Biomedical Engineering and Bioengineering Commons^™

Decellularized Matrices Effect On The Adaptive Immune Response, Kegan Sowers

Theses and Dissertations

Decellularized extracellular matrices have been a growing area of interest in the biomedical engineering fields of tissue engineering and regenerative medicine.As these materials move toward clinical applications, the immune response to these materials will be a driving force toward their success in clinical approaches. Fully digested decellularized matrix constructs derived from porcine liver, muscle and lung were created to test the adaptive immune response. Hydrogel characterization ensured that the materials had relatively similar stiffness levels to reduce variability, and in vitro studies were conducted. Each individual construct as well as a gelatin control were plated with a co-culture of macrophages …

Effects Of Protein-Coated Nanofibers On Conformation Of Gingival Fibroblast Spheroids: Potential Utility For Connective Tissue Regeneration, Gili Kaufman, Ryan A. Whitescarver, Laiz Nunes, Xavier-Lewis Palmer, Drago Skrtic, Wojtek Tutak

Engineering Technology Faculty Publications

Deep wounds in the gingiva caused bytrauma or surgery require a rapid and robust healing of connective tissues. Wepropose utilizing gas-brushed nanofibers coated with collagen and fibrin for that purpose. Our hypotheses are that protein-coated nanofibers will: (i) attract and mobilize cells in various spatial orientations, and (ii) regulate the expression levels ofspecific extracellular matrix (ECM)-associated proteins, determining the initial conformational nature ofdense and soft connective tissues. Gingival fibroblast monolayers and3D spheroids were cultured onECMsubstrate and covered with gas-blown poly-(DL-lactide-co-glycolide)(PLGA) nanofibers (uncoated/coated with collagen and fibrin). Cell attraction and rearrangement was followed byF-actin staining and confocal microscopy. Thicknesses ofthe cell …

Collective Chemotaxis Of Retinal Neural Cells From Drosophila Melanogaster In Controlled Microenvironments, Stephanie Zhang

Dissertations and Theses

More than 172 million people are influenced by a retinal disorder that stems from either age-related or developmental causes. Of those, 1.5 million people endure a developmental retinal disorder. In the developing retina, neural cells undergo a series of highly complicated differentiation and migration process. A main cause of these diseases is abnormal collective migration of neural progenitors hindering the retinogenesis process. However, our grasp of collective migration and signaling molecules, critical to the developing retina, is incompletely understood. Understanding the molecular mechanisms, such as the fibroblast growth factor pathway, that regulate glial and neuronal migration provides decisive insights in …

Bowel Sounds Identification And Migrating Motor Complex Detection With Low-Cost Piezoelectric Acoustic Sensing Device, Xuhao Du, Gary Allwood, Katherine Mary Webberley, Adam Osseiran, Barry J. Marshall

Research outputs 2014 to 2021

Interpretation of bowel sounds (BS) provides a convenient and non-invasive technique to aid in the diagnosis of gastrointestinal (GI) conditions. However, the approach’s potential is limited by variation between BS and their irregular occurrence. A short, manual auscultation is sufficient to aid in diagnosis of only a few conditions. A longer recording has the potential to unlock additional understanding of GI physiology and clinical utility. In this paper, a low-cost and straightforward piezoelectric acoustic sensing device was designed and used for long BS recordings. The migrating motor complex (MMC) cycle was detected using this device and the sound index as …

Mechanical And Material Characterization Of Advanced Materials For Tissue Regeneration, Bailey Kylara Ricketts Jackson

Theses and Dissertations

In natural disasters and military deployment operations, injury to long bone can cause extensive damage and be difficult to treat and heal quickly. Explosive devices and trauma often produce long-bone (>2-cm length) wounds that are more complicated than common fractures. Due to the size and complexity of these injuries, they can be difficult to treat in a battlefield environment and take a long time to heal completely and properly. Even after the long healing period, these injuries often require rehabilitation to strengthen the muscles that have weakened in the wounded limb. For military applications especially, these effects can put …

Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.

In Vivo Raman Spectroscopy For Biochemical Monitoring Of The Human Cervix Throughout Pregnancy, Christine M. O'Brien, Elizabeth Vargis, Amy Rudin, James C. Slaughter, Giju Thomas, J. Michael Newton, Jeff Reese, Kelly A. Bennett, Anita Mahadevan-Jansen

Biological Engineering Faculty Publications

Background

The cervix must undergo significant biochemical remodeling to allow for successful parturition. This process is not fully understood, especially in instances of spontaneous preterm birth. In vivo Raman spectroscopy is an optical technique that can be used to investigate the biochemical composition of tissue longitudinally and noninvasively in human beings, and has been utilized to measure physiology and disease states in a variety of medical applications.

Objective

The purpose of this study is to measure in vivo Raman spectra of the cervix throughout pregnancy in women, and to identify biochemical markers that change with the preparation for delivery and …

การพัฒนาระบบตรวจวัดแคลเซียมออกซาเลตในปัสสาวะเพื่อการคัดกรองโรคนิ่วไต, พิชญุตม์ ฤกษนันทน์

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์นี้ได้ทำการพัฒนาระบบตรวจคัดกรองผู้ที่มีโอกาสเสี่ยงต่อโรคนิ่วไต (Kidney stone disease) โดยใช้วิธี Indole Calcium Oxalate Crystalization Index : iCOCI ซึ่งเป็นการตรวจวัดความเข้มสีที่เกิดจากปฏิกิริยาระหว่างออกซาเลตในปัสสาวะกับสาร Indole reagent โดยได้ทำการศึกษาถึงตัวแปรต่าง ๆ ที่มีผลต่อการวัดเพื่อปรับปรุงประสิทธิภาพของวิธี iCOCI ซึ่งพบว่าสามารถลดเวลาในขั้นตอนการบ่มปัสสาวะได้เหลือเพียง 10 นาที และการใช้ Indole reagent ที่ความเข้มข้น 2.5 mg/ml สามารถให้ความแยกชัดในการตรวจคัดกรองได้สูงที่สุด จากนั้นได้ทำการทดสอบประสิทธิภาพของการตรวจคัดกรองโดยนำตัวอย่างปัสสาวะของกลุ่มผู้ที่มีสุขภาพดีและกลุ่มผู้ป่วยโรคนิ่วไต กลุ่มล่ะ 60 ตัวอย่างมาทำการตรวจวัดโดยใช้วิธี iCOCI ร่วมกับระบบวัดทางแสงที่พัฒนาขึ้นโดยใช้เซนเซอร์อาเรย์ที่ตอบสนองต่อแสงที่ความยาวคลื่นต่าง ๆ ซึ่งพบว่าการใช้ค่าการดูดกลืนแสงของสารตัวอย่างที่ความยาวคลื่น 600 nm จะสามารถให้ประสิทธิภาพของการตรวจคัดกรองได้สูงสุดคือได้ค่าความไวและความจำเพาะในการตรวจคัดกรองมากกว่า 70% ซึ่งเพียงพอต่อการนำไปใช้งานเพื่อตรวจคัดกรองในทางคลีนิค นอกจากนี้ยังได้ทำการพัฒนาระบบผสมและนำส่งสาร และระบบแปลและแสดงผลการตรวจคัดกรองเพื่อทดสอบความเป็นไปได้ในการนำไปพัฒนาเป็นระบบแบบอัตโนมัติโดยใช้ไมโครคอนโทรลเลอร์ในการควบคุม ซึ่งจากการทดสอบพบว่าระบบทั้งหมดที่พัฒนาขึ้นสามารถนำไปใช้ในการตรวจวัดที่ใกล้เคียงกับการนำไปใช้งานจริงนอกสถานพยาบาลได้อย่างเหมาะสม จึงทำให้มีความเป็นไปได้ในการนำระบบที่ได้พัฒนาขึ้นนี้ไปใช้ในการตรวจคัดกรองโรคนิ้วไตแบบไม่รุกล้า (Non-invasive) ได้ต่อไป

Surface Functionalization Via Photoinitiated Radical Polymerization For Rare Cell Isolation And Mechanical Protection, Calvin Frank Cahall

Theses and Dissertations--Chemical and Materials Engineering

Surface functionalization of living cells for cell therapeutics has gained substantial momentum in the last two decades. From encapsulating islets of Langerhans, to cell laden gels for tissue scaffolds, to individual cell encapsulation in thin hydrogels, to surface adhesives and inert surface camouflage, modification of living cell surfaces has a wide array of important applications. Here we use hydrogel encapsulation of individual cells as a mode of protection from mechanical forces for high throughput cell printing, and chemical stimuli for the isolation of rare cells in blood.

In the first study, we review methods of surface functionalization and establish a …

Using Crosslinked Hyaluronic Acid (Ha) And Collagen Scaffolds With Sustained Brain-Derived Neurotrophic Factor (Bdnf) Release For Post-Sci Nerve Regeneration, Panth Doshi

UROP Posters

Traumatic events resulting in spinal cord injuries (SCIs) often leave people paralyzed or with partial loss of motor function. The physical disabilities arising from traumatic events prevent people from functioning at the same level as pre-injury. My work aims to identify a plausible method to overcome the inhibitory post-SCI environment and to regenerate nervous tissue in order to restore neural function and, subsequently, motor function. I identified components of a new, hypothetical nerve scaffold based on the immune response after SCIs and the efficacy of currently used scaffolds for nerve regeneration. Hyaluronic acid (HA) polymer scaffolds and collagen-based scaffolds are …

Degradability Of Poly(Ethylene) Based Microgels And Methods Of Improving High Polydispersity Index, Abrar Alniemi

Williams Honors College, Honors Research Projects

In order to improve upon the utilization of poly(ethylene glycol) (PEG) microgel-based scaffolds in drug delivery applications, this work explores the use of degradable and non-degradable PEG for tunable scaffolds. Previously, issues concerning the required uniformity in microgel size and low polydispersity index have been encountered. As such, methods of refining polymer synthesis, microgel fabrication, and microgel size separation were explored. Overall, no solution has been found to correct the issue for the microgels were still observed to have high polydispersity index regardless of varied troubleshooting alterations.

Development Of Entubulation Strategies For Treating Central Nervous System Injuries, Ivy Brosch

Williams Honors College, Honors Research Projects

According to the McKnight Brain Institute, at least 10,000 people annually in the USA suffer from a central nervous system (CNS) injury. These injuries can cause serve disabilities including paralysis. Due to the complexity of the spinal cord, it is common that potential CNS treatments are first applied to an optic nerve crush (ONC) model in rats. Two proposed treatments were employed; one where nerve growth factor (NGF) was immobilized to a chitosan substrate to stimulate axonal regeneration, and the other using pentadecafluorooctanoyl chloride modified methacrylamide chitosan (MAC(Ali15)F) hydrogel to enhance local oxygenation. The two different treatments were formed into …

Modification Of Bacterial Cellulose Using Organosilanes To Enhance Cell Adhesion And Growth, Kristi Ferrato

Williams Honors College, Honors Research Projects

In this project, drying bacterial cellulose (BC) to maintain its structural integrity, and treating BC with organosilanes 3-aminopropyltriethoxysilane (APTES) and (3-Mercaptopropyl)trimethoxysilane (MPTMS) as well as with various concentration of gelatin to increase the cells per area was studied. Drying BC with hexamethyldisilazane (HMDS) by soaking the BC in ascending concentrations of ethanol and HMDS did not protect the structural integrity of the BC grown in lab but did for the BC grown in Dr. Siriporn Taokaew’s lab. Freeze drying also did not fully protect the structural integrity as the BC was placed in a freezer for several hours at -20oC …

Reducing Uncertainty In Head And Neck Radiotherapy With Plastic Robotics, Mark R. Ostyn

Theses and Dissertations

One of the greatest challenges in achieving accurate positioning in head and neck radiotherapy is that the anatomy at and above the cervical spine does not act as a single, mechanically rigid body. Current immobilization techniques contain residual uncertainties that are especially present in the lower neck that cannot be reduced by setting up to any single landmark. The work presented describes the development of a radiotherapy friendly mostly-plastic 6D robotic platform for positioning independent landmarks, (i.e., allowing remote, independent positioning of the skull relative to landmarks in the thorax), including analysis of kinematics, stress, radiographic compatibility, trajectory planning, physical …

Engineering Surface Properties To Modulate Inflammation And Stem Cell Recruitment Through Macrophage Activation, Kelly M. Hotchkiss

Theses and Dissertations

Biomaterials are becoming the most commonly used therapeutic method for treatment of lost or damaged tissue in the body. Metallic materials are chosen for high strength orthopaedic and dental applications. Titanium (Ti) implants are highly successful in young, healthy patients with the ability to fully integrate to surrounding tissue. However the main population requiring these corrective treatments will not be healthy or young, therefore further research into material modifications have been started to improve outcomes in compromised patients. The body’s immune system will generate a response to any implanted material, and control the final outcome. Among the first and most …

Optimization Of Plga And Plga-Dasatinib Particles Through A Taguchi Design Approach, Rayeanne N Balgemann

Electronic Theses and Dissertations

Proliferative vitreoretinopathy (PVR) is a disease of the retina in the human eye. Retinal pigment epithelium cells (RPE) undergo an epithelial to mesenchymal transition in response to retinal trauma. This transition gives the cells mobility and allows them to potentially infiltrate the vitreous chamber and deposit on either side of the retina. Once cell deposition has occurred, along with several other transformed cells derived from cell types such as Müller glia, these migratory cells can form a membrane contiguous with the retinal extracellular matrix and, upon contraction, cause wrinkling of the retina. If left untreated PVR can lead to traction …

Wild-Type P53 Enhances Endothelial Barrier Function By Mediating Rac1 Signalling And Rhoa Inhibition, Nektarios Barabutis, Christiana Dimitropoulou, Betsy Gregory, John D. Catravas

Bioelectrics Publications

Inflammation is the major cause of endothelial barrier hyper-permeability, associated with acute lung injury and acute respiratory distress syndrome. This study reports that p53 "orchestrates" the defence of vascular endothelium against LPS, by mediating the opposing actions of Rac1 and RhoA in pulmonary tissues. Human lung microvascular endothelial cells treated with HSP90 inhibitors activated both Rac1- and P21-activated kinase, which is an essential element of vascular barrier function. 17AAG increased the phosphorylation of both LIMK and cofilin, in contrast to LPS which counteracted those effects. Mouse lung microvascular endothelial cells exposed to LPS exhibited decreased expression of phospho-cofilin. 17AAG treatment …

Dielectric Properties Of Isolated Adrenal Chromaffin Cells Determined By Microfluidic Impedance Spectroscopy, A. C. Sabuncu, M. Stacey, G. L. Graviso, N. Semenova, P. T. Vernier, N. Leblanc, I. Chatterjee, J. Zaklit

Bioelectrics Publications

Knowledge of the dielectric properties of biological cells plays an important role in numerical models aimed at understanding how high intensity ultrashort nanosecond electric pulses affect the plasma membrane and the membranes of intracellular organelles. To this end, using electrical impedance spectroscopy, the dielectric properties of isolated, neuroendocrine adrenal chromaffin cells were obtained. Measured impedance data of the cell suspension, acquired between 1 kHz and 20 MHz, were fit into a combination of constant phase element and Cole-Cole models from which the effect of electrode polarization was extracted. The dielectric spectrum of each cell suspension was fit into a Maxwell-Wagner …

A Preliminary Evaluation Of The Ability Of Keratotic Tissue To Act As A Prognostic Indicator Of Hip Fracture Risk, J. Renwick Beattie, Diane Feskanich, M. Clare Caraher, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Studies have shown that Raman spectroscopic analysis of fingernail clippings can help differentiate between post-menopausal women who have and who have not suffered a fracture. However, all studies to date have been retrospective in nature, comparing the proteins in nails sourced from women, post-fracture. The objective of this study was to investigate the potential of a prospective test for hip fracture based on spectroscopic analysis of nail tissue. Archived toenail samples from post-menopausal women aged 50 to 63 years in the Nurses' Health Study were obtained and analysed by Raman spectroscopy. Nails were matched case-controls sourced from 161 women; 82 …

Eeg And Emg Sensorimotor Measurements To Assess Proprioception Following Acl Reconstruction, Teagan Frances Northrup

Honors Theses and Capstones

The Anterior Cruciate Ligament (ACL) is the primary source of rotational stability in the knee by preventing the tibia from sliding in front of the femur. When the ACL is torn, it typically must be repaired through reconstructive surgery which results in proprioceptive deficiencies in the knee. Proprioception plays an important role in understanding where one’s knee is in space, sensing movement and reacting accordingly. This study examines an alternative method of measuring proprioceptive responses to a stimulus (motion) by using electromyogram (EMG) and electroencephalogram (EEG) signals to observe muscle and brain activity. Two participants (one with an ACL reconstruction …