Matching Items (4)
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- All Subjects: Microparticles
- All Subjects: Fluid Dynamics
- Creators: VanAuker, Michael
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
A fetus physiologically relies on blood for nutrients given by the mother. Blood supply is provided to a fetus through an umbilical cord having the structure of two pulsatile arteries with smooth muscle surrounding a thin walled vein. The two arteries transport deoxygenated blood from the fetus in the direction of the placenta while the one vein transports oxygenated blood in the direction of the fetus. This process of the movement of blood is continuous throughout the gestation cycle. Conventionally, there are two arterial coils for every one coil of the vein. Undercoiling and overcoiling of the arteries leads to fetal distress, resulting in researchers to speculate that there is a relationship between these geometries with altered blood flow patterns that may be deleterious to the fetus. The fluid dynamics of an umbilical cord artery blood flow has not been extensively modeled on a computer, meaning there is an absence of knowledge on the ideal pitch of the coiling of the umbilical cord arteries. In this study, I developed computer models with ANSYS Fluent containing fluid dynamic variables and boundary conditions including: density of blood, viscosity of blood, diameter of each artery, pitch of artery coil, flow rate in each artery, and inlet velocity. Care was taken to investigate the effect of fluid finite element size, through mesh refinement, to improve accuracy of the models. The finalized models illustrate velocity and stress distribution in a coiled artery, showing different patterns in a model representing normal as compared to abnormal pitch. Further study of the fluid mechanics in the coil of the umbilical cord arteries, may elucidate the correlation between ideal pitch and fetal distress.
ContributorsSeaney, Amanda Marie (Author) / VanAuker, Michael (Thesis director) / Lilien, Lawrence (Committee member) / Harrington Bioengineering Program (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