they are intrinsically biodegradable while also being durable, are produced from sustainable feedstocks, and can be ingested safely.

The techniques use a combination of nanoscale self-assembly to produce protein filaments, with microfluidics-mediated structuring to create the microcapsules. This means that the microcapsules are pure proteins with no additional components. In some cases the protein of interest to the end application can itself be formed into the microcapsules, greatly increasing its stability and shelf-life. For example, native silk undergoes a sol-gel transition to create solid silk, and cannot be stored in its unformed sol state. By using the microcapsule technique, the team have created stable silk microcapsules containing native silk in its unstable gel state. These can be stored for several months, and the silk sol can be released when needed.

Other areas of interest include food proteins, such as lysozyme and beta-lactoglobulin, which can also be formed into filaments and microcapsules, opening up the possibility of creating protein-based emulsions to replace the fat-based ones found in products such as ice cream. Many new drug treatments are now based on antibodies or short peptides, all of which are prone to aggregation or degradation, have short shelf lives, and in some cases need to be injected daily. This technique could also help to stabilise these valuable treatments, and make them easier to store and administer.

The challenge for the i-Team is to investigate the areas where it would be important to have a protein-based microcapsule, instead of the currently-used polymer ones. By talking to experts from a range of industries, they will be asked to recommend the next areas of focus for the research team, as they move this technology towards a commercial reality.