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Biomedical Engineering and Bioengineering Commons™

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Articles 31 - 60 of 88

Full-Text Articles in Biomedical Engineering and Bioengineering

Scratch Damage Evolution On Metals In Total Joint Replacements, Caleb Eljach Dec 2013

Scratch Damage Evolution On Metals In Total Joint Replacements, Caleb Eljach

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The goal of total joint replacement (TJR) is to replace nonfunctioning joint components and relieve pain, improve quality of life, and to improve joint function. Although TJR is a successful procedure, more than 54,000 knee revisions occur each year due to factors, such as wear, loosening, infection, fracture, instability, and patient related factors (Ranawat, 2010). TJRs consist of components typically composed of polyethylene and a metallic counterface (Navarro, 2008). The sliding contact that occurs between the metal and polyethylene components has been well studied and is shown to produce both surface damage and wear of the implant components (Barbour, 1997; …

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Interstitial Cell Seeding And Dynamic Conditioning Of Aortic Heart Valve Scaffolds, Allison Kennamer Dec 2013

Interstitial Cell Seeding And Dynamic Conditioning Of Aortic Heart Valve Scaffolds, Allison Kennamer

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In 2011, U.S. Markets for Heart Valve Repair and Replacement Products estimated that roughly four million people in the United States are diagnosed with a heart valve disorder annually. And in the following year, the American Heart Association reported that approximately 35,000 deaths in the US were either directly or indirectly attributed to heart valve disease. Diseases of the heart valve are degenerative in nature and therefore progressively worsen unbeknownst to the patient until symptoms become clinically relevant. By this time, the valve is in such poor condition that complete replacement is often the only effective treatment. Current solutions are …

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Functional Stroke Recovery Through Tissue Engineered Niche Neural Constructs, Natasha Topoluk Dec 2013

Functional Stroke Recovery Through Tissue Engineered Niche Neural Constructs, Natasha Topoluk

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According to the Centers for Disease Control and Prevention, stroke is statistically responsible for 1 in every 19 deaths of American citizens.5 Stroke is the leading cause of permanent disability due to the fact that it compromises both cellular and tissue components of the brain, leading to the formation of a physical void within the tissue. Current research approaches address the cellular component by injecting stem cells into this void; however, extremely low cell engraftment, high injected cell death, and overall no matrix regeneration are observed. Additionally, these stem cells do not remain committed to a neural lineage. We propose …

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The Development Of A Rapid Fiber-Based Immunoassay As A Point-Of-Care Or In-Home Diagnostic Test, Christopher Waddell Aug 2013

The Development Of A Rapid Fiber-Based Immunoassay As A Point-Of-Care Or In-Home Diagnostic Test, Christopher Waddell

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Early diagnosis of conditions allows for physicians to treat patients earlier, and ultimately improve patient outcomes. Two conditions of particular interest for earlier and cheaper diagnosis are the influenza virus and human immunodeficiency virus (HIV). Antiviral treatment administered within the first 48 hours of influenza infection decreases symptom severity, risk of complications, and reduced healthcare costs. Early diagnosis of HIV can decrease the risk of transmission of the virus to HIV negative individuals and allow for earlier administration of highly active antiretroviral treatment (HAART), improving patient quality of life and patient outcomes.
Currently, the 'gold standard' for detection of both …

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Problems In The Study And Use Of Ac Dielectrophoresis And Their Consequences: A Study Based On Comsol Multiphysics Modeling, Vandana Devi Pandian Babu Aug 2013

Problems In The Study And Use Of Ac Dielectrophoresis And Their Consequences: A Study Based On Comsol Multiphysics Modeling, Vandana Devi Pandian Babu

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Dielectrophoresis (or DEP) is an important phenomenon which is induced when a dielectric particle is placed in a non-uniform electric field. The force generated by DEP has been exploited for various micro and nano fluidics applications like positioning, sorting and separation of particles involved in medical diagnostics, drug discovery, cell therapeutics, biosensors, microfluidics, nanoassembly, particle filtration etc. The integration of DEP systems into the microfluidics enables inexpensive, fast, highly sensitive, highly selective, label-free detection and also the analysis of target bioparticles.

This work aims to provide a complete compilation of the factors affecting the DEP force. It elucidates the underlying …

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Experimental Development And Analysis Of A Novel Setup For Insulated Dielectrophoresis, Johnie Hodge Aug 2013

Experimental Development And Analysis Of A Novel Setup For Insulated Dielectrophoresis, Johnie Hodge

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Dielectrophoresis has long been studied and utilized for the manipulation of microscale particles in solution. This phenomenon is due to the induced polarization of dielectric particles subjected to an electric field. When the field is also inhomogeneous in terms of the distribution of its strength through space, the polarized particles move and come to rest in certain areas due to the relationship between their and the solvent's relative permittivities. If the electric field is homogenous, such as within a parallel plate capacitor, the particles are polarized according to their permittivity and the field's frequency, but they will not move.
These …

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Extraction Of Antioxidants From Animal Blood And Its Potential Application As A Pet Food Preservative, Chengyi Tu Aug 2013

Extraction Of Antioxidants From Animal Blood And Its Potential Application As A Pet Food Preservative, Chengyi Tu

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Nowadays, more and more people are having pets as members of their family. To the year of 2012, there are 78.2 million dogs and 86.4 million cats owned in the U.S according to the report of the Humane Society of the U.S. The pet food industry as a result has been prosperous, with an estimated market size of $21 billion in the year of 2013. However, there is a common problem for the industry - fat rancidification. Pet foods usually contain relatively high levels of fat, which, if not well protected, are prone to oxidation and generate unfavorable products including …

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Evaluating Mechanical Performance Of Hydrogel-Based Adhesives For Soft Tissue Applications, Nitin Balakrishnan May 2013

Evaluating Mechanical Performance Of Hydrogel-Based Adhesives For Soft Tissue Applications, Nitin Balakrishnan

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According to the National Center for Health Statistics, an estimated 22 million women have undergone a hysterectomy procedure in the United States. The most common complication during hysterectomies is accidental laceration of the urinary bladder during the surgery with incidence between 0.2-8.3% with the current gold standard wound repair method being sutures. Yet, sutures come with their own limitations in that they necessitate use of a catheter and collection bag during healing due to preventing proper distention of the bladder tissue at normal pressures. The long-term goal of our study is to eliminate the need for suturing by creating a …

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Evaluation Of Angular Velocity Data From Inertial Measurement Units For Use In Clinical Settings, Chelsea Ex-Lubeskie May 2013

Evaluation Of Angular Velocity Data From Inertial Measurement Units For Use In Clinical Settings, Chelsea Ex-Lubeskie

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Evaluating the human gait cycle with inertial measurement units (IMU) may prove beneficial for applications such as diagnoses of musculoskeletal diseases and assessment of rehabilitation regimes. An IMU system is potentially applicable for diagnosing and assessing rehabilitation outcomes for a variety of neuromuscular diseases since it is small, portable, and less expensive than a camera system. IMUs directly measure angular velocity, whereas position data from a camera system must be processed twice to obtain this information. The purpose of this research is to determine repeatability of IMU angular velocity data, and agreement between angular velocity data from an IMU system …

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Development Of An Ex Vivo Tissue Testing System For Three Dimensional Biomechanical Analysis Of Abdominal Aortic Aneurysm, Bradley Johns May 2013

Development Of An Ex Vivo Tissue Testing System For Three Dimensional Biomechanical Analysis Of Abdominal Aortic Aneurysm, Bradley Johns

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Abdominal aortic aneurysms (AAA) are localized, progressive dilations of the aortic wall and are the 13th most common cause of death in the United States (~15,000 per year) and surgery is usually recommended when the aneurysm is 5 cm or larger in diameter. Because of this clinical parameter, previous studies of AAA biomechanics have utilized a one-dimensional analysis that focuses solely on changes in wall diameter and have attempted to model geometric changes with mathematical formulas, generally based on the LaPlace equation. This is not sufficient however, as the mechanical behavior of the tissue at sites of aneurysm have been …

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A Regenerative Medicine Approach To Improved Tendon Healing And Repair, Grace Margaret Dion May 2013

A Regenerative Medicine Approach To Improved Tendon Healing And Repair, Grace Margaret Dion

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Surgical repair of torn tendons is a common orthopaedic procedure in the United States, with nearly 400,000 repairs occurring annually. Despite improvements in surgical techniques used to re-attach the tendon to its boney insertion, clinically successful outcomes amongst patients are variable and re-tear rates can be exceedingly high. The use of stem cells as an adjunct to surgical repair to aid in improving tendon healing and repair strength has gained much interest amongst the clinical community. Accordingly, many investigators have begun examining the ability of stem cells to differentiate into tenocytes using various methodologies including the application of growth factors …

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Characterization Of Potential Wear Sources In Knee Arthroplasty Prostheses After In Vivo Function, Nicole Durig May 2013

Characterization Of Potential Wear Sources In Knee Arthroplasty Prostheses After In Vivo Function, Nicole Durig

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Total joint arthroplasty (TJA) is a common procedure generally performed in patients with osteoarthritis. While TJA continues to be a successful treatment for degenerative joint disease, there are many studies that demonstrate wear and its sequelae as the major limitation of joint replacement longevity. Previous studies have shown that wear debris originates from four main locations: articulating surfaces, modular component surfaces, surfaces of fixation, and adjuvant fixation devices. Each of these possible wear sources can initiate the cascade of failure associated with wear-induced osteolysis and lead to subsequent revision surgery. The objective of this thesis is to characterize the in …

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Post-Market Surveillance Of Total Knee Replacement Combining Clinical Outcomes And Quantitative Image Processing Techniques, Leah Nunez May 2013

Post-Market Surveillance Of Total Knee Replacement Combining Clinical Outcomes And Quantitative Image Processing Techniques, Leah Nunez

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Total knee replacement (TKR) is a successful procedure for the relief of pain, correction of deformity, and restoration of function in patients with knee arthritis.1-3 In the United States, the number of primary TKR surgeries performed in 2030 is projected to be between 2,938,000 to 4,136,000 and revision surgeries between 193,000 to 381,000.4 Osteolysis, pain, and aseptic loosening are the most common causes of revision TKR surgery.5 The purpose of this thesis is to complete assessments for post-market surveillance of total knee replacement (TKR) targeting areas for improving polymer bearings through evaluation of clinical outcomes and analysis of prosthesis retrieved …

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Dynamic Transcriptional Response Of Escherichia Coli To Inclusion Body Formation, Faraz Baig May 2013

Dynamic Transcriptional Response Of Escherichia Coli To Inclusion Body Formation, Faraz Baig

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Escherichia coli is used intensively for recombinant protein production due to its many unique advantages, but one key challenge with the use of E. coli is the tendency of recombinant proteins to misfold and aggregate into insoluble inclusion bodies (IBs). The presence of IBs stresses cells and can hinder overall growth. Additionally, IBs contain high concentrations of recombinant protein in an inactive form and thus require recovery steps to salvage functional recombinant protein. Currently, no universally effective method exists to prevent IB formation in recombinant E. coli. Further research into the gene expression response to insoluble recombinant protein may …

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The Effects Of Low Dose Ionizing Radiation Exposure On The Metabolic And Mechanical Properties Of Articular Cartilage, Carl Lindburg Dec 2012

The Effects Of Low Dose Ionizing Radiation Exposure On The Metabolic And Mechanical Properties Of Articular Cartilage, Carl Lindburg

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Radiation therapy is necessary treatment for many cancer patients due to its non-surgical, yet aggressive and efficacious properties. In fact, over 50% of patients with cancer will undergo some form of radiotherapy during the course of their treatment. While the biological response to ionizing radiation has been examined over the years and many adverse effects have been identified, the effects of radiation on mature cartilage and musculoskeletal tissues are not well understood. Bone, once thought to be a tissue relatively resistant to radiation, has recently been shown to have osteoporosis-like bone atrophy after exposure to low doses (2 Gy) of …

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Bioswellable Amphiphilic Copolymers, David Ingram Dec 2012

Bioswellable Amphiphilic Copolymers, David Ingram

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The suture is one of the most commonly used medical devices, consisting of a fiber, a surgical needle and the packaging in which it is stored. The fiber itself remains after implantation for a defined time and is responsible for the approximation of the wound during the healing process. The needle merely serves to aid in insertion, and preferably has a diameter larger than the diameter of the fiber .
The 1970's marked the birth of a new family of fibrous materials for the approximation of wounds: synthetic absorbable sutures. This family has the ability to provide wound support during …

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Effects Of Physiological Dynamic Compression Loading On Gold Nanoparticle Permeation Of Articular Cartilage, Britton Mccaskill Aug 2012

Effects Of Physiological Dynamic Compression Loading On Gold Nanoparticle Permeation Of Articular Cartilage, Britton Mccaskill

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Articular cartilage is essential part of the human body that aids in support and locomotion. It has unique biochemical and biomechanical properties that allow it to act as a shock absorber to disperse and distribute loading of the joints. However, it has a limited capacity to repair itself because it is not vascularized and must receive its nutrients from the surrounding synovial fluid. Articular cartilage damage can lead to many pathological conditions, including osteoarthritis. Currently, there are many surgical treatment methods that repair some of the damage if it is localized, but for widespread degradation seen in osteoarthritis, there are …

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Oral Delivery Of Peptide Drugs For Mitigation Of Crohn's Disease, Paul Blichmann Aug 2012

Oral Delivery Of Peptide Drugs For Mitigation Of Crohn's Disease, Paul Blichmann

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Protein drugs are typically administered intravenously, but this practice has clear disadvantages such as widespread circulation and swift clearance from the body. Orally delivered protein drugs are not yet available but potentially offer improved distribution, retention, and activity by use of protective matrices and cell-specific targeting. Much work has been done on delayed release formulations for the upper intestine, but there has not been overwhelming evidence of protection of peptides from gastric conditions. In many instances the large intestine may be a better release target due to lower proteolytic activity. Afflictions of the colon such as Inflammatory Bowel Disease and …

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The Formulation Of A Bone Targeted Drug Delivery System Of Poly(Glycolic Acid)-Poly(Ethylene Glycol) Coated Hydroxyapatite Nanoparticles For The Delivery Of Statins, Erika Jelen Aug 2012

The Formulation Of A Bone Targeted Drug Delivery System Of Poly(Glycolic Acid)-Poly(Ethylene Glycol) Coated Hydroxyapatite Nanoparticles For The Delivery Of Statins, Erika Jelen

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Bone is a form of mineralized connective tissue that provides strength and rigidity to the skeleton. The two primary components within bone tissue are an organic extracellular matrix, containing type I collagen, and an inorganic mineral component composed mainly of calcium phosphate hydroxyapatite crystals. Over time the microarchitecture of bone can break down due to a variety of different factors, mainly the onset of osteoporosis in post-menopausal women, Paget's disease, and the experience of a loss of gravity during space flight. Currently there are about ten million people in the United States alone suffering from osteoporosis.
The prevention of further …

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Stabilization Of Extracellular Matrix Components In Bioprosthetic Heart Valves Using Neomycin And Pentagalloyl Glucose Enhanced Crosslinking, Daniel Tripi Aug 2012

Stabilization Of Extracellular Matrix Components In Bioprosthetic Heart Valves Using Neomycin And Pentagalloyl Glucose Enhanced Crosslinking, Daniel Tripi

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Bioprosthetic heart valves (BHVs) fail within 12-15 years of implantation due to limited durability. This limits their application to elderly population. Younger patients with contraindications for long-term anticoagulant therapy necessary for mechanical heart valves may also receive BHVs. Investigation into improving valve durability can lead to longer implant life, increased quality of life for patients receiving BHVs, and a broadened patient demographic.
Current BHVs are chemically treated with glutaraldehyde (GLUT) to stabilize collagen via chemical crosslinking and to reduce tissue antigenicity. GLUT fails to adequately stabilize elastin and glycosaminoglycans (GAGs), essential extracellular matrix components for valve function and durability. Degradation …

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The Effects Of Coated Gold Nanorods On Porcine Atrioventricular Valve Tissues Using Atomic Force Microscopy, Heather L'Ecuyer May 2012

The Effects Of Coated Gold Nanorods On Porcine Atrioventricular Valve Tissues Using Atomic Force Microscopy, Heather L'Ecuyer

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In this Master's thesis we examine the effect of surface modified gold nanorods (AuNRs) coated with polyelectrolyte multilayers (PEMs) on the mechanical properties of porcine mitral valve tissue ex vivo. The presence of healthy mitral valve tissue in the body is important to ensuring unidirectional flow of blood through the systemic circuit. Unfortunately, due to its anatomic complexity and unique mechanical behavior, pathological mitral valve tissue remains difficult to treat with conventional methods. We hope that the knowledge gleaned from these studies could be useful for developing new and novel treatments treating pathological mitral valve mechanical properties.
Specifically, we examine …

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Effects Of Different Microenvironmental Conditions On The Growth And Differentiation Of Dental Pulp Stem Cells, Matthew Cupelli May 2012

Effects Of Different Microenvironmental Conditions On The Growth And Differentiation Of Dental Pulp Stem Cells, Matthew Cupelli

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Human teeth are very complex structures that are susceptible to many different pathologies due to poor dental health. Currently, there are many restorative methods to reestablish some of the function that teeth have, but the materials used in these methods all have drawbacks and cannot fully mimic the native teeth. Tissue engineering research groups have begun to explore regenerating bone or dental tissue using mesenchymal stem cells derived from the bone marrow. However, our group focuses on regenerating dental tissues using multipotent stem cells from dental pulp.
Dental pulp stem cells (DPSCs) have shown similarities to bone marrow stem cells …

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Development Of A Lower Extremity Mobility Assessment Methodology For Motor Vehicle Operation And Initial Validation, Justin Arnosky May 2012

Development Of A Lower Extremity Mobility Assessment Methodology For Motor Vehicle Operation And Initial Validation, Justin Arnosky

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Limited quantifiable data exists on lower extremity mobility and function during driving. To date, the most appropriate existing measures of successful driving function are assessed by a driving rehabilitation specialist during an on-road evaluation. Establishing the kinematic chain- or the order and magnitude in which joints are moved- during driving may prove to be a useful tool in lower extremity function assessment in drivers. To this end, a study was conducted instrumenting both the left and right legs of healthy licensed male drivers (18-26 years old) with a system of angle measuring goniometers (Biometrics, Ltd.) in a driving simulator (DriveSafety …

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Electrochemical Capacitance Measurements To Study Molecular Surface Interactions, Nrutya Madduri May 2012

Electrochemical Capacitance Measurements To Study Molecular Surface Interactions, Nrutya Madduri

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The behavior of biological molecules such as proteins at the electrode/electrolyte has been of considerable interest for the development of biosensors. Several investigative techniques including Potentiometry, Voltammetry, Amperometry, and Electrochemical Impedance Spectroscopy are being employed to study and analyze these molecular surface interactions. Investigative techniques such as cyclic voltammetry involve the application of a large potential to probe the electrode characteristics and capture the bulk membranous events to obtain the required measurements. This study looks to achieve two major objectives through the use of a novel technique, namely, the double layer capacitive method: 1) to analyze the electrochemical behavior of …

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Dynamic Endothelialization Of Aortic Heart Valve Scaffolds, Richard Pascal Jan 2012

Dynamic Endothelialization Of Aortic Heart Valve Scaffolds, Richard Pascal

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Cardiovascular disease is the number one killer worldwide affecting both the heart and blood vessels. Valvular heart disease can arise from calcification, and structural deterioration resulting in a stenotic or regurgitant valve incapable of proper function. With approximately 275,000 valve replacements performed annually worldwide, the need for replacement heart valves is well established. Currently, treatment of valvular heart disease is limited to two options (mechanical and bioprosthetic). Both replacement valves have their own drawbacks, which have driven research in the bioengineering field to focus on the development of a tissue engineered heart valve (TEHV) capable of growth and self-repair.
A …

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A Computational Investigation For Potential Improvements, Angela Grujicic Dec 2011

A Computational Investigation For Potential Improvements, Angela Grujicic

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Mild traumatic brain injury (mTBI), colloquially known as a concussion, is the most common injury in modern wars. This domination of mTBI is hypothesized to be due to a combination of unconventional explosives and better protection and care of the patients, increasing survivability. While the majority of the body is covered in armor, the head is left relatively unprotected. The current Advanced Combat Helmet (ACH) has been designed to protect the warfighter against ballistic impacts and impacts against a hard surface, with little to no regard to blast loading. Polyureas, a class of microsegregated, elastomeric copolymers, has been shown to …

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'Exploring The Potential Of Using Antimicrobial Peptides And Copper Nanoparticles In Tackling Surgical Site Infections', Sriram Sankar Dec 2011

'Exploring The Potential Of Using Antimicrobial Peptides And Copper Nanoparticles In Tackling Surgical Site Infections', Sriram Sankar

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Postoperative wound site infections remain a major source of illness with approximately 500,000 infections per year, among an estimated 27 million surgical procedures. Such infections account for approximately one quarter of the estimated 2 million nosocomial infections in the United States which causes about 90,000 deaths each year. More than 70% of the bacteria that causes such infections are resistant to at least one of the antibiotics and result in longer hospitalization; besides requiring second option treatments that may be less effective, more toxic and expensive. Hence, there is a frenetic search for alternatives and in this regard, antimicrobial peptides …

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Vascular Smooth Muscle Cells In Response To Gold Nanoparticles, William Mcallister May 2011

Vascular Smooth Muscle Cells In Response To Gold Nanoparticles, William Mcallister

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In this master's thesis we look at elucidating the interactions between nanoparticles and cells. Specifically, we looked at how the cell mechanics are affected, cytotoxicity of the nanoparticles, and shifts in cell phenotypes. There has been much research looking into whether nanoparticles are cytotoxic, but limited amounts looking at their effect on mechanics especially with vascular smooth muscle cells. This cell type has two distinct phenotypes of synthetic and contractile that each serve different purposes physiologically.
The first experiments we did were cytotoxicity assays to see if the cells could survive the treatment with nanoparticles. If the cells died within …

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Effects Of Microenvironment On Growth And Differentiation Of Human Dental Pulp Cells, Laura Datko May 2011

Effects Of Microenvironment On Growth And Differentiation Of Human Dental Pulp Cells, Laura Datko

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Dental pulp stem cells (DPSCs) have recently been described as a potential stem cell source for various regenerative medicine and tissue engineering applications. They appear to be multipotent, however more characterization is necessary to determine the true potential of these cells. An important aspect of using DPSCs, or any stem cell type, tissue engineering application is the microenvironment within the construct. The microenvironment could include construct mechanical properties, construct composition, and 3D dynamic conditions in vivo. This work aims to study those specific microenvironment effects on DPSCs. To determine the effects of mechanical properties of the substrate on DPSCs, they …

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Exploring The Potential Of Inkjet Printing For The Fabrication Of Tissue Test Systems, Vidya Seshadri Jan 2011

Exploring The Potential Of Inkjet Printing For The Fabrication Of Tissue Test Systems, Vidya Seshadri

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Animal models and two-dimensional assays involved in drug testing, vaccine development and basic scientific discovery are not an accurate representation of the human body; hence there is a need to develop new bench top methodologies which are better suited to yield information about in vivo behavior. There is a paucity of reliable in vitro-derived information regarding the reasons for the cause and progression of diseases. These concerns have lead to the development of three-dimensional systems which can facilitate improved understanding of disease etiology and also can bridge the path to the clinic.
The long term goal, beyond the scope of …

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