Hypochlorous Acid: An Ideal Wound Care Agent With Powerful Microbicidal, Antibiofilm, and Wound Healing Potency

Serhan Sakarya, MD; Necati Gunay, MS; Meltem Karakulak, MS; Barcin Ozturk, MD; Bulent Ertugrul, MD

Disclosures

Wounds. 2014;26(12):342-350. 

In This Article

Results

Minimal Bactericidal Concentration and Time Kill

Minimum bactericidal concentration of HOCl for all standard microorganisms was 1/64 dilution and for clinical isolates ranged from 1/32 to 1/64 dilutions (Table 1). All the microorganisms were killed within 0 minutes. The accurate killing time of HOCl on green fluorescent protein (GFP) expressing P. aeruginosa was 12 seconds (Figure 1).

Figure 1.

Screen capture of a video microscopic image of the time kill of green fluorescent protein-transfected P. aeruginosa with 1/32 dilution of stabilized HOCl solution at 1, 6, and 12 seconds.

Antibiofilm and Bactericidal Effects of Hypochlorous Acid Within Biofilm

The treatment of microorganisms with stable HOCl solution decreased the amount of biofilm, and the amount of microorganisms within the biofilm with the dose-dependent manner depending on species.

Although the effective concentration of the stable HOCl solution was varied between species, microbial killing rates within the biofilm was relevant to the biofilm impairment concentrations for each species. The effective dose of HOCl on biofilm impairment of S. aureus, P.aeruginosa, and C. albicans was 1/32, 1/16, and 1 dilution, respectively. The microbicidal effects within biofilm and antibiofilm concentration was the same for each of the microorganisms. These data showed HOCl has antibiofilm activity and actively penetrated through the biofilm and killed the microorganism within the biofilm (Figure 2).

Figure 2.

Antibiofilm and microbicidal effect within biofilm of stabilized hypochlorous acid (HOCl) solution on S. aureus (A, A1), P. aeruginosa (B, B1), and C. albicans (C, C1).
*Significantly decreased in stabilized HOCl solution-treated microorganism biofilim compared to the media control at P < 0.05.

The Effect of Povidone Iodine and Stabilized Hypochlorous Acid Solution on the Skin Fibroblast and Human Skin Keratinocyte Cell Line Migration in Wound Healing Assay

Since antiseptic solutions have harmful effects on wound healing, the authors compared the effects of povidone iodine and stabilized HOCl on the injury-induced migratory response. Migration in wound healing assay with povidone iodine-treated skin fibroblast cells was disrupted and cells detached from the matrix in all concentrations and times. Contrastly, stabilized HOCl solution treatment migration was decreased in high concentrations (1/2 and 1/4 dilution), but increased in low concentrations when compared to the media control (Figures 3 and 4). In human skin keratinocyte cells, povidone iodine treatment decreased migration after 4 hours. Migration with a stabilized HOCl solution was the same when compared to the media control at 4 and 8 hours at all concentrations, but increased at 1/16 and 1/32 dilution at 24 hours (Figures 5 and 6). The 10-minute treatment results were the same as the long term treatment results (data not shown). These results suggest that a stabilized HOCl solution enhances wound healing in contrast to povidone iodine.

Figure 3.

Effect of stabilized hypochlorous acid (HOCl) solution treatment on skin fibroblast cell migration in a wounding healing assay. Skin fibroblast cells were cultured to confluence, and a single wound was made across each monolayer. At 0, 4, 8, and 24 hours, images of each monolayer were captured and cell migration into the wound after 4, 8, and 24 hours was compared to the monolayer at 0 hours.
*Significantly decreased in stabilized HOCl solution treated skin fibroblast cells migration compared to the media control at P < 0.05.

Figure 4.

Images of wounded skin fibroblast cell monolayer with 1/32 dilution of povidone iodine and hypochlorous acid solution at 24 hours. Dotted lines indicate wound boundaries at 0 hours. h: hours

Figure 5.

Effect of stabilized hypochlorous acid (HOCl) solution and povidone iodine treatment on human skin keratinocyte cell migration in a wound healing assay. Human skin keratinocyte cells were cultured to confluence, and a single wound was made across each monolayer. At 0, 4, 8, and 24 hours, images of each monolayer were captured and cell migration into the wound after 4, 8, and 24 hours was compared to the monolayer at 0 hours.
*Significantly decreased in povidone iodine treated human skin keratinoyte cell migration; ** Significantly increased in stabilized HOCl solution compared to the media control at P < 0.05.

Figure 6.

Images of wounded human skin keratinoyte monolayer with 1/32 dilution of povidone iodine and hypochlorous acid at 24 hours. Dotted lines indicate wound boundaries at 0 hours. h: hours

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