Sodium hypochlorite (NaClO, SHC)/hypochlorous acid (HClO, HCA) wound irrigation solutions have experienced a renaissance in the prevention and treatment of low-level wound infections. They are attributed with lower cytotoxicity and have therefore gained increasing attention in daily clinical practice. To determine the cytotoxicity and antimicrobial efficacy of six NaClO/HClO wound irrigation solutions. For cytotoxicity evaluation (based on DIN EN 10993-5), human keratinocytes (HaCaT) and human skin fibroblasts (BJ) were used. Staphylococcus aureus and Pseudomonas aeruginosa were used for antimicrobial efficacy evaluation (based on DIN EN 13727). Solutions were evaluated after 1, 5 and 15 min of exposure. Additionally, physicochemical properties (pH and oxidation-reduction potential values) were investigated. Efficacy and cytotoxicity varied significantly between solutions. Generally, increasing antimicrobial activity was associated with decreasing cell viability. Furthermore, a concentration- and time-dependent impact on pathogens and cells was observed: cytotoxic and antimicrobial activity increased with rising NaClO/HClO solution concentrations and extended exposure times. Based on these in vitro evaluations, the following ranking (lowest to highest microbicidal effect and cytotoxic impact) was found: Microdacyn60® (SHC/HCA-M) < Granudacyn® (SHC/HCA-G) < Veriforte™ (SHC/HCA-V) < KerraSol™ (SHC-K) < Lavanox® (SHC-L) ≪ ActiMaris®forte (SHC/SM-A). The presented results indicate that microbicidal effects are almost always associated with certain negative side effects on cell proliferation. Efficacy and biocompatibility of NaClO/HClO solutions depend on their specific formulation and physicochemical properties. The investigations also underline the necessity for exact product- and application-specific efficacy profiles.

The antimicrobial activity of Cetylpyridinium chloride (CPC) and Miramistin (MST) solutions in different concentrations (5 x 10-5 to 0.4%) and a fleece, containing 0.15% CPC, were tested against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli after 30 minutes (solutions) and 60 minutes (fleece) of incubation, respectively. Furthermore, cytotoxic effects of CPC and MST were examined in human keratinocyte (HaCaT) and murine fibroblast (L929) cell lines.

In this study polyaminopropyl biguanide (PAPB) was compared to the molecularly closely related polyhexamethylene biguanide (PHMB) regarding chemical relationship, antiseptic efficacy and cytotoxicity in-vitro. Cytotoxicity for human keratinocytes (HaCaTs) and murine fibroblasts (L929) was determined according to ISO EN 10993-5 for both substances. Antimicrobial efficacy tests were performed via identification of the minimal bactericidal concentration (MBC), quantitative suspension method for substances and investigation of two PAPB or PHMB containing dressings against S. aureus, E. coli and P. aeruginosa, according to international standards. Prior, mass spectrometry was performed for chemical differentiation of the investigated substances. PHMB showed high toxicity even in low concentrations for both tested cell lines and a high antimicrobial efficacy against S. aureus and E. coli. In case of PAPB, no or only low cytotoxicity was detected after 72 h, while comparable antibacterial features are lacking, as PAPB showed no relevant antimicrobial effects. Even though chemically closely related, PAPB proved to be ineffective regarding bacterial eradication, whilst PHMB showed a high efficacy. Discovery and Establishment of safe and effective alternative antiseptics is an important issue for the treatment of infected wounds. Especially rising bacterial resistances for established agents as well as ongoing discussions of potential toxic or carcinogenic effects emphasize this necessity. Nevertheless, the presented results highlight that even small changes in chemical structure of related agents such as PHMB and PAPB can dramatically affect their efficacy and therefore need to be carefully distinguished and assessed side by side.

Biofilms pose a relevant factor for wound healing impairment in chronic wounds. With 78% of all chronic wounds being affected by biofilms, research in this area is of high priority, especially since data for evidence-based selection of appropriate antimicrobials and antiseptics is scarce. Therefore, the objective of this study was to evaluate the anti-biofilm efficacy of commercially available hypochlorous wound irrigation solutions compared to established antimicrobials. Using an innovative complex in-vitro human plasma biofilm model (hpBIOM), quantitative reduction of Pseudomonas aeruginosa, Staphylococcus aureus, and Methicillin-resistant S. aureus (MRSA) biofilms by three hypochlorous irrigation solutions [two <0.08% and one 0.2% sodium hypochlorite (NaClO)] was compared to a 0.04% polyhexanide (PHMB) irrigation solution and 0.1% octenidine-dihydrochloride/phenoxyethanol (OCT/PE). Efficacy was compared to a non-challenged planktonic approach, as well as with increased substance volume over a prolonged exposure (up to 72 h). Qualitative visualization of biofilms was performed by scanning electron microscopy (SEM). Both reference agents (OCT/PE and PHMB) induced significant biofilm reductions within 72 h, whereby high volume OCT/PE even managed complete eradication of P. aeruginosa and MRSA biofilms after 72 h. The tested hypochlorous wound irrigation solutions achieved no relevant penetration and eradication of biofilms despite increased volume and exposure. Only 0.2% NaClO managed a low reduction under prolonged exposure. The results demonstrate that low-dosed hypochlorous wound irrigation solutions are significantly less effective than PHMB-based irrigation solution and OCT/PE, thus unsuitable for biofilm eradication on their own. The used complex hpBIOM thereby mimics the highly challenging clinical wound micro-environment, providing a more profound base for future clinical translation.

Background: Chronic wounds, such as diabetic foot ulcers, venous leg ulcers, and post-surgical wound healing disorders pose a significant challenge due to prolonged healing, risk of infection, and impaired quality of life. Persistent inflammation and impaired tissue remodeling are common in these wounds. Traditional diagnostic methods, including visual inspection and microbiological cultures, offer limited insight into the wound micro-environment. Immunomarker profiling could provide a deeper understanding of the molecular mechanisms underpinning wound healing, offering potential biomarkers for infection status and healing progression. Methods: This observational, multi-center cohort study, part of the ‘Wound-BIOME’ project, analyzed 110 swab samples from patients with acute and chronic wounds using multiplex immunoassays. Clinical parameters such as wound type, healing status, regeneration stage, and microbial burden were recorded. Total protein concentration was assessed, and 35 key immunomarkers, including cytokines (e.g. IL- 1α, IL- 1β), chemokines (CCL2, CXCL8, CXCL10), growth factors (FGF- 2, VEGF) and matrix metalloproteinases (MMP- 7, MMP- 9, MMP- 13), were quantified. Statistical analyses were performed to correlate immunomarker levels with clinical outcomes. Results: Pro-inflammatory markers, such as IL- 1β, IL- 18 and chemokines like CCL2 and CXCL8, were significantly elevated in non-healing and infected wounds compared to healing wounds. The study identified two new immunomarker ratios – IL- 1β/IL- 1RA and CXCL8/CXCL10 – as potential predictors of wound healing status. The IL- 1β/IL- 1RA ratio showed the highest accuracy for distinguishing healing from non-healing wounds (AUC = 0.6837), while the CXCL8/CXCL10 ratio was most effective in identifying infection (AUC = 0.7669). Conclusions: Immunomarker profiling via wound swabbing offers valuable insights into the wound healing process. Elevated levels of pro-inflammatory cytokines and MMPs are associated with chronic inflammation and impaired healing. The IL- 1β/IL- 1RA and CXCL8/CXCL10 ratios emerge as promising biomarkers to distinguish between infection and inflammation, with potential in targeted wound care. Further studies are needed to validate these findings and implement them in clinical practice.

Due to demographical changes the number of elderly patients depending on oral anticoagulation is expected to rise. Prolonged bleeding times in case of traumatic injuries represent the drawback of these medications, not only in major trauma, but also in superficial wounds. Therefore, dressings capable of accelerating coagulation onset and shortening bleeding times are desirable for these patients. The hemostatic potential and physical properties of different types of superficial wound dressings (standard wound pad, two alginates, chitosan, collagen (Lyostypt®), oxidized cellulose, and QuikClot®) were assessed in vitro. For this purpose the clotting times of blood under the influence of the named hemostatics from healthy volunteers were compared with Marcumar® or ASS® treated patients. For that, a newly developed coagulation assay based on spectrophotometric extinction measurements of thrombin activity was used. The fastest coagulation onset was observed for oxidized cellulose (Ø 2.47 min), Lantor alginate-l (Ø 2.50 min) and QuikClot® (Ø 3.01 min). Chitosan (Ø 5.32 min) and the collagen Lyostypt® (Ø 7.59 min) induced clotting comparatively late. Regarding physical parameters, QuikClot® showed the lowest absorption capacity and speed while chitosan and both alginates achieved the highest. While oxidized cellulose displayed the best clotting times, unfortunately it also revealed low absorption capacity. All tested specimens seem to induce clotting independently from the administered type of oral anticoagulant, providing the possibility to neglect the disadvantage in clotting times arising from anticoagulation on a local basis. QuikClot®, oxidized cellulose and unexpectedly alginate-l were superior to chitosan and Lyostypt®. Due to its additional well-known positive effect on wound healing alginate-l should be considered for further investigations.