Moist Wound Healing with Commonly Available Dressings

Abstract

Significance: A moist wound environment has several benefits that result in faster and better quality of healing. It facilitates autolytic debridement, reduces pain, reduces scarring, activates collagen synthesis, facilitates and promotes keratinocyte migration over the wound surface, and supports the presence and function of nutrients, growth factors, and other soluble mediators in the wound microenvironment. Recent Advances: Wound dressings can be utilized to create, maintain, and control a moist environment for healing. Moist wound dressings can be divided into films, foams, hydrocolloids, hydrogels, and alginates. We are also including negative pressure wound therapy systems in the moist dressings. Critical Issues: An optimal wound dressing should provide a moist environment and have an optimal water vapor transmission rate (WVTR) and absorptive capacity. It should also protect the wound against trauma and contamination and be easy to apply, painless to remove, and esthetically acceptable or even pleasing. Future Directions: Interventions, particularly dressing changes, by medical caregivers are labor intensive and expensive and there should be a continuous effort to reduce their number per week. Smart dressings with integrated microsensors and delivery capabilities that would allow wireless real-time monitoring and treatment of the wound would be very advantageous. This way the state of the wound as well as the wear time of the dressing could be assessed without dressing removal or visit to the wound care center. In addition, an ability to adjust the WVTRs to the exudate level of the wound (or having a large absorptive capacity without changing the WVTR) would be useful. This feature would guarantee an optimal level of hydration of the wound surface throughout the treatment.

Keywords: absorptive capacity; antimicrobials; moist wound dressings; moist wound healing; negative pressure wound therapy; water vapor transmission rate; wear time.

Kristo Nuutila, MSc, PhD

Figure 1.

Several studies have also shown that if a moist wound environment is established soon after injury, it decreases tissue loss and burn wound progression. Grolman et al. treated deep partial-thickness porcine burn wounds with an agarose hydrogel. Histological analysis of the burns on day 4 postburn showed that a topical application of agarose hydrogel immediately after the burn reduced the depth of tissue necrosis in comparison to control treatments. The burn depth in agarose hydrogel-treated and gauze-treated burns was 227 and 358 μm, respectively. Thus, it was concluded that immediate establishment of a moist environment and maintenance for 4 days reduced the amount of tissue necrosis by almost 40%. This picture is modified from Grolman et al. ****p < 0.0001.

Figure 2.

Optimizing the wound microenvironment is essential for healing. Several factors such as temperature, pressure (positive or negative), hydration, gases (oxygen supply and CO₂), pH, microbial content, and antimicrobial treatment affect the healing outcome. Wound dressings can be utilized to create, maintain, and control a moist environment for healing. In addition, NPWT is commonly used to accelerate the healing process. The WVTR of a wound dressing is significant because it directly regulates and adjusts the moisture level of the wound. The lower the WVTR of the dressing, the smaller the water loss, and the higher the WVTR of the dressing, the bigger the water loss. Another very important property of a wound dressing is its capacity to absorb fluid, which should match the amount of fluid the wound is producing to avoid accumulation of exudate or dehydration. NPWT, negative pressure wound therapy; WVTR, water vapor transmission rate.

Figure 3.

Moist wound dressings can be divided into films, foams, hydrocolloid dressings, hydrogels, alginate dressings, and NPWT dressings. Examples of different moist dressing types that are on the market.