Nicole Natarelli, BA ¹ , Yvonne Nong, MS ^2,3,4 , Jessica Maloh, ND ^2,3 , Raja Sivamani, MD, MS, AP ^{2,3,5,6 a}

¹ Morsani College of Medicine, University of South Florida, Tampa, Florida, 2 Pacific Skin Institute, Sacramento, CA, 3 Zen Dermatology, Sacramento,

CA, ⁴ Michigan State University College of Human Medicine, Flint, Michigan, 5 Department of Dermatology, University of California-Davis, Sacramento,

CA , ⁶ College of Medicine, California Northstate University, Elk Grove, CA

Keywords: hypochlorous acid, integrative dermatology, wound healing, scar management, infection, atopic dermatitis, pruritus

Relevance

Hypochlorous acid (HClO) is a weak acid and powerful oxidant traditionally used as an active ingredient in various sanitizers and disinfectants. HClO is produced endogenously from activated leukocytes, and it was first exogenously synthesized in 1834, later to be used medicinally as a wound disinfectant during World War I and II.

Objective

In this review, we aim to review the literature assessing the efficacy and safety of dermatologic uses of topical hypochlorous acid.

Methods

A PubMed search for articles with the following keywords was performed: “hypochlorous acid” AND “dermatology” OR “dermis” OR “dermal.” Forty-one reports were included in the efficacy and safety analysis.

Results

Hypochlorous acid exhibits antimicrobial properties and has been demonstrated to promote re-epithelialization in wound healing with low cytotoxicity to keratinocytes and fibroblasts. Recent work has highlighted its anti-inflammatory properties via modulation of the NF-kβ signaling pathway and downregulation of inflammatory cytokines; reports have discussed its application for the management of various inflammatory skin conditions including atopic dermatitis and psoriasis.

Conclusion

Dermatologic application of hypochlorous acid includes infection prevention, wound care and scar management, inflammatory modulation, treatment in atopic dermatitis and pruritus. Emerging research has discussed potential applications in acne vulgaris, seborrheic dermatitis, and tumor suppression.

Le´o-Paul Tricou,^1–3 Marie-Lynn Al-Hawat,¹ Katia Cherifi,¹ Gabriela Manrique,¹ Benjamin R. Freedman,^4,* and Simon Matoori^1,*

¹Faculte´ de Pharmacie, Universite´ de Montre´al, Montre´al, Canada.

²ISPB Faculte´ de Pharmacie, Universite´ Claude Bernard Lyon 1, Lyon, France.

³Chemical Engineering Department, Polytechnique Montreal, Montre´al, Canada.

⁴Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston,

Massachusetts, USA.

Significance: Chronic diabetic wounds on the lower extremities (diabetic foot ulcers, DFU) are one of the most prevalent and life-threatening complications of diabetes, responsible for significant loss of quality of life and cost to the health care system. Available pharmacologic treatments fail to achieve com plete healing in many patients. Recent studies and investigational treatments have highlighted the potential of modulating wound pH in DFU.

Recent Advances: Data from in vitro, preclinical, and clinical studies highlight the role of pH in the pathophysiology of DFU, and topical administration of pH-lowering agents have shown promise as a therapeutic strategy for diabetic wounds. In this critical review, we describe the role of pH in DFU patho-physiology and present selected low-molecular-weight and hydrogel-based pH-modulating systems for wound healing and infection control in diabetic.

Critical Issues: The molecular mechanisms leading to pH alterations in diabetic wounds are complex and may differ between in vitro models, animal models of diabetes, and the human pathophysiology. Wound pH-lowering bandages for DFU therapy must be tested in established animal models of diabetic wound healing and patients with diabetes to establish a comprehensive benefit-risk profile.

Future Directions: As our understanding of the role of pH in the pathophysiology of diabetic wounds is deepening, new treatments for this therapeutic target are being developed and will be tested in preclinical and clinical studies. These therapeutic systems will establish a target product profile for pH-lowering treatments such as an optimal pH profile for each wound healing stage. Thus, controlling wound bed pH could become a powerful tool to accelerate chronic diabetic wound healing.

Keywords: pH management, diabetic wound healing, diabetes, pH-lowering strategies, pH modulation, acidic wound dressings

H.Guan¹,M.Nuth¹, S.R. Weiss², A. Fausto², Y. Liu³, H. Koo³, M.S. Wolff⁴ , and R.P. Ricciardi^1,5

Abstract

The COVID-19 pandemic has escalated the risk of SARS-CoV-2 transmission in the dental practice, especially as droplet-aerosol particles are generated by high-speed instruments. This has heightened awareness of other orally transmitted viruses, including influenza and herpes simplex virus 1 (HSV1), which are capable of threatening life and impairing health. While current disinfection procedures commonly use surface wipe-downs to reduce viral transmission, they are not fully effective. Consequently, this provides the opportunity for a spectrum of emitted viruses to reside airborne for hours and upon surfaces for days. The objective of this study was to develop an experimental platform to identify a safe and effective virucide with the ability to rapidly destroy oral viruses transported within droplets and aerosols. Our test method employed mixing viruses and virucides in a fine-mist bottle atomizer to mimic the generation of oral droplet-aerosols. The results revealed that human betacoronavirus OC43 (related to SARS-CoV-2), human influenza virus (H1N1), and HSV1 from atomizer-produced droplet-aerosols were each fully destroyed by only 100 ppm of hypochlorous acid (HOCl) within 30 s, which was the shortest time point of exposure to the virucide. Importantly, 100 ppm HOCl introduced into the oral cavity is known to be safe for humans. In conclusion, this frontline approach establishes the potential of using 100 ppm HOCl in waterlines to continuously irrigate the oral cavity during dental procedures to expeditiously destroy harmful viruses transmitted within aerosols and droplets to protect practitioners, staff, and other patients.

Keywords: virucide, saliva, infection, high-speed instruments, waterlines, prevention

Tingting Yin¹ , Qiaowen Li² , Huan Sun³ , Jin Zheng⁴ , Yuanyuan Wang⁵ , Yi Luo6 and Li Wang^7*

Abstract

Background This work intended to assess the disinfection efficacy of hypochlorous acid (HA) and silver nanoparticles (AgNP) disinfectants in disinfecting the dental unit waterlines (DUWL) during comprehensive oral treatment and explore their potential applications in the oral medical environment. Methods: Firstly, AgNP solution was prepared and evaluated through X-ray diffraction (XRD), field emission transmission electron microscope (FE-TEM), and stability tests. Subsequently, 15 dental units were selected and randomly assigned to three groups, each receiving a different disinfection method. Specifically, one group (5 units) received HA disinfectant (HA group), one group (5 units) received AgNP disinfectant (AgNP group), and another group (5 units) received a combination of HA and AgNP disinfectant (HA+AgNP group). Bacterial counts before and after disinfection were compared and analyzed at four sites on the dental units: high-speed handpiece tubing, mouthwash, ultrasonic scaler, and three-way syringe.

Results The growth of biofilm on the waterlines was observed using scanning electron microscopy (SEM) and laser confocal microscopy (LCM). The results indicated that AgNP solution was successfully prepared and demonstrated excellent stability. There was no significant difference in the average weekly number of patients treated across the three groups (P>0.05). After disinfection, bacterial counts were significantly reduced in all groups. Compared to the HA and AgNP groups, the HA+AgNP group exhibited a markedly lower bacterial count, with statistical significance (P<0.05). The compliance rates observed during the first disinfection and two weeks post-disinfection were slightly lower in the HA and AgNP groups compared to the HA+AgNP group, although no significant statistical difference was found (P>0.05). SEM images revealed uneven biofilm plaques on the inner surface of the pipes prior to disinfection, embedded within a dense matrix, while the biofilm was visibly disrupted post-disinfection. LCM software analysis showed that, compared to the HA and AgNP groups, the HA+AgNP group had a significantly lower percentage of live bacteria on the biofilm post-disinfection (P<0.05).

Conclusion Compared to any single disinfectant regimen, the combined use of HA and AgNPs effectively inhibited bacterial growth and exerted a significant destructive effect on biofilms. Therefore, this combination is expected to be a viable option for disinfection of DUWL in the oral healthcare setting.

Clinical trial number Not applicable.

Keywords Dentistry, Therapeutics, Waterline disinfectant, Hypochlorous acid, Silver nanoparticles