Publications by authors named "Deryl Troyer"

We report the design and adaptation of iron/iron oxide nanoparticle-based optical nanobiosensors for enzymes or cytokine/chemokines that are established biomarkers of lung diseases. These biomarkers comprise ADAM33, granzyme B, MMP-8, neutrophil elastase, arginase, chemokine (C-C motif) ligand 20 and interleukin-6. The synthesis of nanobiosensors for these seven biomarkers, their calibration with commercially available enzymes and cytokines/chemokines, as well as their validation using bronchoalveolar lavage (BAL) obtained from a mouse model of TLR3-mediated inflammation are discussed here.

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Article Synopsis
  • Major concerns about viral vectors for gene therapy include risks like cancer resistance and potential fatalities, prompting researchers to explore nonviral alternatives.
  • The study developed a new gene delivery nanocarrier using a cell-penetrating peptide called WTAS and a protective polymer, poly(β-amino ester) (PBAE), which enhances cell absorption and stability.
  • Testing showed that this PBAE-WTAS nanocarrier has low toxicity and achieves over 90% effectiveness in delivering GFP plasmid DNA to cells, suggesting it could potentially be adapted for various genetic therapies.
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Peptide nanosponges of low polydispersity are spontaneously formed from trigonal supramolecular building blocks in aqueous buffers, which feature cationic and/or anionic oligopeptides ( = 5-20) and a hydrophobic unit. In contrast to classical liposomes/vesicles, nanosponges feature interwoven hydrophilic and hydrophobic nanodomains and are readily taken up by mammalian cells. Perillyl alcohol is known to be a simple, but effective small molecule drug against glioma multiforme.

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Numerous proteases, such as matrix metalloproteinases (MMPs), cathepsins (CTS), and urokinase plasminogen activator (UpA), are dysfunctional (that is, over- or under-expressed) in solid tumors, when compared to healthy human subjects. This offers the opportunity to detect early tumors by liquid biopsies. This approach is of particular advantage for the early detection of pancreatic cancer, which is a "silent killer".

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The structure of novel binary nanosponges consisting of (cholesterol-(K/D) DEVDGC)-trimaleimide units possessing a trigonal maleimide linker, to which either lysine (K) or aspartic acid (D) are tethered, has been elucidated by means of TEM. A high degree of agreement between these findings and structure predictions through explicit solvent and then coarse-grained molecular dynamics (MD) simulations has been found. Based on the nanosponges' structure and dynamics, caspase-6 mediated release of the model drug 5(6)-carboxyfluorescein has been demonstrated.

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Background: Wharton's jelly cells (WJCs) have multiple differentiation potentials and are easily harvested in large numbers. WJCs are well tolerated in allogeneic environments and there is a growing list of their therapeutic effects. Most therapies require administering large numbers of cells and this is generally accomplished by intravenous injection.

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Animal models are essential to cancer research, but current xenograft models are limited in their utility especially due to the lack of an immune system. Here we demonstrate that a xenograft tumor model can be developed in immunocompetent mice by tolerizing murine fetuses to human tumor cells. A375 human melanoma cells were injected into day E14 fetuses and after birth mice were challenged with A375 cells to determine their ability to develop tumors.

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A novel type of supramolecular aggregate, named a "nanosponge" was synthesized through the interaction of novel supramolecular building blocks with trigonal geometry. The cholesterol-(K/D)DEVDGC)-trimaleimide unit consists of a trigonal maleimide linker to which homopeptides (either K or D) of variable lengths (n=5, 10, 15, 20) and a consensus sequence for executioner caspases (DEVDGC) are added via Michael addition. Upon mixing in aqueous buffer cholesterol-(K)DEVDGC)-trimaleimides and a 1:1 mixture of cholesterol-(K/D)DEVDGC)-trimaleimides form stable nanosponges, whereas cholesterol-(D)DEVDGC)-trimaleimide is unable to form supramolecular aggregates with itself.

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Purpose: Integrating small-animal experimental hyperthermia instrumentation with magnetic resonance imaging (MRI) affords real-time monitoring of spatial temperature profiles. This study reports on the development and preliminary in vivo characterisation of a 2.45 GHz microwave hyperthermia system for pre-clinical small animal investigations, integrated within a 14 T ultra-high-field MRI scanner.

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Here, we report the synthesis, characterization, and efficacy study of Fe/Fe₃O₄-nanoparticles that were co-labeled with a tumor-homing and membrane-disrupting oligopeptide and the iron-chelator Dp44mT, which belongs to the group of the thiosemicarbazones. Dp44mT and the peptide sequence PLFAERL([KLAKLAKKLAKLAK])CGKRK were tethered to the surface of Fe/Fe₃O₄ core/shell nanoparticles by utilizing dopamine-anchors. The 26-mer contains two important sequences, which are the tumor targeting peptide CGKRK, and [KLAKLAK]₂, known to disrupt the mitochondrial cell walls and to initiate programmed cell death (apoptosis).

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Metritis, a uterine disease caused by bacterial infection, is highly prevalent in dairy cattle after parturition. Uterine disease has negative effects on milk production and reproductive efficiency. Finding markers or indicators that can predict cows at greater risk for uterine disease could be beneficial to mitigating these deleterious effects.

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Red blood cells (RBCs) are the natural resident of the vascular lumen, therefore delivery of any agents within the vascular lumen could benefit by unique natural transporting features of RBCs. RBCs continuously circulate for ∼100 days before being sequestered in the spleen, they only extravasate at sites of vascular hemorrhage. Taking advantages of these features, we engineered RBC as a carrier in order to design a unique delivery system capable of delivering X-ray computed tomography (CT) contrast agents, gold nanoparticles (AuNPs), thereby acting as CT-contrast agent.

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A nanobiosensor for arginase detection was designed and synthesized. It features a central dopamine-coated iron/iron oxide nanoparticle to which sulfonated cyanine 7.0 is tethered via a stable amide bond.

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Proteases, including matrix metalloproteinases (MMPs), tissue serine proteases, and cathepsins (CTS) exhibit numerous functions in tumor biology. Solid tumors are characterized by changes in protease expression levels by tumor and surrounding tissue. Therefore, monitoring protease levels in tissue samples and liquid biopsies is a vital strategy for early cancer detection.

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The recent WHO report on antibiotic resistances shows a dramatic increase of microbial resistance against antibiotics. With only a few new antibiotics in the pipeline, a different drug delivery approach is urgently needed. We have obtained evidence demonstrating the effectiveness of a cell based drug delivery system that utilizes the innate immune system as targeting carrier for antibacterial drugs.

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Human and rat umbilical cord matrix mesenchymal stem cells (UCMSC) possess the ability to control the growth of breast carcinoma cells. Comparative analyses of two types of UCMSC suggest that rat UCMSC-dependent growth regulation is significantly stronger than that of human UCMSC. Their different tumoricidal abilities were clarified by analyzing gene expression profiles in the two types of UCMSC.

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Cell-based therapeutics have advanced significantly over the past decade and are poised to become a major pillar of modern medicine. Three cell types in particular have been studied in detail for their ability to home to tumors and to deliver a variety of different payloads. Neural stem cells, mesenchymal stem cells and monocytes have each been shown to have great potential as future delivery systems for cancer therapy.

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The quest for renewable and cleaner energy sources to meet the rapid population and economic growth is more urgent than ever before. Being the most abundant carbon source in the atmosphere of Earth, CO2 can be used as an inexpensive C1 building block in the synthesis of aromatic fuels for internal combustion engines. We designed a process capable of synthesizing benzene, toluene, xylenes and mesitylene from CO2 and H2 at modest temperatures (T = 380 to 540 °C) employing Fe/Fe3O4 nanoparticles as catalyst.

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Heparin has been extensively used as an anticoagulant for the last eight decades. Recently, the administration of a contaminated batch of heparin caused 149 deaths in several countries including USA, Germany, and Japan. The contaminant responsible for the adverse effects was identified as oversulfated chondroitin sulfate (OSCS).

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Numerous proteases are known to be necessary for cancer development and progression including matrix metalloproteinases (MMPs), tissue serine proteases, and cathepsins. The goal of this research is to develop an Fe/Fe3O4 nanoparticle-based system for clinical diagnostics, which has the potential to measure the activity of cancer-associated proteases in biospecimens. Nanoparticle-based "light switches" for measuring protease activity consist of fluorescent cyanine dyes and porphyrins that are attached to Fe/Fe3O4 nanoparticles via consensus sequences.

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Polymorphonuclear neutrophils (PMNs) are the most abundant circulating blood leukocytes. They are part of the innate immune system and provide a first line of defense by migrating toward areas of inflammation in response to chemical signals released from the site. Some solid tumors, such as breast cancer, also cause recruitment and activation of PMNs and release of myeloperoxidase.

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We report a study on chemiluminescence-based chemical analyses using luminol molecules covalently attached to 10 nm diameter gold nanoparticles (GNPs). Chemiluminescence (CL) has been systematically studied under two schemes by varying the concentrations of luminol-labeled GNPs and [Fe(CN)6](3-) catalyst, respectively. The CL signal of luminol-labeled GNPs is enhanced by 5 to 10 times compared to the bulk luminol solutions of the same concentration.

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The mycobacterial porin MspA is one of the most stable channel proteins known to date. MspA forms vesicles at low concentrations in aqueous buffers. Evidence from dynamic light scattering, transmission electron microscopy and zeta-potential measurements by electrophoretic light scattering indicate that MspA behaves like a nanoscale surfactant.

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Animal models for cancer therapy are invaluable for preclinical testing of potential cancer treatments; however, therapies tested in such models often fail to translate into clinical settings. Therefore, a better preclinical model for cancer treatment testing is needed. Here we demonstrate that an immunodeficient line of pigs can host and support the growth of xenografted human tumors and has the potential to be an effective animal model for cancer therapy.

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