Alice Li

Treatment Strategy for Composite Tissue Limb Trauma

A majority of all fractures in current US armed conflicts are open fractures, in which a soft tissue injury is sustained along with the bone fracture.  Even with gold standard treatment, in which muscle flaps are used to cover bony defects, patients often do not regain normal function of their extremity, highlighting the necessity for tissue engineering strategies for this complex clinical problem. Due to a substantial amount of tissue damage and debridement treatment in composite injuries, a large volume of cells and extracellular matrix (ECM) proteins that are necessary for tissue healing are removed from the body. In the replacement of large volumes of tissue, nutrient transfer necessitates a vascular supply to maintain the viability of delivered cells. The objective of this project was to examine the regenerative potential of engineered matrix constructs and stem cells on composite bone & muscle defects. We hypothesized that stem cells delivered on engineered matrix constructs into the muscle defect will aid in muscle regeneration and promote bone healing, ultimately resulting in superior functional limb recovery. These studies established multiple preclinical platforms for testing tissue engineering strategies as well as models that can be used to gain insights on the healing of VML and composite VML/bone defects. From some of the insights gained on the vascularization of the defect sites, a vascular treatment strategy was tested within these platforms and shown to have varying results in the treatment of complex multi-tissue injuries.