biostudies-literaturePrinz JMonique Dornonville de la Cour FoundationWolfermann-Naegeli Foundation118https://www.ebi.ac.uk/biostudies/studies/S-EPMC9854686biostudies-literatureUnknown12(1)Periprosthetic joint infections (PJI) are difficult to treat due to biofilm formation on implant surfaces, often requiring removal or exchange of prostheses along with long-lasting antibiotic treatment. This in vitro study investigated the effect of methylene blue photodynamic therapy (MB-PDT) on PJI-causing biofilms on different implant materials. MB-PDT (664 nm LED, 15 J/cm²) was tested on different <i>Staphylococcus aureus, Staphylococcus epidermidis</i>, <i>Escherichia coli</i> and <i>Cutibacterium acnes</i> strains in both planktonic form and grown in early and mature biofilms on prosthetic materials (polyethylene, titanium alloys, cobalt-chrome-based alloys, and bone cement). The minimum bactericidal concentration with 100% killing (MBC_100%) was determined. ChemAntibiotics (Basel, Switzerland)Effective Biofilm Eradication on Orthopedic Implants with Methylene Blue Based Antimicrobial Photodynamic Therapy In Vitro.PMC9854686naGrob MCWalt HNeuhaus SPrinz JWink MBosshard PPAchermann YfalseEffective Biofilm Eradication on Orthopedic Implants with Methylene Blue Based Antimicrobial Photodynamic Therapy In Vitro.Periprosthetic joint infections (PJI) are difficult to treat due to biofilm formation on implant surfaces, often requiring removal or exchange of prostheses along with long-lasting antibiotic treatment. This in vitro study investigated the effect of methylene blue photodynamic therapy (MB-PDT) on PJI-causing biofilms on different implant materials. MB-PDT (664 nm LED, 15 J/cm²) was tested on different <i>Staphylococcus aureus, Staphylococcus epidermidis</i>, <i>Escherichia coli</i> and <i>Cutibacterium acnes</i> strains in both planktonic form and grown in early and mature biofilms on prosthetic materials (polyethylene, titanium alloys, cobalt-chrome-based alloys, and bone cement). The minimum bactericidal concentration with 100% killing (MBC_100%) was determined. Chem2023-01-01T00:00:00Z2023 Jan2025-04-04T11:33:18.922Z2025-04-04T11:33:18.922ZS-EPMC98546863667131910.3390/antibiotics12010118