Katie A. Edwards

Binghamton University | SUNY Binghamton · Pharmaceutical Sciences

The COVID-19 pandemic has had a devastating impact worldwide and has brought clinical assays both for acute diagnosis and prior exposure determination to the forefront. Serological testing intended for point-of-care or laboratory use can be used to determine more accurate individual and population assessments of prior exposure to SARS-CoV-2; improv...

A deficiency of thiamine (vitamin B1), an essential cofactor for enzymes involved in metabolic processes, can be caused by the enzyme thiaminase. Thiaminase in food stocks has been linked to morbidity and mortality due to thiamine depletion in many ecologically and economically important species. Thiaminase activity has been detected in certain bac...

Fish population declines from thiamine (vitamin B1) deficiency have been widespread in ecologically and economically valuable organisms, ranging from the Great Lakes to the Baltic Sea and, most recently, the California coast. Thiamine deficiencies in predatory fishes are often attributed to a diet of prey fishes with high levels of thiamine-degradi...

Thiamine (vitamin B1) is an essential vitamin serving in its diphosphate form as a cofactor for enzymes in the citric acid cycle and pentose-phosphate pathways. Its concentration reported in the pM and nM range in environmental and clinical analyses prompted our consideration of the components used in pre-analytical processing, including the select...

Periplasmic binding proteins provide gram-negative bacteria with mechanisms for nutrient uptake and sensing their environments through recognition and transport of small molecules and ions. In the assay development realm, the biosensing niche that these proteins fulfill is the recognition and detection of non-immunogenic targets, including inorgani...

Background: Phosphorodiamidate morpholino oligomer (PMO)-mediated exon skipping is currently used in clinical development to treat Duchenne muscular dystrophy (DMD), with four exon-skipping drugs achieving regulatory approval. Exon skipping elicits a truncated, but semi-functional dystrophin protein, similar to the truncated dystrophin expressed i...

https://www.sciencedirect.com/science/article/pii/S0039914019307945#appsec1

Deficiencies in thiamine (vitamin B1) cause a host of neurological and reproductive impairments yielding morbidity and mortality across environmental and clinical realms. In a technique analogous to immunomagnetic separation, we introduce the use of thiamine periplasmic binding protein (TBP)-conjugated magnetic beads to isolate thiamine from comple...

Exon skipping is a promising genetic therapeutic strategy for restoring dystrophin expression in the treatment of Duchenne muscular dystrophy (DMD). The potential for newly synthesized dystrophin to trigger an immune response in DMD patients, however, is not well established. We have evaluated the effect of chronic morpholino (PMO) treatment on ske...

The function of thiaminase I has remained a long-standing, unsolved mystery. The enzyme is only known to be produced by a small subset of microorganisms, although thiaminase I activity has been associated with numerous plants and animals, and is implicated in thiamine deficiencies brought on by consumption of organisms containing this enzyme. Genom...

The microbiota of Drosophila melanogaster has a substantial impact on host physiology and nutrition. Some effects may involve vitamin provisioning, but the relationships between microbe-derived vitamins, diet, and host health remain to be established systematically. We explored the contribution of microbiota in supplying sufficient dietary thiamine...

http://pubs.acs.org/doi/abs/10.1021/ac501219u

http://pubs.acs.org/doi/abs/10.1021/acs.analchem.6b02092

http://pubs.acs.org/doi/abs/10.1021/ac303258n

https://link.springer.com/article/10.1007/s00216-010-3765-x

Clinical and environmental analyses frequently necessitate rapid, simple, and inexpensive point-of-care or field tests. These semiquantitative tests may be later followed up by confirmatory laboratory-based assays, but provide an initial scenario assessment important for resource mobilization and threat confinement. Lateral-flow assays (LFAs) and d...

Thiamine (vitamin B1) is essential to the health of all living organisms and deficiency has long been associated with diseases in animals such as fish, birds, alligators, and domesticated ruminant mammals. Thiamine is also implicated in several human diseases including Alzheimer's, diabetes, dementia, depression and, most notably, Wernicke–Korsakof...

Supplementary

Although antibodies and aptamers are commonly used bioaffinity recognition elements, they are not available for many important analytes. As an alternative, we demonstrate use of a periplasmic binding protein (PBP) to provide high affinity recognition for thiamine (vitamin B1), an analyte of great importance to human and environmental health for whi...

Nanoparticles are ubiquitously used for signal enhancement in (bio)sensors, but their true possible performance is typically hampered by non-specific binding. A better understanding of the nature and the prevention of non-specific binding through surface engineering of the particles and sensor surfaces is needed to intelligently design (bio)sensors...

Liposomes have been widely explored in the drug delivery realm over the past decades. Many of the properties that made them well suited for drug delivery applications, such as the internal space to encapsulate a large payload of hydrophilic molecules and the inherent protection from exterior stresses, have also been exploited in unique analytical m...

Interactions between solution phase analytes and surface immobilized biorecognition elements in heterogeneous binding assay formats, such as enzyme-linked immunosorbent assays (ELISAs), are often hindered by mass transfer limitations. In order to improve detection limits and decrease assay times, an applied magnetic field can be used to promote tar...

A periplasmic binding protein (PBP) was investigated as a novel binding species in a similar manner to an antibody in a competitive enzyme linked immunosorbent assay (ELISA), resulting in a highly sensitive and specific assay utilizing liposome-based signal amplification. PBPs are located at high concentrations (10 M) between the inner and outer me...

Myoglobin is one of several cardiac markers which become elevated in the blood following an acute myocardial infarction and can aid in the diagnosis of a heart attack. Here, a sandwich immunoassay for myoglobin was developed, including a thorough optimization of fluorescent dye-encapsulating liposomes versus enzymatic amplification (alkaline phosph...

Liposomes are often used for targeted and controlled delivery of sensitive pharmaceutical compounds. They may be synthesized encapsulating drugs within their aqueous cores and their surfaces may be functionalized with antibodies and polyethylene glycol (PEG) for site-specific delivery and increased circulation time, respectively. Here we investigat...

Biorecognition-element labeled liposomes are simple and versatile tools used to amplify signals for the detection of analytes of environmental, clinical, food safety, and national security interest. Relying on measurement of encapsulated species via electrochemical or spectroscopic techniques, or properties inherent to liposomes themselves (such as...

We studied aptamer binding events in a heterogeneous format using label-free and fluorescence measurements for the purpose of developing an aptamer-based sandwich assay on a standard microtiter plate platform. The approach allowed visualization of the underlying aptamer immobilization and target binding events rather than relying on only an endpoin...

Fluorescent dye-encapsulating liposomes tagged with aptamers were developed and used as reporting signals in an aptamer-based sandwich assay. α-Thrombin was utilized as a prototypical analyte as two well-studied aptamers binding distinct epitopes are available to form a sandwich complex. Cholesteryl-TEG-modified aptamers were embedded into the lipo...

A modular system for the DNA-directed immobilization of antibodies was applied to capture living cells on microstructured DNA surfaces. It is demonstrated in two different set-ups, static incubation and hydrodynamic flow, that this approach is well suited for specific capture and selection of cells from culture medium. The adhered cells show intact...

Clinical and environmental analyses frequently necessitate rapid, simple, and inexpensive point-of-care or field tests. These semiquantitative tests may be later followed up by confirmatory laboratory-based assays, but can provide an initial scenario assessment important for resource mobilization and threat confinement. Lateral-flow assays (LFAs) a...

Fluorescence and electrochemical microfluidic biosensors were developed for the detection of cholera toxin subunit B (CTB) as a model analyte. The microfluidic devices were made from polydimethylsiloxane (PDMS) using soft lithography from silicon templates. The polymer channels were sealed with a glass plate and packaged in a polymethylmethacrylate...

Vibrio cholerae, the causative agent for cholera, expresses a toxin required for virulence consisting of two subunits: the pentameric cholera toxin B (CTB) and cholera toxin A (CTA). CTB is frequently used as an indicator of the presence of pathogenic V. cholerae and binds to the G(M1) ganglioside on the surface of epithelial cells. To study V. cho...

Dye-encapsulating liposomes can serve as signaling reagents in biosensors and biochemical assays in place of enzymes or fluorophores. Detailed here is the use and preparation of streptavidin-coupled liposomes which offer a universal approach to biotinylated target detection. The universal approach provides two advantages, i.e. only one type of lipo...

Vibrio cholerae, the causative agent for cholera, infects its host by expressing a protein consisting of two subunits: the pentameric cholera toxin B (CTB) and cholera toxin A (CTA). CTB frequently is used as an indicator of the presence of pathogenic V. cholerae and typically is detected using enzyme-linked immunosorbent assays (ELISAs). In lieu o...

A novel liposome-based signal amplification system was developed by encapsulating DNA oligonucleotides within antibody-tagged liposomes and subsequently detecting the oligonucleotide with dye-encapsulating liposomes for double signal enhancement. In this sandwich immunoassay, the model analyte, protective antigen protein from B. anthracis, was capt...

RNA or DNA aptamers have received much attention in recent literature as therapeutic agents and chromatographic matrices, however, their use in analytical methodologies is relatively unexplored. We describe here investigations aiming to combine this promising technology with versatile liposomes in a competitive assay format. Thus, a phospholipid de...

Dye-encapsulating unilamellar DNA oligonucleotide-tagged liposomes were prepared and characterized for use as signal-enhancing reagents in a microtiter plate sandwich-hybridization analyses of single-stranded RNA or DNA sequences. The liposomes were synthesized using the reversed-phase evaporation method and tagged with DNA oligonucleotides by addi...

A novel protocol for the synthesis of dye-encapsulating liposomes tagged with DNA oligonucleotides at their outer surface was developed. These liposomes were optimized for use as signal enhancement agents in lateral-flow sandwich-hybridization assays for the detection of single-stranded RNA and DNA sequences. Liposomes were synthesized using the re...

A sequential injection analysis lab-on-valve (SIA-LOV) system was developed for the specific detection of single-stranded nucleic acid sequences via sandwich hybridization of specific DNA probes to the target sequence. One DNA probe was tagged with fluorescein; the other was biotinylated and immobilized to streptavidin-coated porous beads. The syst...

The use of liposomes as analytical and bioanalytical reagents has been shown to be successful of in a variety of different applications that will be reviewed here. Due to their high surface area, large internal volume, and ability to conjugate bilayer lipids with a variety of biorecognition elements liposomes have been used in homogenous and hetero...

Liposomes are highly versatile structures for research, therapeutic, and analytical applications. In order to assess the quality of liposomes and obtain quantitative measures that allow comparison between different batches of liposomes, various parameters should be monitored. For liposomes used in analytical and bioanalytical applications, the main...

B. anthracis, the causative agent for anthrax, has been well studied for over 150 years. Due to the genetic similarities among various Bacillus species, as well as its existence in both a spore form and a vegetative state, the detection and specific identification of B. anthracis have been proven to require complex techniques and/or laborious metho...

Thesis (Ph. D.)--Cornell University, May, 2005. Includes bibliographical references.

Thesis (M.S.)--Cornell University, August, 2002. Includes bibliographical references.