Assessment of photodynamic therapy efficacy against

Significance: In orthopedic trauma surgery, spatially structured biofilm ecosystems of bacteria that colonize orthopedic devices account for up to 65% of all healthcare infections, including tens of millions of people affected in the United States. These biofilm infections typically show increased resistance to antibiotics due to their structure and composition, which contributes significantly to treatment failure. Anti-biofilm approaches are needed together with clinically usable microscopic-resolution imaging techniques for treatment efficacy assessment. Aim: Antimicrobial photodynamic therapy (aPDT) has been recently proposed to combat clinically relevant biofilms (chronic wound infections, dental biofilms, etc.) using photosensitizers excited with visible light to generate reactive oxygen species that can kill bacteria residing within pathogenic biofilms. We aim to assess the efficacy of this treatment for eradication of biofilms typically present on surfaces of orthopedic devices (e.g., intramedullary nails and osseointegrated prosthetic implants). Approach: In the first phase reported here, we test aPDT Results: The antibacterial efficiency of 5-ALA-based aPDT showed nonlinear dependence on the photosensitizer concentration and the light power density, with low parameters ( Conclusions: Performed experiments enable the translation of this portable treatment/imaging platform to the second phase of the study: aPDT treatment response assessment of biofilms grown on orthopedic hardware.