Engineering Commons^™

Analyzing Heat Generated From Electro-Osmotic Flow Utilizing Computational Fluid Dynamics, Jordan Elizabeth Grothe

Honors Thesis

Without extensive vascularization, the transfer of fluid and nutrients through human tissue is limited to diffusion and weak interstitial flow. Electroosmosis, or the flow of fluid driven by an electrical field, has become a promising solution. Scientists have begun applying electricity to human tissue to promote stronger interstitial flow; however, optimization of this process has proven to be a challenge due to ohmic heating. Cells function within a small range of temperatures and exposure to voltages exceeding the threshold will cause cells to degrade and die prematurely. This research seeks to better understand and quantify the range of voltage where …

Development Of A 3d Printed Conductive Biopolymer For Cardiac Tissue Engineering, Britanny Lizeth Stark

Open Access Theses & Dissertations

Cardiovascular disease (CVD) is the leading cause of death in the US, with approximately 859,000 deaths each year. The major contributor to CVD is Acute Myocardial Infarction (AMI), which causes the death of approximately 25% of the cardiomyocytes present in the left ventricle of the heart. After AMI, the adult human heart has a very limited regenerative capacity. Moreover, the electrical propagation of the myocardium is severely disrupted, making the heart more susceptible to failure and patient death. However, current pharmacological treatments do not address the loss of cardiomyocytes and the disruption of electrical propagation in the heart. Tissue engineering …

Fatigue Behaviour Of Load-Bearing Polymeric Bone Scaffolds: A Review, Hamed Bakhtiari, Alireza Nouri, Mehrdad Khakbiz, Majid Tolouei-Rad

Research outputs 2022 to 2026

Bone scaffolds play a crucial role in bone tissue engineering by providing mechanical support for the growth of new tissue while enduring static and fatigue loads. Although polymers possess favourable characteristics such as adjustable degradation rate, tissue-compatible stiffness, ease of fabrication, and low toxicity, their relatively low mechanical strength has limited their use in load-bearing applications. While numerous studies have focused on assessing the static strength of polymeric scaffolds, little research has been conducted on their fatigue properties. The current review presents a comprehensive study on the fatigue behaviour of polymeric bone scaffolds. The fatigue failure in polymeric scaffolds is …

Optimizing Channel Formation In Peg Maleimide Hydrogels, Bakthavachalam Kannadasan

Masters Theses

Blood vessels including the arteries, veins, and capillaries are a critical and indispensable component of various organisms. Some studies estimate that if all the blood vessels present in our body are arranged in line, they would amount to a total length of approximately 60,000 miles. This distance is enough to circle the world two and a half times! In addition to being all pervasive, blood vessels perform certain key functions such as delivery of oxygen and nutrients to various tissues in the body. They also assist in the spread of diseases such as cancer. Therefore, it is important to study …

Correlative Imaging Of Three-Dimensional Cell Culture On Opaque Bioscaffolds For Tissue Engineering Applications, Mone’T Sawyer, Josh Eixenberger, Olivia Nielson, Jacob Manzi, Cadré Francis, Raquel Montenegro-Brown, Harish Subbaraman, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Three-dimensional (3D) tissue engineering (TE) is a prospective treatment that can be used to restore or replace damaged musculoskeletal tissues, such as articular cartilage. However, current challenges in TE include identifying materials that are biocompatible and have properties that closely match the mechanical properties and cellular microenvironment of the target tissue. Visualization and analysis of potential 3D porous scaffolds as well as the associated cell growth and proliferation characteristics present additional problems. This is particularly challenging for opaque scaffolds using standard optical imaging techniques. Here, we use graphene foam (GF) as a 3D porous biocompatible substrate, which is scalable, reproducible, …

In Vitro And In Vivo Diabetic Models For Assessment Of Tissue Engineered Vascular Grafts, Juan Carlos Carrillo Garcia

All Dissertations

Diabetes has become one of the leading causes of lower-limb loss worldwide. Every 30 seconds, a person loses a limb due to diabetic-related vascular complications. About one-third of patients needing lower-limb bypass surgery have debilitated autologous vessels unsuitable for use, and no other good long-term options are available. These detrimental effects on the vasculature are caused mainly by the hyperglycemic and hyperlipidemic conditions derived from diabetes. Under these conditions, an increase in advanced glycation end products (AGEs) and reactive oxygen species leads to irreversible crosslinks of extracellular matrix proteins, accelerating vascular pathology through vascular stiffening, endothelial dysfunction, inflammation, atherosclerosis, fibrosis, …

Editorial: Intervertebral Disc Degeneration And Osteoarthritis: Mechanisms Of Disease And Functional Repair., Graciosa Q Teixeira, Jana Riegger, Raquel M Gonçalves, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

No abstract provided.

Structure-Property-Processing Analysis Of Graphene Bioscaffolds For Viability And Differentiation Of C2c12 Cells, Lynn Karriem

Boise State University Theses and Dissertations

We investigated the structure – property – processing correlation of graphene bioscaffolds produced using three different methods. Bioscaffolds were prepared by chemical vapor deposition (CVD), sublimation of Silicon Carbide (SiC), and printed solvent assisted exfoliated graphene ink. To gain insight into the roughness and topography of graphene, AFM was performed on each bioscaffold. Raman spectroscopy mapping demonstrated differences in the I_2D/I_G ratio for each scaffold. Young’s modulus was determined by nanoindentation and indicated that epitaxial graphene had the highest average stiffness, followed by CVD, with printed graphene demonstrating the lowest average stiffness. To investigate the biocompatibility of …

Mechanical Properties And Morphological Alterations In Fiber-Based Scaffolds Affecting Tissue Engineering Outcomes, James Dolgin, Samerender Nagam Hanumantharao, Stephen Farias, Carl G. Simon, Smitha Rao

Michigan Tech Publications

Electrospinning is a versatile tool used to produce highly customizable nonwoven nanofiber mats of various fiber diameters, pore sizes, and alignment. It is possible to create electrospun mats from synthetic polymers, biobased polymers, and combinations thereof. The post-processing of the end products can occur in many ways, such as cross-linking, enzyme linking, and thermal curing, to achieve enhanced chemical and physical properties. Such multi-factor tunability is very promising in applications such as tissue engineering, 3D organs/organoids, and cell differentiation. While the established methods involve the use of soluble small molecules, growth factors, stereolithography, and micro-patterning, electrospinning involves an inexpensive, labor …

Recent Advances In Centrifugal Spinning And Their Applications In Tissue Engineering, Shaik Merkatur Hakim Marjuban, Musfira Rahman, Syeda Sharmin Duza, Mohammad Boshir Ahmed, Dinesh K. Patel, Md Saifur Rahman, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Over the last decade, researchers have investigated the potential of nano and microfiber scaffolds to promote wound healing, tissue regeneration, and skin protection. The centrifugal spinning technique is favored over others due to its relatively straightforward mechanism for producing large quantities of fiber. Many polymeric materials have yet to be investigated in search of those with multifunctional properties that would make them attractive in tissue applications. This literature presents the fundamental process of fiber generation, and the effects of fabrication parameters (machine, solution) on the morphologies such as fiber diameter, distribution, alignment, porous features, and mechanical properties. Additionally, a brief …

Development Of A Cell-Based Regenerative Strategy To Modulate Angiogenesis And Inflammation In Ischemic Muscle, Fiona E. Serack

Electronic Thesis and Dissertation Repository

The delivery of human adipose-derived stromal cells (hASCs) to ischemic tissues represents a promising strategy to promote vascular regeneration for patients with critical limb ischemia (CLI). This thesis focused on the evaluation of hydrogels to enhance the retention and pro-angiogenic capacity of hASCs following delivery in vivo. Additionally, priming strategies to augment the paracrine function of hASCs were developed and assessed.

Recognizing the importance of endogenous macrophages in the pro-regenerative function of hASCs, delivery using a previously-developed hydrogel system, composed of peptide-functionalized methacrylated glycol chitosan (MGC-RGD) and a copolymer of poly(ethylene glycol) and poly(trimethylene carbonate) (PEG(PTMC-A)₂), was …

Fibroblast-Generated Extracellular Matrix Guides Anastomosis During Wound Healing In An Engineered Lymphatic Skin Flap, Alvis Chiu, Wenkai Jia, Yumeng Sun, Jeremy Goldman, Feng Zhao

Michigan Tech Publications

A healthy lymphatic system is required to return excess interstitial fluid back to the venous circulation. However, up to 49% of breast cancer survivors eventually develop breast cancer-related lymphedema due to lymphatic injuries from lymph node dissections or biopsies performed to treat cancer. While early-stage lymphedema can be ameliorated by manual lymph drainage, no cure exists for late-stage lymphedema when lymph vessels become completely dysfunctional. A viable late-stage treatment is the autotransplantation of functional lymphatic vessels. Here we report on a novel engineered lymphatic flap that may eventually replace the skin flaps used in vascularized lymph vessel transfers. The engineered …

Investigation Of Dynamic Culture On Matrix-Derived Microcarriers As A Strategy To Modulate The Pro-Regenerative Phenotype Of Human Adipose-Derived Stromal Cells, Mckenna R. Tosh

Electronic Thesis and Dissertation Repository

Pre-conditioning of adipose-derived stromal cells (ASCs) by tuning the cellular microenvironment during expansion has the potential to modulate their pro-regenerative functionality. The current study investigated the effects of microcarrier composition (decellularized adipose tissue versus collagen), oxygen tension (2% versus ~20% O₂) and stirring rate (static, 20, 40 rpm) on human ASCs cultured within spinner flask bioreactors. Dynamic culturing under 20% O₂ resulted in more consistent cell growth on both microcarrier substrates, leading to increases in microcarrier contraction and stiffness. Culturing on the microcarriers modulated the hASC immunophenotype, with varying CD90 and CD26 expression levels observed under the …

Finite Element Analysis Of 3d-Printed Pcl Scaffolds, Ireolu K. Orenuga, Joao Soares, Phillip D. Glass, Daeha Joung Ph.D.

Undergraduate Research Posters

Finite Element Analysis of 3D-printed PCL Scaffolds for Synergizing Cellular Micro-Environment and Mechanical Stimuli to Enhance Engineered Tissue Growth in Vitro

Ireolu Orenuga,1 Phillip Glass,2 Daeha Joung,2 Joao S. Soares1

1. Department of Mechanical and Nuclear Engineering, College of Engineering, Virginia Commonwealth University
2. Department of Physics, College of Humanities & Sciences, Virginia Commonwealth University

Introduction: Tissue engineering aims to create viable and functional engineered tissues via biodegradable scaffolds and autologous cells. Scaffolds play an essential part in organizing the architecture of developing tissues and aid in the proper function of implants acutely by serving as mechanical support and long-term by …

Renal Proximal Tubule Tissue Chips For Disease Modeling And Drug Toxicity Testing, Leslie Donoghue

All ETDs from UAB

The current pathway for drug discovery is associated with costs of $2.55 billion and between 10-15 years of development for a single drug to reach the market. The challenges in predicting drug toxicities and efficacies are attributed to inherent species differences in drug-metabolizing enzyme activities and cell-type-specific sensitivities to toxicants. Organs-on-a-chip are an emerging technology in disease modeling and screening therapeutics to address discrepancies between animal models and human clinical trials. They utilize tissue engineering, fluid mechanics, and biomaterials to replicate in vivo architectures and functions of complex organs and tissues. Herein, the effect of pressure and stretch on bioengineered …

Decellularization Strategies Of Naturally Derived Biomaterials For Tissue Engineering Applications, Julia Elizabeth Hohn

Theses and Dissertations

In 2017, over 3.5 million peripheral vascular surgeries were performed worldwide with over 400,000 vascular repair or replacement surgeries being performed in the United States each year alone. As the number of vascular repair surgeries, including both coronary and peripheral bypass grafting procedures, continues to increase each year, these statistics indicate an urgent need for more effective and readily available replacement materials. Regenerative medicine and tissue engineering (TE) approaches, including the design, fabrication, and validation of suitable biomaterials in vitro that direct the repair and regeneration of damaged tissues, have been proposed to alleviate this problem. While advanced biomaterials have …

Bioengineered Scaffolds To Induce Alignment And Promote Axon Regeneration Following Spinal Cord Injury, Kiet Anh Tran

Theses and Dissertations

Scaffolds delivered to injured spinal cords to stimulate axon connectivity often act as a bridge to stimulate regeneration at the injured area, but current approaches lack the permissiveness, topology and mechanics to mimic host tissue properties. This dissertation focuses on bioengineering scaffolds through the means of altering topology in injectables and tuning mechanics in 3D-printed constructs as potential therapies for spinal cord injury repair. A self-assembling peptide scaffold, RADA-16I, is used due to its established permissiveness to axon growth and ability to support vascularization. Immunohistochemistry assays verify that vascularized peptide scaffolds promote axon infiltration, attenuate inflammation and reduce astrogliosis. Furthermore, …

Engineering Of Ideal Systems For The Study And Direction Of Stem Cell Asymmetrical Division And Fate Determination, Martina Zamponi

Biomedical Engineering Theses & Dissertations

The cellular microenvironment varies significantly across tissues, and it is constituted by both resident cells and the macromolecules they are exposed to. Cues that the cells receive from the microenvironment, as well as the signaling transmitted to it, affect their physiology and behavior. This notion is valid in the context of stem cells, which are susceptible to biochemical and biomechanical signaling exchanged with the microenvironment, and which plays a fundamental role in establishing fate determination and cell differentiation events. The definition of the molecular mechanisms that drive stem cell asymmetrical division, and how these are modulated by microenvironmental signaling, is …

A Novel Electroconductive Nanofibrous Scaffold For Bone Regeneration, Mitchell Kenter

Medical Engineering Theses

The goal of this study was to develop a biodegradable and conductive scaffold to mimic the piezoelectric properties of bone and the architecture of the extracellular matrix. Poly(3,4- ethylenedioxythiophene) (PEDOT) is a conductive polymer of great interest in tissue engineering due to excellent electrical stability and biocompatibility. To enhance its conductivity, dopants such as dimethyl sulfoxide (DMSO) can be added. Engineered graphene oxide (GO) can also be introduced as oxidant to enhance conductivity and mechanical properties. PEDOT nanocomposites were synthesized by oxidative polymerization of 3, 4-Etylenedioxythiophene monomer (EDOT) in the presence of GO, DMSO, ferric chloride and various solvents. The …

A Comparative Study On The Functionality Of Porcine Dura As A Tissue-Engineered Dura Mater Graft For Clinical Applications, Ashma Sharma

Theses and Dissertations

Damage to dura mater may occur during intracranial or spinal surgeries, which can result in cerebrospinal fluid leakage as well as other potentially fatal physiological changes. As a result, biological scaffolds derived from xenogeneic materials are typically used to repair and regenerate dura mater post intracranial or spinal surgeries. In this study we explore the mechanics, structure, and immunological capacity of xenogeneic dura mater to be considered as a replacement for human dura. A comparative analysis is done between native porcine dura and a commercially available bovine collagen-based dura graft. Native porcine dura mater was decellularized and subjected to mechanical …

Quantifying Shear Stresses In Tissue Engineered Aortic Heart Valves, Raj Nitin Dave

All Theses

Present heart valve prosthesis have limitations such as capability to grow, repair and remodel post implantation. Tissue engineering offers to be a promising alternative to overcome these limitations. Maturation of seeded human cells on the valve subjected to favorable growth conditions in the bioreactor is critical to the success of tissue engineered heart valves. Mechanical stress and strain which results from the pressure and flow conditions in the bioreactor plays a critical role on the developing valve tissue and are currently unknown. The goal of this research is to relate the magnitude of wall shear stress (WSS) within the heart …

Characterizing Mechanical Regulation Of Bone Metastatic Breast Cancer Cells, Boyuan Liu

Doctoral Dissertations

Breast cancer most frequently metastasizes to the skeleton. Bone metastatic cancer is incurable and induces wide-spread bone osteolysis, resulting in significant patient morbidity and mortality. Mechanical stimuli in the skeleton are an important microenvironmental parameter that modulates tumor formation, osteolysis, and tumor cell-bone cell signaling, but which mechanical signals are the most beneficial and the corresponding molecular mechanisms are unknown. This work focused on bone matrix deformation and interstitial fluid flow based on their well-known roles in bone remodeling and in primary breast cancer. The goal of our research was to establish a platform that could define the relationship between …

Development Of Zinc Oxide/Hydroxyapatite/Poly(D,L-Lactic Acid) Fibrous Scaffold For Tissue Engineering Applications, Victoria Padilla-Gainza, Heriberto Rodríguez-Tobías, Graciela Morales, Antonio Ledezma-Pérez, Carmen Alvarado-Canché, Raúl Loera-Valencia, Cristóbal Rodríguez, Robert Gilkerson, Carlos Trevino De Leo, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Scaffolds based on polymeric fibers represent an engaging biomedical device due to their particular morphology and similarity with extracellular matrices. The biggest challenge to use fibrous materials in the biomedical field is related to their favorable platform for the adhesion of pathogenic microorganisms. Therefore, their optimum performance not only depends on their bioactive potential but also on their antimicrobial properties. The aim of this work was the design of antimicrobial (zinc oxide, ZnO) and bioactive (hydroxyapatite, Hap) fibrous materials using poly(D, L-lactic acid) (PDLLA) as the polymer fiber substrate. Fiber based composite scaffolds were developed using the Forcespinning® technique. For …

Piezoelectric Signals In Vascularized Bone Regeneration, Delfo D’Alessandro, Claudio Ricci, Mario Milazzo, Giovanna Strangis, Francesca Forli, Gabriele Buda, Mario Petrini, Stefano Berrettini, M. Jasim Uddin, Serena Danti, Paolo Parchi

Chemistry Faculty Publications and Presentations

The demand for bone substitutes is increasing in Western countries. Bone graft substitutes aim to provide reconstructive surgeons with off-the-shelf alternatives to the natural bone taken from humans or animal species. Under the tissue engineering paradigm, biomaterial scaffolds can be designed by incorporating bone stem cells to decrease the disadvantages of traditional tissue grafts. However, the effective clinical application of tissue-engineered bone is limited by insufficient neovascularization. As bone is a highly vascularized tissue, new strategies to promote both osteogenesis and vasculogenesis within the scaffolds need to be considered for a successful regeneration. It has been demonstrated that bone and …

Characterization Of Tissue-Specific Matrix-Derived Bioscaffolds For Nucleus Pulposus Cell Culture, Marco A. Herrera Quijano

Electronic Thesis and Dissertation Repository

Bioscaffolds derived from the extracellular matrix (ECM) have shown the capacity to promote regeneration by providing tissue-specific biological instructive cues that can enhance cell survival and direct lineage-specific differentiation. This study focused on the development and characterization of two-dimensional (2-D) and three-dimensional (3-D) cell culture platforms incorporating decellularized nucleus pulposus (DNP). First, a novel detergent-free protocol was developed for decellularizing bovine NP tissues that was effective at removing cellular content while preserving key ECM constituents including collagens and glycosaminoglycans. Culture studies showed that 2-D coatings derived from the DNP could support cell attachment but did not maintain or rescue the …

Synthesis And Performance Testing Of Ecm Fiber Scaffolds, Cassandra Reed

Graduate Theses and Dissertations

The progression of regenerative medicine has advanced the treatment of multiple illnesses and injuries throughout the years. A good example of the benefits of this research is the work that has gone into volumetric muscle loss (VML), where more than 20% of the muscle is loss. Skeletal muscle makes up 40% of the human body so a loss of that size greatly diminishes the strength, the flexibility, physiology, and quality of life of the injured individual. For that reason, various techniques are used to counteract the loss of structure and innate cellular signaling in order to circumvent that from happening. …

Impact Of Angiogenic And Osteogenic Factors In The Presence Of Biodegradable Piezoelectric Films, Jayla Millender

University Scholar Projects

One of the most common causes of bone graft rejection is lack of a vascular network connecting the graft to the existing native tissue – allowing for nutrient flow. Under current grafting techniques, the existing blood vessel network in the patient slowly invades the implant in order to supply the injured site with its necessary nutrients. The purpose of this research is to determine if a synthetic bone graft with a stable microvascular network can be developed in vitro. I hypothesize that the use of indirect angiogenic factors such as sonic hedgehog homolog and hypoxia-inducible factor-1 in combination with the …

Impact Of Angiogenic And Osteogenic Factors In The Presence Of Biodegradable Piezoelectric Films, Jayla Millender

Honors Scholar Theses

One of the most common causes of bone graft rejection is lack of a vascular network connecting the graft to the existing native tissue – allowing for nutrient flow. Under current grafting techniques, the existing blood vessel network in the patient slowly invades the implant in order to supply the injured site with its necessary nutrients. The purpose of this research is to determine if a synthetic bone graft with a stable microvascular network can be developed in vitro. I hypothesize that the use of indirect angiogenic factors such as sonic hedgehog homolog and hypoxia-inducible factor-1 in combination with the …

Electroactive Polymeric Composites To Mimic The Electromechanical Properties Of Myocardium In Cardiac Tissue Repair, Kaylee Meyers, Bruce Lee, Rupak Rajachar

Michigan Tech Publications

Due to the limited regenerative capabilities of cardiomyocytes, incidents of myocardial infarction can cause permanent damage to native myocardium through the formation of acellular, non-conductive scar tissue during wound repair. The generation of scar tissue in the myocardium compromises the biomechanical and electrical properties of the heart which can lead to further cardiac problems including heart failure. Currently, patients suffering from cardiac failure due to scarring undergo transplantation but limited donor availability and complications (i.e., rejection or infectious pathogens) exclude many individuals from successful transplant. Polymeric tissue engineering scaffolds provide an alternative approach to restore normal myocardium structure and function …

Engineering Cardiac Tissues With Three-Dimensional Bioprinting For Biomedical Applications, Matthew Alonzo

Open Access Theses & Dissertations

The role of a biomedical engineer is to solve unmet health-related needs that face society. For the past couple of decades, heart disease (HD) has remained the leading cause of mortality and morbidity worldwide. The disease is characterized by various pathologies that affect the heart. Indeed, malfunction of one of the bodyâ??s most vital organs is bound to manifest poor health and even death in patients. Despite advances in medicine and technology, heart disease continues to be prevalent and diminishes the quality of life for many around the world. Certainly, there exists a need for developing new tools to better …