Heat Enhances Antibiotics Against Prosthetic Infections
Dallas, Mar 13: Heat generated by alternating magnetic fields helps common antibiotics work better against prosthetic joint infections, researchers at UT Southwestern Medical Center found.
The study, published in Scientific Reports, advances previous research at UT Southwestern that demonstrated the efficacy of AMF in eradicating biofilm from the surface of prosthetic joints such as those used in knee and hip replacement surgeries.
“Prosthetic joint infections can be devastating to patients, requiring additional surgeries and long courses of antibiotics,” said study leader David Greenberg, M.D., Professor of Internal Medicine and Microbiology and a member of the Division of Infectious Diseases and Geographic Medicine at UTSW. “Many patients experience substantial declines in physical, emotional, and even financial well-being following diagnosis because of the length and costs of treatment. Our findings may play a role in developing a new approach that can make a significant difference in patient recovery.”
Prosthetic joint infections occur when bacteria latch onto the metal surface of an implant and form a sticky protective layer called biofilm. This coating blocks antibiotics and shields the bacteria from the body’s immune system. Eradicating biofilm would be a critical step forward in enhancing treatment protocols for patients who experience postsurgical infections.
“We know from earlier studies at UT Southwestern that alternating magnetic fields can be used to generate heat that disrupts biofilm,” said Dr. Greenberg, who invented the AMF technology and is a Distinguished Teaching Professor. “This study builds on our earlier findings by testing AMF against multiple bacterial strains and in combination with the most commonly used antibiotics that treat prosthetic infections.”
The laboratory study found that across all pathogens and antibiotics tested, AMF significantly improved biofilm eradication, achieving greater reductions in bacteria levels compared with the use of antibiotics alone.
The findings were consistent across different types of metal composition, suggesting the therapy may have broad applicability. The approach worked best when the magnetic field generated a brief, two‑minute burst of heat – enough to reach about 80 degrees Celsius – which helped break apart the biofilm.
Importantly, researchers have found that changing the design of the coil used to create AMF can result in magnetic fields that heat a complex shape, such as a knee, within the desired temperature range.
“This technology could result in a paradigm shift in how patients are treated for these infections,” Dr. Greenberg said. “Our goal is to identify a therapeutic approach to enable implant retention so patients can avoid the risks and costs associated with multiple surgeries.”
Other UTSW researchers who contributed to this study are co-first author Miranda Hairgrove, M.D., former UT Southwestern Medical School student; co-first author Sneha Banerjee, B.S., former Research Technician in the Greenberg Lab; Madhab Sapkota, Ph.D., Instructor of Internal Medicine; and Gerald Kramer, B.S., Senior Research Scientist.
This work was sponsored by a research agreement with Solenic Medical and partially funded by a grant from the National Institute of Allergy and Infectious Diseases Dr. Greenberg is Chief Medical Officer for Solenic Medicine, which is commercializing the technology. UTSW is a shareholder in the company.
