SARS-CoV-2 has remained a global health burden, primarily due to the continuous evolution of different mutant strains. These mutations present challenges to the detection of the virus, as the target genes of qPCR, the standard diagnostic method, may possess sequence alterations. In this study, we develop an isothermal one-step detection method using rolling circle amplification (RCA) for SARS-CoV-2.
View Article and Find Full Text PDFMost common methods of cellular analysis employ the top-down approach (investigating proteomics or genomics directly), thereby destroying the cell, which does not allow the possibility of using the same cell to correlate genomics with functional assays. Herein we describe an approach for single-cell tools that serve as a bottom-up approach. Our technology allows functional phenotyping to be conducted by observing the cytotoxicity of cells and then probe the underlying biology.
View Article and Find Full Text PDFUnlabelled: This study aimed to develop a label-free fluorescent aptasensor for the detection of diazinon (DZN) on a cyclic olefin copolymer (COC) substrate. The aptasensor design was based on rolling circle amplification (RCA) technology and the use of self-assembled copper nanoparticles (CuNPs). A dual-function (DF) probe, capable of binding to circular DNA and an aptamer, was designed and immobilized on a COC-bottom 96-well plate.
View Article and Find Full Text PDFBiosens Bioelectron
July 2021
Mercury is one of the most common heavy metals and a major environmental pollutant that affects ecosystems. Since mercury and its compounds are toxic to humans, even at low concentrations, it is very important to monitor mercury contamination in water and foods. Although conventional mercury detection methods, including inductively coupled plasma mass spectrometry, atomic absorption spectroscopy, and gas chromatography-mass spectrometry, exhibit excellent sensitivity and accuracy, they require operation by an expert in a sophisticated and fully controlled laboratory environment.
View Article and Find Full Text PDFScreening target microorganisms from a mutated recombinant library plays a crucial role in advancing synthetic biology and metabolic engineering. However, conventional screening tools have several limitations regarding throughput, cost, and labor. Here, we used the fluid array platform to conduct high-throughput screening (HTS) that identified 'TesA thioesterase mutants producing elevated yields of free fatty acids (FFAs) from a large (10) mutant library.
View Article and Find Full Text PDFA point-of-care testing chip was developed for the colorimetric detection of inorganic mercury ion (Hg). The disposable chip fabricated by three-dimensional printing technology contains DNAzymes produced by rolling circle amplification (RCA); a color change caused by the enzymatic reaction between DNAzymes and the peroxidase substrate 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) is measured using a portable spectrophotometer. In the "turn-off"-type RCA reaction, the annealing of the T(12) primer that initiates the RCA reaction is blocked by the interaction of thymine with Hg; thus, the amount of amplified DNAzymes causing a color change is decreased depending on Hg concentration.
View Article and Find Full Text PDFBackground: Thin or damaged endometrium causes uterine factor-derived infertility resulting in a failure of embryonic implantation. Regeneration of endometrium is a major issue in gynecology and reproductive medicine. Various types of cells and scaffolds were studied to establish an effective therapeutic strategy.
View Article and Find Full Text PDFBackground: In mammals, UV radiation induces melanin synthesis in melanocyte for protecting their skin through the stimulation of α-melanocyte stimulating hormone (α-MSH) from keratinocytes. In this study, the inhibitory effects of dehydroglyasperin C (DGC), an useful component of Glycyrrhiza uralensis (G. uralensis), was investigated on melanogenesis induced by α-melanocyte stimulating hormone (α-MSH) and its mechanisms.
View Article and Find Full Text PDFA compartmentalized microfluidic chamber array that offers not only separate cell culture environments but also independent control of the diffusion of small molecules provides an extremely useful platform for cell cultivations and versatile cellular assays. However, it is challenging to incorporate both cell compartmentalization and active diffusion control in real-time and precise manners. Here, we present a novel nanoscale hydrodynamic film (NHF) that is formed between a solid substrate and a polydimethylsiloxane (PDMS) surface.
View Article and Find Full Text PDFNanowires (NWs) with a high surface-to-volume ratio are advantageous for bio- or chemical sensor applications with high sensitivity, high selectivity, rapid response, and low power consumption. However, NWs are typically fabricated by combining several nanofabrication and even microfabrication processes, resulting in drawbacks such as high fabrication cost, extensive labor, and long processing time. Here, we show a novel NW fabrication platform based on "crack-photolithography" to produce a micro-/nanofluidic channel network.
View Article and Find Full Text PDFThe screening and isolation of target microorganisms from mutated recombinant libraries are crucial for the advancement of synthetic biology and metabolic engineering. However, conventional screening tools present several limitations in throughput, cost, and labor. Herein, we describe a novel microfluidic high-throughput screening (HTS) platform with several advantages.
View Article and Find Full Text PDFMultiple copies of a cadC homolog encoding a heavy metal-responsive transcription factor were found in the genome of a bacterium isolated from ocean sediment, and the heavy metal responses of the encoded proteins were characterized using a fluorescence reporter assay. Each CadC regulator exhibited distinct specificity in response to heavy metal ions, indicating their potential use as modular heavy metal biosensors. Next, we constructed CadC-controlled T7 RNA transcription systems for intracellular signal amplification, i.
View Article and Find Full Text PDFA microbial biosensor is an analytical device with a biologically integrated transducer that generates a measurable signal indicating the analyte concentration. This method is ideally suited for the analysis of extracellular chemicals and the environment, and for metabolic sensory regulation. Although microbial biosensors show promise for application in various detection fields, some limitations still remain such as poor selectivity, low sensitivity, and impractical portability.
View Article and Find Full Text PDFIn this study, Polygonum aviculare L. extract, which has superior antioxidative and cellular membrane protective activity, was loaded onto cell penetrating peptide (CPP) conjugated liposomes to enhance transdermal delivery. The physical characteristics of typical liposomes and CPP-conjugated liposomes containing P.
View Article and Find Full Text PDFReporter-gene-based microbial biosensors have high potential for detecting small molecules, including heavy metal ions (HMIs), in a sensitive and selective manner by involving low costs. However, the sensitivity and dynamic range of the sensing mechanism are largely limited by the conventional culture environment that relies on the batch-type addition of the small molecules in nutrients and the subsequent genetic induction of sensing microbes. Here, we describe a high-throughput, chemostat-like microfluidic platform that can continuously supply both nutrients and inducers (HMIs) using microfabricated ratchet structures and a mixing microchannel network.
View Article and Find Full Text PDFPurpose: To evaluate choroidal thickness in diabetes patients using spectral-domain optical coherence tomography.
Methods: We examined 203 eyes of 203 diabetic participants and 48 eyes of 48 healthy controls. The choroidal thickness at the foveal lesion was measured by enhanced-depth imaging optical coherence tomography.
Purpose: To evaluate dry eye symptoms, tear film function and ocular surface changes in patients with psoriasis.
Methods: The Dry Eye Questionnaire and ophthalmic examination including the Schirmer test, tear break-up time, corneal fluorescein test, meibomian gland obstruction and conjunctival impression cytology were assessed in patients with chronic plaque psoriasis. Results were compared between 30 patients and 30 healthy controls.
Purpose: To evaluate the clinical features and surgical outcomes for primary rhegmatogenous retinal detachments (RDs) in patients with pseudophakia after phacoemulsification.
Methods: The medical records of patients with pseudophakia after phacoemulsification and intraocular lens implantation who had undergone surgery for primary rhegmatogenous RDs with a minimum duration of follow-up of 12 months were reviewed retrospectively.
Results: A total of 104 patients were enrolled in this study and 106 eyes were analyzed.
Purpose: To compare the effect of an intravitreal injection of bevacizumab alone (IVB) or combined with triamcinolone (IVB/IVT) versus triamcinolone (IVT) in patients with diabetic macular edema (DME).
Methods: In this randomized three-arm clinical trial, eligible eyes were assigned randomly to one of the three study arms: the IVB group, 2 injections of 1.25 mg of bevacizumab with 6-week intervals; the IVB/IVT group, 1.
Korean J Ophthalmol
August 2011
We report a case of posterior scleritis effectively managed with intravitreal bevacizumab. A 71-year-old woman was diagnosed with posterior scleritis. Although she was initially treated with systemic steroids, her clinical presentation deteriorated.
View Article and Find Full Text PDFPurpose: To evaluate the levels of aqueous humor cytokines in the eyes of patients with central serous chorioretinopathy (CSC) before an intravitreal injection of bevacizumab.
Methods: In a prospective interventional trial, 20 eyes of 20 patients with symptomatic CSC of at least 3 months duration and 20 eyes of 20 patients with cataract as control were included. Eyes with CSC received a single intravitreal injection of bevacizumab (1.
Aim: To compare the effect of intravitreal bevacizumab and triamcinolone in patients with macular edema after central retinal vein occlusion (CRVO), presenting with poor visual acuity.
Materials And Methods: It was a retrospective, comparative case series of 38 consecutive eyes, with macular edema secondary to CRVO, with 20/200 or worse vision, which were treated primarily either with intravitreal bevacizumab (1.25 mg; 24 eyes) or intravitreal triamcinolone (4 mg; 14 eyes).