Topical Administration of Allogeneic Mesenchymal Stem Cells Seeded in a Collagen Scaffold Augments Wound Healing and Increases Angiogenesis in the Diabetic Rabbit Ulcer

There is a critical clinical need to develop therapies for non-healing diabetic foot ulcers. Topically applied mesenchymal stromal cells (MSCs) provide a novel treatment to augment diabetic wound healing. A central pathological factor in nonhealing diabetic ulcers is an impaired blood supply. It was hypothesized that topically applied allogeneic MSCs would improve wound healing by augmenting angiogenesis. Allogeneic non-diabetic bone-marrow derived MSCs were seeded in a collagen scaffold. The cells were applied to a full thickness cutaneous wound in the alloxaninduced diabetic rabbit ear ulcer model in a dose escalation fashion. Percentage wound closure and angiogenesis at 1 week was assessed using wound tracings and stereology respectively. The topical application of 1,000,000 MSCs on a collagen scaffold demonstrated increased percentage wound closure when compared to lower doses. The collagen and collagen seeded with MSCs treatments result in increased angiogenesis when compared to untreated wounds. An improvement in wound healing as assessed by percentage wound closure was observed only at the highest cell dose. This cell-based therapy provides a novel therapeutic strategy for increasing wound closure and augmenting angiogenesis which is a central patho-physiological deficit in the non-healing diabetic foot ulcer. Page 2 of 36 Diabetes