In hospitals, there is always a risk of spreading bacteria between patients. Some bacteria strains, such MRSA (or “staph”) are particularly prone to spreading in hospitals because they are resistant to many antibiotics—which puts vulnerable patients at risk. Research coming out of the University of Sheffield in the UK, which consists of 3D printing antibacterial parts, could help stop or reduce the spread of bacteria like MRSA in hospitals and care homes.
The research marks a milestone in the 3D printing sphere, as the parts created by the Sheffield team are reportedly the first 3D printed components to show resistance to common bacteria. Led by an interdisciplinary team from the University’s Department of Mechanical Engineering and the School of Clinical Dentistry, the research integrates a silver-based antibacterial compound into 3D printing materials.
The team was able to mix the compound into existing 3D printing materials without affecting the printability of the material or the mechanical properties of the printed part. Printed parts were tested extensively and ultimately demonstrated antibacterial properties and no toxicity to humans.
In practice, the antibacterial 3D printing material could be used to produce medical devices, oral health products and consumer goods. Perhaps most importantly, the material could be used to 3D print parts in hospitals which come into the most contact with humans—like door handles or children’s toys.
“Managing the spread of harmful bacteria, infection and the increasing resistance to antibiotics is a global concern,” explained Dr. Candice Majewski, who led the project from the Centre for Advanced Additive Manufacturing at the University of Sheffield. “Introducing antibacterial protection to products and devices at the point of manufacture could be an essential tool in this fight. Most current 3D printed products don’t have additional functionality. Adding antibacterial properties at the manufacturing stage will provide a step-change in our utilisation of the processes’ capabilities.”
3D printed sample parts underwent extensive testing to determine the viability of the antibacterial material. Antibacterial and non-antibacterial parts were submerged in bacterial solutions and tested after 24 hours to see how many bacteria had clung to each material. The 3D printed parts with silver compounds were found to be most effective against two main bacteria groups: Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa).
The antibacterial parts also proved to be effective against a particular phenomenon in which bacteria form a biofilm on a surface, becoming more difficult to remove. Because much of the bacteria was not able to survive on the surface of the printed parts, a biofilm was not able to form.
There are still some limitations to the technology, however. For instance, the researchers note that the 3D printed components were less effective in nutrient-rich liquids, which inhibited the silver compounds. This could limit the use of the antibacterial material to certain hospital applications.
“Our interactions with microbes are complex and contradictory—they’re essential to our survival and they can knock us dead,” said Dr. Bob Turner from the university’s Department of Computer Science. “Technology like this will be key to informed and sustainable management of this crucial relationship with nature.”
Dr. Joey Shepherd from the School of Clinical Dentistry, concluded: “Incorporating antibacterial activity into 3D printed parts is an intriguing novel direction only made possible by working as part of a great team with complementary skills and experience.”
The innovative research was published today in Scientific Reports.