Publications by authors named "Sanghwa Jeong"

Ovarian cancer is the deadliest gynecological cancer because it has few early symptoms and metastasizes to the surrounding organs at advanced stages. Cancer stem cells (CSCs), a subpopulation of cells with acquired drug resistance, contribute to the recurrence and poor prognosis of ovarian cancer. CD109, a cell surface glycoprotein, has been reported to be a marker of CSCs; however, it remains unclear whether CD109 is secreted by CSCs.

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Single-walled carbon nanotubes (SWCNTs) have gained significant interest for their potential in biomedicine and nanoelectronics. The functionalization of SWCNTs with single-stranded DNA (ssDNA) enables the precise control of SWCNT alignment and the development of optical and electronic biosensors. This study addresses the current gaps in the field by employing high-throughput systematic selection, enriching high-affinity ssDNA sequences from a vast random library.

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Oxytocin plays a critical role in regulating social behaviors, yet our understanding of its function in both neurological health and disease remains incomplete. Real-time oxytocin imaging probes with spatiotemporal resolution relevant to its endogenous signaling are required to fully elucidate oxytocin's role in the brain. Herein, we describe a near-infrared oxytocin nanosensor (nIROXT), a synthetic probe capable of imaging oxytocin in the brain without interference from its structural analogue, vasopressin.

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Owing to the value of DNA-wrapped single-walled carbon nanotube (SWNT)-based sensors for chemically specific imaging in biology, we explore machine learning (ML) predictions DNA-SWNT serotonin sensor responsivity as a function of DNA sequence based on the whole SWNT fluorescence spectra. Our analysis reveals the crucial role of DNA sequence in the binding modes of DNA-SWNTs to serotonin, with a smaller influence of SWNT chirality. Regression ML models trained on existing data sets predict the change in the fluorescence emission in response to serotonin, Δ/, at over a hundred wavelengths for new DNA-SWNT conjugates, successfully identifying some high- and low-response DNA sequences.

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In this study, we employed a novel approach to improve the serotonin-responsive ssDNA-wrapped single-walled carbon nanotube (ssDNA-SWCNT) nanosensors, combining directed evolution and machine learning-based prediction. Our iterative optimization process is aimed at the sensitivity and selectivity of ssDNA-SWCNT nanosensors. In the three rounds for higher serotonin sensitivity, we substantially improved sensitivity, achieving a remarkable 2.

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Background/purpose: Human dental pulp stem cells (hDPSCs) possess excellent proliferative and osteogenic differentiation potentials. This study aimed to elucidate the role of lysophosphatidic acid (LPA) signaling in the proliferation and osteogenic differentiation of hDPSCs.

Materials And Methods: hDPSCs were treated with LPA and proliferation was measured using the cell counting kit-8 assay.

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Article Synopsis
  • Photoacoustic imaging is a technique that uses natural and artificial substances (contrast agents) to visualize biological processes at the molecular level, enhancing our understanding of tissues.
  • The review discusses the principles of photoacoustic imaging, focusing on how light absorption and sound generation work together, as well as how different tissue types interact with various wavelengths of light.
  • It examines a variety of contrast agents, such as organic dyes and nanoparticles, highlighting their effectiveness in the near-infrared range to improve imaging quality and offering insights for future research development.
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DNA-wrapped single walled carbon nanotube (SWNT) conjugates have distinct optical properties leading to their use in biosensing and imaging applications. A critical limitation in the development of DNA-SWNT sensors is the current inability to predict unique DNA sequences that confer a strong analyte-specific optical response to these sensors. Here, near-infrared (nIR) fluorescence response data sets for ∼100 DNA-SWNT conjugates, narrowed down by a selective evolution protocol starting from a pool of ∼10 unique DNA-SWNT candidates, are used to train machine learning (ML) models to predict DNA sequences with strong optical response to neurotransmitter serotonin.

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The global SARS-CoV-2 coronavirus pandemic has led to a surging demand for rapid and efficient viral infection diagnostic tests, generating a supply shortage in diagnostic test consumables including nucleic acid extraction kits. Here, we develop a modular method for high-yield extraction of viral single-stranded nucleic acids by using "capture" ssDNA sequences attached to carbon nanotubes. Target SARS-CoV-2 viral RNA can be captured by ssDNA-nanotube constructs hybridization and separated from the liquid phase in a single-tube system with minimal chemical reagents, for downstream quantitative reverse transcription polymerase chain reaction (RT-qPCR) detection.

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This paper demonstrates fabrication of silica-shell-coated magnetic nanoparticle clusters (SMNCs) and subsequent surface engineering of SMNCs to produce surface-modified SMNCs that have zwitterionic and primary amine ligands (SMNC-ZW/Am). SMNC-ZW/Am was passivated by zwitterionic ligands for improved colloidal stability and reduced nonspecific adsorption and by primary amine ligands for facilitated conjugation with biomolecules. Hydrodynamic (HD) size and zeta potential of SMNC-ZW/Am could be flexibly tuned by controlling the relative amounts of zwitterionic and primary amine ligands.

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Near-infrared (NIR) luminescent materials have emerged as a growing field of interest, particularly for imaging and optics applications in biology, chemistry, and physics. However, the development of materials for this and other use cases has been hindered by a range of issues that prevents their widespread use beyond benchtop research. This review explores emerging trends in some of the most promising NIR materials and their applications.

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To effectively track and eliminate COVID-19, it is critical to develop tools for rapid and accessible diagnosis of actively infected individuals. Here, we introduce a single-walled carbon nanotube (SWCNT)-based optical sensing approach toward this end. We construct a nanosensor based on SWCNTs noncovalently functionalized with ACE2, a host protein with high binding affinity for the SARS-CoV-2 spike protein.

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To effectively track and eliminate COVID-19, it is critical to develop tools for rapid and accessible diagnosis of actively infected individuals. Here, we introduce a single-walled carbon nanotube (SWCNT)-based optical sensing approach towards these ends. We construct a nanosensor based on SWCNTs noncovalently functionalized with ACE2, a host protein with high binding affinity for the SARS-CoV-2 spike protein.

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Graphene quantum dots (GQDs) are an allotrope of carbon with a planar surface amenable to functionalization and nanoscale dimensions that confer photoluminescence. Collectively, these properties render GQDs an advantageous platform for nanobiotechnology applications, including optical biosensing and delivery. Towards this end, noncovalent functionalization offers a route to reversibly modify and preserve the pristine GQD substrate, however, a clear paradigm has yet to be realized.

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When quantifying mechanical properties of blood samples flowing in closed fluidic circuits, blood samples are collected at specific intervals. Centrifugal separation is considered as a required procedure for preparing blood samples. However, the use of centrifuge is associated with several issues, including the potential for red blood cell (RBC) lysis, clotting activation, and RBC adhesions in the tube.

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Imaging neuromodulation with synthetic probes is an emerging technology for studying neurotransmission. However, most synthetic probes are developed through conjugation of fluorescent signal transducers to preexisting recognition moieties such as antibodies or receptors. We introduce a generic platform to evolve synthetic molecular recognition on the surface of near-infrared fluorescent single-wall carbon nanotube (SWCNT) signal transducers.

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The product of ferulic acid decarboxylation, 4-vinylguaiacol (4-VG), is an important antioxidant and is reported to have an antioxidant capacity comparable to α-tocopherol. In this study, evaluation on antioxidant capacities of ferulic acid, catechin, and 4-VG was performed when 200 ppm of each compound was added in a 10% O/W emulsion for 50 days. Peroxide value (POV) results of the O/W emulsion containing 4-VG were noteworthy.

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Generation, identification, and validation of optical probes to image molecular targets in a biological milieu remain a challenge. Synthetic molecular recognition approaches leveraging the intrinsic near-infrared fluorescence of single-walled carbon nanotubes are promising for long-term biochemical imaging in tissues. However, generation of nanosensors for selective imaging of molecular targets requires a heuristic approach.

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PbS/CdS core/shell quantum dots (QDs) that emit at the second near-infrared (NIR-II, 1000-1700 nm) window are synthesized. The PbS seed size and CdS shell thicknesses are carefully controlled to produce bright and narrow fluorescence that are suitable for multiplexing. A polymer encapsulation yields polymer-encapsulated NIR-II QDs (PQDs), which provides the QDs with long-term fluorescence stability over a week in biological media.

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A supra-quantum dot (SQD) is a three-dimensional structure formed by the attachment of quantum dots. The SQDs have sizes of tens of nanometer and they maintain the characteristics of the individual quantum dots fairly well. Moreover, their sizes and elemental compositions can be tuned precisely.

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Decarboxylation of ferulic acid would increase the solubility in oils. Rice bran extract (RBE) containing 29 mg ferulic acid/g RBE was decarboxylated to obtain decarboxylated rice bran extract (DRBE), and its antioxidant capacity in oil system was studied. After addition of DRBE (500 ppm), oxidation was monitored for 20 days at 60 °C under the dark.

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Article Synopsis
  • - Recent advancements in fluorescence imaging have progressed into the second near-infrared region (NIR-II), which allows for high-resolution imaging through deep tissues, although effective fluorophores are still limited in this region.
  • - The study introduces a new enzyme-activatable NIR-II probe that lights up in response to matrix metalloprotease activity within tumor environments, utilizing specially designed quantum dots (QDs) for enhanced brightness and stability.
  • - Experiments with a colon cancer mouse model showed that this probe provides targeted fluorescence signal activation at tumor sites, achieving a 3-fold increase in signal in just 10 minutes, outperforming traditional imaging dyes.
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'Smart' gold nanoparticles can respond to mild acidic environments, rapidly form aggregates, and shift the absorption to red and near-infrared. They were used as a photoacoustic imaging agent responsive to the cancer microenvironment, and have demonstrated the cancer-specific accumulation at the cellular level and an amplified signal which is twice higher than the control in vivo.

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Quantum dot (QD) imaging capability was investigated by the imaging depth at a near-infrared second optical window (SOW; 1000 to 1400 nm) using time-modulated pulsed laser excitations to control the effective fluence rate. Various media, such as liquid phantoms, tissues, and in vivo small animals, were used and the imaging depths were compared with our predicted values. The QD imaging depth under excitation of continuous 20 mW/cm(2) laser was determined to be 10.

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A simple direct-writing technique can be used to fabricate a stretchable UV-vis-NIR nanowire photodetector (NWPD) consisting of PbS quantum dot (QD)-poly(3-hexylthiopehene) (P3HT) hybrid NWs. The hybrid NWPD shows superior sensitivity and response speed in the UV-vis to NIR range. The stretchable UV-vis-NIR NWPD shows a nearly identical photoresponse under extreme (up to 100%) and repeated (up to 100 cycles) stretching conditions.

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