0.01% Hypochlorous Acid as an Alternative Skin Antiseptic: An In Vitro Comparison

C, Balcom P, Omole DO, Álvarez-Mejía C, López-Ramrez V, Gadgil A. Low-cost, local production of a safe and effective disinfectant for resource-constrained communities

Improved hygiene depends on the accessibility and availability of effective disinfectant solutions. These disinfectant solutions are unavailable to many communities worldwide due to resource limitations, among other constraints. Safe and effective chlorine-based disinfectants can be produced via simple electrolysis of salt water, providing a low-cost and reliable option for on-site, local production of disinfectant solutions to improve sanitation and hygiene. This study reports on a system (herein called "Electro-Clean") that can produce concentrated solutions of hypochlorous acid (HOCl) using readily available, low-cost materials. With just table salt, water, graphite welding rods, and a DC power supply, the Electro-Clean system can safely produce HOCl solutions (~1.5 liters) of up to 0.1% free chlorine (i.e.,1000 ppm) in less than two hours at low potential (5 V DC) and modest current (~5 A). Rigorous testing of free chlorine production and durability of the Electro-Clean system components, described here, has been verified to work in multiple locations around the world, including microbiological tests conducted in India and Mexico to confirm the biocidal efficacy of the Electro-Clean solution as a surface disinfectant. Cost estimates are provided for making HOCl locally with this method in the USA, India, and Mexico. Findings indicate that Electro-Clean is an affordable alternative to off-the-shelf commercial chlorinator systems in terms of first costs (or capital costs), and cost-competitive relative to the unit cost of the disinfectant produced. By minimizing dependence on supply chains and allowing for local production, the Electro-Clean system has the potential to improve public health by addressing the need for disinfectant solutions in resource-constrained communities.

Efficacy of hypochlorous acid as an alternative oral antimicrobial agent on human gingival fibroblasts, Aggregatibacter actinomycetemcomitans, and Candida albicans biofilms in vitro

This study compared the cytotoxicity and antimicrobial activity of hypochlorous acid (HOCl) at 50 ppm and 200 ppm and 0.2% chlorhexidine (CHX) at various time intervals, in vitro. Cell viability and cytotoxicity of human gingival fibroblasts (HGF) were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and the lactate dehydrogenase assay. Antimicrobial effects on Aggregatibacter actinomycetemcomitans and Candida albicans were determined using the time-kill method. All solutions exhibited a significant impact on HGFs in a dose- and time-dependent manner. 50 ppm HOCl demonstrated the highest cell viability, followed by 200 ppm HOCl. Both HOCl solutions were less cytotoxic to HGFs than 0.2% CHX. 50 ppm and 200 ppm HOCl demonstrated stronger efficiencies than CHX against A. actinomycetemcomitans and C. albicans. The data suggest that HOCl solutions have potential as an alternative antiseptic to CHX due to their lower cytotoxicity and superior antimicrobial activity, but optimal dosage of HOCl requires further investigations.

Ocular surface and glaucoma, a mutual relationship. Practical suggestions for classification and management

The chronic use of glaucoma medications could improve the development of an ocular comorbidity, the glaucoma therapy-related ocular surface disease. This could be related to the exposure of the conjunctiva to preservatives, but also active compounds such as prostaglandin analogues may improve the risk of ocular surface inflammation. Inflammation has a negative impact on tolerability and adherence to eyedrops and to the outcome of filtration surgery as well. A stratification of glaucoma patients based not only on visual field progression but also on glaucoma therapy-related ocular surface disease would be desirable for a strategic management. Early diagnosis, individualized treatment, and safe surgical management should be the hallmarks of glaucoma treatment. One of the main issues for the proper and successful management of patients is the right timing, effectiveness and safety for both medical and surgical treatment options leading to a precision medicine in glaucoma disease as the best modern treatment.

0.01% Hypochlorous Acid Treats Aspergillus fumigatus Keratitis in Rats by Reducing Fungal Load and Inhibiting the Inflammatory Response

Purpose

To investigate the antifungal and anti-inflammatory effects of 0.01% hypochlorous acid (HCLO) on rats with Aspergillus fumigatus keratitis.

Methods

The time-kill assay and broth microdilution procedures were used in vitro to demonstrate that 0.01% HCLO was fungicidal and fungistatic. The severity of the disease was evaluated in vivo using a clinical score and slit-lamp photographs. Fungal load, polymorphonuclear neutrophil infiltration, and the production of related proteins were determined using colony plate counting, in vivo confocal microscopy, periodic acid-Schiff staining, fungal fluorescence staining, immunofluorescence staining, myeloperoxidase assay, and Western blotting.

Result

In vitro, 0.01% HCLO can destroy A. fumigatus spores in 1 minute. The optical density of the 0.01% HCLO group was significantly lower than that of the phosphate-buffered saline control group (P < 0.01), and no visible mycelium was observed using a fluorescence microscope. 0.01% HCLO reduced the severity of A. fumigatus keratitis in rats by decreasing the clinical score, fungal loading (periodic acid-Schiff, plate count, and fungal fluorescence staining), and inhibiting neutrophil infiltration and activity (immunofluorescence staining and myeloperoxidase). Furthermore, the Western blot analysis revealed that 0.01% HCO decreased protein expression levels of tumor necrosis factor-α and IL-1β.

Conclusions

According to our findings, 0.01% HCLO can kill A. fumigatus spores in vitro. It has antifungal and anti-inflammatory effects on A. fumigatus keratitis in rats. It also inhibited A. fumigatus growth; decreased neutrophil infiltration, tumor necrosis factor-α, and IL-1β expression; and provided a potential treatment for fungal keratitis.

Translational Relevance

This study provides a potential treatment for fungal keratitis in the clinic.

Staphylococcus capitis: Review of Its Role in Infections and Outbreaks

In June 2021, a national incident team was formed due to an increased detection of Staphylococcus capitis in samples from hospitalised infants. Staphylococcus capitis has been known to cause outbreaks in neonatal units across the globe, but the extent of the UK spread was unclear. A literature review was undertaken to support case identification, clinical management and environmental infection control. A literature search was undertaken on multiple databases from inception to 24 May 2021, using keywords such as “Staphylococcus capitis”, “NRCS-A”, “S. capitis”, “neonate”, “newborn” and “neonatal intensive care unit” (NICU). After screening, 223 articles of relevance were included. Results show incidences of S. capitis outbreaks have frequently been associated with the outbreak clone (NRCS-A) and environmental sources. The NRCS-A harbours a multidrug resistance profile that includes resistance to beta-lactam antibiotics and aminoglycosides, with several papers noting resistance or heteroresistance to vancomycin. The NRCS-A clone also harbours a novel SCCmec-SCCcad/ars/cop composite island and increased vancomycin resistance. The S. capitis NRCS-A clone has been detected for decades, but the reasons for the potentially increased frequency are unclear, as are the most effective interventions to manage outbreaks associated with this clone. This supports the need for improvements in environmental control and decontamination strategies to prevent transmission.

Antimicrobial activity effects of electrolytically generated hypochlorous acid-treated pathogenic microorganisms by isothermal kinetic simulation

This study involves isothermal kinetic simulation to evaluate the parameters of inhibition conditions for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of high-risk pathogens. This is because the new type of the 2019 novel coronavirus (2019-nCoV) is continuously spreading and the importance of public health issues. Environmental disinfection and personal wearing of masks have become important epidemic prevention measures. Selection of concentration kinetics could be estimated best for E. coli and S. aureus of pathogens, 2.74 × 10⁴ and 10⁵ and 2.44 × 10⁴ and 10⁵ colony-forming units (CFU mL^-1), by isothermal micro-calorimeter (TAM Air) tests, respectively. Comparisons were made of different doses of 0-70 ppm (in 20 mL test ampoule) hypochlorous acid treatment for conducting nth-order and autocatalytic reaction simulation to evaluate the inhibition reaction parameters, which determined the autocatalytic kinetic model that was beneficially applied on the E. coli and S. aureus. We developed the inhibition reaction parameters of the pathogens, which included the activation energy (E _a), the natural logarithm of pre-exponential factor (lnk ₀), the enthalpy of inhibition microbial growth reaction (∆H), inhibition microbial growth, and the inhibition growth analysis. Overall, we conducted isothermal kinetic simulation to understand the antimicrobial activity effects of electrolytically generated hypochlorous acid-treated pathogenic microorganisms, which will provide reference for public health and medical-related fields for SDG3, and can contribute to ensuring human health and hygiene.

The antibacterial and antibiofilm activity of Granudacyn in vitro in a 3D collagen wound infection model

Objective:

It is widely agreed that infection and the formation of biofilms play a major role in increasing inflammation and delaying wound healing. The aim of this study was to evaluate, in vitro, the antimicrobial activity of the wound irrigation solution, Granudacyn (Mölnlycke Health Care AB, Sweden) against planktonic bacteria and mature biofilms of clinically relevant bacterial species.

Method:

Quantitative evaluation of bacterial numbers and confocal and/or scanning electron microscopy were used to evaluate the wound irrigation solution's antimicrobial/antibiofilm activity in standard laboratory conditions as well as in a three-dimensional (3D) collagen wound infection model.

Results:

The wound irrigation solution exhibited a rapid and strong antibacterial activity against both Gram-positive and Gram-negative strains isolated from infected wounds in planktonic form, with a reduction in bacterial number of >4 Logs after as little as one minute of treatment. The wound irrigation solution also exerted an evident activity against preformed biofilms of Pseudomonas aeruginosa and Staphylococcus aureus (>3 Log and >1 Log reduction in colony forming unit number, respectively, after 15 minutes of incubation). Although the wound irrigation solution was partially inhibited in the presence of simulated wound fluid, it maintained a marked antibiofilm activity in in vivo-like conditions (ie. in a 3D collagen wound infection model) with a strong killing and a mild debridement effect, which was superior to standard saline.

Conclusion:

The results obtained in this study suggest that although the wound irrigation solution used might be partially inhibited by wound exudate, it has the potential to effectively kill wound infecting planktonic as well as biofilm bacteria.

Comparison of hypochlorous acid and Povidone Iodine as a disinfectant in neonatal circumcision

INTRODUCTION

Neonatal circumcision is a procedure used worldwide which has very low rates of complication if conducted by a specialist. The present research aims to examine the wound healing effects of Hypochlorous Acid (HCOL) and Povidone Iodine (PI) used as a disinfectant prior to the procedure of circumcision and their antibacterial effectiveness.

MATERIAL AND METHOD

The findings of sixty infants subjected to neonatal circumcision at the Hisar Intercontinental Hospital between January 2021 and June 2021 were prospectively recorded. Based on the disinfectant used, the patients were divided into two group: Group 1 including 28 patients for whom HCOL was used as an antiseptic solution, and Group 2 including 32 patients to whom PI was administered.

RESULTS

Group 1 was formed of 28 patients while Group 2 included 32 patients. The mean ages of each group was 15.46 ± 10.58 (2-29) and 12.63 ± 10.00 (2-28) days, respectively. When the complications were examined individually, no significant difference was found between the groups. However, when all complications were analyzed collectively, it was determined that there was a significant difference, and the complication rate of Group 2 was greater (p = 0.037). In Group 2, the rate of edema and wound healing delay was significantly greater than that of Group 1 (p: 0.037 p: 0.036) (Table 1).

CONCLUSION

It was determined that HCOL is reliable to be used as a disinfectant prior to neonatal circumcision.

Acute inhalation toxicity of aerosolized electrochemically generated solution of sodium hypochlorite

OBJECTIVE

The objective was to determine the inhalation toxicity of the electrochemically generated sodium hypochlorite solution after its single administration to laboratory animals in the form of a highly dispersed aerosol.

MATERIALS AND METHODS

The study has been conducted according to the OECD Test Guideline №403 'Acute Inhalation Toxicity.' Laboratory animals were exposed to inhalation of an aerosol containing 1.7 ± 0.13 mg/m³ of active chlorine. The hematological and biochemical parameters of the blood of experimental animals have been determined, as well as specific parameters: the activity of cathepsins B and L, catalase, and α1-antitrypsin. Histological study of the lungs of animals has been carried out.

RESULTS

During inhalation and 14 days after it, no death of the animals was observed; the behavior, appearance, and weight gain did not differ from the control group. There were no significant deviations in hematological parameters, except the decrease in the level of platelets. The biochemical study showed slight changes in the activity of alkaline phosphatase and aspartate aminotransferase on the 1st day after inhalation; these parameters returned to normal within 14 days of observation. Specific biochemical parameters did not show the development of oxidative stress. No specific histological pathologies of lung tissue have been found.

CONCLUSIONS

Thus, the studied electrochemically generated sodium hypochlorite solution under single inhalation exposure in aerosol form practically does not cause a toxic effect. The data obtained allow classifying such solution to the 4th (or even 5th - after additional studies) class of toxicity in accordance with Globally Harmonized System of Classification and Labeling of Chemicals.

The High Impact of Staphylococcus aureus Biofilm Culture Medium on In Vitro Outcomes of Antimicrobial Activity of Wound Antiseptics and Antibiotic

The staphylococcal biofilm-based infections of wounds still pose a significant therapeutical challenge. Treated improperly, they increase the risk of limb amputation or even death of the patient. The present algorithms of infected wound treatment include, among others, the application of antiseptic substances. In vitro wound biofilm models are applied in order to scrutinize their activity. In the present work, using a spectrum of techniques, we showed how the change of a single variable (medium composition) in the standard in vitro model translates not only to shift in staphylococcal biofilm features but also to the change of efficacy of clinically applied wound antimicrobials such as octenidine, polyhexamethylene biguanide, chlorhexidine, hypochlorite solutions, and locally applied gentamycin. The data presented in this study may be of a pivotal nature, taking into consideration the fact that results of in vitro analyses are frequently used to propagate application of specific antimicrobials in hospitals and ambulatory care units.

Comparison of Skin Antiseptic Agents and the Role of 0.01% Hypochlorous Acid

BACKGROUND

Hypochlorous acid (HA) has both anti-microbial and wound-healing properties with a growing role for utilization in pre-procedural care on the face.

OBJECTIVES

The authors sought to compare the antiseptic property of 0.01% HA solution, 5% povidone iodine (PI), 4% chlorhexidine gluconate (CHG), and 70% isopropyl alcohol (IPA) antiseptic on facial skin.

METHODS

This was a prospective single-center clinical trial.

RESULTS

A total of 21 participants were recruited. Bacterial growth was seen in CHG (10%), IPA (71%), PI (81%), and HA (95%) of specimens (P < 0.001). CHG had less growth compared with HA (P = <0.001), IPA (P = <0.001), and PI (P = <0.001). No difference in bacterial growth was noted between HA and IPA (P = 0.063) or HA and PI (P = 0.25). Significant differences in mono-microbial and poly-microbial growth were seen between HA and IPA (P = 0.046) and HA and CHG (P = <0.001). Staphylococcus epidermidis grew less frequently in CHG (10%), followed by IPA (29%), PI (71%), and HA (71%). Staphylococcus capitis grew less frequently in CHG (0%), followed by PI (14%), HA (24%), and IPA (29%).

CONCLUSIONS

CHG reduced the bacterial growth compared with HA, PI, and IPA. However, HA, PI, and IPA had insignificant differences in bactericidal effects. Our study provides a supporting role of HA to be considered as an antiseptic.

LEVEL OF EVIDENCE: 2

Subcutaneous tissue disinfection significantly reduces Cutibacterium acnes burden in primary open shoulder surgery

BACKGROUND

Cutibacterium acnes is one of the major pathogens responsible for infection after shoulder surgery. Surgical dissection of the dermis may expose C acnes from sebum-producing hair follicles. Because of contact with the surgeon's gloves and instruments, further spread occurs throughout the surgical field. The purpose of this study was to determine whether subcutaneous tissue disinfection could reduce the C acnes culture rate in primary open shoulder surgery.

METHODS

All patients eligible for primary open shoulder surgery by a deltopectoral approach were prospectively enrolled in our 2-arm, randomized, single-blinded clinical trial. In all patients, a skin swab of the operative field was taken prior to standard surgical skin preparation. After exposure of the deltoid fascia, the disinfection group received an additional preparation of the subcutaneous layer with povidone-iodine solution. Once the proximal humerus was completely exposed, 5 swabs from different sites were taken for microbiological examination according to a strict specimen collection protocol. All cultures were incubated in aerobic and anaerobic conditions for 14 days.

RESULTS

Between February and December 2019, 108 patients were enrolled in the 2 groups: treatment (n = 70) and control (n = 38). The 2 groups did not show any significant difference in terms of sex, age, body mass index, or occurrence of diabetes. The subcutaneous disinfection protocol significantly reduced the positive culture rate of the operating field for all germs combined (P = .036) and specifically for C acnes (P = .013). The reduction of positive swabs for C acnes was significant for the surgeon's gloves (P = .041), as well as the retractors (P = .007).

CONCLUSION

Disinfection of the subcutaneous tissue significantly reduced the C acnes culture rate during primary open shoulder surgery. We highly recommend this simple step as an adjunct to the current surgical practice to limit iatrogenic contamination of the surgical field. Future studies may observe a reduction in postoperative shoulder infection owing to this practice.

Hypochlorous Acid 0.01% vs Povidone-Iodine 5% for Ocular Antisepsis

Purpose:

An alternative ocular antiseptic is needed for patients who do not tolerate povidone-iodine (PI). The purpose of this study is to compare the antimicrobial effect of hypochlorous acid (HA) 0.01% with PI 5% applied topically to the ocular surface.

Methods:

Swabs of the inferior conjunctiva and posterior lower eyelid margin of 40 patients were taken from both eyes and plated onto blood agar plates. One eye was treated with HA and the other with PI, and swabs were taken after 1-minute exposure. The eye treated with PI was rinsed with sterile saline and another swab was taken. Colony-forming units (CFUs) were recorded after 2 days. Patients rated the level of irritation after treatment in each eye.

Results:

HA and PI both gave significant reduction in CFUs from baseline ( P < .001 for HA and P = .002 for PI). The mean reduction in logCFU ± 95% CI was 0.850 ± 0.387 or greater for HA and 0.749 ± 0.385 or greater for PI; this was equivalent to a mean reduction of 7.1-fold or greater or 86% or greater (95% CI, 66%-94%) for HA and 5.6-fold or greater or 82% or greater (95% CI, 57%-93%) for PI. CFUs increased in 17 eyes after saline rinse. PI caused substantial irritation in 31 of the 40 participants, whereas no individuals had any irritation from topical HA.

Conclusions:

Both HA and PI were effective in reducing ocular bacterial load. Unlike PI, HA was not irritating to the eye. Saline rinse after topical PI may increase bacterial counts in some individuals.

In Vitro Efficacy of Bacterial Cellulose Dressings Chemisorbed with Antiseptics against Biofilm Formed by Pathogens Isolated from Chronic Wounds

Local administration of antiseptics is required to prevent and fight against biofilm-based infections of chronic wounds. One of the methods used for delivering antiseptics to infected wounds is the application of dressings chemisorbed with antimicrobials. Dressings made of bacterial cellulose (BC) display several features, making them suitable for such a purpose. This work aimed to compare the activity of commonly used antiseptic molecules: octenidine, polyhexanide, povidone-iodine, chlorhexidine, ethacridine lactate, and hypochlorous solutions and to evaluate their usefulness as active substances of BC dressings against 48 bacterial strains (8 species) and 6 yeast strains (1 species). A silver dressing was applied as a control material of proven antimicrobial activity. The methodology applied included the assessment of minimal inhibitory concentrations (MIC) and minimal biofilm eradication concentration (MBEC), the modified disc-diffusion method, and the modified antibiofilm dressing activity measurement (A.D.A.M.) method. While in 96-well plate-based methods (MIC and MBEC assessment), the highest antimicrobial activity was recorded for chlorhexidine, in the modified disc-diffusion method and in the modified A.D.A.M test, povidone-iodine performed the best. In an in vitro setting simulating chronic wound conditions, BC dressings chemisorbed with polyhexanide, octenidine, or povidone-iodine displayed a similar or even higher antibiofilm activity than the control dressing containing silver molecules. If translated into clinical conditions, the obtained results suggest high applicability of BC dressings chemisorbed with antiseptics to eradicate biofilm from chronic wounds.

Worldwide survey of Corynebacterium striatum increasingly associated with human invasive infections, nosocomial outbreak, and antimicrobial multidrug-resistance, 1976-2020

Corynebacterium striatum is part of microbiota of skin and nasal mucosa of humans and has been increasingly reported as the etiologic agent of community-acquired and nosocomial diseases. Antimicrobial multidrug-resistant (MDR) C. striatum strains have been increasingly related to various nosocomial diseases and/or outbreaks worldwide, including fatal invasive infections in immunosuppressed and immunocompetent patients. Although cases of infections by C. striatum still neglected in some countries, the improvement of microbiological techniques and studies led to the increase of survival of patients with C. striatum nosocomial infections at different levels of magnitude. Biofilm formation on abiotic surfaces contributes for the persistence of virulent C. striatum and dissemination of antimicrobial resistance in hospital environment. Besides that, empirical antibiotic therapy can select multi-resistant strains and transfer intra and interspecies genes horizontally. In this study, a worldwide survey of C. striatum human infections and nosocomial outbreaks was accomplished by the analysis of clinical–epidemiological and microbiological features of reported cases from varied countries, during a 44-year period (1976–2020).

Hypochlorous acid antiseptic washout improves patient comfort after intravitreal injection: A patient reported outcomes study

Purpose:

Current ocular antiseptic practice for intravitreal injection (IVI) employs 5% povidone–iodine (Betadine^®) drops which frequently cause ocular discomfort and prolonged irritation. In an effort to improve comfort while maintaining efficacy, we studied a hypochlorous acid (HOCL 0.01%) spray washout prior to injection.

Methods:

Patients had received a minimum of 3 IVIs prepared with Betadine^® antisepsis prior to entry in this study. Their subsequent IVIs were prepared with Betadine^® followed by HOCL 0.01% washout. Facets of comfort were measured by a Likert-scaled questionnaire to compare their experiences after IVI.

Results:

Thirty-seven participants were enrolled. Addition of HOCL 0.01% spray after Betadine^® reduced the duration of discomfort (P = 0.001) and need for artificial tears postinjection (P = 0.003). It improved their reported quality of life (P = 0.04) and sleep (P = 0.01). There were neither HOCL-related side effects nor endophthalmitis during this study.

Conclusion:

Topical HOCL 0.01% spray after topical Betadine^® antisepsis significantly improved patient comfort following IVIs.

In Vivo Comparison of Chlorine-Based Antiseptics versus Alcohol Antiseptic for Surgical Hand Antisepsis

Despite being commonly used as effective preparation for surgical hand antisepsis, alcohol solutions have major drawbacks, such as drying effect, emergence of hand eczema, and other diseases. This study aimed to demonstrate the effectiveness of sodium hypochlorite (NaOCl) and hydrogen peroxide (H₂O₂) as antiseptic in comparison to single sodium hypochlorite and 70% ethanol. In 5-day tests, the effects of 3 antiseptics were established according to standard test methods. The antiseptics were applied to the hands of 82 volunteers, and samples of bacteria were collected on days 1 and 5, immediately after drying and 6 hours later after antiseptic application. Student's t test and ANOVA were applied in a statistical study. The NaOCl with H₂O₂ composition demonstrated noninferiority to both sodium hypochlorite only and alcohol products and superiority to these antiseptics on day 5 (P < 0.05 at a significance level of 5% for each comparative trial in this day) at equivalence margin of 20%. The effectiveness of the NaOCl plus H₂O₂ composition as an antiseptic was explained by the formation of singlet oxygen in the system. Together, these data suggest that NaOCl and H₂O₂ may be an effective hand antisepsis that avoids the drawbacks seen with alcohol solutions.

Bactericidal and virucidal activity of ethanol and povidone-iodine

Ethanol and povidone‐iodine (PVP‐I) are important microbicides that inactivate bacteria and viruses. The present study provides a review of literature data on the concentration‐dependent bactericidal and virucidal activity of ethanol and PVP‐I in vitro. A systematic search was performed using the meta‐database for biomedicine PubMed. Eventually, 74 studies with original data on the reduction of bacterial and viral infectivity using in vitro tests were analyzed. A safe bactericidal effect of ethanol can be expected at concentrations between 60% and 85%, and the exposure times vary between ≤0.5 and ≥5 min. Within an exposure of up to 5 min, 80%–90% ethanol also exerts virucidal/low‐level activity, which includes its action against enveloped viruses plus adeno‐, noro‐, and rotaviruses. For PVP‐I, the best bactericidal and virucidal/high‐level effect is present at a concentration range of approx. 0.08%–0.9% depending on the free iodine concentration. The maximum exposure times are 5 min for bacteria and 60 min for viruses. The available data may help optimize the significant inactivation of bacteria and viruses in various areas. However, as the conditions in application practice can vary, concrete recommendations for the application can only be derived to a limited extent.

Hypochlorous acid-generating electrochemical scaffold eliminates Candida albicans biofilms

AIMS

Wound infections involving Candida albicans can be challenging to treat because of the fungus' ability to penetrate wound tissue and form biofilms. The goal of this study was to assess the activity of a hypochlorous acid (HOCl)-generating electrochemical scaffold (e-scaffold) against C. albicans biofilms in vitro and on porcine dermal explants (ex vivo).

METHODS AND RESULTS

C. albicans biofilms were grown either on acrylic-bottom six-well plates (in vitro) or on skin tissue excised from porcine ears (ex vivo), and the polarized e-scaffold was used to generate a continuous supply of low concentration HOCl near biofilm surfaces. C. albicans biofilms grown in vitro were reduced to undetectable amounts within 24 h of e-scaffold exposure, unlike control biofilms (5·28 ± 0·034 log₁₀  (CFU cm^{- 2} ); P < 0·0001). C. albicans biofilms grown on porcine dermal explants were also reduced to undetectable amounts in 24 h, unlike control explant biofilms (4·29 ± 0·057 log₁₀ (CFU cm^{- 2} ); P < 0·0001). There was a decrease in the number of viable mammalian cells (35·6 ± 6·4%) in uninfected porcine dermal explants exposed to continuous HOCl-generating e-scaffolds for 24 h compared to explants exposed to nonpolarized e-scaffolds (not generating HOCl) (P < 0·05).

CONCLUSIONS

Our HOCl-generating e-scaffold is a potential antifungal-free strategy to treat C. albicans biofilms in chronic wounds.

SIGNIFICANCE AND IMPACT OF THE STUDY

Wound infections caused by C. albicans are difficult to treat due to presence of biofilms in wound beds. Our HOCl producing e-scaffold provides a promising novel approach to treat wound infections caused by C. albicans.