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- All Subjects: Drug Delivery
- All Subjects: Technology
- Creators: Harrington Bioengineering Program
- Resource Type: Text
Description
The primary objective of this research project is to develop dual layered polymeric microparticles with a tunable delayed release profile. Poly(L-lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA) phase separate in a double emulsion process due to differences in hydrophobicity, which allows for the synthesis of double-walled microparticles with a PLA shell surrounding the PLGA core. The microparticles were loaded with bovine serum albumin (BSA) and different volumes of ethanol were added to the PLA shell phase to alter the porosity and release characteristics of the BSA. Different amounts of ethanol varied the total loading percentage of the BSA, the release profile, surface morphology, size distribution, and the localization of the protein within the particles. Scanning electron microscopy images detailed the surface morphology of the different particles. Loading the particles with fluorescently tagged insulin and imaging the particles through confocal microscopy supported the localization of the protein inside the particle. The study suggest that ethanol alters the release characteristics of the loaded BSA encapsulated in the microparticles supporting the use of a polar, protic solvent as a tool for tuning the delayed release profile of biological proteins.
ContributorsFauer, Chase Alexander (Author) / Stabenfeldt, Sarah (Thesis director) / Ankeny, Casey (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2015-05
Description
Military personnel are affected by muscle fatigue during the various missions and training regimens for their work. Muscle fatigue is caused by the overuse and lack of nutrients to muscles. When a soldier is fatigued, they are unable to perform at their maximum potential and are also more susceptible to injury. For military personnel to save time and money as well as become more efficient within the missions they deploy soldiers, muscle fatigue should be predicted. Predicting fatigue will allow for a reduced rate of negative exercise-related impacts. This means that soldiers will be able to avoid potential life threatening situations they encounter due to the muscle fatigue. The newest technology in wearable devices includes clothing that incorporates heart rate monitors, breathing rate and breathing depth sensors, and a database that converts this information into the amount of calories burned during a workout. Fatigue can be tracked and predicted in the military using wearable clothing with activity sensors, preventing further injury to the soldiers and optimizing performance output at all times. For military personnel, the ability to predict fatigue using this technology would be beneficial to the soldiers and the military as a whole.
ContributorsFalk, Brady Thomas (Author) / Lockhart, Thurmon (Thesis director) / Williams, Deborah (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
For many, a long-distance hike on the 2,650+ mile Pacific Crest Trail (PCT) is the adventure of a lifetime. The federally designated National Scenic Trail passes through 48 Wilderness Areas in California, Washington, and Oregon on its way from Mexico to Canada. The trail experience on the PCT has been changing rapidly over the last 20 years due to two main factors: a four-fold increase in hikers attempting the whole trail each season; and hikers’ rapid adoption of digital technology like smartphones, GPS, and satellite messengers. Through a literature review and accompanying hiker survey, this study aimed to determine how these two factors have combined to alter the trail experience. Despite increased traffic on the trail, hikers appear to still be able to find ample solitude and a feeling of escape from society, and they reported being more likely to form lasting friendships as part of a “trail family”. However, increased traffic has altered many of the sensitive natural landscapes along the trail, contributed to the retirement of some iconic “trail angels” and led to increased conflict between subcultures within the community. Digital technology usage, particularly the use of smartphones and GPS-capable mapping apps, seems to be linked to decreased feelings of solitude, self-sufficiency, and escape. However, digital devices have helped democratize long-distance hiking by simplifying the logistics of long-distance hikes. Users of the devices also did not report reduced feelings of freedom or challenge from their hikes. Moreover, device users still felt that they were disconnecting with technology when hiking on the trail. Acknowledging both positive and negative effects of the changing trail experience, hikers can make more informed decisions about how to mitigate the negative impacts and maximize the positive impacts on the aspects of the trail experience they care the most about.
ContributorsDeSimone, Dante (Author) / Shaeffer, Duncan (Thesis director) / Schmidt, Peter (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
One of the most prominent biological challenges for the field of drug delivery is the blood-brain barrier. This physiological system blocks the entry of or actively removes almost all small molecules into the central nervous system (CNS), including many drugs that could be used to treat diseases in the CNS. Previous studies have shown that activation of the adenosine receptor signaling pathway through the use of agonists has been demonstrated to increase BBB permeability. For example, regadenoson is an adenosine A2A receptor agonist that has been shown to disrupt the BBB and allow for increased drug uptake in the CNS. The goal of this study was to verify this property of regadenoson. We hypothesized that co-administration of regadenoson with a non-brain penetrant macromolecule would facilitate its entry into the central nervous system. To test this hypothesis, healthy mice were administered regadenoson or saline concomitantly with a fluorescent dextran solution. The brain tissue was either homogenized to measure quantity of fluorescent molecule, or cryosectioned for imaging with confocal fluorescence microscopy. These experiments did not identify any significant difference in the amount of fluorescence detected in the brain after regadenoson treatment. These results contradict those of previous studies and highlight potential differences in injection methodology, time windows, and properties of brain impermeant molecules.
ContributorsWohlleb, Gregory Michael (Author) / Sirianni, Rachael (Thesis director) / Stabenfeldt, Sarah (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2015-05
Description
The aim of the present study was to review the symptoms and current treatment options of the most common skin infections seen in outpatient settings and develop a preliminary alternative treatment solution. The specific skin infections evaluated were those caused by Staphylococcus and Streptococcus bacterial species, and are frequently treated with a wide variety of systemic antibiotics or topical ointments. Systemic antibiotics have shown increased occurrence of adverse side effects as well as the development of antibiotic-resistant bacteria. Additionally, these medications are usually overprescribed, which may further exacerbate negative side effects. Another issue that is addressed is the development of infections following treatment of a new laceration or other trauma to the skin. A patient may be treated for their wound with stitches or another alternative, but there is still the possibility of developing an infection later.
This study synthesizes information found from extensive research and provides a review of the most optimal techniques for developing an alternative to systemic antibiotics. The final deliverable is a report detailing the significant findings and discussing the ways that this solution may be developed further and implemented in a clinical setting. The solution is a hydrogel bandage designed to deliver antibiotics directly to the wound site, while also offering protection and enhanced wound healing. The target population is patients suffering from skin conditions in an outpatient setting. The antibiotics of interest for this solution are clindamycin, doxycycline, and trimethoprim-sulfamethoxazole (co-trimoxazole), as they offer excellent treatment against gram-positive bacteria and methicillin-resistant Staphylococcus aureus. However, other broad-spectrum antibiotics could potentially be incorporated to protect against gram-negative bacteria. The design features a polyvinyl alcohol (PVA) hydrogel that has shown many properties that are beneficial to biomedical applications, including biocompatibility, flexibility, high drug-loading capacity, high absorption of wound exudate, increased promotion of wound healing, and more. Preliminary mathematical models of the hydrogel’s drug delivery behaviors are also included. Due to the scope and timeframe of this project, the majority of findings herein are based on research of prior literature instead of development of the novel device. Future directions would include further research and development of the mechanisms behind the device, creation of a physical prototype, experimental testing, and statistical analyses to verify device specifications and capabilities.
This study synthesizes information found from extensive research and provides a review of the most optimal techniques for developing an alternative to systemic antibiotics. The final deliverable is a report detailing the significant findings and discussing the ways that this solution may be developed further and implemented in a clinical setting. The solution is a hydrogel bandage designed to deliver antibiotics directly to the wound site, while also offering protection and enhanced wound healing. The target population is patients suffering from skin conditions in an outpatient setting. The antibiotics of interest for this solution are clindamycin, doxycycline, and trimethoprim-sulfamethoxazole (co-trimoxazole), as they offer excellent treatment against gram-positive bacteria and methicillin-resistant Staphylococcus aureus. However, other broad-spectrum antibiotics could potentially be incorporated to protect against gram-negative bacteria. The design features a polyvinyl alcohol (PVA) hydrogel that has shown many properties that are beneficial to biomedical applications, including biocompatibility, flexibility, high drug-loading capacity, high absorption of wound exudate, increased promotion of wound healing, and more. Preliminary mathematical models of the hydrogel’s drug delivery behaviors are also included. Due to the scope and timeframe of this project, the majority of findings herein are based on research of prior literature instead of development of the novel device. Future directions would include further research and development of the mechanisms behind the device, creation of a physical prototype, experimental testing, and statistical analyses to verify device specifications and capabilities.
ContributorsTanner, Emily Christine (Author) / Pizziconi, Vincent (Thesis director) / Nguyen, Eric (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Previous studies have found that the detection of near-threshold stimuli is decreased immediately before movement and throughout movement production. This has been suggested to occur through the use of the internal forward model processing an efferent copy of the motor command and creating a prediction that is used to cancel out the resulting sensory feedback. Currently, there are no published accounts of the perception of tactile signals for motor tasks and contexts related to the lips during both speech planning and production. In this study, we measured the responsiveness of the somatosensory system during speech planning using light electrical stimulation below the lower lip by comparing perception during mixed speaking and silent reading conditions. Participants were asked to judge whether a constant near-threshold electrical stimulation (subject-specific intensity, 85% detected at rest) was present during different time points relative to an initial visual cue. In the speaking condition, participants overtly produced target words shown on a computer monitor. In the reading condition, participants read the same target words silently to themselves without any movement or sound. We found that detection of the stimulus was attenuated during speaking conditions while remaining at a constant level close to the perceptual threshold throughout the silent reading condition. Perceptual modulation was most intense during speech production and showed some attenuation just prior to speech production during the planning period of speech. This demonstrates that there is a significant decrease in the responsiveness of the somatosensory system during speech production as well as milliseconds before speech is even produced which has implications for speech disorders such as stuttering and schizophrenia with pronounced deficits in the somatosensory system.
ContributorsMcguffin, Brianna Jean (Author) / Daliri, Ayoub (Thesis director) / Liss, Julie (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Advancements in healthcare and the emergence of an aging population has led to an increase in the number of prosthetic joint procedures in the United States. According to Healthcare Cost and Utilization Project, 660,876 and 348,970 total hip and knee arthroplasties were performed in 2014[1].The percentage of total hip or knee procedures that are revised due to an infection is 1.23% and 1.21% respectively[3], [4]. Although the percent of infections may be small, an infection can have a tremendous burden on the patient and healthcare system. It is expected that prosthetic joint infections (PJIs) will cost the healthcare system an estimated $1.62 billion by 2020[5]. PJIs are often difficult to treat due to the formation of biofilm at the site of the infection. A large majority of PJIs are the result of a bacterial biofilm, but around 1% of PJIs are due to fungal infections[3]. The current method of treatment is to surgically remove all infected tissue at the site of infection through a process called debridement and then insert a medicated bone cement spacer[7], [10]–[12]. One such medication that is loaded into the bone cement is caspofungin, a member of the echinocandin class of compounds that inhibit the synthesis of 1,3-β-D-glucan which is a crucial element of the cell wall of the target fungi[13]–[15]. For the studies reported herein, the caspofungin-loaded bone cement samples were made at 5 dosage strengths according to standard operating room practices. The elution of the drug was analyzed using ultraviolet spectrophotometry. The elution profiles were analyzed for 19 days consecutively, during which the 70 mg, 1 g, and 5 g dosage groups showed a prolonged, sustained release of the caspofungin. The 70 mg and 1 g dosage cumulative mass release profiles were not statistically significant, but it is unlikely that the difference would not have a clinical significance especially in the treatment of a fungal biofilm infection. The determination of the elution profile for caspofungin from loaded-bone cement can provide clinicians with a basis for how the drug will release into the infected joint.
ContributorsMoore, Rex C. (Author) / Vernon, Brent (Thesis director) / Overstreet, Derek (Committee member) / Industrial, Systems & Operations Engineering Prgm (Contributor) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
With microspheres growing in popularity as viable systems for targeted drug therapeutics, there exist a host of diseases and pathology induced side effects which could be treated with poly(lactic-co-glycolic acid) [PLGA] microparticle systems [6,10,12]. While PLGA systems are already applied in a wide variety the clinical setting [11], microparticles still have some way to go before they are viable systems for drug delivery. One of the main reasons for this is a lack of fabrication processes and systems which produce monodisperse particles while also being feasible for industrialization [10]. This honors thesis investigates various microparticle fabrication techniques \u2014 two using mechanical agitation and one using fluid dynamics \u2014 with the long term goal of incorporating norepinephrine and adenosine into the particles for metabolic stimulatory purposes. It was found that mechanical agitation processes lead to large values for dispersity and the polydispersity index while fluid dynamics methods have the potential to create more uniform and predictable outcomes. The research concludes by needing further investigation into methods and prototype systems involving fluid dynamics methods; however, these systems yield promising results for fabricating monodisperse particles which have the potential to encapsulate a wide variety of therapeutic drugs.
ContributorsRiley, Levi Louis (Author) / Vernon, Brent (Thesis director) / VanAuker, Michael (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Previous research has shown that a loud acoustic stimulus can trigger an individual's prepared movement plan. This movement response is referred to as a startle-evoked movement (SEM). SEM has been observed in the stroke survivor population where results have shown that SEM enhances single joint movements that are usually performed with difficulty. While the presence of SEM in the stroke survivor population advances scientific understanding of movement capabilities following a stroke, published studies using the SEM phenomenon only examined one joint. The ability of SEM to generate multi-jointed movements is understudied and consequently limits SEM as a potential therapy tool. In order to apply SEM as a therapy tool however, the biomechanics of the arm in multi-jointed movement planning and execution must be better understood. Thus, the objective of our study was to evaluate if SEM could elicit multi-joint reaching movements that were accurate in an unrestrained, two-dimensional workspace. Data was collected from ten subjects with no previous neck, arm, or brain injury. Each subject performed a reaching task to five Targets that were equally spaced in a semi-circle to create a two-dimensional workspace. The subject reached to each Target following a sequence of two non-startling acoustic stimuli cues: "Get Ready" and "Go". A loud acoustic stimuli was randomly substituted for the "Go" cue. We hypothesized that SEM is accessible and accurate for unrestricted multi-jointed reaching tasks in a functional workspace and is therefore independent of movement direction. Our results found that SEM is possible in all five Target directions. The probability of evoking SEM and the movement kinematics (i.e. total movement time, linear deviation, average velocity) to each Target are not statistically different. Thus, we conclude that SEM is possible in a functional workspace and is not dependent on where arm stability is maximized. Moreover, coordinated preparation and storage of a multi-jointed movement is indeed possible.
ContributorsOssanna, Meilin Ryan (Author) / Honeycutt, Claire (Thesis director) / Schaefer, Sydney (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Smartphones have become an integral component of lifestyles worldwide, acting as mobile computers capable of life organization. They remain the most quickly cycled consumer electronic, owned for no more than 3 years on average. Individuals continue to upgrade their smartphones quickly, stemming from the desire for more power and better features. In 2016, there were 1.15 billion smartphone upgrades, resulting in a growing used smartphone market valued at \$18 billion. Individuals continue to invest time and effort to sell their smartphone, receiving payment of less than market value. In regards to value-minded users with solidified schedules, I created Trusted Trade-in. This startup provides the bustling middle class with the ability to upgrade their smartphone in an efficient and valuable manner. Compared to current solutions, Trusted Trade-in offers an all-in-one upgrade system. The creation of this startup involved the complete creation of a business model in addition to the coding of a responsive website. An online-based business, customers will be able to visit the Trusted Trade-in website and be given the options to trade-in or trade-up. Competing against Craigslist, eBay and Verizon, Trusted Trade-in features a combined smartphone resale and upgrade process. If the decision is made to trade-in, the customer will be quoted for their current smartphone according to specific physical criteria. The trade-up option will request the same information from the customer and allow them to select a new model for their upgrade. This exciting and innovative marketplace will completely transform the way people upgrade their smartphones through financial and time-based savings.
ContributorsWoods, Quintin Delane (Author) / Sebold, Brent (Thesis director) / Lin, Elva S. Y. (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05