Peek behind the paper: 3D printing antibacterial surfaces
In this exclusive interview with Joey Shepherd, Senior Lecturer in Microbiology at The University of Sheffield (UK), 3DMedNet takes a closer look at the potential for including antibacterial properties in 3D-printed artefacts.
I am a Senior Lecturer in microbiology at the University of Sheffield’s School of Clinical Dentistry (UK).
My research career has come full circle since graduating from the University of Leeds (UK) in 1995 with a degree in microbiology. A move to the University of Sheffield followed with an M.Med.Sci. in microbial pathogenicity (1996) and a 2-year stint as a Research Technician in the Vascular Surgery Unit at Sheffield’s Northern General Hospital (UK). I completed a PhD (1998–2002) and Postdoc (2002–2004) at the University of Sheffield and then continued as a Fellow at Harvard Medical School (2004–2007; MA, USA) working for Professor Peter Libby. A move back to Sheffield saw another three postdoc posts come and go and I took up my first academic post as a Senior Lecturer in microbiology at Sheffield Hallam University (20014–2015, UK). I then returned to the University of Sheffield as a Lecturer in microbiology at the School of Clinical Dentistry in 2015 and was promoted to a Senior Lecturer in December 2019.
My current research interests are largely translational and interdisciplinary in nature and lie primarily in novel approaches to:
- the acceleration of wound healing;
- detecting, preventing and treating bacterial and fungal infections without traditional use of antibiotics, including the use of polymer-based systems, ultrasound and acoustic vibration, novel wound dressings, antimicrobial biomaterials for dentistry and bone and using 3D tissue engineered models to examine effects of planktonic and biofilm infection and treatment on both bacteria and human cells.
When not squinting down microscopes I enjoy travel with my family, socializing, reading (mostly dystopian novels!), and training with the Exiles, a historical European martial arts club.
Could you please tell us about the project covered in the recent 3DMedNet news piece, as well as any other related projects you may currently be working on?
This was a very collaborative EPSRC-funded project, led by Candice Majewski of the Department of Mechanical Engineering at the University of Sheffield, who is really the driver behind the additive manufacturing aspect. The team also comprises PhD student, James Wingham, and two postdocs: Bob Turner and Tom Paterson (all University of Sheffield).
Between us, we used our complimentary skills to create and test 3D-printed parts composed of polyamide 12 as a base powder with a commercially available antimicrobial, silver phosphate glass, incorporated into it. It’s the first laser sintered material that we know of to incorporate an antimicrobial.
The silver phosphate glass is distributed throughout the material so it won’t ‘wear off’ the surface (published in another paper, ‘Micro-CT for analysis of laser sintered micro-composites’) and has numerous potential uses, as you can imagine. We are currently working on fully characterizing these materials in terms of, for example, how they perform after sterilization and the best ways to do that, and are continuing to test how the materials perform against a broader range of microbes.
What challenges have you faced developing a technique for 3D printing antibacterial properties into objects?
We found that the antibacterial properties of the objects very much differ in different environments. For example, Bob Turner ran a set of experiments that showed that the antibacterial properties of the objects varied according to what was present in the surrounding media. This was really important work as it informs both future experimental setups and under which conditions the parts will perform best in future.
What challenges associated with the production or management of commonplace clinical surfaces are you hoping your approach will help to overcome?
We anticipate that our material could be used for many heavily used surfaces, such as light switches in hospitals, which people handle or touch a lot.
We hope that using materials that are inherently antimicrobial for these surfaces will help to prevent the spread of infection in both clinical and non-clinical settings.
What’s next for you and your research?
While the School of Clinical Dentistry has a large interest in 3D printing/AM – the Bioengineering and Health Technologies team here is printing custom scaffolds for facial regeneration, craniofacial and dental prosthetics. I am personally very much more on the microbiological side and continue to collaborate with engineers, materials scientists and chemists to create novel antimicrobial treatments that don’t rely on traditional antibiotics.
The growth in antimicrobial resistance is something we should all be worried about, but there is much work going on globally to circumvent this phenomenon.
I will be continuing to work alongside Candice Majewski and her excellent team in the additive manufacturing realm.
We have some ideas for our next project but I’m afraid you’ll have to watch this space!
Where do you see medical 3D printing in 5–10 years time? How could research such as yours be applied to this?
There are so many possibilities on the horizon and as groups become both quicker and more creative with their work, it’s difficult to predict. The idea of printing complex organs has been around for a while now but I think that will take a little longer to actually achieve. I hope customized prosthetics will be in more regular use as costs come down and the prospect of printing implants which could also be customized is interesting.
Our research incorporating antibacterial properties into laser sintered objects is easily applicable to many of these future scenarios, although further work characterizing the materials is of course necessary.
Nonetheless, the future of medical 3D printing promises to be exciting!
The opinions expressed in this feature are those of the interviewee/author and do not necessarily reflect the views of 3DMedNet or Future Science Group.