When the drugs don't work... Manufacturing our pathogen defenses

The average person comes into contact with millions of bacteria every day, especially in areas with a high throughput of people. In the majority of cases we are peacefully oblivious, with this having little tangible effect on our lives. However, where a person has a lower immune system than normal these bacteria can become deadly. With an increase in drug-resistant strains of bacteria, preventing them from settling or spreading therefore become a critical challenge, particularly in hospital wards and care homes housing the most vulnerable members of our population. 'Normal' products and surfaces all become potential breeding grounds for bacteria, and therefore potential routes to infection. Addressing this issue is the main focus of this work.

The overall vision for this research is the production of medical and consumer products and devices with inherent anti-bacterial properties. For the majority of products for which this is important, standard techniques include rigorous (and often complex) cleaning or sterilisation procedures, or coating the product with an anti-bacterial compound. Whilst these provide a level of protection, each has limitations; for example cleaning and sterilisation procedures can be subject to human error and coatings may become scratched or damaged, leaving some areas unprotected. Products with complex geometries (including those incorporating some degree of personalisation), are of great interest in the healthcare sector but also present the greatest challenge in ensuring consistency of anti-bacterial protection.

By introducing anti-bacterial behaviour into a product directly, many of these issues could be reduced or eliminated. This project will provide crucial early-stage investigations into the possibility of combining cutting-edge Additive Manufacturing (3D Printing) techniques with a silver-based anti-bacterial compound in order to produce highly complex products incorporating anti-bacterial properties. Additive Manufacturing techniques are well-recognised for their ability to produce complicated geometries with little of no cost penalty, and the anti-bacterial properties of silver have been known for millennia. Bringing the two together presents a real opportunity to provide a significant impact on our ability to guard against infection.

This project will investigate the potential of this technique for applications in a wide range of areas including medical devices (e.g. endoscopes or other intrusive devices used for multiple patients), general hospital products subjected to high levels of human contact (e.g. door handles or taps), oral health products (e.g. dentures) and consumer products (e.g. mobile phone cases or personalised shoe insoles). Further projects are planned in each of these areas, following successful proof of concept here.

Societal: Managing bacterial spread, infection, and increasing resistance to antibiotics, is a key global concern; introducing anti-bacterial protection to products and devices at point of manufacture could be an essential tool in this fight. It is unlikely that we will see surgical devices re-used without sterilisation between patients in the near future; however the inherent anti-bacterial properties of the product will provide a major increase in protection - in effect any cleaning/sterilisation procedure will become a 'back-up' rather than the main line of defence. For many products, particularly those with complex geometries, effective cleaning can be complex and time-consuming. Removing or reducing the care needed for these items will reduce the potential for bacterial spread, with associated reductions in infections. Protection for commonly-used, bacteria-prone items may also help to maintain an environment in which patients can receive community-based care with reduced risk of infection.
Technological: The majority of products and devices produced using Additive Manufacturing (AM) techniques remain 'passive' objects, whereby geometry is their most important attribute. Adding functionality to the product at the manufacturing stage will provide a step-change in our utilisation of the process capabilities. Throughout the project we will also develop an enhanced understanding of the behaviour of functional materials within the AM process. The UK's strength in both AM and in advanced/functional materials is well-recognised, and this understanding will help us to maintain and enhance the UK's technology leadership in these areas.
Environmental: AM techniques can provide reductions in material wastage (and therefore utilisation of natural resources), greater energy efficiency, and reduced transportation costs through realising the potential for localised manufacture. The addition of anti-bacterial protection into AM products may provide additional benefits, for example through a reduction in the need for disposable anti-bacterial devices and covers.
Economic: In the long-term, reductions in bacterial infection and re-infection rates will reduce the cost of treating these infections, allowing the NHS to re-invest the financial savings into other areas. Reducing the number of processing steps required to manufacture a specific product (e.g. removing the need for an anti-bacterial coating) will help to reduce costs, complexity and overheads, reducing the cost to the NHS and other customers. At a market level the ability to incorporate this additional functionality into consumer products is expected to generate immediate economic impact for early adopters, whether through increased prices as a result of the added-value provided to the product, or through capturing a higher proportion of the market share through the addition of extra functionality at no added cost.
People: This project will help to strengthen links between manufacturing and micro-biology and the PI/PDRA will engage with members of the relevant departments throughout this and subsequent projects. The PDRA will enhance and refine a large number of skills throughout the course of this project, both through increased understanding of micro-biology, polymer materials, technical skills with Laser Sintering and material testing, and with broader skills such as research planning, publishing, and presenting. UG/MSc projects will be allocated in non-critical areas of the work, in order to generate additional data and results. It is hoped that exposure to cutting-edge scientific research within this area will encourage these and other students to consider undertaking postgraduate research in this area, broadening the UK's future research base in this area. Outreach activities will ensure wider visibility of the project and its results, with a particular focus on engaging our younger generation and demonstrating that Engineering is both exciting and necessary!