Safety of Human Adipose Stromal Vascular Fraction Cells Isolated with a Closed System Device in an Immunocompetent Murine Pressure Ulcer Model

Pressure ulcers (PUs) result in part due to ischemia-reperfusion injury to the skin and present frequently in elderly or quadriplegic patients with reduced mobility. Despite the high economic and societal cost of this condition, PU therapy relies primarily on preventive strategies and invasive surgical intervention. A growing body of clinical literature suggests that localized injection of adipose-derived cells can accelerate and enhance the closure of PUs. The current study systematically evaluated the safety of human adipose stromal vascular fraction (SVF) cells isolated using a closed system device when injected into a murine PU injury model. The human SVF cells were characterized by colony-forming unit-fibroblast and differentiation assays before use. Young (2 months) immunocompetent C57BL/6 mice subjected to a magnet-induced ischemia-reperfusion injury were injected subcutaneously with human SVF cells at increasing doses (0.25-2 million cells). The size of the PU was monitored over a 20-day period. Both female and male mice tolerated the concentration-dependent injection of the SVF cells without complications. While male mice trended toward more rapid wound closure rates in response to lower SVF cell concentrations (0.25-0.5 million cells), female mice responded favorably to higher SVF cell concentrations (1-2 million cells); however, outcomes did not reach statistical significance in either sex. Overall, the study demonstrates that human SVF cells prepared with a closed system device designed for use at point of care can be safely administered for PU therapy in an immunocompetent host animal model.