Advancing Breathability of Respiratory Nanofilter by Optimizing Pore Structure and Alignment in Nanofiber Networks.

Respiratory masks are the primary and most effective means of protecting individuals from airborne hazards such as droplets and particulate matter during public engagements. However, conventional electrostatically charged melt-blown microfiber masks typically require thick and dense membranes to achieve high filtration efficiency, which in turn cause a significant pressure drop and reduce breathability. In this study, we have developed a multielectrospinning system to address this issue by manipulating the pore structure of nanofiber networks, including the use of uniaxially aligned nanofibers created via an electric-field-guided electrospinning apparatus.

Discrimination of the H1N1 and H5N2 Variants of Influenza A Virus Using an Isomeric Sialic Acid-Conjugated Graphene Field-Effect Transistor.

There has been a continuous effort to fabricate a fast, sensitive, and inexpensive system for influenza virus detection to meet the demand for effective screening in point-of-care testing. Herein, we report a sialic acid (SA)-conjugated graphene field-effect transistor (SA-GFET) sensor designed using α2,3-linked sialic acid (3'-SA) and α2,6-linked sialic acid (6'-SA) for the detection and discrimination of the hemagglutinin (HA) protein of the H5N2 and H1N1 viruses. 3'-SA and 6'-SA specific for H5 and H1 influenza were used in the SA-GFET to capture the HA protein of the influenza virus.

Multifunctional Filter Membranes Based on Self-Assembled Core-Shell Biodegradable Nanofibers for Persistent Electrostatic Filtration through the Triboelectric Effect.

The massive production of polymer-based respiratory masks during the COVID-19 pandemic has rekindled the issue of environmental pollution from nonrecyclable plastic waste. To mitigate this problem, conventional filters should be redesigned with improved filtration performance over the entire operational life while also being naturally degradable at the end. Herein, we developed a functional and biodegradable polymeric filter membrane consisting of a polybutylene adipate terephthalate (PBAT) matrix blended with cetyltrimethylammonium bromide (CTAB) and montmorillonite (MMT) clay, whose surface properties have been modified through cation exchange reactions for good miscibility with PBAT in an organic solvent.

Violacein-embedded nanofiber filters with antiviral and antibacterial activities.

Most respiratory masks are made of fabrics, which only capture the infectious virus carriers into the matrix. However, these contagious viruses stay active for a long duration (∼7 days) within the fabric matrix possibly inducing post-contact transmissions. Moreover, conventional masks are vulnerable to bacterial growth with prolonged exposure to exhaled breaths.

Diagnostic performance and clinical feasibility of a novel one-step RT-qPCR assay for simultaneous detection of multiple severe acute respiratory syndrome coronaviruses.

Coronavirus disease 2019 (COVID-19) is an acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Other coronaviruses (CoVs) can also infect humans, although the majority cause only mild respiratory symptoms. Because early diagnosis of SARS-CoV-2 is critical for preventing further transmission events and improving clinical outcomes, it is important to be able to distinguish SARS-CoV-2 from other SARS-related CoVs in respiratory samples.

Reusable surface amplified nanobiosensor for the sub PFU/mL level detection of airborne virus.

We developed a reusable surface-amplified nanobiosensor for monitoring airborne viruses with a sub-PFU/mL level detection limit. Here, sandwich structures consisted of magnetic particles functionalized with antibodies, target viruses, and alkaline phosphatases (ALPs) were formed, and they were magnetically concentrated on Ni patterns near an electrochemical sensor transducer. Then, the electrical signals from electrochemical markers generated by ALPs were measured with the sensor transducer, enabling highly-sensitive virus detection.

A rapid quantitative on-site coronavirus disease 19 serological test.

On-site severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) serological assays allow for timely in-field decisions to be made regarding patient status, also enabling population-wide screening to assist in controlling the coronavirus disease 2019 (COVID-19) pandemic. Here we propose a rapid microfluidic serological assay with two unique functions of nanointerstice filling and digitized flow control, which enable the fast/robust filling of the sample fluid as well as precise regulation of duration and volume of immune reaction. Developed microfluidic assay showed enhanced limit of detection, and 91.

A single snapshot multiplex immunoassay platform utilizing dense test lines based on engineered beads.

Co-circulation of coronavirus disease 2019 (COVID-19) and dengue fever has been reported. Accurate and timely multiplex diagnosis is required to prevent future pandemics. Here, we developed an innovative microfluidic chip that enables a snapshot multiplex immunoassay for timely on-site response and offers unprecedented multiplexing capability with an operating procedure similar to that of lateral flow assays.

Fast and Easy Disinfection of Coronavirus-Contaminated Face Masks Using Ozone Gas Produced by a Dielectric Barrier Discharge Plasma Generator.

During the COVID-19 pandemic, face masks have become limited in stock. Most of sterilization methods are not applicable for eliminating virus from face masks without compromising the filtration efficiency of the masks. In this study, using a human coronavirus (HCoV-229E) as a surrogate for SARS-CoV-2 contamination on KF94 face masks, we show that the virus loses its infectivity with a 4 log reduction when exposed for 10 s to 120 ppm ozone gas produced by a dielectric barrier discharge plasma generator.

Fabrication and Application of Levan-PVA Hydrogel for Effective Influenza Virus Capture.

To prevent the transmission of pathogenic microorganisms such as the influenza virus, efficient pathogen-capturing materials are required. Here, we report a new pathogen-capturing and recovery material using levan polysaccharide. We fabricated hydrogels by blending levan and poly(vinyl alcohol) (PVA) and by using glutaraldehyde as a cross-linking agent.

Integrated Microfluidic Preconcentration and Nucleic Amplification System for Detection of Influenza A Virus H1N1 in Saliva.

Influenza A viruses are often present in environmental and clinical samples at concentrations below the limit of detection (LOD) of molecular diagnostics. Here we report an integrated microfluidic preconcentration and nucleic amplification system (μFPNAS) which enables both preconcentration of influenza A virus H1N1 (H1N1) and amplification of its viral RNA, thereby lowering LOD for H1N1. H1N1 virus particles were first magnetically preconcentrated using magnetic nanoparticles conjugated with an antibody specific for the virus.

Highly Sensitive in Vitro Diagnostic System of Pandemic Influenza A (H1N1) Virus Infection with Specific MicroRNA as a Biomarker.

Several microRNAs (miRNAs) have been reported to be closely related to influenza A virus infection, replication, and immune response. Therefore, the development of the infectious-disease detection system using miRNAs as biomarkers is actively underway. Herein, we identified two miRNAs (miR-181c-5p and miR-1254) as biomarkers for detection of pandemic influenza A H1N1 virus infection and proposed the catalytic hairpin assembly-based in vitro diagnostic (CIVD) system for a highly sensitive diagnosis; this system is composed of two sets of cascade hairpin probes enabling to detect miR-181c-5p and miR-1254.

Oscillatory flow-assisted efficient target enrichment with small volumes of sample by using a particle-based microarray device.

In the study, we describe an oscillatory flow-assisted efficient target enrichment method by using a particle-based microarray device. Periodic oscillating flow effectively increased the mixing and binding performance between the target molecules in the sample solution and surface functionalized microparticles. Particles were trapped, secured, and released with an elastic microvalve structure operated via differences in the flow conditions.

Development of a Rapid Diagnostic Test Kit to Detect IgG/IgM Antibody against Zika Virus Using Monoclonal Antibodies to the Envelope and Non-structural Protein 1 of the Virus.

We developed a Rapid Diagnostic Test (RDT) kit for detecting IgG/IgM antibodies against Zika virus (ZIKV) using monoclonal antibodies to the envelope (E) and non-structural protein 1 (NS1) of ZIKV. These proteins were produced using baculovirus expression vector with Sf9 cells. Monoclonal antibodies J2G7 to NS1 and J5E1 to E protein were selected and conjugated with colloidal gold to produce the Zika IgG/IgM RDT kit (Zika RDT).

Photo-crosslinkable hydrogel-based 3D microfluidic culture device.

We developed the photo-crosslinkable hydrogel-based 3D microfluidic device to culture neural stem cells (NSCs) and tumors. The photo-crosslinkable gelatin methacrylate (GelMA) polymer was used as a physical barrier in the microfluidic device and collagen type I gel was employed to culture NSCs in a 3D manner. We demonstrated that the pore size was inversely proportional to concentrations of GelMA hydrogels, showing the pore sizes of 5 and 25 w/v% GelMA hydrogels were 34 and 4 μm, respectively.

Self-assembled levan nanoparticles for targeted breast cancer imaging.

We report on the targeted imaging of breast cancer using self-assembled levan nanoparticles. Indocyanine green (ICG) was encapsulated in levan nanoparticles via self-assembly. Levan-ICG nanoparticles were found to be successfully accumulated in breast cancer via specific interaction between fructose moieties in levan and overexpressed glucose transporter 5 in breast cancer cells.

Multiplexed detection of various breast cancer cells by perfluorocarbon/quantum dot nanoemulsions conjugated with antibodies.

The effective targeting of cancer cell surface antigens is an attractive approach in cancer diagnosis and therapy. Multifunctional nanoprobes with cell-targeting specificity are likely to find important applications in bioanalysis, biomedicine, and clinical diagnosis. In this study, we have fabricated biocompatible perfluorocan/quantum dot nanoemulsions as bimodal imaging nanoprobes for the targeting of breast cancer cells.

Highly enhanced optical properties of indocyanine green/perfluorocarbon nanoemulsions for efficient lymph node mapping using near-infrared and magnetic resonance imaging.

The near-infrared (NIR) fluorescence probe has better tissue penetration and lower autofluorescence. Indocyanine green (ICG) is an NIR organic dye for extensive biological application, and it has been clinically approved for human medical imaging and diagnosis. However, application of this dye is limited by its numerous disadvantageous properties in aqueous solution, including its concentration-dependent aggregation, poor aqueous stability in vitro, and low quantum yield.

Folate-conjugated cross-linked magnetic nanoparticles as potential magnetic resonance probes for in vivo cancer imaging.

Superparamagnetic iron oxide nanoparticles are widely used as nanoprobes for magnetic resonance imaging (MRI). In this study, a novel type of cross-linked magnetic nanoparticle was developed in an effort to improve the structural stability of amphiphilic polymer-coated iron oxide nanoparticles. Iron oxide nanocrystals were coated with a cross-linkable amphiphilic graft copolymer, poly(succinimide) grafted with folate-conjugated polyethylene glycol (PEG) and alkyl chains.

Synthesis of Fe3O4-ZnS/AgInS2 composite nanoparticles using a hydrophobic interaction.

Magnetic nanoparticles and fluorescent quantum dots (QDs) can make many effective applications in biomedical system. Here, we demonstrated one way of synthetic method and its surface modification to use for biomedical applications. Fe3O4 nanoparticles are well known as magnetic materials and its magnetic property can be used in magnetic resonance imaging (MRI), cell detection.

Bimodal perfluorocarbon nanoemulsions for nasopharyngeal carcinoma targeting.

Purpose: The aim of this study was to perform the detection of folate receptor (FR)-positive tumors with a bimodal imaging contrast agent, a perfluorocarbon (PFC)/rhodamine nanoemulsion, providing both 19F-based magnetic resonance imaging (MRI) and fluorescence imaging capabilities.

Procedures: The PFC/rhodamine nanoemulsion was further infused with phospholipid-anchored folate to improve the ability to target FR-expressing tumors. The preferential accumulation of the FR-targeted bimodal nanoemulsion in FR-positive tumor sites was monitored by both 19F-MRI and optical imaging.

Bifunctional nanoparticles constructed using one-pot encapsulation of a fluorescent polymer and magnetic (Fe3O4) nanoparticles in a silica shell.

Integration of biocompatible silica with a fluorescent polymer (PDDF) and superparamagnetic iron oxide nanoparticles (Fe3 O4 ) to form uniform core-shell nanostructures has the great potential to form particles for use in multimodal bioimaging applications. Core-shell nanoparticles (PDDF/Fe3 O4 @SiO2 ) exhibit fluorescent and magnetic properties that are favorable for their use in magnetic separation and guiding applications, as well as optical and magnetic resonance (MR) imaging capabilities. With the biological analysis in an in vitro intracellular permeation and cytotoxicity test, chemical conjugation of the surface using folic acid (FA) molecules can provide the nanoparticles with cell-targeting properties, localizing the nanoparticles to folate receptors (FRs) on target KB cells that over-express the FRs.