Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), poses significant challenges in healthcare settings due to its ability to form biofilms on various surfaces. These biofilms enhance bacterial survival and increase resistance to conventional treatments, complicating infection control efforts. This study evaluated the efficacy of combined povidone-iodine (PVP-I) and hydrogen peroxide (H₂O₂) to disrupt pre-formed S. aureus biofilms. A series of assays—including crystal violet staining, colony-forming unit (CFU) enumeration, gene expression analysis, and confocal laser scanning microscopy—were performed to assess the effects of each treatment individually and in combination. The combined treatment resulted in significantly greater reductions in biofilm biomass and viable bacteria compared with either agent alone. Gene expression analysis revealed downregulation of key biofilm-associated genes (icaA, icaB, icaD, icaR, and clfA), suggesting interference with biofilm stability and maintenance. While formal synergy quantification was not conducted, the observed effects suggest a potentially synergistic or additive interaction between the two agents. These findings support the use of dual antiseptic strategies as a promising approach to biofilm eradication and highlight the potential clinical utility of dual antiseptic strategies. However, we underscore the need for further optimization and safety evaluation.

Zhou H, et al. Korean Circ J. 2024 Oct;55:e6. https://doi.org/10.4070/kcj.2024.0093

Staphylococcus aureus biofilms formed on titanium surfaces are highly relevant to orthopedic implant-associated infection and remain difficult to control after maturation. This study aimed to evaluate whether ultraviolet A (UVA, 365 nm) combined with cinnamaldehyde (CA) could improve antibiofilm activity against titanium-associated S. aureus biofilms in a stage-resolved in vitro model and to examine whether the observed responses were associated with reactive oxygen species (ROS). Early stage (8 h) and 24 h biofilm models were established on total hip arthroplasty (THA)-derived titanium discs. After condition screening, 0.5 mM CA combined with 5 min UVA exposure was selected for subsequent experiments. Biofilm biomass was assessed by crystal violet staining, bacterial viability by live/dead staining and colony-forming unit (CFU) enumeration, ROS-associated fluorescence by dihydroethidium (DHE) imaging, and biofilm-associated gene expression by quantitative real-time PCR (qRT-PCR). Chondrocyte viability was also evaluated under the selected antibiofilm-effective conditions. The combined treatment showed stage-dependent antibiofilm effects, with greater biomass reduction in the 8 h biofilm model and marked impairment of bacterial viability and culturability in both models. ROS-associated fluorescence increased under combined exposure and was partially attenuated by N-acetyl-L-cysteine (NAC) in the 24 h biofilm model. In parallel, CA + UVA was associated with lower expression levels of clfA, icaA, and icaD in the 8 h biofilm model and of icaA, icaB, and icaD in the 24 h biofilm model, with partial NAC attenuation in the latter. Chondrocyte viability was lower in all treatment groups than in the untreated control, although the combined treatment did not show an obvious additional decrease compared with the single-treatment groups. These findings indicate that UVA combined with CA exerts stage-dependent antibiofilm effects in an in vitro titanium-associated S. aureus biofilm model. The observed ROS-associated responses were consistent with, but do not establish, mechanistic involvement. The current treatment setting also requires further optimization before translational applicability can be more confidently considered.

Staphylococcus aureus, particularly its methicillin-resistant strains (MRSA), poses significant challenges in healthcare settings due to its propensity to form biofilms on various surfaces. These biofilms enhance bacterial survival and increase resistance to conventional treatments, complicating infection control efforts. This study investigates the efficacy of a novel approach combining povidone-iodine (PVP-I) and hydrogen peroxide (H₂O₂) to combat Staphylococcus aureus biofilm formation in hospital environments. A range of methodologies were employed, including biofilm formation assays, gene expression analysis, colony-forming unit (CFU) enumeration, and confocal microscopy, to assess the effects of PVP-I and H₂O₂, both individually and in combination. The results demonstrated a synergistic effect when these agents were combined, significantly reducing biofilm formation compared to the use of either compound alone. PVP-I, an io-dine-based antiseptic, and H₂O₂, a potent oxidizing agent, each exhibit potential in disrupting bacterial biofilms when used independently. However, their combined application appears to enhance penetration into the biofilm matrix and increase overall antimicrobial activity. These findings have important implications for infection control strategies in healthcare settings. By harnessing the complementary mechanisms of PVP-I and H₂O₂, this approach offers a promising solution for preventing and eradicating biofilm-associated infections on medical devices and hospital surfaces. Additionally, the use of two agents with different modes of action may help mitigate the risk of developing antimicrobial resistance. This study lays the groundwork for future research aimed at optimizing concentrations, application methods, and assessing the long-term efficacy and safety of this combined approach. Ultimately, this research contributes to improved patient outcomes and a reduction in the economic burden associated with biofilm-related complications.

Vascular calcification is an actively regulated process driven by vascular smooth muscle cell (VSMC) osteogenic reprogramming and promoted by oxidative stress and extracellular matrix remodeling. We investigated whether the novel histone deacetylase inhibitor YAK577 mitigates calcification by modulating an MMP14–NOX2/ROS-associated pathway in calcification medium (CM)-treated VSMCs and a vitamin D₃-induced arterial calcification model in 8-week-old male C57BL/6N mice. Calcification was assessed by Alizarin Red S/von Kossa staining and calcium quantification; osteogenic markers (BMP2, RUNX2, MSX2) and MMPs were examined by qRT-PCR and immunoblotting; intracellular ROS was measured by DHE staining with N-acetylcysteine as an antioxidant control; and MMP14 was manipulated by siRNA knockdown or plasmid overexpression. YAK577 was non-cytotoxic at effective concentrations and reduced CM-induced calcium deposition and osteogenic marker expression. YAK577 reduced MMP14 expression and suppressed CM-induced NOX2/p47phox activation and ROS accumulation, while GSK2795039 attenuated CM-induced DHE fluorescence. MMP14 silencing attenuated, whereas MMP14 overexpression enhanced, osteogenic signaling and increased NOX2. In vivo, YAK577 reduced vitamin D₃-induced aortic calcium burden, histological calcification, and the expression of MMP14, NOX2, and osteogenic markers. These data support a working model in which YAK577 alleviates vascular calcification, at least in part, by suppressing an MMP14-associated NOX2/p47phox–ROS axis.