Treatment of Venous Leg Ulcers with a Bioengineered Living Cell Construct Reactivates the Acute Wound Healing Response

Chronic non-healing venous leg ulcers (VLUs) are a widespread debilitating disease with high morbidity and associated costs, as approximately $15 billion annually are spent on the care of VLUs. Despite their socioeconomic burden, there is a paucity of novel treatments targeted towards healing VLUs, which can be attributed to both lack of pathophysiologic insight into VLU development as well as lack of knowledge regarding biologic actions of VLU-targeted therapies. Currently, the bioengineered bilayered living cellular construct (BLCC) skin substitute is the only FDA-approved biologic treatment for healing VLUs. To elucidate the mechanisms through which the BLCC promotes healing of chronic VLUs, we conducted a clinical trial (NCT01327937) in which patients with non-healing VLUs were treated with either standard care (compression therapy) or with BLCC together with standard care. Tissue was collected from the VLU edge before and 1 week after treatment, and samples underwent comprehensive microarray, mRNA and protein analyses. Ulcers treated with BLCC skin substitute displayed three distinct patterns suggesting the mechanisms by which BLCC shifted a non-healing into a healing tissue response: it modulated inflammatory and growth factor signaling; it activated keratinocytes; and it attenuated Wnt/-catenin signaling. In these ways, BLCC application orchestrated a shift of the chronic non-healing ulcer microenvironment into a distinctive healing milieu resembling that of an acute, healing wound. Our findings also provide first patient-derived in vivo evidence of specific biologic processes that can be targeted in the design of therapies to promote healing of chronic VLUs.

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Stone RC, Stojadinovic O, Rosa AM, Ramirez HA, Badiavas E, Blumenberg M, Tomic-Canic M