Biomechanics and Biotransport Commons^™

Polymeric Biomaterials Approaches For Engineering The In Vitro Cellular Microenvironment For Mscs, Mahsa Letter-Mahsa Haseli

Graduate Theses and Dissertations

Cell therapy is a technology that relies on replacing diseased or dysfunctional cells with healthy functioning ones. One of the cells used for such advanced therapies are stem cells, owing to their ability to differentiate into specific cells required for repairing damaged or defective tissues or cells. The majority of cell-based products are intended to transiently persist in the patient, secreting factors which then allow the patient’s body to heal; in these products, the cells are subsequently eliminated from the body. Furthermore, unique manufacturing platforms, in addition to novel commercialization strategies, will be required to create a successful, sustainable cell …

Blood Flow Regulates Atherosclerosis Progression And Regression, Morgan A. Schake

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Atherosclerosis is the most prevalent pathology of cardiovascular disease with no known cure. Despite the many systemic risk factors for atherosclerosis, plaques do not form randomly in the vasculature. Instead, they form around bifurcations and the inner curvature of highly curving arterial segments that contain so-called disturbed blood flow that is low in magnitude and multidirectional over the cardiac cycle. Conversely, straight, non-bifurcated arterial segments that contain moderate-to-high and unidirectional (i.e., normal) blood flow are protected from plaque development. Thus, blood flow is a key regulator of atherosclerosis that may be able to be leveraged to develop new therapeutics. Towards …

A Magneto-Rheological Platform To Dynamically Control Afterload In Engineered Micro Heart Muscles, David Schuftan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cardiovascular disease is the leading cause of death is the United States, accounting for nearly 1 in 5 deaths. Many types of cardiovascular disease are linked to the mechanical forces placed on the heart. However, how these mechanical forces exactly affect the cellular biology of the heart is not well defined. In vitro models using cardiomyocytes derived from human induced pluripotent stem cells enable researchers to develop medium throughput systems to study cardiac mechanobiology at the cellular level. Previous models have been developed to enable the study of mechanical forces such as cardiac afterload. However, most of these models require …

Development Of A Fish Robot Equipped With Novel 3d-Printed Soft Bending Actuators, Steven Steele, Jorge Diaz Rodriguez, Sharun Sripathy, Turaj Ashuri, Saleh Gharaie, Yusun Chang, Amir Ali Amiri Moghadam

Symposium of Student Scholars

This paper reports on design and fabrication of a novel soft fish robot. Application of soft actuators for the fish tail will generates continuum bending motion which resembles the natural motion of the fish. However, most soft actuator mechanisms are complex and have low efficiency. Thus, to address this issue we have developed a 3D printed soft bending actuator which can be actuated with an electromotor. The basic design idea of the soft bending actuator is explained, and iteration of the design showed to create the desired motion for the soft tail. The soft actuator has been successfully integrated with …

Histological Evidence For The Therapeutic Effect Of Chitosan Nanofibrous Dressing On Acute Skin Wounds In A Rat Model, Mahboubeh Ghanbari, Sayed Ahmadreza Razian, Sara Cartwright, Yury Salkovskiy, Jason Mactaggart, Mark A. Carlson

UNO Student Research and Creative Activity Fair

Introduction: Large-area skin traumas, such as thermal burns, are among the most severe health issues that decrease patients’ quality of life and burden healthcare systems. The CDC estimates that there are 1.1 million burns requiring medical attention each year, with more than 20,000 cases involving at least 25% of the body surface, resulting in 4,500 deaths. In addition, about 10,000 people die from burn-related infections. A promising solution to alleviate this problem is using wound dressings based on biopolymers with inherent wound healing properties and biodegradability. One of these biopolymers is chitosan, which is derived from arthropod shells and exhibits …

The Effects Of Demographics And Risk Factors On The Morphological Characteristics Of Human Femoropopliteal Arteries, Sayed Ahmadreza Razian, Majid Jadidi, Alexey Kamenskiy

UNO Student Research and Creative Activity Fair

Background: Disease of the lower extremity arteries (Peripheral Arterial Disease, PAD) is associated with high morbidity and mortality. During disease development, the arteries adapt by changing their diameter, wall thickness, and residual deformations, but the effects of demographics and risk factors on this process are not clear.

Methods: Superficial femoral arteries from 736 subjects (505 male, 231 female, 12 to 99 years old, average age 51±17.8 years) and the associated demographic and risk factor variables were used to construct machine learning (ML) regression models that predicted morphological characteristics (diameter, wall thickness, and longitudinal opening angle resulting from the …

Time Evolution Is A Source Of Bias In The Wolf Algorithm For Largest Lyapunov Exponents, Kolby Brink, Tyler Wiles, Nicholas Stergiou, Aaron Likens

UNO Student Research and Creative Activity Fair

Human movement is inherently variable by nature. One of the most common analytical tools for assessing movement variability is the largest Lyapunov exponent (LyE) which quantifies the rate of trajectory divergence or convergence in an n-dimensional state space. One popular method for assessing LyE is the Wolf algorithm. Many studies have investigated how Wolf’s calculation of the LyE changes due to sampling frequency, filtering, data normalization, and stride normalization. However, a surprisingly understudied parameter needed for LyE computation is evolution time. The purpose of this study is to investigate how the LyE changes as a function of evolution time …

Concurrent Validity Study Of 3d Motion Measurement Systems: Vicon Vs. Xsens, Pias Das

Masters Theses

As the Inertial Measurement System (IMS) being a potential alternative to the Optoelectronic Measurement System (OMS) in terms of capturing comprehensive and objective musculoskeletal data, they need to be verified concurrently with the OMS before we start using the IMS in clinical motion analysis. To achieve this, a concurrent validity experiment of the Xsens system (IMS) in comparison to the Vicon system (OMS) was conducted for both upper and lower extremity movements during walk, squat, and lateral lunge (left and right) to quantify the degree of similarity of kinematic data between the two systems by direct comparison, root mean square …

Making Sense Of Big (Kinematic) Data: A Comprehensive Analysis Of Movement Parameters In A Diverse Population, Naomi Wilma Nunis

University of the Pacific Theses and Dissertations

OBJECTIVE

The purpose of this study was to determine how kinematic, big data can be evaluated using computational, comprehensive analysis of movement parameters in a diverse population.

METHODS

Retrospective data was collected, cleaned, and reviewed for further analysis of biomechanical movement in an active population using 3D collinear resistance loads. The active sample of the population involved in the study ranged from age 7 to 82 years old and respectively identified as active in 13 different sports. Moreover, a series of exercises were conducted by each participant across multiple sessions. Exercises were measured and recorded based on 6 distinct biometric …

Quantifying Fibronectin Mechanical Properties Using Antibody-Mediated Optical Tweezing (Amot), Caleb Dalton

Theses and Dissertations

Despite decades of investigations into fibronectin (FN) fibrillogenesis, fibril mechanics remain unclear. One of the most important roles for FN fibrils is in the arena of cellular mechanotransduction. Numerous studies have demonstrated that cells sense and respond to the mechanical properties of their surroundings; since FN fibrils are a major constituent of the ECM that links cells to their surroundings, mechanotransduction cannot be fully understood without understanding the mechanical properties of FN fibrils. In this proposal, a novel biomechanical assay is developed to probe isolated FN fibrils and quantify their response to specific loading conditions. This will be accomplished by …

Integrating Shear Flow And Trypsin Treatment To Assess Cell Adhesion Strength, Antra Patel, Bhavana Bhavanam, Trevor Keenan, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

Cell adhesion is of fundamental importance in cell and tissue organization and for designing cell-laden constructs for tissue engineering. Prior methods to assess cell adhesion strength for strongly adherent cells using hydrodynamic shear flow either involved the use of specialized flow devices to generate high shear stress or used simpler implementations like larger height parallel plate chambers that enable multihour cell culture but generate low wall shear stress and are, hence, more applicable for weakly adherent cells. Here, we propose a shear flow assay for adhesion strength assessment of strongly adherent cells that employs off-the-shelf parallel plate chambers for shear …

Defining Sagittal Plane Gait Mechanics And Joint Loading In People With Marfan Syndrome, Justin Melan Pol

Theses and Dissertations--Biomedical Engineering

Marfan syndrome (MFS) is a genetic condition that is associated with altered muscle composition, which leads to muscle dysfunction. People with MFS exhibit high instances of lower extremity (LE) joint pain that inhibits their ability to perform activities of daily living, such as walking. Despite these detrimental impacts of MFS, there have been no attempts to characterize the effects of MFS on LE joint loading and health during walking that are associated with LE pain and dysfunction. As people with MFS exhibit a high incidence rate of osteoarthritis (OA), the need to understand the potential alterations in LE extremity mechanics …

Long-Range Aceo Phenomena In Microfluidic Channel, Diganta Dutta, Keifer Smith, Xavier Palmer

Electrical & Computer Engineering Faculty Publications

Microfluidic devices are increasingly utilized in numerous industries, including that of medicine, for their abilities to pump and mix fluid at a microscale. Within these devices, microchannels paired with microelectrodes enable the mixing and transportation of ionized fluid. The ionization process charges the microchannel and manipulates the fluid with an electric field. Although complex in operation at the microscale, microchannels within microfluidic devices are easy to produce and economical. This paper uses simulations to convey helpful insights into the analysis of electrokinetic microfluidic device phenomena. The simulations in this paper use the Navier–Stokes and Poisson Nernst–Planck equations solved using COMSOL …

An Investigation Of The Effect Of Cyclic Loading Of Bone On Osteocyte Processes Spanning Micro-Cracks As A Driver Of Targeted Remodelling Of Bone, Morgana Pires Afonso Shirsath

Doctoral

Bone remodelling is essential to maintain and improve the quality of bones. This occurs with the action of specialised cells - osteoclasts and osteoblasts - which replace the old bone tissue with new in regions where damage has occurred. Osteocytes are responsible for signalling the presence of damage and trigger the bone remodelling response. According to the Scissors Model, the presence of micro-cracks causes rupture of the osteocyte processes by fatigue because of the repeated stretching resulting from the relative movement of micro-crack faces, when bone is subjected to cyclic loads.

Assessment Of Material Properties In Bone Surrounding Microdamage, Niovi Dollas

Dissertations and Theses

Bisphosphonates [BPs] are the mainstay for osteoporosis treatment. They suppress bone resorption/remodeling, preventing bone loss. However, BPs also suppress the beneficial bone remodeling that replaces microscopically damaged bone that occurs from normal mechanical wear-and-tear or fatigue, leading to impaired tissue material properties and in some instances atypical femoral fractures.

In these studies, we assessed the effects of acute fatigue, fatigue induced remodeling, and fatigue microdamage with remodeling suppression using the clinical BP, alendronate [ALN], on local bone material properties. Studies were performed on cortical bone sections from rat ulnae into which fatigue damage had been introduced in vivo. Rat …

Mechanically Driven In Vivo Osteocyte Ca2+ Signaling: Aging And Pharmacologic Effects, James Padgett

Dissertations and Theses

Bone’s ability to respond and adapt to mechanical loading declines significantly with age which is a major contributor to bone fragility. It is widely accepted that osteocytes are the key cells responsible for orchestrating the development of the “ideal” skeleton. This ability is attributed to osteocyte’s role as the primary mechanosensing cell that is responsible for maintaining the skeleton’s integrity throughout life. Recent work from our laboratory has shed light into how osteocytes respond to mechanical loading in vivo. The breakthrough approaches that enabled these discoveries were development of: (1) the first ever reporter mouse model with a genetically encoded …

Development Of A Crosslinked Osteochondral Xenograft And A Collagen Stabilizing Intra-Articular Injection To Remediate Cartilage Focal Lesions To Prevent Osteoarthritis, Mark Lewis Mosher

Theses and Dissertations

Osteoarthritis is one of the most common causes of disability in adults in America. It is a progressive and degenerative disease where the articular cartilage is broken down and lost from the surfaces of bones causing chronic pain and swelling in the joints, and currently has no cure. The most commonly osteoarthritis starts from a focal lesion on the cartilage surface, which will expand on the surface and downwards through the thickness of the tissue. The current gold standard for correcting cartilage focal lesions is the osteochondral autograft/allograft transplantation (OAT), which replaces the defect with a fresh osteochondral graft. The …

In Vitro Bioreactor For Mechanical Control And Characterization Of Tissue Constructs, Samuel Coeyman

All Dissertations

Heart failure (HF) currently affects over 6 million Americans, 50% of whom die within 5 years of their initial diagnosis. A major contributor to the onset of HF is cardiac fibrosis in the myocardium, which arises when fibroblasts (FBs) are activated in response to heightened mechanical stress from overload conditions like hypertension. Activated FBs remodel the extracellular matrix (ECM) and secrete ECM proteins including collagen. FB remodeling has been studied in the past by applying forces and/or deformations to three-dimensional, cell-seeded gels and tissue constructs in vitro. Unfortunately, previous stretching platforms have traditionally not enabled mechanical property assessment to be …

Tibial Compression During Activities Of Daily Living In Young And Older Adults, Elijah Miles Walker

Boise State University Theses and Dissertations

Introduction: Stress fracture, particularly in the tibia, is a growing concern among older adults (greater than 65 years). Older adults may have inherent stress fracture risk from ageing-related changes to their musculoskeletal system. Specifically, older adults reduced ankle neuromuscular function may impair their ability to attenuate repetitive compressive forces experienced during daily locomotor tasks and increase the likelihood of suffering bone damage from decreased bone tissue elasticity. Yet, it is currently unknown if older adults exhibit greater tibial compression than their younger counterparts during locomotor tasks. Purpose: This study sought to quantify tibial compression for older and younger adults when …

Computational Simulations Of The Effects Of Gravity On Lymphatic Transport, Huabing Li, Huajian Wei, Timothy P. Padera, James W. Baish, Lance L. Munn

Faculty Journal Articles

Physical forces, including mechanical stretch, fluid pressure, and shear forces alter lymphatic vessel contractions and lymph flow. Gravitational forces can affect these forces, resulting in altered lymphatic transport, but the mechanisms involved have not been studied in detail. Here, we combine a lattice Boltzmann-based fluid dynamics computational model with known lymphatic mechanobiological mechanisms to investigate the movement of fluid through a lymphatic vessel under the effects of gravity that may either oppose or assist flow. Regularly spaced, mechanical bi-leaflet valves in the vessel enforce net positive flow as the vessel walls contract autonomously in response to calcium and nitric oxide …