Abstract text (incl. figure legends and references)
Introduction: Periprosthetic joint infections are a devastating complication after arthroplasty, leading to rejection of the prosthesis. Septic loosening may be prevented by coating of the implant surface with an antimicrobial active agent as Poly(hexamethylene) biguanide (PBMH) a microbiocidal substance with low cytotoxicity and a long-lasting microbicidal effect.
Objectives: To preclude aseptic loosening by excessive activation of the immune system, possible inflammatory effects on monocytes upon contact with PHMB-coated surfaces were analyzed.
Materials & methods: Monocytes were isolated from human buffy coat and incubated on PHMB-coated Ti6Al4V alloy for up to 7 days. Next to analysis of cell adherence, actin filaments were stained for identifying effects on the cytoskeleton and cytokine secretion was quantified. Afterwards, monocytes were co-cultured with SaOs-2 osteoblasts to identify effects on osteoneogenesis. For that, cell viability, generation of alkaline phosphatase and mineralization were quantified.
Results: In comparison to the control (non-coated material), monocytes on PHMB-coated material were not spreading on the specimen"s surface. On PHMB-coated surfaces, monocytes secreted higher amounts of inflammatory cytokines. In co-culture, viability of SaOs-2 osteoblasts on PHMB-coated material is as high as on non-coated surfaces. There was no effect on the generation of alkaline phosphatase but mineralization was reduced.
Conclusion: The surface treatment with PHMB led to an activation of monocytes to secrete inflammatory different cytokines. In co-culture, this cytokine secretion had no effect on SaOs-2 cell viability and alkaline phosphatase but it had effects on mineralization that has to be analyzed in more detail and long-term studies to preclude effects on osteoneogenesis.