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Full-Text Articles in Biomedical Engineering and Bioengineering

Identification Of Novel Genes Regulating Elastic Fiber Formation Through Expression Profiling Analysis Of Elastogenic Models, Erin Sproul Dec 2013

Identification Of Novel Genes Regulating Elastic Fiber Formation Through Expression Profiling Analysis Of Elastogenic Models, Erin Sproul

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Background: Particularly important to the mechanical performance of native arterial blood vessels is elastin, an extracellular matrix (ECM) protein deposited by VSMCs in the form of elastic fibers, arranged in concentric lamellae in the media of the vessel wall. In addition to serving as major structural elements of arterial walls, providing extensibility and elastic recoil, elastic fibers also influence vascular cell behaviors. For these reasons tissue engineers are attempting to exploit elastic fiber biology to enhance vascular graft design and patency. Therefore, developing a greater understanding of the molecular mechanisms of elastogenesis may offer opportunities to control elastogenesis in tissue ...


Vascular Nanomedicine: Site Specific Delivery Of Elastin Stabilizing Therapeutics To Damaged Arteries, Aditi Sinha Dec 2013

Vascular Nanomedicine: Site Specific Delivery Of Elastin Stabilizing Therapeutics To Damaged Arteries, Aditi Sinha

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Elastin, a structural protein in the extra-cellular matrix, plays a critical role in the normal functioning of blood vessels. Apart from performing its primary function of providing resilience to arteries, it also plays major role in regulating cell-cell and cell-matrix interactions, response to injury, and morphogenesis. Medial arterial calcification (MAC) and abdominal aortic aneurysm (AAA) are two diseases where the structural and functional integrity of elastin is severely compromised. Although the clinical presentation of MAC and AAA differ, they have one common underlying causative mechanism--pathological degradation of elastin. Hence prevention of elastin degradation in the early stages of MAC and ...


In Vitro Simulation Of Pathological Bone Conditions To Predict Clinical Outcome Of Bone Tissue Engineered Materials, Duong Nguyen Dec 2013

In Vitro Simulation Of Pathological Bone Conditions To Predict Clinical Outcome Of Bone Tissue Engineered Materials, Duong Nguyen

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According to the Centers for Disease Control, the geriatric population of ≥65 years of age will increase to 51.5 million in 2020; 40% of white women and 13% of white men will be at risk for fragility fractures or fractures sustained under normal stress and loading conditions due to bone disease, leading to hospitalization and surgical treatment. Fracture management strategies can be divided into pharmaceutical therapy, surgical intervention, and tissue regeneration for fracture prevention, fracture stabilization, and fracture site regeneration, respectively. However, these strategies fail to accommodate the pathological nature of fragility fractures, leading to unwanted side effects, implant ...


Biological Scaffolds For Peripheral Vascular Surgery, George Fercana Dec 2013

Biological Scaffolds For Peripheral Vascular Surgery, George Fercana

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The gold standards for small diameter peripheral vascular graft replacement are autologous arteries or veins; however, one-third of patients lack such vessels due to previous vessel harvesting or advanced vascular disease. A promising approach for patients in this category is tissue engineering with off-the-shelf biological vascular grafts. Three small diameter acellular scaffolds were developed and evaluated as vascular grafts. Porcine renal arteries (2-3 mm diameter, 20 mm length) were decellularized by immersion and stabilized with penta-galloyl glucose (PGG) with and without subsequent heparinization via carbodiimide chemistry. Bovine mammary (4-6 mm ID, 250 mm length) and femoral arteries (6-8 mm ID ...


Engineering Beta-Cell Spheroids For Type 1 Diabetes Treatment, Xiaoyan Liu Dec 2013

Engineering Beta-Cell Spheroids For Type 1 Diabetes Treatment, Xiaoyan Liu

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Diabetes mellitus, the third most common disease in the world, is a chronic metabolic disorder caused by a failure of insulin production and/or an inability to respond to insulin. Specifically, type 1 diabetes is a disorder characterized by targeted autoimmune-directed destruction of a patient's beta-cell population within the pancreatic islets of Langerhans. The current primary treatment for type 1 diabetes is daily multiple insulin injections. However, this treatment cannot provide sustained physiological release, and the insulin amount is not finely tuned to glycemia. Pancreatic transplants or islet transplants would be the preferred treatment method but the lack of ...


Ion Channel-Mediated Hydrostatic Pressure Mechanotransduction In Urothelial Cells, Kevin Champaigne Aug 2013

Ion Channel-Mediated Hydrostatic Pressure Mechanotransduction In Urothelial Cells, Kevin Champaigne

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A majority of men and women aged 40 and over experience lower urinary tract symptoms, including urgency, incontinence, and frequency, which often affect the individual's quality of life. Although often considered a simple structure, the bladder is a complex system with sophisticated sensory and motor feedback mechanisms that allow for the sensation of fullness and pain, reflexive responses to bladder filling, and conscious control over the time and place of micturition. Although disruptions of these sensory mechanisms are believed to cause certain lower urinary tract dysfunctions, the specific mechanisms involved in sensing bladder fullness, distension, tension, or pressure at ...


Spatial Control Of Magnetic Nanoparticles Integrated With Cellular Spheroids As Tissue Engineered Building Blocks, Brandon Mattix Aug 2013

Spatial Control Of Magnetic Nanoparticles Integrated With Cellular Spheroids As Tissue Engineered Building Blocks, Brandon Mattix

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Magnetic nanoparticles (MNPs) have been investigated in tissue engineering applications to provide in situ imaging, drug delivery, and tissue patterning, but direct and prolonged interaction between cells and MNPs can have adverse effects on cell function. Therefore, methods which reduce or limit the interaction of MNPs with cells, or utilize more biocompatible MNP-based strategies will improve upon the commonly used iron oxide MNPs. We investigated a variety of methods to improve upon the use of MNPS in tissue engineering.
Cell aggregates, or spheroids, have been used as tissue engineered building blocks that can closely mimic the native three-dimensional in vivo ...


A Novel Hybrid Hydrogel For Scaffold-Mediated Gene Delivery, Jeremy Zhang Aug 2013

A Novel Hybrid Hydrogel For Scaffold-Mediated Gene Delivery, Jeremy Zhang

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Scaffold-mediated nonviral gene delivery avoids several drawbacks of systemic injection such as clearance by the reticulo-endothelial system and serum aggregation. Existing synthetic and natural polymers used in gene delivery scaffolds are primarily derived from other tissue engineering applications with design parameters focused on the physicochemical properties of the scaffold and its biocompatibility. Common synthetic materials used in polymeric scaffolds such as PEG are practically bio-inert with minimal cell and protein interaction. Therefore, an opportunity exists for the rational design novel gene delivery scaffolds with components capable of increasing the expression of incorporated transgene by including scaffold components that interact with ...


Implantable Biosensors For Physiologic Status Monitoring During Hemorrhage, Christian Kotanen Aug 2013

Implantable Biosensors For Physiologic Status Monitoring During Hemorrhage, Christian Kotanen

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Trauma diagnostics and management are major aims of research for implantable amperometric enzyme biosensor technology. Biosensors are capable of monitoring metabolic variables in a minimally invasive manner and have great potential to augment current wireless vital sign monitoring technologies in order to make a more robust physiologic status monitoring platform. The dual responsive Electrochemical Cell-on-a-Chip Microdisc Electrode Array (ECC MDEA 5037) is a recently developed electrochemical transducer for use in a wireless, implantable biosensor system for the continuous measurement of interstitial glucose and lactate. Hyperglycemia arising from insulin resistance and hyperlactatemia arising from anaerobic metabolism both occur following trauma and ...


Feeling For Failure: Haptic Force Perception Of Soft Tissue Constraints In A Simulated Minimally Invasive Surgery Task, Lindsay Long Aug 2013

Feeling For Failure: Haptic Force Perception Of Soft Tissue Constraints In A Simulated Minimally Invasive Surgery Task, Lindsay Long

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In minimally invasive surgery (MIS), the ability to accurately interpret haptic information and apply appropriate force magnitudes onto soft tissue is critical for minimizing bodily trauma. Force perception in MIS is a dynamic process in which the surgeon's administration of force onto tissue results in useful perceptual information which guides further haptic interaction and it is hypothesized that the compliant nature of soft tissue during force application provides biomechanical information denoting tissue failure. Specifically, the perceptual relationship between applied force and material deformation rate specifies the distance remaining until structural capacity will fail, or indicates Distance-to-Break (DTB). Two experiments ...


Biofabrication Of Scaffolds For Intervertebral Disc (Ivd) Tissue Regeneration, Benjamin Whatley Aug 2013

Biofabrication Of Scaffolds For Intervertebral Disc (Ivd) Tissue Regeneration, Benjamin Whatley

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The ultimate goal of tissue regeneration is to replace damaged or diseased tissue with a cell-based or biomaterial-based tissue that accurately mimics the functionality, biology, mechanics, and cellular and extracellular matrix (ECM) composition of the native tissue. Specifically, the ability to control the architecture of tissue engineered constructs plays a vital role in all of these issues as scaffold architecture has an affect on function, biomechanics, and cellular behavior. Many tissue engineered scaffolds focus on the ability to mimic natural tissue by simulating the ECM due to the fact that in each distinct tissue, the ECM serves as a structural ...


Engineering A Biomimetic Structure For Human Long Bone Regeneration, Eleni Katsanevakis May 2013

Engineering A Biomimetic Structure For Human Long Bone Regeneration, Eleni Katsanevakis

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Bone tissue serves many functions, including structural support, protection of internal organs, and mineral and growth factor storage, to name a few. Moreover, human bone exhibits excellent mechanical properties, demonstrating superb compressive strength as well as significant elasticity, due to its collagen content. However, defects still occur at a relatively high rate in this tissue. Critical sized defects in bone are defined as defects that cannot form a union and heal on their own. These types of defects occur often, and typically require surgical intervention. The current gold standard treatment for critical sized defects in bone is the use of ...


Multifunctional Nanophosphors For Tissue Imaging And Drug Delivery, Hongyu Chen May 2013

Multifunctional Nanophosphors For Tissue Imaging And Drug Delivery, Hongyu Chen

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X-rays have been used for non-invasive high-resolution imaging of thick biological specimens since their discovery in 1895. They are widely used for structural imaging of bone, metal implants, and cavities in soft tissue. Recently, a number of new contrast methodologies have emerged which are expanding X-ray's biomedical applications to functional as well as structural imaging. However, traditional X-ray imaging provides high spatial resolution imaging through tissue but do not measure chemical concentrations. In this dissertation, we describe an X-ray excited optical luminescence (XEOL) technique which uses a scanning X-ray beam to irradiate Gd2O2S phosphors and detect the resulting visible ...


Highly Sensitive Fiber-Based Devices For Gene And Protein Analysis, Victor Maximov May 2013

Highly Sensitive Fiber-Based Devices For Gene And Protein Analysis, Victor Maximov

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Single cell probing has found a number of applications in different areas of research. It can help us to better understand cell-to-cell interactions; it has found numerous applications in immunology, cancer research, detection of pathogenic infections and genetic abnormalities. The single cell analysis is very important in stem cells research and development of cells. The main obstacle in the single cell analysis is the small amount of analyte that a single cell could provide. Another difficulty is connected to the cell-to-cell variability inside the uniform population due to the differences of single cells in size, activity, mitotic stage, and functions ...


Sustained Release Of Estrogens From Pegylated Nanoparticles For Treatment Of Secondary Spinal Cord Injury, John Barry May 2013

Sustained Release Of Estrogens From Pegylated Nanoparticles For Treatment Of Secondary Spinal Cord Injury, John Barry

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Spinal Cord Injury (SCI) is a debilitating condition which causes neurological damage and can result in paralysis. SCI results in immediate mechanical damage to the spinal cord, but secondary injuries due to inflammation, oxidative damage, and activated biochemical pathways leading to apoptosis exacerbate the injury. The only currently available treatment, methylprednisolone, is controversial because there is no convincing data to support its therapeutic efficacy for SCI treatment. In the absence of an effective SCI treatment option, 17β-estradiol has gained significant attention for its anti-oxidant, anti-inflammatory, and anti-apoptotic abilities, all events associated with secondary. Sadly, 17β-estradiol is associated with systemic adverse ...