Engineering Commons^™

Relating Ion Release And Ph To In Vitro Cell Viability For Gallium-Inclusive Bioactive Glasses, Timothy J. Keenan, L. M. Placek, T. L. Mcginnity, Mark R. Towler, M. M. Hall, A. W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

A bioactive glass (BG) in which Ga was substituted for Zn was formulated to investigate whether the ionic form of Ga can elicit effects similar to gallium nitrate. The ion release and pH of BG extracts were evaluated, as well as the in vitro cytocompatibility of extracts in contact with mouse fibroblasts and human osteoblasts. After incubation times of 1 year, the glass (TGa-1) containing the smaller Ga-addition (8 mol%) released the most sodium (Na) (1420 mg/L), silicon (Si) (221 mg/L), and Ga (1295 mg/L), while the glass (TGa-2) containing the larger Ga-addition (16 mol%), exhibited release levels between TGa-1, …

Inorganic Hemostats: The State-Of-The-Art And Recent Advances, Sara Pourshahrestani, Ehsan Zeimaran, Ivan Djordjevic, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hemorrhage is the most common cause of death both in hospitals and on the battlefield. The need for an effective hemostatic agent remains, since all injuries are not amenable to tourniquet use. There are many topical hemostatic agents and dressings available to control severe bleeding. This article reviews the most commonly used inorganic hemostats, subcategorized as zeolite and clay-based hemostats. Their hemostatic functions as well as their structural properties that are believed to induce hemostasis are discussed. The most important findings from in vitro and in vivo experiments are also covered.

Influence Of Nb On The Β → Α″ Martensitic Phase Transformation And Properties Of The Newly Designed Ti-Fe-Nb Alloys, Shima Ehtemam-Haghighi, Yujing Liu, Guanghui Cao, Lai-Chang Zhang

Research outputs 2014 to 2021

A series of Ti-7Fe-xNb (x = 0, 1, 4, 6, 9, 11 wt.%) alloys was designed and cast to investigate the β → α″ martensitic phase transformation, β phase stability, the resulting microstructure and mechanical properties. Phase analysis revealed that only Ti-7Fe-11Nb alloy shows a single body-centred cubic β phase microstructure while the others are comprised of β and orthorhombic α″ phases. Moreover, Nb addition up to 11 wt.% enhances the stability and volume fraction of β phase in the microstructure, hence reducing the propensity of the alloy system to form α″ phase during quenching. Compressive yield strength and hardness …

An Algorithm For Extracting The Ppg Baseline Drift In Real-Time, Tuan Ngoc Nguyen

Theses: Doctorates and Masters

Photoplethysmography is an optical technique for measuring the perfusion of blood in skin and tissue arterial vessels. Due to its simplicity, accessibility and abundance of information on an individual’s cardiovascular system, it has been a pervasive topic of research within recent years. With these benefits however there are many challenges concerning the processing and conditioning of the signal in order to allow information to be extracted. One such challenge is removing the baseline drift of the signal, which is caused by respiratory rate, muscle tremor and physiological changes within the body as a response to various stimuli.

Over the years …

A Model Microfluidics-Based System For The Human And Mouse Retina., Shawn Mishra, Ankush Thakur, Stephen Redenti, Maribel Vazquez

Publications and Research

The application of microfluidics technologies to the study of retinal function and response holds great promise for development of new and improved treatments for patients with degenerative retinal diseases. Restoration of vision via retinal transplantation therapy has been severely limited by the low numbers of motile cells observed post transplantation. Using modern soft lithographic techniques, we have developed the μRetina, a novel and convenient biomimetic microfluidics device capable of examing the migratory behavior of retinal lineage cells within biomimetic geometries of the human and mouse retina. Coupled computer simulations and experimental validations were used to characterize and confirm the formation …

Effects Of Cell Adhesion Peptides, Ph, And Matrix Shape On Maintenance Of Breast Cancer Stem Cells In An Engineered Hydrogel Matrix, Leily Daneshian

Theses and Dissertations

Metastasis, resistance to chemo- and radiotherapy, and eventual relapse has been attributed to a tumor subpopulation known as cancer stem cells (CSCs). CSCs are regulated in their tumor microenvironment by various factors. Synthetic hydrogels can be used to investigate the effects of individual environmental factors on CSCs by providing inert 3D matrices. In this thesis, poly ethylene glycol diacrylate (PEGDA) hydrogel with 5kpa modulus has been used as a culture system to study the effect of; I) integrin and heparin binding peptides, 2) pH, and 3) the shape of the microenvironment on breast CSCs maintenance and tumorsphere formation in PEGDA. …

Egf As A New Therapeutic Target For Medulloblastoma Metastasis, Jennifer Rico-Varela, Tanya Singh, Sean Mccutcheon, Maribel Vazquez

Publications and Research

Medulloblastoma (MB) is a malignant pediatric brain tumor known for its aggressive metastatic potential. Despite the well-documented migration of MB cells to other parts of the brain and spinal column, MB chemotaxis is poorly understood. Herein, we examined the in vitro migratory and cellular responses of MB-derived cells to external signaling of Epidermal Growth Factor (EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF-BB), and the stromal cellderived factors 1-alpha (SDF-1). Experiments utilized transwell assays and immunocytochemistry to identify receptor activation in MB migration, and used a microfluidic platform to examine directionality, trajectory, and gradient-dependence of motile cells. Data illustrates …

High Throughput Screening Of Priming Candidates For Impact On Nonviral Gene Delivery, Albert L. Nguyen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Priming, in the context of nonviral gene delivery, is the treatment of cells with a compound prior to gene transfer that enhances transfection efficiency and/or transgene expression. Essentially, it is the application of an adjuvant approach to gene delivery. Effective transfection strategies may require priming to compete with the efficiency of viral transduction in order to achieve clinically relevant efficiency and expression in vivo. To search for priming compounds, a high throughput screen of the NIH Clinical Collection was performed using 25kDa b-PEI, an EGFP/luciferase plasmid, and HEK293T cells. The EGFP reporter was multiplexed with Hoechst 33342 and Resazurin fluorescence …

A Collagen Based Tissue Engineered Heart Valve Shows Excellent Functionality And Remodelling After Dynamic Conditioning, Claire Brougham, Ricardo Moreira, Tanya J. Levingstone, Stefan Jockenhoevel, Petra Mela, Fergal J. O'Brien

Conference Papers

No abstract provided.

Effect Of Tendon Vibration On Hemiparetic Arm Stability In Unstable Workspaces, Megan O. Conrad, Bani Gadhoke, Robert A. Scheidt, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic …

An Intra-Bone Axial Load Transducer: Development And Validation In An In-Vitro Radius Model, Nikolas K. Knowles, Michael Gladwell, Louis M. Ferreira

Surgery Publications

Background

Accurate measurement of forces through the proximal radius can assess the effects of some surgical procedures on radioulnar load sharing, but is difficult to achieve given the redundant loading nature of the musculoskeletal system. Previously reported devices have relied on indirect measurements that may alter articular joint location and function. An axial load transducer interposed in the diaphysis of the radius may accurately quantify unknown axial loads of the proximal radius, and maintain articular location.

Methods

An in-vitro radius model was developed by interposing an axial load transducer in the diaphysis of the proximal radius. Static loads of 20, …

Investigation Of The Inherent Chemical, Structural, And Mechanical Attributes Of Bio-Engineered Composites Found In Nature: Alligator Gar’S Exoskeleton Fish Scales, Wayne Derald Hodo

Graduate Theses and Dissertations

The U.S. Army has determined a huge cost savings of up to 51% can be accomplished by reducing the gross vehicle weight, for their personnel carrier, by 33%. To cut cost, composite materials are needed. Man-made composites can have superior material properties (high-strength, high-fracture toughness, and lightweight), but they are prone to delamination at the glued-layered interface. In contrast, fish scale is a natural composite that has the same material properties and, additionally, tend not to delaminate.

The focus of this study was to learn how nature integrates hard and soft materials at each length scale to form a layered …

Magnetic Resonance Imaging Of Cerebrovascular Reactivity Using Gas Inhalation Challenges, Harshan Ravi

Bioengineering Dissertations - Archive

Cerebrovascular reactivity (CVR) is a measure of dilation capacity of cerebral vasculature. It is an important biomarker for the vascular functionality and integrity, and may have clinical indications in stroke, atherosclerosis, Moyamoya disease, multiple sclerosis, brain tumor, and other neurological disorders. The most commonly used approach to measure CVR is by applying a physiological maneuver to alter the arterial carbon dioxide (CO2) concentration (e.g. inhaling a small amount of CO2 which is a potent vasodilator), while continuously acquiring BOLD MR images. However, the current method suffers from several limitations related to specificity, sensitivity, and physiological modeling of the measured signal. …

An Investigation Of The Relation Between Sleep Disordered Breathing And Cognitive Function, Nazaneen Mousavi

Bioengineering Theses - Archive

Obstructive sleep apnea (OSA) is one of the most prevalent sleep related breathing disorders, with an estimated amount 17% of affected adults in the U.S. Research has linked OSA to mood and cognitive disorders, including Alzheimer’s disease. Structural changes in the brain have also been found to be associated with OSA. Several studies have shown deterioration of cognition in OSA patients because of structural and physiological changes due to apnea. The purpose of this research is to study the correlational relationships between cognitive measures and 1) quantitative measures of sleep quality; 2) measures of sleep disordered breathing; and 3) hypoxia …

Synthesis And Functional Evaluation Of Peptide Modified Poly (Lactic-Co-Glycolic Acid) Nanoparticles To Inhibit Porphyromonas Gingivalis Biofilm Formation., Paridhi Kalia

Electronic Theses and Dissertations

Periodontal disease is an oral inflammatory disorder that afflicts roughly 46% of the adults in the U.S. Currently, treatment of periodontal disease involves the removal of plaque from the gingival pocket (with possible antibiotic treatment) and if necessary, gingival surgery. To our knowledge, no therapeutic approach exists that promotes host-biofilm homeostasis by limiting pathogen recolonization of the oral cavity after prophylaxis or treatment. The interaction of the pathogen Porphyromonas gingivalis with commensal streptococci is critical for initiation of periodontitis and represents a target for limiting P. gingivalis colonization of the oral cavity. Previous studies showed that a synthetic peptide …

Decellularized Bovine Nucleus Pulposus As A Biomimetic Scaffold For Intervertebral Disc Regeneration, Christopher Fernandez

All Theses

Low back pain (LBP) is a significant burden with a lifetime prevalence of 84% and estimated expenditures of $85.9 billion.[1,2] Although LBP is multifactorial; it has been shown that LBP can originate from degenerating intervertebral discs (IVDs); a process which initiates in the nucleus pulposus (NP); a hydrated tissue primarily composed of type 2 collagen and proteoglycan. Current therapies for IVD degeneration (IDD) are palliative and merely delay surgical management. While these procedures may relieve pain temporarily, they fail to address the underlying cause of degeneration and make no attempt to regenerate the effected tissue. Additional concerns with the use …

Analysis Of Citrate Content In Bone Using High Performance Liquid Chromatography, Matthew Konstantin Pysh

All Theses

Approximately 1.5 wt. % of bone is comprised of citrate molecules bound to the surface of apatite crystals. Furthermore, 80 to 90% of physiological citrate is contained within bone. Recently, interest in citrate has increased due to the potential of a citrate based method for estimation of postmortem intervals, time since death, of skeletal remains. The broad objective of this research was to develop and validate a High-Performance Liquid Chromatography (HPLC) method for quantitative and qualitative analysis of citrate in bone. An appropriate HPLC column and operating conditions for the detection of citrate were selected and subsequently used to analyze …

Supervised Machine Learning For Classification Of The Electrophysiological Effects Of Chronotropic Drugs On Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes, Christopher Heylman, Rupsa Datta, Agua Sobrino, Steven George, Enrico Gratton

Biomedical Engineering

Supervised machine learning can be used to predict which drugs human cardiomyocytes have been exposed to. Using electrophysiological data collected from human cardiomyocytes with known exposure to different drugs, a supervised machine learning algorithm can be trained to recognize and classify cells that have been exposed to an unknown drug. Furthermore, the learning algorithm provides information on the relative contribution of each data parameter to the overall classification. Probabilities and confidence in the accuracy of each classification may also be determined by the algorithm. In this study, the electrophysiological effects of β–adrenergic drugs, propranolol and isoproterenol, on cardiomyocytes derived from …

Phospho1 Deficiency Transiently Modifies Bone Architecture Yet Produces Consistent Modification In Osteocyte Differentiation And Vascular Porosity With Ageing, Behzad Javaheri, Alessandra Carriero, Katherine Ann Staines, Y.-M. Chang, D. A. Houston, Karla J. Oldknow, José Luis Millán, Bassir N. Kazeruni, Phil L. Salmon, Sandra J. Shefelbine

Biomedical Engineering and Sciences Faculty Publications

PHOSPHO1 is one of principal proteins involved in initiating bone matrix mineralisation. Recent studies have found that Phospho1 KO mice ( Phospho1-R74X) display multiple skeletal abnormalities with spontaneous fractures, bowed long bones, osteomalacia and scoliosis. These analyses have however been limited to young mice and it remains unclear whether the role of PHOSPHO1 is conserved in the mature murine skeleton where bone turnover is limited. In this study, we have used ex-vivo computerised tomography to examine the effect of Phospho1 deletion on tibial bone architecture in mice at a range of ages (5, 7, 16 and 34. weeks of age) …

The Effect Of Recency To Human Mobility, Hugo Barbosa, Fernando B. De Lima-Neto, Alexandre Evsukoff, Ronaldo Menezes

Biomedical Engineering and Sciences Faculty Publications

In recent years, we have seen scientists attempt to model and explain human dynamics and in particular human movement. Many aspects of our complex life are affected by human movement such as disease spread and epidemics modeling, city planning, wireless network development, and disaster relief, to name a few. Given the myriad of applications, it is clear that a complete understanding of how people move in space can lead to considerable benefits to our society. In most of the recent works, scientists have focused on the idea that people movements are biased towards frequently-visited locations. According to them, human movement …

Midfield Rf Signal Detector, Dawei Zhang

Electrical Engineering

This project is part of a Master’s thesis which looks at alternative ways to measure blood glucose. The Master’s thesis uses mid-field signals in order to match impedance and therefore lose less power as they travel through flesh. The goal of this senior project is to build a receiver for those signals and give accurate RSSI (received signal strength indicator) measurements. Mid-fields were originally explored by Stanford professor Dr. Ada Poon [3] who used the signaling technique to recharge the batteries of deeply implanted devices. Devices implanted near the surface of the skin were able to have their batteries recharged …

Modulation Of Valve Interstitial Cell Function Through Cell Shape And Phenotype, Atefeh Razavi

Graduate Theses and Dissertations

The aortic valve is a highly dynamic structure responding to actively to the chemical, mechanical and physical cues of the valve microenvironment. Valve interstitial cells are dispersed throughout the valve tissue and play an important role in maintaining the integrity and optimum function of the valve. They are a heterogeneous population composed of various phenotype. These phenotypes have specific functions characteristic of valve physiological and pathological conditions. The effect of mechanical loading and chemical modulators on the behavior of the valve interstitial cells have largely been studied. However the role of valve interstitial cell shape as an intrinsic physical cue …

Rupture In Abdominal Aortic Aneurysm, Qusay Alfaori

Graduate Theses and Dissertations

Quantification of abdominal aortic aneurysm development, its growth kinetics, and rupture criteria are important to decrease the risk of this life-threatening event. Uniaxial testing of healthy and collagen degraded aortic specimens from pigs was performed. A mathematical model, from the literature, for the stress-strain relationship that is suitable for describing the behavior of abdominal aortic tissue was used to derive specific tissue properties/parameters as a function of strain rate and as a function of specimen orientation. Analyses consisting of Finite Element Modeling of healthy and collagen degraded abdominal aortas were performed using ABAQUS finite element code and the measured properties. …

Wireless Monitoring Of Driver's Pulse Rate And Temperature Using Hand Gloves Approach, Rohith Reddy Narala

Graduate Theses and Dissertations

There is growing concern about dangers correlated with driving, for people with known cardiovascular diseases. However, the association between having a chronic cardiovascular disease and being involved in a motor vehicle crash remains controversial. This study aims to monitor people with known medical emergencies or other medical conditions while driving [1]. It also helps the co-passengers to be cautious while the person is driving with an abnormal health condition. Designed it to be convenient and also can be easily adaptable by the end user.

The proposed project focuses on a wearable sensor glove that equipped with a pulse rate sensor, …

Image Processing And Visualization Of Terahertz Pulsed Imaging Of Breast Cancer Tumors, Yuhao Wu

Graduate Theses and Dissertations

Terahertz imaging technology has grown substantially in recent years. With new advances made in the generation, manipulation, and detection of terahertz radiation, terahertz imaging has found its application as inspection tools in a wide range of areas including biomedicine, materials science, and aerospace industries. In the field of medical imaging, terahertz (THz) has emerged as a new imaging modality due to some fundamental physical properties of the THz wave. THz imaging has been used to examine various biological structures, and THz tomography has been developed to probe the 3D structures of those samples.

THz pulsed imaging (TPI) is one of …

Prediction Of Rupture In Abdominal Aortic Aneurysm, Qusay Alfaori

Graduate Theses and Dissertations

Studying the development of abdominal aortic aneurysm (AAA) through quantification of its growth kinetics and rupture criteria is important to decrease the risk of this life-threatening event. Uniaxial and biaxial testing of healthy and time-dependent Type-I collagen degraded aortic specimens from pigs was performed. Stress-strain suitable mathematical models describing the behavior of abdominal aortic tissue were utilized to derive specific tissue properties and parameters. Reduction in Type-I collagen fraction was observed using picrosirius red staining method, bright field microscopy, and MATLAB. Finite Element Modeling (FEM) of healthy and time-dependent Type-I collagen degraded abdominal aortas were performed using ABAQUS finite element …

Development Of A Vascularized, Induced Pluripotent Stem Cell-Derived Liver-Tissue Mimic For Therapeutic Applications., Venkat Madhav Ramakrishnan

Electronic Theses and Dissertations

This dissertation describes the incorporation of several technologies (stem cells, gene therapy, tissue engineering and regenerative medicine) into a single project that aims to produce a liver-tissue mimic for therapeutic applications. The liver is arguably one of the most complex organs in the body. In addition to its remarkable capacity to regenerate, it performs a host of vital functions. As a result, its impairment has widespread systemic consequences. The work described herein focused on the liver in the context of cardiovascular disease and used the heritable disorder Familial Hypercholesterolemia (FH) as a clinical disease model. As (a) the only definitive …

When 1 + 1 > 2: Nanostructured Composites For Hard Tissue Engineering Applications, Vuk Uskoković

Pharmacy Faculty Articles and Research

Multicomponent, synergistic and multifunctional nanostructures have taken over the spotlight in the realm of biomedical nanotechnologies. The most prospective materials for bone regeneration today are almost exclusively composites comprising two or more components that compensate for the shortcomings of each one of them alone. This is quite natural in view of the fact that all hard tissues in the human body, except perhaps the tooth enamel, are composite nanostructures. This review article highlights some of the most prospective breakthroughs made in this research direction, with the hard tissues in main focus being those comprising bone, tooth cementum, dentin and enamel. …

The Effect Of Neurostimulation On Ischemic Pain And Methods Of Assessing Pain, Kaylee Keck

Biomedical Engineering

Peripheral arterial disease (PAD) impacts approximately eight million people in the United States [1]. Disease progression leads to chronic ischemic pain, hindering quality of life. Pharmaceuticals are a typical treatment for pain associated with PAD; but as few as 30% of patients have a significant reduction of pain (≥50%) [2].

Neurostimulation is commonly used as a treatment for various diseases and injuries, including Parkinson’s disease and sports-related back and knee injuries [2]. The objective of the study was to explore neurostimulation and its effect on pain and paresthesia for a model of acute peripheral ischemia in young college students.

Pain …

Novel Biomechanical Test Method For Cancellous Bone Screws And Screw Augmentation With Cement., Kevin Lancaster

Electronic Theses and Dissertations

It is often difficult to achieve adequate screw fixation for plate constructs in fractures with poor quality bone or in metaphyseal bone with extensive bone loss or comminution[7][17]. Furthermore, rescuing or augmenting failed screw fixation in inadequate bone with various cement products has yielded mixed results when tested with pure axial pullout loading[20][21]. In most cases, plate/screw constructs experience both vertical (translational) and horizontal (pullout) forces during physiologic loading[17][20][21]. The increased use of locked screws in plate constructs has also changed the loading patterns of bone screws. For this study, a novel “toggle-out” testing method was developed to more realistically …