Leaf-Derived Vascular Scaffolds (LeaVS): A multifunctional platform for skin regeneration

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Each year, 3 - 4 million people in the United States require treatment for traumatic injuries, venous ulcers, and pressure sores. Current solutions, including autologous skin grafts and bioengineered skin substitutes, have shown limited success due to an inability to overcome critical limitations including prolonged revascularization rates, impaired tissue ingrowth and delayed reepithelialization at the wound site. As such, there remains a significant unmet need to develop implantable dermal scaffolds that contain vascular networks to promote rapid vascularization, downregulate inflammation and maximize functional skin regeneration. Our laboratory developed a novel decellularized leaf-derived vascular scaffold (LeaVS) with pre-existing hierarchical networks of branched, perfusable channels that remain patent and perfusable. These biocompatible scaffolds can be functionalized to support growth of a contiguous layers of keratinocytes with characteristic cobblestone morphology and progressive epithelial stratification, as well as fibroblast attachment and proliferation. From these observations, we hypothesize that LeaVS can be engineered to enhance the rate of graft neovascularization and improve the rate of pro-regenerative endothelial, dermal and epithelial tissue formation in a full thickness wound model. To systemically test our hypothesis, we propose the following specific aims: In our first aim, we will functionalize LeaVS and we will determine surface chemistries that maximize endothelialization and vascular budding within LeaVS. Then, we will investigate the LeaVS endothelialization strategy that maximizes the rate of epithelialization and neodermal formation on the scaffolds. In our second aim, we will modulate the inflammatory responses to decellularized leaf scaffolds by selectively removing extravascular elements from the LeaVS. Partially digested scaffolds will be cultured with neutrophils and macrophages to assess the LeaVS degradation strategy that minimizes inflammatory responses. In our final aim, we will determine the synergistic roles of LeaVS vascular network and inflammatory modulation on maximizing the regeneration of functional vascularized skin tissue in a full thickness wound in a small animal model. We anticipate that the results of this study will provide the first in vivo data demonstrating that functionalized LeaVS improve the rate of functional skin regeneration and scar reduction for the treatment of skin injures. Our innovative approach describes the first efforts to create a tissue engineered skin substitute on functionalized leaf-based vascular scaffolds (LeaVS). The findings from this study will enable the future development of an implantable, plant-derived scaffold to facilitate the rapid regeneration of injury skin tissue and to enable to a new standard of care for the treatment of traumatic wounds, venous ulcers and pressure sores.