Matching Items (24)
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- All Subjects: Traumatic Brain Injury
- All Subjects: Biomedical
- Creators: Harrington Bioengineering Program
- Resource Type: Text
Description
Traumatic brain injury (TBI) may result in numerous pathologies that cannot currently be mitigated by clinical interventions. Stem cell therapies are widely researched to address TBI-related pathologies with limited success in pre-clinical models due to limitations in transplant survival rates. To address this issue, the use of tissue engineered scaffolds as a delivery mechanism has been explored to improve survival and engraftment rates. Previous work with hyaluronic acid \u2014 laminin (HA-Lm) gels found high viability and engraftment rates of mouse fetal derived neural progenitor/stem cells (NPSCs) cultured on the gel. Furthermore, NPSCs exposed to the HA-Lm gels exhibit increased expression of CXCR4, a critical surface receptor that promotes cell migration. We hypothesized that culturing hNPCs on the HA-Lm gel would increase CXCR4 expression, and thus enhance their ability to migrate into sites of tissue damage. In order to test this hypothesis, we designed gel scaffolds with mechanical properties that were optimized to match that of the natural extracellular matrix. A live/dead assay showed that hNPCs preferred the gel with this optimized formulation, compared to a stiffer gel that was used in the CXCR4 expression experiment. We found that there may be increased CXCR4 expression of hNPCs plated on the HA-Lm gel after 24 hours, indicating that HA-Lm gels may provide a valuable scaffold to support viability and migration of hNPCs to the injury site. Future studies aimed at verifying increased CXCR4 expression of hNPCs cultured on HA-Lm gels are necessary to determine if HA-Lm gels can provide a beneficial scaffold for stem cell engraftment therapy for treating TBI.
ContributorsHemphill, Kathryn Elizabeth (Author) / Stabenfeldt, Sarah (Thesis director) / Brafman, David (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
DescriptionMy main goal for my thesis is in conjunction with the research I started in the summer of 2010 regarding the creation of a TBI continuous-time sensor. Such goals include: characterizing the proteins in sensing targets while immobilized, while free in solution, and while in free solution in the blood.
ContributorsHaselwood, Brittney (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Cook, Curtiss (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2011-12
Description
The endogenous response of neural stem cell/progenitor (NPSC) recruitment to the brain injury environment following a traumatic brain injury (TBI) is currently under heavy investigation. Mechanisms controlling NPSC proliferation and migration to the brain injury environment remain unclear; however, it is thought that the vascular extracellular matrix proteins (e.g. laminin, fibronectin, and vitronectin) and vascular endothelial growth factor (VEGF) play a role in mediating NPSC behavior through vasophillic interactions. This project attempts to uncover potential VEGF-ECM crosstalk in mediating migration and proliferation. To investigate migration, neurospheres were seeded on ECM-coated wells supplemented with VEGF and without VEGF, and neural outgrowth was measured at days 0, 1, 3, and 8 using differential interference contrast microscopy. Furthermore, single-cell NPSCs were seeded on ECM-coated Transwell membranes with VEGF supplemented media on one side and without VEGF to look at chemotactic migration. Migrated NPSCs were visualized with DAPI nuclear stain and imaged with an inverted fluorescent microscope. To investigate NPSC proliferation, NPSCs were seeded on ECM coated plates as in the radial migration assay and visualized with EdU on day 8. Total proliferation was measured by seeding NPSCs on ECM coated 96-well plates and incubating them with MTT on days 3 and 6. Proliferation was measured using a spectrophotometer at 630nm and 570nm wavelengths. It was found that VEGF-laminin crosstalk synergistically increased radial migration, but may not play a role in chemotactic migration. Understanding the mechanisms behind VEGF-laminin crosstalk in NPSC proliferation and migration may provide crucial information for the design of stem cell transplantation therapies in the future.
ContributorsMillar-Haskell, Catherine Susan (Author) / Stabenfeldt, Sarah (Thesis director) / Addington, Caroline (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2015-05
Description
Spasticity is a neurological disorder in which a target group of muscles remain in a contracted state. In addition to interfering with the function of these muscles, spasticity causes chronic pain and discomfort. Often found in patients with cerebral palsy, multiple sclerosis, or stroke history, spasticity affects an estimated twelve million people worldwide. Not only does spasticity cause discomfort and loss of function, but the condition can lead to contractures, or permanent shortenings of the muscle and connective tissue, if left untreated. Current treatments for spasticity are primarily different forms of muscle relaxant pharmaceuticals. Almost all of these drugs, however, carry unwanted side effects, including total muscle weakness, liver toxicity, and possible dependence. Additionally, kinesiotherapy, conducted by physical therapists at rehabilitation clinics, is often prescribed to people suffering from spasticity. Since kinesiotherapy requires frequent practice to be effective, proper treatment requires constant professional care and clinic appointments, discouraging patient compliance. Consequently, a medical device that could automate relief for spasticity outside of a clinic is desired in the market. While a number of different dynamic splints for hand spasticity are currently on the market, research has shown that these devices, which simply brace the hand in an extended position, do not work through any mechanism to decrease spastic tension over time. Two methods of temporarily reducing spasticity that have been observed in clinical studies are cryotherapy, or the decrease of temperature on a target area, and electrotherapy, which is the delivery of regulated electrical pulses to a target area. It is possible that either of these mechanisms could be incorporated into a medical device aimed toward spastic relief. In fact, electrotherapy is used in a current market device called the SaeboStim, which is advertised to help stroke recovery and spastic reduction. The purpose of this paper is to evaluate the viability of a potential spastic relief device that utilizes cryotherapy to a current and closest competitor, the SaeboStim. The effectiveness of each device in relieving spasticity is reviewed. The two devices are also compared on their ability to address primary customer needs, such as convenience, ease of use, durability, and price. Overall, it is concluded that the cryotherapy device more effectively relieves hand spasticity in users, although the SaeboStim's smaller size and better convenience gives it market appeal, and reveals some of the shortcomings in the preliminary design of the cryotherapy device.
ContributorsWiedeman, Christopher Blaise (Author) / Kleim, Jeffrey (Thesis director) / Buneo, Christopher (Committee member) / W.P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
In this paper, β-estradiol was characterized utilizing electrochemical impedance spectroscopy (EIS) techniques for the purpose of developing a multi-marker fertility sensor. β-estradiol was immobilized onto the surface of gold disk electrodes to find the optimal binding frequency of estradiol and its respective antibody, anti-17β-estradiol, which was determined to be 37.46Hz. At this frequency a logarithmic relationship between concentration and impedance (Z/ohm) was established creating a concentration calibration curve with a slope of 211 ohm/ln(pg mL-1), an R-squared value of 0.986 and a lower limit of detection of 742 fg mL-1. The specificity and cross-reactivity of the antibody with other hormones was tested through interferent and non-target experiments. Signal-to-noise ratio analysis verified that anti-17β-estradiol exhibited minimal chemical reactions with other hormones (SNR< 3) in non-target experiments. Additionally, there were minimal changes in the amount of signal collected during interferent testing, with albumin and follicle stimulating hormone having SNR values greater than 3. These results, along with the unique frequency response of the antibody-target binding reaction, allow for the possibility of using anti-17β-estradiol and β-estradiol for detecting multiple fertility biomarkers on a single sensor.
ContributorsSmith, Victoria Ann (Author) / LaBelle, Jeffrey (Thesis director) / Spano, Mark (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Diabetes mellitus is a disease characterized by many chronic and acute conditions. With the prevalence and cost quickly increasing, we seek to improve on the current standard of care and create a rapid, label free sensor for glycated albumin (GA) index using electrochemical impedance spectroscopy (EIS). The antibody, anti-HA, was fixed to gold electrodes and a sine wave of sweeping frequencies was induced with a range of HA, GA, and GA with HA concentrations. Each frequency in the impedance sweep was analyzed for highest response and R-squared value. The frequency with both factors optimized is specific for both the antibody-antigen binding interactions with HA and GA and was determined to be 1476 Hz and 1.18 Hz respectively in purified solutions. The correlation slope between the impedance response and concentration for albumin (0 \u2014 5400 mg/dL of albumin) was determined to be 72.28 ohm/ln(mg/dL) with an R-square value of 0.89 with a 2.27 lower limit of detection. The correlation slope between the impedance response and concentration for glycated albumin (0 \u2014 108 mg/dL) was determined to be -876.96 ohm/ln(mg/dL) with an R-squared value of 0.70 with a 0.92 mg/dL lower limit of detection (LLD). The above data confirms that EIS offers a new method of GA detection by providing unique correlation with albumin as well as glycated albumin. The unique frequency response of GA and HA allows for modulation of alternating current signals so that several other markers important in the management of diabetes could be measured with a single sensor. Future work will be necessary to establish multimarker sensing on one electrode.
ContributorsEusebio, Francis Ang (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Currently, the management of diabetes mellitus (DM) involves the monitoring of only blood glucose using self-monitoring blood glucose devices (SMBGs) followed by taking interventional steps, if needed. To increase the amount of information that diabetics can have to base DM care decisions off of, the development of an insulin biosensor is explored. Such a biosensor incorporates electrochemical impedance spectroscopy (EIS) to ensure an extremely sensitive platform. Additionally, anti-insulin antibody was immobilized onto the surface of a gold disk working electrode to ensure a highly specific sensing platform as well. EIS measurements were completed with a 5mV sine wave that was swept through the frequency spectrum of 100 kHz to 1 Hz on concentrations of insulin ranging from 0 pM to 100 μM. The frequency at which the interaction between insulin and its antibody was optimized was determined by finding out at which frequency the R2 and slope of the impedance-concentration plot were best. This frequency, otherwise known as the optimal binding frequency, was determined to be 459 Hz. Three separate electrodes were developed and the impedance data for each concentration measured at 459 Hz was averaged and plotted against the LOG (pM insulin) to construct the calibration curve. The response was calculated to be 263.64 ohms/LOG(pM insulin) with an R2 value of 0.89. Additionally, the average RSD was determined to be 19.24% and the LLD was calculated to be 8.47 pM, which is well below the physiological normal range. These results highlight the potential success of developing commercial point-of-care insulin biosensors or multi-marker devices operating with integrated insulin detection.
ContributorsDecke, Zachary William (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Cook, Curtiss (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
The main objective of this research is to develop and characterize a targeted contrast agent that will recognize acute neural injury pathology (i.e. fibrin) after traumatic brain injury (TBI). Single chain fragment variable antibodies (scFv) that bind specifically to fibrin have been produced and purified. DSPE-PEG micelles have been produced and the scFv has been conjugated to the surface of the micelles; this nanoparticle system will be used to overcome limitations in diagnosing TBI. The binding and imaging properties will be analyzed in the future to determine functionality of the nanoparticle system in vivo.
ContributorsRumbo, Kailey Michelle (Author) / Stabenfeldt, Sarah (Thesis director) / Kodibagkar, Vikram (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
As the rates of anxiety in adults rapidly swell, new and creative treatment methods become increasingly relevant. Individuals with an anxiety disorder may experience challenging symptoms that interfere with daily activities and impede academic and social success. The purpose of this project is to design and engineer a portable heart rate monitor that communicates with an iOS mobile application for use by individuals suffering from anxiety or panic disorders. The proposed device captures the innovation of combining biosensor feedback with new, creative therapy methods on a convenient iOS application. The device is implemented as an Arduino Uno which translates radial pulse information onto an LCD screen from a wristband. Additionally, the iOS portion uses a slow expanding and collapsing animation to guide the user through a calming breathing exercise while displaying their pulse in beats per minute. The user's awareness or his or her ability to control one's own physiological state supports and facilitates an additional form of innovative therapy. The current design of the iOS app uses a random-number generator between 40 to 125 to imitate a realistic heart rate. If the value is less than 60 or greater than 105, the number is printed in red; otherwise the heart rate is displayed in green. Future versions of this device incorporate bluetooth capabilities and potentially additional synchronous methods of therapy. The information presented in this research provides an excellent example of the integrations of new mobile technology and healthcare.
ContributorsTadayon, Ramesh (Author) / Muthuswamy, Jit (Thesis director) / Towe, Bruce (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Engineers have a strong influence on everyday lives, ranging from electronics and trains to chemicals and organs [1]. However, in the United States, there is a large knowledge gap in the roles of engineers, especially in K-12 students [2] [3]. The National Academy of Engineering (NAE) recognizes the current problems in engineering, such as the dominance of white males in the field and the amount of education needed to become a successful engineer [4]. Therefore, the NAE encourages that the current engineering community begin to expose the younger generations to the real foundation of engineering: problem-solving [4]. The objective of this thesis is to minimize the knowledge gap by assessing the current perception of engineering amongst middle school and high school students and improving it through engaging and interactive presentations and activities that build upon the students’ problem-solving abilities.
The project was aimed towards middle school and high school students, as this is the estimated level where they learn biology and chemistry—key subject material in biomedical engineering. The high school students were given presentations and activities related to biomedical engineering. Additionally, within classrooms, posters were presented to middle school students. The content of the posters were students of the biomedical engineering program at ASU, coming from different ethnic backgrounds to try and evoke within the middle school students a sense of their own identity as a biomedical engineer. To evaluate the impact these materials had on the students, a survey was distributed before the students’ exposure to the materials and after that assesses the students’ understanding of engineering at two different time points. A statistical analysis was conducted with Microsoft Excel to assess the influence of the activity and/or presentation on the students’ understanding of engineering.
The project was aimed towards middle school and high school students, as this is the estimated level where they learn biology and chemistry—key subject material in biomedical engineering. The high school students were given presentations and activities related to biomedical engineering. Additionally, within classrooms, posters were presented to middle school students. The content of the posters were students of the biomedical engineering program at ASU, coming from different ethnic backgrounds to try and evoke within the middle school students a sense of their own identity as a biomedical engineer. To evaluate the impact these materials had on the students, a survey was distributed before the students’ exposure to the materials and after that assesses the students’ understanding of engineering at two different time points. A statistical analysis was conducted with Microsoft Excel to assess the influence of the activity and/or presentation on the students’ understanding of engineering.
ContributorsLlave, Alison Rose (Author) / Ganesh, Tirupalavanam (Thesis director) / Parker, Hope (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2017-05