A study published in the journal Antibiotics found that photodisinfection, using a methylene blue-based photosensitizer in combination with a specific wavelength of light, effectively eradicated pathogens commonly found on arthroplasty materials used in joint replacements
- Implantable joint infections are life-threatening and extremely hard-to-treat.
- The annual cost of treating periprosthetic joint infections in the US is $1.62 billion.
- Photodisinfection successfully eradicated key pathogens associated with implantable joint infections, including Staphylococcus aureus and Escherichia coli (ESKAPE pathogens).
A study published in the journal Antibiotics found that photodisinfection, using a methylene blue-based photosensitizer in combination with a specific wavelength of light, effectively eradicated pathogens commonly found on arthroplasty materials used in joint replacements. The results suggest that photodisinfection could be used as an effective treatment method for periprosthetic joint infections (PJI), replacing current, more invasive approaches and potentially reducing the need for antibiotic treatment. This would not only improve patients’ quality of life, but also reduce morbidity, mortality, and high healthcare costs.
The in vitro study, conducted by a research team from University Hospital Zurich, found that photodisinfection achieved >99.99% eradication (4-7 log10 kill) of the key pathogens in biofilms associated with PJI, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Cutibacterium acnes, with no reported regrowth.
The photodisinfection treatment did not cause any relevant surface modification on any of the different prosthesis materials, suggesting that the therapy does not harm the material and is safe to use in vivo. The proprietary methylene blue-based photosensitizer used in the study was provided by Canadian life sciences company, Ondine Biomedical.
Lead author and Senior Physician for Internal Medicine and Infectious Diseases at Zollikerberg Hospital, Dr. Yvonne Achermann, commented:
“This is the first study to show that photodisinfection, also known as photodynamic therapy (PDT), could be an effective novel treatment for periprosthetic joint infections. This is particularly exciting as it provides a much-needed alternative to antibiotics as resistance levels in biofilm-forming bacteria continue to grow. We are planning a clinical safety study to further explore the potential of photodisinfection to treat and even prevent PJIs.”
Patients undergoing major surgeries like hip or knee replacements face the risk of life-threatening infections with the majority of these related to the patients’ own microflora. PJIs are typically extremely hard to treat,[i] often requiring surgical intervention and prolonged treatment with high-dose antibiotics. In the US alone, the annual cost of treating PJIs is estimated at $1.62 billion.[ii]
PJIs are difficult to treat due to biofilm formation on implant surfaces. These infections often require removal or exchange of prostheses and long-duration antibiotic treatment. The study found that photodisinfection effectively eradicated important pathogens involved in PJI – whether in planktonic form or biofilms grown on commonly used arthroplasty materials – and without harming the prosthetic materials.
Photodisinfection is a broad-spectrum antimicrobial that uses a light-activated microbial stain. In a few minutes, this innovative therapy destroys all types of pathogens through an oxidative burst without harming the implant or human tissue. Importantly, photodisinfection is effective against drug-resistant pathogens and does not cause resistance-formation, giving it distinct advantages over antibiotics.
The full research paper can be accessed here. The University Hospital Zurich research team is planning further clinical studies of photodisinfection for the treatment of PJIs, starting with a clinical safety study.
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Department of Dermatology, University Hospital Zurich, University of Zurich, Switzerland:
Yvonne Achermann
Email: yvonne.achermann@usz.ch
Media Contact:
Simon Vane Percy
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