Inspired by the wings of dragonflies and cicadas, the University of Illinois Urbana-Champaign researchers have developed advanced coatings for orthopaedic implants capable of monitoring device strain, early detection of implant failures, and eliminating bacteria that cause infections. These coatings incorporate flexible sensors and a nanostructured antibacterial surface.
Study leader Qing Cao underscored this research as combining bio-inspired nanomaterial design and flexible electronics to address a complex, long-term biomedical challenge. Cao emphasised that both infection and device failure pose significant challenges in the context of orthopaedic implants, affecting approximately 10% of patients.
He explained that previous attempts to combat infection had limitations: water-repelling surfaces can still develop biofilms, and coatings containing antibiotic chemicals or drugs lose their effectiveness within a few months while potentially causing harm to surround tissue. Additionally, these coatings have limited efficacy against drug-resistant strains of bacteria.
Usha Varshney, acting deputy director of National Science Foundation (NSF) Electrical Divison, Communications, and Cyber Systems, expressed her optimism about the newly developed coatings. She believes that they have the potential to revolutionise orthopaedics within the healthcare system, particularly for an ageing population.
“These coatings can effectively eliminate infection-causing bacteria and monitor device strain, providing early warnings of implant failures,” she explained.
To evaluate the effectiveness of their prototype devices, the engineers collaborated with veterinarian Annette McCoy. They implanted nanoscale pillar-textured foils in live mice and closely monitored them for signs of infection, even when bacteria were introduced.
Moreover, they applied the coatings to commercially available spinal implants and monitored the strain experienced by the implants in sheep spines under normal load to diagnose potential device failures. The coatings successfully fulfilled both functions.
Although the prototype electronics necessitated wires, the researchers intend to progress to the development of wireless power and data communication interfaces for their coatings.
This step is crucial for the technology’s clinical application, as Cao highlighted. Furthermore, the team is working on establishing a large-scale production method for the bacteria-killing foils with nanopillar texture.
Cao emphasised the broad potential applications of such antibacterial coatings. Since their approach utilises a mechanical mechanism, it avoids using chemicals or heavy metal ions currently employed in commercial antimicrobial coatings. This characteristic makes the coatings particularly suitable for scenarios where the presence of chemicals or heavy metal ions could be detrimental.
Stephanie George, a program director in the Division of Chemical, Bioengineering, Environmental, and Transport Systems at the National Science Foundation (NSF), appreciates their ability to derive inspiration from the natural world, thoroughly explore fundamental scientific and engineering principles, and utilise this knowledge to develop innovative bioinspired design strategies for antimicrobial films.
“This recognition highlights the significance of their work in bridging the gap between scientific understanding and practical applications, ultimately contributing to advancements in the field of biomaterials and antimicrobial technologies,” she said.
Furthermore, she also underscores the importance of interdisciplinary research that combines insights from nature with scientific principles to create novel solutions with broad potential impacts, “Working within multidisciplinary teams is crucial as it allows for the enrichment and expansion of knowledge,” she concluded.
