Publications by authors named "Colin L Hisey"

Astrocytes play many essential roles in the central nervous system (CNS) and are altered significantly in disease. These reactive astrocytes contribute to neuroinflammation and disease progression in many pathologies, including glioblastoma (GB), an aggressive form of brain cancer. Current in vitro platforms do not allow for accurate modeling of reactive astrocytes.

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Surface-enhanced Raman spectroscopy (SERS) is a powerful tool that provides valuable insight into the molecular contents of chemical and biological samples. However, interpreting Raman spectra from complex or dynamic datasets remains challenging, particularly for highly heterogeneous biological samples like extracellular vesicles (EVs). To overcome this, we developed a tunable and interpretable deep autoencoder for the analysis of several challenging Raman spectroscopy applications, including synthetic datasets, chemical mixtures, a chemical milling reaction, and mixtures of EVs.

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The role of extracellular vesicles (EVs) in human health and disease has garnered considerable attention over the past two decades. However, while several types of EVs are known to interact dynamically with the extracellular matrix and there is great potential value in producing high-fidelity EV micropatterns, there are currently no label-free, high-resolution, and tunable platform technologies with this capability. We introduce Light-induced Extracellular Vesicle Adsorption (LEVA) as a powerful solution to rapidly advance the study of matrix- and surface-bound EVs and other particles.

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Optical and non-optical techniques propelled the field of single extracellular particle (EP) research through phenotypic and morphological analyses, revealing the similarities, differences, and co-isolation of EP subpopulations. Overcoming the challenges of optical and non-optical techniques motivates the use of orthogonal techniques while analyzing extracellular particles (EPs), which require varying concentrations and preparations. Herein, we introduce the nano-positioning matrix (NPMx) technique capable of superimposing optical and non-optical modalities for a single-EP orthogonal analysis.

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The molecular heterogeneity of extracellular vesicles (EVs) and the co-isolation of physically similar particles, such as lipoproteins (LPs), confounds and limits the sensitivity of EV bulk biomarker characterization. Herein, we present a single-EV and particle (siEVP) protein and RNA assay ( PRA) to simultaneously detect mRNAs, miRNAs, and proteins in subpopulations of EVs and LPs. The PRA immobilizes and sorts particles via positive immunoselection onto micropatterns and focuses biomolecular signals in situ.

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Extracellular vesicles (EVs) are lipid-bound vesicles released from cells that play a crucial role in many physiological processes and pathological mechanisms. As such, there is great interest in their biodistribution. One currently accessible technology to study their fate in vivo involves fluorescent labelling of exogenous EVs followed by whole-animal imaging.

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Extracellular vesicles (EVs) have emerged as promising diagnostic and therapeutic candidates in many biomedical applications. However, EV research continues to rely heavily on in vitro cell cultures for EV production, where the exogenous EVs present in fetal bovine (FBS) or other required serum supplementation can be difficult to remove entirely. Despite this and other potential applications involving EV mixtures, there are currently no rapid, robust, inexpensive, and label-free methods for determining the relative concentrations of different EV subpopulations within a sample.

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Extracellular vesicle (EV) research has grown rapidly in recent years, largely due to the potential use of EVs as liquid biopsy biomarkers or therapeutics. However, in-depth characterisation and validation of EVs produced using conventional cultures can be challenging due to the large area of cell monolayers and volumes of culture media required. To overcome this obstacle, multiple bioreactor designs have been tested for EV production with varying success, but the consistency of EVs produced over time in these systems has not been reported previously.

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Article Synopsis
  • * We created two deep learning methods using cascaded convolutional neural networks (CNN) that can preprocess raw Raman spectroscopy data automatically, minimizing the need for human intervention.
  • * Our methods demonstrated quicker training and improved accuracy in classifying various Raman spectra, making them well-suited for handling large, complex datasets in biomedical applications like cancer detection and analysis of extracellular vesicles.
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In Brief: Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) have shown promise as off-the-shelf therapeutics; however, producing them in sufficient quantities can be challenging. In this study, MSCs were isolated from preimplantation equine embryos and used to produce EVs in two commercially available bioreactor designs.

Abstract: Mesenchymal stromal cells (MSC) have recently been explored for their potential use as therapeutics in human and veterinary medicine applications, such as the treatment of endometrial inflammation and infertility.

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Electrochemical techniques offer great opportunities for the capture of chemical and biological entities from complex mixtures and their subsequent release into clean buffers for analysis. Such methods are clean, robust, rapid, and compatible with a wide range of biological fluids. Here, we designed an electrochemically addressable system, based on a conducting terpolymer [P(EDOTEDOTSAcEDOTEG)] coated onto a carbon cloth substrate, to selectively capture and release biological entities using a simple electrochemical redox process.

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Placental extracellular vesicles (EVs) play an essential role in pregnancy by protecting and transporting diverse biomolecules that aid in fetomaternal communication. However, in preeclampsia, they have also been implicated in contributing to disease progression. Despite their potential clinical value, current technologies cannot provide a rapid and effective means of differentiating between healthy and diseased placental EVs.

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The process of proplatelet formation (PPF) requires coordinated interaction between megakaryocytes (MKs) and the extracellular matrix (ECM), followed by a dynamic reorganization of the actin and microtubule cytoskeleton. Localized fluxes of intracellular calcium ions (Ca2+) facilitate MK-ECM interaction and PPF. Glutamate-gated N-methyl-D-aspartate receptor (NMDAR) is highly permeable to Ca2+.

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The efficient production of extracellular vesicles (EVs) from adherent cells in vitro can be challenging when using conventional culture flasks. Issues such as low cell density leading to low EV yield, and the inability to completely remove bovine serum EVs without starvation contribute to this challenge. By comparison, the two-chamber CELLine adherent bioreactor can produce significantly more EVs with improved time, space, and resource efficiency.

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Extracellular vesicles (EVs) are micro and nanoscale lipid-enclosed packages that have shown potential as liquid biopsy targets for cancer because their structure and contents reflect their cell of origin. However, progress towards the clinical applications of EVs has been hindered due to the low abundance of disease-specific EVs compared to EVs from healthy cells; such applications thus require highly sensitive and adaptable characterization tools. To address this obstacle, we designed and fabricated a novel space curvature-inspired surfaced-enhanced Raman spectroscopy (SERS) substrate and tested its capabilities using bioreactor-produced and size exclusion chromatography-purified breast cancer EVs of three different subtypes.

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Extracellular vesicles (EVs) are emerging as key players in breast cancer progression and hold immense promise as cancer biomarkers. However, difficulties in obtaining sufficient quantities of EVs for the identification of potential biomarkers hampers progress in this area. To circumvent this obstacle, we cultured BT-474 breast cancer cells in a two-chambered bioreactor with CDM-HD serum replacement to significantly improve the yield of cancer cell-associated EVs and eliminate bovine EV contamination.

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Extracellular vesicles (EVs) are micro and nanoscale packages that circulate in all bodily fluids and play an important role in intercellular communication by shuttling biomolecules to nearby and distant cells. However, producing sufficient amounts of EVs for many types of in vitro studies using standard culture methods can be challenging, and despite the success of some bioreactors in increasing EV-production, it is still largely unknown how individual culture conditions can alter the production and content of EVs. In this study, we demonstrate a simple and inexpensive micropatterning technique that can be used to produce polystyrene microtracks over a 100 mm diameter growth surface area.

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There is a significant and growing research interest in the isolation of extracellular vesicles (EVs) from large volumes of biological samples and their subsequent concentration into clean and small volumes of buffers, especially for applications in medical diagnostics. Materials that are easily incorporated into simple sampling devices and which allow the release of EVs without the need for auxiliary and hence contaminating reagents are particularly in demand. Herein, we report on the design and fabrication of a flexible, microporous, electrochemically switchable cloth that addresses the key challenges in diagnostic applications of EVs.

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Article Synopsis
  • Highly migratory cancer cells significantly contribute to metastasis and recurrence, leading to high mortality rates in various cancers despite treatment efforts.
  • A new microfluidic device has been developed to seed single cancer cells onto microtracks, enabling controlled study of their migratory behavior influenced by topography.
  • Research found that U87 glioblastoma cells migrate slower and maintain more directional persistence on specially designed microtracks compared to flat surfaces, which can enhance drug screening and personalized medicine approaches.
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Because of limits on specificity and purity to allow for in-depth protein profiling, a standardized method for exosome isolation has yet to be established. In this study, we describe a novel, in-house microfluidic-based device to isolate exosomes from culture media and patient samples. This technology overcomes contamination issues because sample separation is based on the expression of highly specific surface markers CD63 and EpCAM.

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Exosomes are nanoscale vesicles found in many bodily fluids which play a significant role in cell-to-cell signaling and contain biomolecules indicative of their cells of origin. Recently, microfluidic devices have provided the ability to efficiently capture exosomes based on specific membrane biomarkers, but releasing the captured exosomes intact and label-free for downstream characterization and experimentation remains a challenge. We present a herringbone-grooved microfluidic device which is covalently functionalized with antibodies against general and cancer exosome membrane biomarkers (CD9 and EpCAM) to isolate exosomes from small volumes of high-grade serous ovarian cancer (HGSOC) serum.

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Achieving highly enriched single wall carbon nanotubes (SWNTs) is one of the major hurdles today because their chirality-dependent properties must be uniform and predictable for use in nanoscale electronics. Due to the unique wrapping and groove-binding mechanism, DNA has been demonstrated as a highly specific SWNT dispersion and fractionation agent, with its enrichment capabilities depending on the DNA sequence and length as well as the nanotube properties. Salmon genomic DNA (SaDNA) offers an inexpensive and scalable alternative to synthetic DNA.

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