The ideal environment for wound healing is one that is clean, insulated, protected from further trauma and, very importantly, moist. While moist wound healing is beneficial, an excessively damp wound environment, where the exudate is allowed to pool for example, is not ideal. This can potentially lead to maceration of the periwound. Macerated skin is vulnerable to breakdown, potentially leading to an increase in wound size, delaying the healing process. Moist wound healing is therefore a fine balancing act between avoiding maceration, while simultaneously maintaining sufficient levels of tissue hydration.
The advantages of moist wound healing have been documented extensively and the widely reported benefits include:1
In today’s one-size-fits-all world, choosing an ideal wound dressing material can be difficult. It is not enough for a dressing to only maintain optimal moisture levels in the wound, ideally dressings need to:
An ideal dressing should allow the wound to “breathe” and prevent the wound from drying out while simultaneously allowing for the exchange of gases, particularly oxygen, CO2 and water vapour which are essential for wound healing.
Occlusive dressings, like impermeable hydrogels, films and foams excel in the controlling the local wound environment’s exposure to pathogens. However, this occlusive nature can come at a disadvantage for both the wound and then of course the patient. When occlusive dressings are used on highly exuding wounds, they may lead to further complications such as periwound maceration and additional skin damage, resulting in an increased risk of infection.
An extract from a blog by Laurie Swezey titled: “Moisture-Associated Skin Damage: Prevention Strategies for Periwound Skin” sums it up perfectly:2
“There is both an art and a science to choosing the correct wound dressing, one that will maintain just the right amount of moisture in the wound bed without allowing the periwound to become macerated.”
Typical woven or non-woven textile based dressings are able to absorb large amounts of exudate while simultaneously possessing a high water vapor transmission rate (WVTR). This rapid WVTR can lead to the excessive loss of moisture from the wound’s micro-environment and could cause the wound to dry out if not managed appropriately.
Gauze dressings have large pores and are typically highly permeable. These large pores result in open access to the wound bed for bacteria and viruses from the external environment, and can leave the wound susceptible to further infection.
The possibility of combining an occlusive dressing with a gauze or a sponge is not an ideal solution. Semi-permeable film dressings, although able to allow for gases to pass through while maintaining a barrier to pathogens, are rarely capable of absorbing much moisture.3
Electrospun fiber materials are ideally suited for advanced wound care. What sets it apart from conventional dressing materials, is the ease of incorporating functionalities into the framework of electrospun fiber. A combination of physical, chemical and mechanical properties allow these materials to curb bacterial colonization and infection, and can simultaneously manage controlled drug release from the porous electrospun framework. Furthermore, electrospun fiber materials’ high surface area and porosity afford these materials the potential to maintain ideal moisture levels while simultaneously allowing gases to pass through unhindered.
Properties of electrospun fiber materials that make them ideal for dressings in advanced wound care are:
Having the benefit of design flexibility allows for the tailoring of the WVTRs of electrospun fibers by modifying the fiber diameter, web density and polymer type.A hydrophilic fiber forming material, coupled with the inherent property of having a high surface area to volume ratio, makes it possible for these materials to absorb large amounts of exudate. Traditional films, although great barriers to infection, only allow for minimal water absorption. By contrast, electrospun fiber materials can absorb water in the range of 18-213 wt%7 with upwards of 2000 wt%8 being reported for highly absorbing polymers.If the fiber forming material is hydrophobic, the exudate can pass straight through, thereby allowing the exudate to be absorbed by a secondary dressing intended to assist with exudate control. This potentially allows the number of primary dressing changes to be minimized.
Through expert design, electrospun fiber dressings have the potential to be an all-encompassing solution for wound healing, specifically when it comes to wounds where moisture control is important. By tailoring electrospun fiber materials to specific functions, these materials can reduce the guesswork associated with wound dressing selection, assisting wound care practitioners by handling virtually all aspects of wound care.
Lastly, I leave you with a quote from Dr. Eugene Smit (PhD) – CEO, SNC:
“It is exactly this kind of art vs. science aspect of wound care that needs to be fixed to turn wound care into wound cure. We need to design dressings that do it right, no uncertainty.”
In future posts we will delve deeper into the individual aspects of electrospun fiber materials as wound dressings. Please feel free to send us a request if you would like specific topics covered in the use of electrospun fiber materials as dressings for advanced wound care.