Browsing by Author "McGilvray, Kirk, advisor"

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Embargo
Backyard to battlefield: multifunctional medical foam for enhanced wound management
(Colorado State University. Libraries, 2025) Stoner, Amelia, author; McGilvray, Kirk, advisor; Wong, Sing-Wan, committee member; Pezzanite, Lynn, committee member
Acute open wounds as a result of traumatic injuries are a prevalent issue for civilians and military personnel across the world. Unfortunately, advanced hospital care for these severe injuries is not always readily available, leaving the morbidity and mortality outcomes of people who suffer these injuries to rely on primary wound care, hopefully applied before it is too late. A complete understanding of traumatic injury's effect on the body remains elusive. However, known complications include hemorrhage and infection of wounds if not treated quickly and effectively. Many primary wound care products exist, but few can perform more than one function. For example, packing a wound with gauze can help stop bleeding, but will not do anything to combat infection. Thus, this work sought to generate a multifunctional therapeutic approach to primary wound care that includes bleeding (tranexamic acid) and infection (vancomycin) control agents delivered through a biopolymer carboxymethyl cellulose foam. This non-solidifying, volume-filling foam was hypothesized to improve the quality of care for those who sustain open wounds from traumatic injuries, especially those who are injured in rural or austere environments without immediate access to advanced care. This work is comprised of four aims that will contribute to the field of emergency wound care. The first aim included generating and characterizing the base foam responsible for delivering selected bleeding and infection control therapeutics topically to the wound. 200% tunability in temporal stability and volumetric expansion was demonstrated, indicating precise control over physical properties. The second aim was to evaluate the in vitro safety of the foam through monolayer live/dead staining of fibroblasts, one of the most prevalent cell types in skin. The foam and its constituents were found to be non-cytotoxic to both murine and human fibroblasts in vitro, indicating base-level safety of the material and potential for successful in vivo experimentation. The third aim focused on in vitro/ex vivo efficacy evaluation of antifibrinolytic and hemostatic properties of the foam on ovine blood with the chosen bleeding control therapeutic. Delivery with the foam demonstrated low clot lysis rates and mechanically robust blood clot rheology compared to other treatment formulations, indicating potential for successful in vivo experimentation in future work. The fourth and final aim evaluated the foam's in vitro/ex vivo antibiotic efficacy on methicillin-resistant Staphylococcus aureus with the selected infection control therapeutic. Delivery with the foam demonstrated 3-4 log bacterial killing of methicillin-resistant Staphylococcus aureus, indicating potential for successful in vivo experimentation in future work. Together, these aims provide novel preliminary data crucial to the product development process and in vivo implementation of the foam as a staple of primary wound care in acute open traumatic injuries.
Open Access
Development of a finite element model of supracondylar fractures stabilized with variable stiffness bone plates
(Colorado State University. Libraries, 2019) Sutherland, Conor J., author; Puttlitz, Christian M., advisor; McGilvray, Kirk, advisor; Easley, Jeremiah, committee member; James, Susan, committee member
Approximately 10% of orthopaedic fracture fixation cases lead to non-union, requiring surgical intervention. Inadequate fixation device stiffness, which causes unwanted fracture gap motion, is believed to be one of the largest factor in poor healing as it prevents ideal tissue proliferation in the callus. By altering the thickness of orthopaedic bone plates, it was theorized that the fracture gap micro-mechanics could be controlled and driven towards conditions that accommodate good healing. The first goal of the project was to create computational FEA models of an ovine femoral supracondylar fracture stabilized with a plate of varying thickness. The models were used to investigate the mechanical behavior of the plate and the callus under different physiological loading conditions. The second goal of this study was to validate the computational model with bench-top experiments using an ex-vivo ovine femoral fracture model. To achieve these goals, novel plates were designed and manufactured with different stiffnesses (100%, 85%, and 66% relative stiffness) to be used to treat a femoral supracondylar fracture model in ovine test subjects; both in-vivo and ex-vivo. The FE models were shown to accurately predict the stress/strain mechanics on both bone and plate surfaces. Micromechanics (strain and pressure) predictions in the fracture gap were reported and used to make tissue type proliferation predictions based on previously reported mechanics envelopes corresponding to bone remodeling. The results indicated that changing plate thickness successfully altered the construct stiffness and consequently, the predicted healing tissue type at the fracture site. The FE methods described could help improve patient specific fracture care and reduce non-union rates clinically. However, further in vivo testing is required to validate the clinical significance of the methods described in this thesis.
Open Access
Development of novel mechanical diagnostic techniques for early prediction of bone fracture healing outcome
(Colorado State University. Libraries, 2021) Wolynski, Jakob G., author; McGilvray, Kirk, advisor; Puttlitz, Christian, advisor; Heyliger, Paul, committee member; James, Susan, committee member; Wang, Zhijie, committee member
To view the abstract, please see the full text of the document.
Embargo
From the ovine to human rotator cuff; tenocyte as to MSC derived exosomes for tendon healing
(Colorado State University. Libraries, 2024) von Stade, Devin P., author; Regan, Daniel, advisor; McGilvray, Kirk, advisor; Santangelo, Kelly, committee member; Hollinshead, Fiona, committee member
Tendinopathies comprise one of the most widespread and economically significant diseases in developed nations. The societal value of rotator cuff tear surgical intervention alone has been estimated at greater than 3.4 billion US dollars despite frequent repair failures (30-79%). This drives great interest in adjunct therapies; however, research is complicated by a limited understanding of the underlying pathogenesis. Recent data suggests that the primary driver is cell-to-cell communication during the acute and chronic stages of rotator cuff tears. Most notably, the paracrine signaling of macrophages, which are preferentially recruited earlier and persist longer than other immune cells, may direct the structural function of injured tendons. Extracellular vesicles (EVs) are the primary contributors to the paracrine signaling responsible for many successful cell therapy studies. Investigations into mesenchymal stromal cell (MSC) derived EVs have served as a launching point toward this end, however, cell origin can dramatically change the effect of EVs on target cells. To explore the effects of exosomes as a function of cell source on tendon healing, we have developed in vitro models in human and ovine cell lines to test the effects of tissue native, tenocyte derived EVs as they compare to MSC derived EVs on key effectors of rotator cuff tears, tenocytes and macrophages. The goal of this work is to (a) describe the direct effect of EV education, as a function of cell source, MSC vs tenocyte, on macrophage gene regulation and cytokine production and tenocyte bioactivity; (b) to then assess the indirect effects of such EV educated macrophages on tenocyte bioactivity. (c) Additionally, the underlying pathogenesis of tendinopathy and the animal models of rotator cuff tears we use will be explored and further defined in the context of contemporary histologic and biomechanical methods.
Open Access
Teaching model for human eye movement: a multidisciplinary senior design project
(Colorado State University. Libraries, 2025) Zito, Michael, author; McGilvray, Kirk, advisor; Brennan-Pierce, Ellen, committee member
This thesis documents the development of an anatomically accurate teaching model demonstrating human ocular movement. The year-long senior design project, sponsored by Colorado State University, was conducted under the guidance of Dr. Leslie Stone-Roy (Neuroscience) and Dr. Kirk McGilvray (Biomedical and Mechanical Engineering). The model effectively represents the human eyes, oculomotor musculature, and the associated neuronal pathways responsible for eye movement. The project allows for the demonstration of both functional and impaired neural pathways via LED sequencing as well as the respective motor functions for each respective path. Development of the project progressed through multiple design evaluations, prototyping iterations, and testing methods. The final project serves as an educational resource for undergraduate neuroscience curriculum at Colorado State University. This project helped to develop personal engineering skills and principles while also creating an impactful educational tool to enhance the comprehension of complex neuroanatomical concepts.