Study Results Show Positive Effects of an Enzymatic Hydrogel on Third-degree Burn Wounds

In this study, the investigators determined that an enzymatic hydrogel solution (EHS) has the ability to enhance healing and reduce bacterial loads in a porcine model.

A burn wound can cause total loss of skin surfaces, resulting in infection and delayed wound healing. Patients can experience high levels of pain when undergoing debridement of the necrotic tissue in the burn wound; enzymatic debridement is a commonly used form that may cause the patient less pain. Considering this, Professor Davis and colleagues presented a study on the antibacterial and healing effects of EHS in lab-created third-degree burn wounds in poster format at the Symposium on Advanced Wound Care Spring | Wound Healing Society meeting (April 7-10, 2022).

Due to its similarities with human skin, the authors chose to use swine as the experimental model. The third-degree burn wounds were created using a branding iron set at 300°C and applied to the skin for 15 seconds. The burn wound measured 27 mm in diameter and 3 mm in depth in the paravertebral and thoracic areas. Thirty minutes after wounding, the swine were allocated to 4 groups with 6 wounds each. The treatment regimen consisted of treating wounds daily with 1 mL of their respective treatment and covered with dressing gauze petroleum jelly and sterile gauze. The microbiology assessment included serial dilutions and quantified using Spiral Plater System. Total bacteria counts were determined based on tryptic soy agar with 5% sheep blood and incubated at 37°C ± 2°C for 24 hours. Colony forming units were calculated per gram. Three wounds were recovered on days 3 and 8 after wounding and initial treatment application. The 6-mm biopsies were weighed and homogenized with an all-purpose neutralizing agent. For histology assessment, there were 3 incisional biopsies from the center of each wound were performed at each assessment day. A dermatopathology specialist blinded to the specimens evaluated them for percent of wound epithelialization, granulation tissue formation, and new blood vessel formation.

The results of this study indicate that the untreated control group had the highest bacterial load on both assessment days compared with the other treatment groups. The EHS concentration x50 group showed the lowest bacterial counts at 7.86 ± .04 log CFU/g—a bacterial reduction of 80.50% when compared with the untreated control group on day 3. At evaluation on day 8, both EHS groups (concentration x5 and x50) had the lowest bacterial counts, with EHS x50 yielding a bacterial reduction of 89.93% when compared with the untreated control group. Histologic analysis showed EHS-treated wounds had the highest percentage (56.3%) on day 8. None of the wounds scored higher than a 2 for granulation tissue. Of the groups, EHS concentration x5 reached the highest score at 1.5. Scores were identical in the EHS concentration x50 and vehicle solution groups. On day 8, the wounds in all groups showed mild angiogenesis scores of 2.3, but the EHS concentration x5 group showed a score of 2.5.

From this study, wounds allocated to the EHS concentration x50 group showed a higher total bacteria count reduction compared with the other treatment and control groups. Both EHS concentration groups showed increased epithelialization (percentage) compared with the control groups, but EHS concentration x5 had the highest percentage of epithelialization and granulation tissue scores. To substantiate the findings, the authors noted that additional animals are needed. –Jaclyn Gaydos, Sr. Managing Editor

Recommended Citation:
Solis M, Gil J, Higa A, et al. The effects of an enzymatic hydrogel on 3rd degree burn wounds in a porcine model. Poster presented at: Symposium on Advanced Wound Care Spring | Wound Healing Society; April 6-10, 2022.