Topical Negative Pressure Stimulates Endothelial Migration and Proliferation : A Suggested Mechanism for Improved Integration of Integra

Topical negative pressure is an effective technique to promote wound healing and the integration of skin graft and synthetic dermal equivalents. We describe an in vitro model to investigate the effect of negative pressure on angiogenesis, a pivotal step. Dermal fibroblasts or human microvascular endothelial cells were cultured on Integra and subjected to intermittent or continuous negative pressure. At fixed intervals of over 120 hours, the Integra was fixed and assessed for cell migration (microscopy), cell viability (MTS assay), and cell proliferation (Ki67 immunostaining). Under control conditions, endothelial cells formed a monolayer and failed to ingress, whereas fibroblasts migrated throughout the Integra within 24 hours. Negative pressure switches endothelial cell to a migratory and proliferative phenotype. Ingress is greatest with intermittent rather than continuous negative pressure. It has no effect on dermal fibroblast function. This study identifies an important, potential pro-angiogenic mechanism by which topical negative pressure promotes wound healing.