The ABM CDT is a partnership between The Universities of Manchester and Sheffield. ALL APPLICATIONS should however, be submitted via the Manchester application system only.
This highly interdisciplinary project combines 3D Printing and silver-based antimicrobial technology in order to reduce the chances of infection following a patient undergoing a Percutaneous endoscopic gastrostomy (PEG).
PEG are routinely used to feed patients for whom oral feeding is impossible, e.g. when recovering from head and neck cancer surgery. Although around 15,000 PEG are placed in the UK each year, mortality and complications following surgery can occur, with the most common complication (infection of the surgical site), occuring in up to 30% of patients.
Infection frequently occurs at the site of suture lock discs (placed on the skin surface to hold sutures anchoring the PEG tube in place until they dissolve or are removed after 2-3 weeks) and in skin underlying external 'bumpers' (which secure the external part of the tube to the abdomen). While there has been some success in prevention of infection using prophylactic antibiotic treatment, the global rise in antibiotic resistance means there is an increasing need for the development of non-antibiotic approaches.
We have previously shown that we can effectively incorporate a silver-based additive into 3D Printed parts, and that these parts successfully prevented and/or killed bacteria under certain conditions. This new project will explore this approach for PEG infections, with a particular focus on understanding its effectiveness against common PEG-related infections, and the length of time it remains effective in the specific environmental conditions encountered in real life. We will also explore the additional geometric complexity achievable with 3D Printing, to determine whether new designs of these products may lead to improvements in clinical outcomes.
Our focus is on the inclusion of silver-based antimicrobial additives into polymers for the Laser Sintering additive manufacturing AM process. The supervisory team previously demonstrated the effectiveness of our approach ( EPSRC funded grant EP/R036748/1) to produce parts able to prevent growth of Gram negative and -positive bacteria, without cytotoxicity to mammalian cells. Crucially, we also showed that including these additives had no detriment to the mechanical integrity of the samples.
In this project the student will build upon these previous results and apply them to a real-world problem. Gastrostomy surgeries, which introduce an enteral feeding tube direct to the stomach for patients unable to eat orally, are one of the most common paediatric surgeries, with approximately 1 in 5000 children receiving a gastrostomy in 2009 . PEGs are placed in patients of all ages and an unacceptably high proportion of these (~30%) become infected [2-5]. Most infections occur at the stoma entrance where an external ‘bumper’ may be placed, or at the site of suture lock discs on the skin surface. Given the large numbers of operations performed and the wide spectrum of patients this creates a large clinical burden and over-utilisation of resources. In this project we hope the student will develop, via advanced AM techniques, novel antimicrobial parts to replace current bumper and lock discs as a way of reducing this infection burden.
Main questions to be answered:
- Can we design and develop antimicrobial, non cytotoxic 3D printed parts with complex geometries via Laser Sintering, with no loss of function following sterilisation, and which are acceptable for use by clinicians?
- Can we design and develop appropriate 3D tissue engineered models of surgical infection on which to test the developed parts?