Effect of Sodium Hypochlorite 0.05% on MMP-9 Extracellular Release in Chronic Wounds

BACKGROUND

In chronic wounds, high concentrations of matrix metalloproteinases (MMPs) can cause excessive proteolysis and slow wound healing. Consequently, restoring a proper MMP balance can help reduce the risk of a chronic wound. An antiseptic solution containing 0.05% sodium hypochlorite (Amukine Med 0.05%, Angelini S.p.A.; hereafter termed NaClO solution) is available on the market. The NaClO solution was proven effective and safe in managing infected skin wounds. To further characterize its activity, this study evaluated the in vitro activity of the NaClO solution on the monocyte release of MMPs.

METHODS

Human monocytic THP-1 (ATCC^® TIB-202™) cell lines were differentiated into macrophages and treated with different concentrations of NaClO (from 0.05% to 5 × 10^-7%). In addition, the THP-1 cell line was stimulated with wound fluid (WF) from patients with active venous leg ulcers in the inflammatory phase. The effect of NaClO (0.025-0.0062%) was also evaluated on healthy human peripheral blood serum samples. The effects of treatments on the gelatinolytic activity of MMP-9 were evaluated by gelatin zymography. The effects on MMPs release were evaluated through the Pro™ Human MMP 9-plex Assay. An exploratory scratch wound healing assay was also performed.

RESULTS

The NaClO solution reduced the gelatinolytic activity of MMP-9 and its activated form. The downregulation of MMP-9 gelatinolytic activity was also observed in peripheral blood serum. The MMPs profile showed a reduction in MMP-1 release (p < 0.05) and a slight reduction of the release of MMP-9 and MMP-12 after the treatment with LPS and the NaClO solution. A slight improvement in wound healing was observed after macrophage activation and treatment with the NaClO solution.

CONCLUSIONS

The results obtained suggest a possible ability of the NaClO solution to modulate the proteolytic pathways in the wound microenvironment, further characterizing its activity and use in clinical practice during wound care.

Effects of benzydamine and mouthwashes containing benzydamine on Candida albicans adhesion, biofilm formation, regrowth, and persistence

Objectives

To assess the effects of benzydamine and mouthwashes (MoWs) containing benzydamine on different stages of Candida albicans biofilm: adhesion, formation, persistence, and regrowth (if perturbed).

Materials and methods

C. albicans CA1398, carrying the bioluminescence ACT1p-gLUC59 fusion product, was employed. Fungal cells were exposed for 1′, 5′, or 15′ to 4 different benzydamine concentrations (0.075 to 0.6%) to 2 mouthwashes (MoWs) containing benzydamine and to a placebo MoW (without benzydamine). Treated cells were tested for adhesion (90 min) and biofilm formation (24-h assay). Next, 24- and 48-h-old biofilms were exposed to benzydamine and MoWs to assess regrowth and persistence, respectively. The effects of benzydamine, MoWs containing benzydamine, and placebo on different biofilm stages were quantified by bioluminescence assay and by the production of quorum sensing (QS) molecules.

Results

Benzydamine and MoWs containing benzydamine impaired C. albicans ability to adhere and form biofilm, counteracted C. albicans persistence and regrowth, and impaired a 48-h-old biofilm. Some of these effects paralleled with alterations in QS molecule secretion.

Conclusions

Our results show for the first time that benzydamine and MoWs containing benzydamine impair C. albicans capacity to form biofilm and counteract biofilm persistence and regrowth.

Clinical relevance

Benzydamine and MoWs containing benzydamine capacity to affect C. albicans biofilm provides an interesting tool to prevent and treat oral candidiasis. Likely, restraining C. albicans colonization through daily oral hygiene may counteract colonization and persistence by other critical oral pathogens, such as Streptococcus mutans, whose increased virulence has been linked to the presence of C. albicans biofilm.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04330-8.

Amuchina Gel Xgerm hand rub in vitro virucidal activity against SARS-CoV-2

Aim: Ethanol is highly effective at inactivating enveloped viruses, including SARS-CoV-2. The aim of this study is to evaluate the virucidal activity of Amuchina Gel Xgerm (74% ethanol) against SARS-CoV-2, according to the European Standard EN14476:2013+A2:2019. Materials & methods: Virucidal activity of the study product was evaluated against SARS-CoV-2 strain USAWA1/2020 in suspension, in the presence of 0.3 g/l of bovine serum albumin. Results: The log₁₀ reduction of SARS-CoV-2 in the presence of bovine serum albumin was ≥4.11 ± 0.12 after 30 s of exposure to the study product (80% dilution). Cytotoxicity was observed in the 10⁰ dilution, affecting the detection limit by 1 log₁₀. Conclusion: Virucidal activity against SARS-CoV-2 supports the effectiveness of this alcohol-based formulation as a prevention measure for COVID-19 illness.

A New Acid-oxidizing Solution: Assessment of Its Role on Methicillin-resistant Staphylococcus aureus (MRSA) Biofilm Morphological Changes

OBJECTIVE

Biofilms represent a key challenge in the treatment of chronic wounds, as they are among the main reasons for delays in chronic wound healing. This in vitro study was aimed at evaluating the activity of a new acid-oxidizing solution (AOS) on biofilm formation. Acid-oxidizing solution contains free chlorine species with stabilized hypochlorous acid in high concentration (> 95%) and is characterized by acidic (pH less than 3) and super-oxidizing (Redox greater than 1000mV) features.

MATERIALS AND METHODS

A 3-dimensional in vitro model of reconstructed human epidermis was used to compare the activity of AOS vs 2 reference products (RP) containing betaine and polyhexanide (RP1) and sodium hypochlorite and hypochlorous acid (RP2). Different approaches were used to assess the prevention and eradication of methicillin-resistant Staphyloccocus aureus biofilm by the study products. Xylitol and chlorhexidine were used as positive controls. The activity of the study products on the biofilm structure was evaluated analyzing the ultrastructural modification by scanning electron microscopy, while skin compatibility was assessed on noncolonized tissues measuring the metabolic activity of the cells.

RESULTS

In all experiments, AOS showed to be active on the biofilm matrix, modifying its structure and allowing bacterial release from the matrix. In all experiments, no cytotoxicity was observed in the tissues treated with the product suggesting a good compatibility of AOS with skin tissues. Reference product 1 affected the biofilm, suggesting a disruption effect; RP2 was slightly less active than AOS in modifying the biofilm structure.

CONCLUSION

Treatment with AOS affects biofilm by modifying its structure and therefore facilitating local bacteria accessibility to bactericidal agents, with consequent potential clinical benefits in the treatment of chronic wounds.