Summary: UCLA researchers in the Department of Orthopaedic Surgery have developed a non-invasive method to disrupt biofilms on orthopaedic implants and decrease the overall rate of infections. Background: Prosthetic joint infection (PJI) remains a serious complication in hip and knee arthroplasty, with skyrocketing revision rates across all orthopaedic implants. The effective treatment of PJI is crucial to the overall success of these implants. Infections occur when a protective biofilm is formed over the orthopaedic implant. This biofilm protects the bacteria from immune reactions and allows the colonization to grow. Biofilms typically form when tissue regeneration at the bone-implant surface has not had enough time to develop. Orthopaedic implants are particularly prone to the growth of these biofilms due to material roughness, hydrophobicity, and surface charge. Typical orthopaedic implants utilize these features to promote bone regrowth; however, this also creates an environment primed for biofilm growth. Specifically, Staphylococcus epidermidis and aureus are the two most common infections that make up two-thirds of all infection cases. Treatment of these infections usually involves prescribed antibiotics; however, new strains are developing which are resistant to modern antibiotic treatments. To address these issues, a novel approach to infection treatments is pivotal to the ongoing success of hip and knee replacements.
Innovation: UCLA researchers have developed an innovative, non-invasive method to treat orthopedic implants using iron-core nanoparticles and pulsed electromagnetic fields. This technique employs magnetic nanoparticles, which are set into oscillation by the magnetic field, to disrupt and break down biofilms that form on orthopedic implants. The mechanical disruption causes the biofilm to break down into smaller particles and detach from the implant, leaving it more susceptible to the body’s natural immune response and antibodies. As a result, the implant surface becomes conducive to colonization by osteoblasts, promoting tissue regrowth and enhancing osseointegration. The inventors have successfully demonstrated the utility of functionalized nanoparticles for bactericidal activity in these combination technologies. This groundbreaking approach has the potential to revolutionize the treatment of infection-related complications in orthopedic surgery, significantly reducing the need for revision surgeries due to prosthetic joint infections. Additionally, nanoparticles can be functionalized with multiple agents simultaneously, with new potential applications in combination drug development.
Potential Applications: • Treatment for periprosthetic join infections in all orthopaedic implants (hip, knee, spine, etc.) • Treatment for infections with fracture fixation devices • Preventative measure for biofilm formation on implants • Treatment of infection in other medical implants (dental implants, cardiovascular stents, etc.) • Chronic wound management
Advantages: • Non-invasive treatment for infection • Decreased incidence of revision surgeries due to periprosthetic joint infection • Enhanced osseointegration of orthopaedic implants • Increase in patient satisfaction levels and overall faster recovery time • Scalability and ease of implantation with current treatment methods (i.e. antibiotics) • Decrease resistance to antibiotics, allowing for a more effective antibiotic treatment regiment Development-To-Date: The invention has not yet been disclosed. One publication has been published that outlines the effect of PEMF in combination with chitosan coatings and one conference presentation was given on the effect of the electromagnetic field on Staphylococcus epidermidis.
Related Papers and Patents: 1. Ghalayani Esfahani A, Lazazzera B, Draghi L, et al. Bactericidal activity of gallium-doped chitosan coatings against staphylococcal infection. J Appl Microbiol. 2019;126(1):87-101. doi: 10.1111/jam.14133MEETINGSR . 2. Juncker; B. Lazazzera; F. Billi - The Use of Pulsed Electromagnetic Fields to Inhibit Staphylococcus Epidermidis Biofilm and Planktonic Cell Growth - ORS, Virtual Meeting, February 12-16, 2021
Reference: UCLA Case No. 2021-334
Lead Inventor: Fabrizio Billi, Professor of Orthopaedic Surgery