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You searched for +publisher:"Clemson University" +contributor:("Dr. Stephen H. Foulger, Committee Chair"). Showing records 1 – 3 of 3 total matches.

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Clemson University

1. Klep, Oleksandr. Programming of Retention Capacity and Release Capabilities of Propargyl Acrylate Nanoparticles Decorated with Poloxamer Copolymer.

Degree: PhD, School of Materials Science and Engineering, 2018, Clemson University

Nanoparticle based drug delivery offers an advantage over free drug deliv-ery as it allows the manufacturer to introduce various control mechanisms either for targeted delivery or for the controlled release profile of the drug. Systems ca-pable to encapsulate different active molecules, ranging from dyes to drugs, gained a lot of attention in recent years. It was shown that it is possible to create a pro-grammable device that can serve multiple functions ranging from enhanced imag-ing techniques to cancer treatment along with extended drug delivery applications. Therefore methods for fabrication and characterization of the devices that can be used in the medical field is in high demand. Proposed is a device build around propargyl acrylate nanoparticle along with a set of methods to fully characterize the final nanocomposite composition. The release rate of the active molecules from the proposed nanocomposite is compared to the composition of the device. The ability to program the release rate and set a burst release temperature for the de-vice is essential for future advances in drug delivery application. Förster Resonance Energy Transfer (FRET) was used to investigate the changes in the surface configuration. To do this, pair of dyes with good spectral overlap was attached to the propargyl acrylate core. The donor dye was immobilized on the surface of the core, while the acceptor dye was attached to the free end of the poloxamer chain. This setup allowed the acceptor dye to have a certain degree of mobility. Based on the changes in the photo-luminescence spectra and applying the FRET theory distance between the dyes was correlated to the temperature of the environment. A possible mechanism of the surface configuration changes with temperature was suggested based on the obtained results. The ability of propargyl acrylate - poloxamer complex to capture, retain and release when triggered small molecules is investigated. Often there is a need to protect or deactivate an active molecule before it reaches its target organ or tissue to prevent development of side-effects during treatment. Additionally, such a sys-tem can be used for waste water treatment applications to remove toxic organic contamination. The ability of the particles to trap and then release upon heating is advantageous compared to the systems that are capable of only trapping because it can be reused and serve the purpose of waste concentration to promote recycling of otherwise wasted materials. Proposed is a scheme of synthesis and characterization of the carrier based on the propargyl acrylate nanoparticles coated with poloxamer copolymer. Carrier stability is greatly enhanced, compared to similar systems found in the literature. Advantage comes from the formation of a covalent bond between the core and the shell, ensuring that no changes of the nano-carrier composition can happen during its lifespan. This study shows the importance of the precise control over the graft-ing density of the poloxamer on the surface of propargyl acrylate… Advisors/Committee Members: Dr. Stephen H. Foulger, Committee Chair, Dr. Konstantin Kornev, Dr. Igor Luzinov, Dr. Thompson Mefford.

Subjects/Keywords: Drug delivery; FRET; Grafting density; Nanocomposite; Poloxamer; Sensor

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APA (6th Edition):

Klep, O. (2018). Programming of Retention Capacity and Release Capabilities of Propargyl Acrylate Nanoparticles Decorated with Poloxamer Copolymer. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/2133

Chicago Manual of Style (16th Edition):

Klep, Oleksandr. “Programming of Retention Capacity and Release Capabilities of Propargyl Acrylate Nanoparticles Decorated with Poloxamer Copolymer.” 2018. Doctoral Dissertation, Clemson University. Accessed October 28, 2020. https://tigerprints.clemson.edu/all_dissertations/2133.

MLA Handbook (7th Edition):

Klep, Oleksandr. “Programming of Retention Capacity and Release Capabilities of Propargyl Acrylate Nanoparticles Decorated with Poloxamer Copolymer.” 2018. Web. 28 Oct 2020.

Vancouver:

Klep O. Programming of Retention Capacity and Release Capabilities of Propargyl Acrylate Nanoparticles Decorated with Poloxamer Copolymer. [Internet] [Doctoral dissertation]. Clemson University; 2018. [cited 2020 Oct 28]. Available from: https://tigerprints.clemson.edu/all_dissertations/2133.

Council of Science Editors:

Klep O. Programming of Retention Capacity and Release Capabilities of Propargyl Acrylate Nanoparticles Decorated with Poloxamer Copolymer. [Doctoral Dissertation]. Clemson University; 2018. Available from: https://tigerprints.clemson.edu/all_dissertations/2133


Clemson University

2. Roeder, Ryan D. Synthetic routes to the surface functionalization of core-shell nanoparticles through the copper(I)-catalyzed azide-alkyne cycloaddition.

Degree: PhD, School of Materials Science and Engineering, 2018, Clemson University

The objective of this dissertation was to construct core-shell colloidal particles with a thermoplastic shell containing alkyne units for CuAAC; establish a method to remove the thermoplastic shell for characterization; measure their optical and thermo-dynamic properties; and discover further applications with this particle morphology. Recent trends have shown a re-emergence of research centered around colloidal particles due to their usefulness in biological applications. Colloids around ca. 100 nm show good stability when suspended in aqueous solutions and are not quickly removed by the body. Thus, particles can be modified with fluorescent chromophores to act as biosensors or could be created to contain therapeutic drugs and act as a vehicle for drug delivery. The possibility of colloids being used as biological agents received a large boost with the classification of a series of reactions known as click chemistry; specifically the Copper(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAC). CuAAC allowed for two materials to be covalently attached if one material contained an azide and the other contained a terminal alkyne. The attractiveness of CuAAC for polymer colloids is due to the high-yielding nature of the reation and that it could be carried out at mild conditions in aqueous solutions. This affords an endless variety of functionalities that could incorporated to the surface of polymer colloids with the only drawback being the inability to thoroughly characterize the success of CuAAC reactions on the colloidal surface. In this current project, ca. 130 nm core-shell particles with a thermoplastic shell are surface-functionalized with optically active moieties via CuAAC and used for the following applications: (1) Seeded emulsion polymerization of a soluble shell with a controlled alkyne surface density: A general methodology for producing ca. 100 nm core-shell colloidal particles in which the shell has an elevated alkyne functionality and yet remains thermoplastic is presented. The availability of accessible alkyne groups on the surface of the aqueous-phase particles allows for the in situ surface modification of the particles through a copper(I) catalyzed Huisgen 1,3-dipolar cycloaddition with an azide-terminated surface agent. The core is an extensively crosslinked polymer which can be easily removed by dispersing the particles in a solvent and centrifuging & collecting the cores, leaving the solubilized shells. This allows for the complete characterization of the colloidal surface reactions in the absence of the volumetrically dominant core. The technique is demonstrated with a core-shell colloid composed of a 135 nm crosslinked polystyrene (PS) core coated with a ca. 10 nm thick uncrosslinked poly(methyl acrylate-co-propargyl acrylate) shell. Due to the applicability of this technique for generating particles useful in biomedical imaging or drug delivery applications, the core-shell particles are surface modified with a variety of azide-terminated poly(ethylene glycol)(PEG) derivatives, including a… Advisors/Committee Members: Dr. Stephen H. Foulger, Committee Chair, Dr. Igor A. Luzinov, Dr. John M. Ballato, Dr. Rhett C. Smith.

Subjects/Keywords: click chemistry; colloid; core-shell; CuAAC; functional ink; R2R printing

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Roeder, R. D. (2018). Synthetic routes to the surface functionalization of core-shell nanoparticles through the copper(I)-catalyzed azide-alkyne cycloaddition. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/2114

Chicago Manual of Style (16th Edition):

Roeder, Ryan D. “Synthetic routes to the surface functionalization of core-shell nanoparticles through the copper(I)-catalyzed azide-alkyne cycloaddition.” 2018. Doctoral Dissertation, Clemson University. Accessed October 28, 2020. https://tigerprints.clemson.edu/all_dissertations/2114.

MLA Handbook (7th Edition):

Roeder, Ryan D. “Synthetic routes to the surface functionalization of core-shell nanoparticles through the copper(I)-catalyzed azide-alkyne cycloaddition.” 2018. Web. 28 Oct 2020.

Vancouver:

Roeder RD. Synthetic routes to the surface functionalization of core-shell nanoparticles through the copper(I)-catalyzed azide-alkyne cycloaddition. [Internet] [Doctoral dissertation]. Clemson University; 2018. [cited 2020 Oct 28]. Available from: https://tigerprints.clemson.edu/all_dissertations/2114.

Council of Science Editors:

Roeder RD. Synthetic routes to the surface functionalization of core-shell nanoparticles through the copper(I)-catalyzed azide-alkyne cycloaddition. [Doctoral Dissertation]. Clemson University; 2018. Available from: https://tigerprints.clemson.edu/all_dissertations/2114


Clemson University

3. Jenkins, Ragini. A Bioresponsive and Multifunctional Polymer Based Nanodevice for Cancer Nanotheranostics.

Degree: PhD, Materials Science and Engineering, 2016, Clemson University

The main objective of this project is to develop a polymer based near infrared (NIR) particle that can serve as both, diagnostic and therapeutic agents, for fighting cancer. Specifically these particles will be designed to have high-contrast, high signal to noise ratios, long in vivo circulation lifetimes, and facilitate easy attachment of functional and target components. Cancer is a disease where the growth of abnormal cells is uncontrollable and is one of the leading causes of death worldwide. Malignant cancer cells are more effectively treated when identified early in the disease. Identification of tumors using fluorophores, small molecules that emit visible light when excited, is gaining clinical interest. Specific interest is in near-infrared emission due to the lack of absorption of this radiation in human tissue, which facilitates deep tissue imaging. During imaging with small molecule fluorophores, the fluorophores clear from the body quickly reducing imaging effectiveness. The effectiveness of imaging can be enhanced by attaching the fluorophores to a particle. Nanometer sized particles do not clear from the body rapidly and allows the material designer to attach other ”payloads” to the particle. This multifunctional ”nano-device” can be used to deliver diagnostic (fluorophores) and therapeutic (drugs) agents to the afflicted tissue. In this current project sub-100 nm poly(propargyl acrylate) (PA) particles are surface-functionalized with fluorophores or targeting molecules through a copper(I) catalyzed azide-alkyne Huisgen 1,3-Dipolar cycloaddition, and used for the following applications: (1) Switching fluorescence of surface modified colloids with near-infrared emitters via pro-tein interaction for contrast-enhanced imaging: The colloidal particles surface-functionalized with fluorophores exhibit a protein triggered activation/deactivation of the emission. Dispersing the par-ticles into an aqueous solution, such as phosphate buffered saline (PBS), results in an aggregation of the hydrophobic fluorophores and a cessation of emission. The emission can be reinstated, or activated, by the conversion of the surface-attached fluorophores from an aggregate to a monomeric species with the addition of an albumin. This activated probe can be deactivated and returned to a quenched state by a simple tryptic digestion of the albumin. The methodology for emission switching offers a path to maximize the signal from the typically weak quantum yield inherent in NIR fluo-rophores. Preliminary fluorescence imaging studies indicate that the brightness of the functionalized polymer based nanoparticles improved considerably. (2) Surface modified colloids with targeting molecules to disrupt Survivin activity and en-hance apoptosis in cancer cells: Survivin belongs to the family of inhibitor of apoptosis proteins (IAP) and is present in most cancers while being below detection limits in most terminally differentiated adult tissues, making it an attractive protein to target for diagnostic and, potentially, therapeutic roles. Sub-100 nm poly(propargyl… Advisors/Committee Members: Dr. Stephen H. Foulger, Committee Chair, Dr. Igor A. Luzinov, Dr. O. Thompson Mefford, Dr. Michael G. Sehorn.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Jenkins, R. (2016). A Bioresponsive and Multifunctional Polymer Based Nanodevice for Cancer Nanotheranostics. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1729

Chicago Manual of Style (16th Edition):

Jenkins, Ragini. “A Bioresponsive and Multifunctional Polymer Based Nanodevice for Cancer Nanotheranostics.” 2016. Doctoral Dissertation, Clemson University. Accessed October 28, 2020. https://tigerprints.clemson.edu/all_dissertations/1729.

MLA Handbook (7th Edition):

Jenkins, Ragini. “A Bioresponsive and Multifunctional Polymer Based Nanodevice for Cancer Nanotheranostics.” 2016. Web. 28 Oct 2020.

Vancouver:

Jenkins R. A Bioresponsive and Multifunctional Polymer Based Nanodevice for Cancer Nanotheranostics. [Internet] [Doctoral dissertation]. Clemson University; 2016. [cited 2020 Oct 28]. Available from: https://tigerprints.clemson.edu/all_dissertations/1729.

Council of Science Editors:

Jenkins R. A Bioresponsive and Multifunctional Polymer Based Nanodevice for Cancer Nanotheranostics. [Doctoral Dissertation]. Clemson University; 2016. Available from: https://tigerprints.clemson.edu/all_dissertations/1729

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