A Closer Look At The Efficacy Of Bioengineered Alternative Tissues For DFUs
Advantages of this product are a long shelf life, immediate availability, ease of application, a relatively low cost in comparison to other bioengineered alternative tissues and similar composition and organization to the native dermis. Some drawbacks include risk of rejection secondary to retained cell remnants and the temporary nature of the product as it will incorporate within the wound or desiccate by three weeks.
With the advent of Oasis, there were questions regarding the persistence and efficacy of growth factors when preserved within a complex matrix for a prolonged period of time. In 2005, Hodde and co-workers investigated the long-term bioactivity of endogenous fibroblast growth factor (FGF-2) in the Oasis wound matrix.13 They found that the product retained its bioactivity when the unstable growth factors were bound within their natural extracellular matrix. Measurement with enzyme-linked immunosorbent assay revealed that the FGF-2 content ranged from 15.3 ng/g to 84.3 ng/g and caused differentiation of cells in culture.
Mostow and colleagues evaluated the efficacy of Oasis for full-thickness chronic venous leg ulcerations.14 In a randomized clinical trial involving 120 patients, they noted that 55 percent experienced complete wound closure with Oasis and compression dressings while only 34 percent healed with compression therapy alone. Additionally, none of the patients treated with Oasis developed a recurrent ulcer by six months.
In a prospective, randomized, controlled multicenter trial, Niezgoda and colleagues compared 12-week healing rates of diabetic ulcers that received either Oasis or becaplermin (Regranex Gel, Healthpoint Biotherapeutics).15 The incidence of complete healing was 49 percent (18/37) for the Oasis group and 28 percent (10/36) for the becaplermin group. Although the difference was not statistically significant due to a small sample size, the study did show that Oasis wound matrix was as effective as Regranex in healing full-thickness diabetic foot ulcers.
Can Graftjacket Have An Impact For DFUs?
Another “bioactive adjunct” is Graftjacket, a bioengineered alternative tissue manufactured from allogenic cadaveric skin that one can apply to both superficial and deep wounds in which tendon and bone are exposed. Like Oasis, this product is acellular and devoid of an epidermis. Processed via glycerol sterilization, Graftjacket retains the natural basket weave pattern of the dermis and contains components of the native papillary side of the basement membrane. These features are believed to promote fibroblast infiltration, ultimately enabling these cells to deposit neodermis in proper orientation. Inherent to the basement membrane are laminin and collagen IV that also aid with wound healing by improving keratinocyte adherence and differentiation.16 Cryogenically stored, this product has an extended shelf life of two years.
As Brigido reported in his 2006 randomized, controlled, prospective study involving 28 patients with chronic diabetic ulcers, one application may result in a significant reduction in wound surface area and depth in comparison to wound gel.17