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Articles 1 - 14 of 14
Full-Text Articles in Physical Sciences and Mathematics
Unimer Suppression Enables Supersaturated Homopolymer Swollen Micelles With Long-Term Stability After Glassy Entrapment, Eric R. Williams, Christian X. Ruff, Morgan Stefik
Unimer Suppression Enables Supersaturated Homopolymer Swollen Micelles With Long-Term Stability After Glassy Entrapment, Eric R. Williams, Christian X. Ruff, Morgan Stefik
Faculty Publications
Micelle sizes are critical for a range of applications where the simple ability to adjust and lock in specific stable sizes has remained largely elusive. While micelle swelling agents are well-known, their dynamic re-equilibration in solution implies limited stability. Here, a non-equilibrium processing sequence is studied where supersaturated homopolymer swelling is combined with glassy-core (“persistent”) micelles. This path-dependent process was found to sensitively depend on unimer concentration as revealed by DLS, SAXS, and TEM analysis. Here, lower-selectivity solvent combinations led to the formation of unimer-homopolymer aggregates and eventual precipitation, reminiscent of anomalous micellization. In contrast, higher-selectivity solvents enabled supersaturated homopolymer …
Precipitation And Coacervation In Polyelectrolyte-Colloid Systems, Fatih Comert
Precipitation And Coacervation In Polyelectrolyte-Colloid Systems, Fatih Comert
Doctoral Dissertations
Complex coacervation between oppositely charged polyelectrolytes (PEs) and colloids (i.e. micelles and proteins) has increasingly become popular due to the use of these materials in a range of applications including but not limited to personal care, biomaterials, protein purification, and food science. In taking advantage of complex coacervation, which is a liquid-liquid phase separation, precipitation has always represented a problem by introducing inhomogeneities, irreversibility and irreproducible kinetics. Therefore, understanding the dominant factors driving the formation of precipitates is important to control outcomes. In this work, we have performed comparative studies of coacervation and precipitation in model PE-colloid systems to investigate …
Synthesis And Catalytic Testing Of A Proline Functionalized Amphiphilic Block Copolymer, Eric Firestone
Synthesis And Catalytic Testing Of A Proline Functionalized Amphiphilic Block Copolymer, Eric Firestone
Master's Theses and Doctoral Dissertations
Catalysts are reagents used to reduce the amount of energy that a reaction needs to execute, allowing it to proceed at a higher rate while not being consumed. The use of catalyst functionalized amphiphilic copolymer allows easier recovery of the catalyst at the end of the synthesis and allows for the reaction. In water, under appropriate conditions, the amphiphilic block copolymers will form micelles and allow the reaction to occur on the interior of the micelle. The synthesis of amphiphilic copolymer with a hydrophobic O-methacryloyl-trans-4- hydroxy-L-proline and methyl methacrylate end and a hydrophilic acrylic acid end was characterized. The polymer …
Poly(Ethyl Glyoxylate)-Poly(Ethylene Oxide) Nanoparticles: Stimuli- Responsive Drug Release Via End-To-End Polyglyoxylate Depolymerization, Bo Fan, Elizabeth Gillies
Poly(Ethyl Glyoxylate)-Poly(Ethylene Oxide) Nanoparticles: Stimuli- Responsive Drug Release Via End-To-End Polyglyoxylate Depolymerization, Bo Fan, Elizabeth Gillies
Chemistry Publications
The ability to disrupt polymer assemblies in response to specifi c stimuli provides the potential to release drugs selectively at certain sites or conditions in vivo. However, most stimuli-responsive delivery systems require many stimuli initiated events to release drugs. “ Self-immolative polymers” offer the potential to provide amplifi ed responses to stimuli as they undergo complete end-to-end depolymerization following the cleavage of a single end-cap. Herein, linker end-caps were developed to conjugate self-immolative poly(ethyl glyoxylate) (PEtG) with poly(ethylene oxide) (PEO) to form amphiphilic block copolymers. These copolymers were self-assembled to form nanoparticles in aqueous solution. Cleavage of the linker …
Phosphonium-Functionalized Polymer Micelles With Intrinsic Antibacterial Activity, Benjamin Hisey, Paul J. Ragogna, Elizabeth Gillies
Phosphonium-Functionalized Polymer Micelles With Intrinsic Antibacterial Activity, Benjamin Hisey, Paul J. Ragogna, Elizabeth Gillies
Chemistry Publications
New approaches to treat bacterial infections are badly needed to address the increasing problem of antibiotic resistance. This study explores phosphonium-functionalized block copolymer micelles as intrinsically antibacterial polymer assemblies. Phosphonium cations with varying alkyl lengths were conjugated to the terminus of a poly(ethylene oxide)− polycaprolactone block copolymer, and the phosphonium-functionalized block copolymers were self-assembled to form micelles in aqueous solution. The size, morphology, and ζ -potential of the assemblies were studied, and their abilities to kill Escherichia coli and Staphylococcus aureus were evaluated. It was found that the minimum bactericidal concentration depended on the phosphonium alkyl chain length, and different …
Synthesis, Self-Assembly, And Immunological Activity Of Α-Galactose-Functionalized Dendron–Lipid Amphiphiles, John Trant, Namrata Jain, D. M. Mazzuca, J Trevor Mcintosh, Bo Fan, S M Mansour Haeryfar, Sebastien Lecommandoux, Elizabeth Gillies
Synthesis, Self-Assembly, And Immunological Activity Of Α-Galactose-Functionalized Dendron–Lipid Amphiphiles, John Trant, Namrata Jain, D. M. Mazzuca, J Trevor Mcintosh, Bo Fan, S M Mansour Haeryfar, Sebastien Lecommandoux, Elizabeth Gillies
Chemistry Publications
Nanoassemblies presenting multivalent displays of biologically active carbohydrates are of significant interest for a wide array of biomedical applications ranging from drug delivery to immunotherapy. In this study, glycodendron–lipid hybrids were developed as a new and tunable class of dendritic amphiphiles. A modular synthesis was used to prepare dendron–lipid hybrids comprising distearylglycerol and 0 through 4th generation polyester dendrons with peripheral protected amines. Following deprotection of the amines, an isothiocyanate derivative of C-linked α-galactose (α-Gal) was conjugated to the dendron peripheries, affording amphiphiles with 1 to 16 α-Gal moieties. Self-assembly in …
Suppression Of Interfering Ions By Using Ionic Liquid And Micelle Moieties In Spectrofluorimetric Analysis Of Manganese, Özlem Öter, Müge Aydin, Kadri̇ye Erteki̇n
Suppression Of Interfering Ions By Using Ionic Liquid And Micelle Moieties In Spectrofluorimetric Analysis Of Manganese, Özlem Öter, Müge Aydin, Kadri̇ye Erteki̇n
Turkish Journal of Chemistry
Eosin-Y exhibits high affinity and emission based spectral response to most of the major ions in water samples. In the present study we performed selective spectrofluorimetric analysis of manganese with eosin-Y in the presence of potential interferents. We employed green chemistry reagents, ionic liquids (ILs) and two different micelles, to suppress the effect of conventional cations and anions on the response of eosin-Y. The experimental data revealed that different test moieties caused enhanced analytical response to Mn$^{2+}$. The highest analytical signal of eosin-Y was obtained in the presence of Triton X-100 at a concentration of 2.0 $\times $ 10$^{-3}$ mol …
Design, Synthesis And Biological Applications Of Polypeptoids And Boron Dipyrromethenes, Sunting Xuan
Design, Synthesis And Biological Applications Of Polypeptoids And Boron Dipyrromethenes, Sunting Xuan
LSU Doctoral Dissertations
The dissertation is about the design, synthesis and biological applications of polypeptoids and boron dipyrromethenes (BODIPYs). The dissertation is divided into seven chapters reporting various aspects of the background to my field of study and the results obtained during my PhD program. Chapter 1 is a concise overview of the fundamental concepts of polypeptoids and hydrogels, as well as their recent developments on synthetic strategies, property investigations, and biological applications in different fields. Chapter 2 presents the design, synthesis and potential application as tissue engineering scaffold of thermoreversible ABC polypeptoid hydrogels. A series of ABC copolypeptoids were synthesized and their …
Aggregation And Interfacial Behavior Of Charged Surfactants In Ionic Liquids, Lang Chen
Aggregation And Interfacial Behavior Of Charged Surfactants In Ionic Liquids, Lang Chen
Doctoral Dissertations
Room-temperature ionic liquids (ILs) exhibit a unique set of properties, leading to opportunities for numerous applications such as green solvents, batteries and lubricants. Their properties can be greatly tuned and controlled by addition of surfactants. It is therefore critical to obtain a better understanding of the aggregation and interfacial behavior of surfactants within ILs. Firstly, the phase diagram and aggregation isotherms of surfactants in several distinct ILs were investigated by solubility and tensiometry. A connection between solubility of the surfactant and the physical properties of the underlying ionic liquid was established. We found that the interfacial energy was crucial in …
Design, Synthesis And Applications Of Polymer Biomaterials, Frankie Costanza
Design, Synthesis And Applications Of Polymer Biomaterials, Frankie Costanza
USF Tampa Graduate Theses and Dissertations
The emergence of antibiotic resistant bacteria has prompted the research into novel kinds of antibacterial small molecules and polymers. Nature has solved this issue with the use of cationic antimicrobial peptides, which act as nonspecific antibiotics against invading species. Herein, we have tried to mimic this general mechanism in a biocompatible and biodegradable polymer micelle based on the polymerization of naturally occurring amino acids lysine and phenylalanine linked to a PEG tether. This amphiphilic structure allows for the spontaneous collapse into stable nanoparticles in solution, which contains a hydrophilic outer layer and a hydrophobic core. Our polymers have shown activity …
Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino
Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino
Masters Theses, 2010-2019
The decline in the development of novel antimicrobials, combined with the misusage and over prescription of antibiotics, has contributed to the increasing prevalence of antimicrobial-resistant infections. Thus development of effective novel disinfectants could reduce the transmission of pathogens and decrease the risk of infection by antibiotic resistant organisms. The antimicrobial activity of amphiphiles, compounds with hydrophobic and hydrophilic regions, was first reported in 1935, and has influenced the synthesis of amphiphiles with variations in structure. In this study, three series of amphiphiles were synthesized by two subsequent Menshutkin reactions. Each amphiphile contains one or two hydrocarbon tails ranging from 8 …
Electrically Controlled Formation And Release Of Admicelles For Solid Phase Extraction, Sukyeon Lee
Electrically Controlled Formation And Release Of Admicelles For Solid Phase Extraction, Sukyeon Lee
Masters Theses & Specialist Projects
Solid phase extraction is one of the most widely used methods to concentrate diluted compounds in a solution. Substances can be extracted into admicelles and hemimicelles, which are surface adsorbed micelles and surfactant monolayers, respectively. Investigations of the electrical control of surfactants on surfaces for the purpose of analyte preconcentration prior to chromatographic analysis are presented. The surfactant layer serves as the “stationary phase” in a solid phase extraction sorbent scenario. Analytes are adsorbed on this layer, and then released from the solid phase via surfactant removal. The attachment and removal of the surfactant are controlled by means of an …
Insight Into The Modulation Of Shaw2 Kv Channels By General Anesthetics: Structural And Functional Studies Of S4-S5 Linker And S6 C-Terminal Peptides In Micelles By Nmr, Jin Zhang, Xiaoguang Qu, Manuel Covarrubias, Markus W. Germann
Insight Into The Modulation Of Shaw2 Kv Channels By General Anesthetics: Structural And Functional Studies Of S4-S5 Linker And S6 C-Terminal Peptides In Micelles By Nmr, Jin Zhang, Xiaoguang Qu, Manuel Covarrubias, Markus W. Germann
Chemistry Faculty Publications
The modulation of the Drosophila Shaw2 Kv channel by 1-alkanols and inhaled anesthetics is correlated with the involvement of the S4–S5 linker and C-terminus of S6, and consistent with stabilization of the channel's closed state. Structural analysis of peptides from S4–S5 (L45) and S6 (S6c), by nuclear magnetic resonance and circular dichroism spectroscopy supports that an α-helical conformation was adopted by L45, while S6c was only in an unstable/dynamic partially folded α-helix in dodecylphosphocholine micelles. Solvent accessibility and paramagnetic probing of L45 revealed that L45 lies parallel to the surface of micelles with charged and polar residues pointing towards the …
Metal-Assisted Hydrolysis Of Biological Molecules, Sarah Shealy Cepeda
Metal-Assisted Hydrolysis Of Biological Molecules, Sarah Shealy Cepeda
Chemistry Dissertations
In Chapter I is a general description of novel metal complexes which hydrolytically cleave peptides, proteins, DNA, and other biological molecules. These reagents are becoming the more important as potential therapeutic agents. A panel of ligands was investigated for coordination to ZrIV and other metals in groups 4, 5, and 6 to effect the greatest degree of hydrolysis. Chapter II describes a ZrIV complex which is capable of hydrolyzing a 30 amino acid peptide, insulin chain B, with amino acid specificity. Oxidized insulin chain B peptide was hydrolyzed after only 4 h of treatment at pH 7.0 and 60 °C …