Can An Emerging Extracellular Matrix Help Treat Acute And Chronic Diabetic Wounds?
A myriad of products exists for the treatment of acute and chronic wounds. The primary goal with any of these products is rapid wound closure. Studies have shown that a lack of reduction in wound size at four weeks of treatment should prompt the provider to engage in advanced wound care modalities to accelerate the wound toward closure.1,2
Several advanced wound care products have established their efficacy through both scientific and anecdotal evidence.3 One of the newer products in the wound care arena is a naturally occurring, non-crosslinked, resorbable, acellular extracellular matrix derived from the lamina propria of porcine urinary bladder (MatriStem, ACell). One of the primary advantages of this product is its ability to generate “site specific” tissue instead of scar tissue to heal a wound. Unlike other wound care products, clinical indications for application include: partial and full thickness wounds, pressure ulcers, venous ulcers, diabetic ulcers, chronic vascular ulcers, surgical wounds and traumatic wounds. It has a two-year shelf life and is currently reimbursable in the surgical setting and certain federal facilities.
This product goes through a process of decellularization, lyophilisation, disinfection and terminal sterilization. It is available in both powder and sheet forms. The wound care sheets range in thickness from one to six layers. Both the powder and sheet forms contain: vascular endothelial growth factor; keratinocyte growth factor; transforming growth factor alpha and beta; bone morphogenetic protein 4; basic fibroblast growth factor; platelet-derived growth factor; insulin-like growth factor; epidermal growth factor; collagen type I, II, III and IV; lamin and elastin.4 Research has shown these growth factors possess antibacterial properties against Staphylococcus aureus and Escherichia coli via the release of antimicrobial peptides as the product degrades.5
The wound care sheets have two sides: an intact basement membrane that faces away from the wound bed and the opposite side, which one places in contact with the wound bed to promote integration of the product. The basement membrane side encourages epithelial and endothelial cell attachment, proliferation and differentiation. The side that comes in contact with the wound bed supports angiogenesis and integration of connective tissue.6 The powder form and single layer sheet do not require hydration. The thicker wound care sheets should be rehydrated for five to 10 minutes in normal saline or lactated Ringer’s solution depending on the amount of exudate from the wound.
Application to the wound bed requires proper wound bed preparation to form a healthy, bleeding, granular base. Apply the powder first and subsequently apply a wound care sheet. The thicker sheets are best for application in the operating room while single sheets are more conducive to application in a clinical setting. There is no proper orientation for application of a single layer wound care sheet on the wound bed. The thicker wound care sheets have a notch that needs to be in the upper right-hand corner to ensure proper application with the basement membrane facing away from the wound bed. Then cover the product with a non-adherent layer like Vaseline impregnated gauze.
The wound care sheets take four to 10 days for incorporation with the rate of resorption being dependent upon the thickness of wound care sheet. As the sheets resorb, they create a green to yellow or tan-colored film, and an odor. Do not remove this film as this is the normal course of resorption of the product. One should consider other secondary clinical signs of infection apart from appearance and odor of the wound to assess for the potential for infection. These signs include increased drainage, increased pain, induration, fluctuance or creptius about the periwound tissue. Another application of the product should occur when there is no more of the product or film from product resorption visible in the wound bed.