Matching Items (7)
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- Creators: Harrington Bioengineering Program
- Creators: Pal, Amrita
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
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
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
An improved system for wireless neurostimulation was investigated through the design and development of sub-millimeter piezoelectric devices. The devices build on prior work in the lab, which was limited by device size and required surgical implantation. A method of manufacturing sub-mm devices was developed, and utilized to construct this new design. The device frequency response was characterized and its resonant modes and output voltages determined through a Fast Fourier Transform. The fundamental thickness mode frequency was found to be 15.4MHz with a corresponding 10.25mV amplitude, and a longitudinal resonant frequency of 3.1Mhz with a corresponding 2.2mV amplitude across a 50Ω resistor. The high miniaturization of the device holds promise for future work for creating an injectable, wireless system for the treatment of neurological disorders.
ContributorsCatchings, Michael Thomas (Author) / Towe, Bruce (Thesis director) / Muthuswamy, Jitendran (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Nerve endings are particularly difficult to target during peripheral nerve block (PNB) procedures, so ultrasound-guided needles are of immense importance to guarantee safe and efficient delivery of the anesthetic to the target nerve. Despite significant progress in needle visualization with ultrasound imaging, there are still several factors that lead to poor needle visibility, the main factor being insertion angle. Introducing cavities and holes in the needle at specific intervals through pitting corrosion may alter the ultrasonic feedback from the sensor, thereby resulting in improved clarity of the reconstructed image. The purpose of this experiment is to investigate the effectiveness of two novel pitting designs on the needle’s visibility under ultrasound. Two different designs and two depths of cut are tested in a 22 factorial that is blocked by insertion angle: a uniform and a non-uniform design. Needles were cut using a Plain Jane and Igor laser cutter and imaged using a GE Logig e BT12 ultrasound imaging machine. Images were compared visually and objectively by using a tool in Photoshop to calculate the luminosity of the needle. Two videos were also taken capturing the difficulty of imaging surgical needles. Results showed that pitting had a major impact on needle visibility at 30° and a marginal impact at 0°. The videos supported these results as it was considerably more difficult to locate the control needle than the experimental needle. This suggests the probe must be in a specific plane with the control needle for it to be visible while the experimental needle is much more lenient. Results from the two depths of cuts showed similar results in that the designs which were cut twice were more visible than their counterparts at 30°. The study showed that pitting has positive effects on needle visibility; it improves visibility by increasing the luminescence of the needle and by decreasing its sensitivity to probe position.
ContributorsTze, David (Author) / Muthuswamy, Jit (Thesis director) / Towe, Bruce (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Polymer drug delivery system offers a key to a glaring issue in modern administration routes of drugs and biologics. Poly(lactic-co-glycolic acid) (PLGA) can be used to encapsulate drugs and biologics and deliver them into the patient, which allows high local concentration (compared to current treatment methods), protection of the cargo from the bodily environment, and reduction in systemic side effects. This experiment used a single emulsion technique to encapsulate L-tyrosine in PLGA microparticles and UV spectrophotometry to analyze the drug release over a period of one week. The release assay found that for the tested samples, the released amount is distinct initially, but is about the same after 4 days, and they generally follow the same normalized percent released pattern. The experiment could continue with testing more samples, test the same samples for a longer duration, and look into higher w/w concentrations such as 20% or 50%.
ContributorsSeo, Jinpyo (Author) / Vernon, Brent (Thesis director) / Pal, Amrita (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
The goal of this research project is to create a Mathcad template file capable of statistically modelling the effects of mean and standard deviation on a microparticle batch characterized by the log normal distribution model. Such a file can be applied during manufacturing to explore tolerances and increase cost and time effectiveness. Theoretical data for the time to 60% drug release and the slope and intercept of the log-log plot were collected and subjected to statistical analysis in JMP. Since the scope of this project focuses on microparticle surface degradation drug release with no drug diffusion, the characteristic variables relating to the slope (n = diffusional release exponent) and the intercept (k = kinetic constant) do not directly apply to the distribution model within the scope of the research. However, these variables are useful for analysis when the Mathcad template is applied to other types of drug release models.
ContributorsHan, Priscilla (Author) / Vernon, Brent (Thesis director) / Nickle, Jacob (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
In an embolization therapy, a material is injected into a vessel to block blood flow. While this therapy is useful in starving cancerous cells it can be dangerous, with some blockades in the brain dislodging and causing strokes or blindness. Currently, embolic materials on the market such as metal coils, balloons, and liquid embolic agents do not have a quick removal procedure. An ultrasound cleavable material could be removed in an emergency situation without invasive surgery. The primary goal of this research is to design and synthesize a polymer that can be broken down by high intensity focused ultrasound (HIFU). Initially, we have tested the ultrasound sensitive qualities on PPODA-QT hydrogel, a common embolic agent, but the gel showed no physical change after HIFU exposure. It is theorized that PNIPAAm combined with HIFU sensitive monomers can develop a temperature and ultrasound sensitive embolic agent. In our studies, poly(NIPAAm-co-tBa) had a slight lower critical solution temperature (LCST) change of about 2˚C from before to after HIFU while the study with poly(NIPAAm-co-ACL-BME) and PPODA-QT showed no change in LCST.
ContributorsLein, Karolena (Author) / Vernon, Brent (Thesis director) / Pal, Amrita (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05