Photoactive Antiviral Face Mask with Self-Sterilization and Reusability
Sumit Kumar, Mamata Karmacharya, Shalik Ram Joshi, Oleksandra Gulenko, Juhee Park, Gun-Ho Kim, and Yoon-Kyoung Cho*
Here, we applied a dual-channel spray-assisted nanocoating hybrid of shellac/copper nanoparticles (CuNPs) to a nonwoven surgical mask, thereby increasing the hydrophobicity of the surface and repelling aqueous droplets. The resulting surface showed outstanding photoactivity (combined photocatalytic and photothermal properties) for antimicrobial action, conferring reusability and self-sterilizing ability to the masks.
 Cancers 2020, 12(10), 2822;
Detection of EGFR mutations using bronchial washing-derived extracellular vesicles in patients with non-small-cell lung carcinoma
Juhee Park, Chaeeun Lee, Jung Seop Eom, Mi-Hyun Kim *, Yoon-Kyoung Cho *
Here, we demonstrate the clinical potential of BW-derived EVs as a liquid-biopsy sample for prognosis and precision medicine in patients with lung cancer. The acquisition of T790M resistance mutation was detected earlier in BW-derived EVs than in plasma or tissue samples. The longitudinal analysis of BW-derived EVs showed excellent correlation with the disease progression measured by CT images.
 Biomaterials, 2021, 265, 120420;
Adaptive Architecture and Mechanoresponse of Epithelial Cells on a Torus
Sun-Min Yu, Bo Li, François Amblard, Steve Granick, Yoon-Kyoung Cho*
Curvature is a geometric feature widely observed in the epithelia and critical to the performance of fundamental biological functions. In this study, we revealed morphological adaptations and mechanobiological behaviors of epithelial cells on a torus surface with Gaussian curvatures. Our results collectively indicate the ability of epithelial cells to sense Gaussian curvatures and increase the expression of cytoplasmic and nucleus intermediate filaments as a protective measure against curvature-induced mechanical stress.
 ACS Nano, 2020, accepted
Three-Dimensional Human Liver-Chip Emulating Pre-Metastatic Niche Formation by Breast Cancer-Derived Extracellular Vesicles
Junyoung Kim, Chaeeun Lee, Inun Kim, Jooyoung Ro, Jungmin Kim, Yoohong Min, Juhee Park, Vijaya Sunkara, Yang-Seok Park, Issac Michael, Young-Ae Kim, Hee Jin Lee, Yoon-Kyoung Cho*
The 3D microfluidic human liver-chip developed in this study demonstrates how breast cancer-derived extracellular vesicles induce the formation of a pre-metastatic niche, promoting the adhesion of circulating tumor cells to a distant organ such as the liver, enabling the investigation of cancer metastasis and a wide range of potential pharmacological therapies.
Boosted molecular mobility during common chemical reactions
Huan Wang, Myeonggon Park, Ruoyu Dong, Junyoung Kim, Yoon-Kyoung Cho, Tsvi Tlusty, Steve Granick*
During a chemical reaction, the reorganization of solvent molecules not directly in contact with reactants and products is normally viewed as a simple diffusion response. Wang et al. studied molecular diffusion in six common reactions—including the copper-catalyzed click reaction and the Diels-Alder reaction—with pulsed-field gradient nuclear magnetic resonance. They observed a boost in mobility relative to Brownian diffusion that was stronger for the catalyzed reactions that were studied. The mobilities for the click reaction were verified with a microfluidic gradient method. They argue that energy release produces transient translational motion of reacting centers that mechanically perturbs solvent molecules.
 Cells, 2020, 9(6), 1434;
Mechanical Adaptations of Epithelial Cells on Various Protruded Convex Geometries
Sun-Min Yu†, Bo Li†, Steve Granick and Yoon-Kyoung Cho*
Here, we cultured cells on various protruded convex structures such as triangle, square, and circle shape fabricated using two-photon laser lithography and quantitatively analyzed individual cells. We found that intermediate filaments, vimentin, and cytokeratin 8/18, play important roles in the growth and adaptation of epithelial cells by enhancing expression level on convex structure depending on the shape. In addition, microtubule building blocks, α-tubulin, was also responded on geometric structure, which indicates that intermediate filaments and microtubules can cooperatively secure the mechanical stability of epithelial cells on the convex surface. Altogether, the current study will expand our understanding of mechanical adaptations of cells on out-of-plane geometry.
 Nature Biomedical Engineering, 2020, Article
A fidget spinner for the point-of-care diagnosis of urinary tract infection
Issac Michael, Dongyoung Kim, Oleksandra Gulenko , Sumit Kumar, Saravana Kumar , Jothi Clara, Dong Yeob Ki, Juhee Park , Hyun Yong Jeong, Taek Soo Kim, Sunghoon Kwon and Yoon-Kyoung Cho *
Here, we describe a custom-made fidget spinner that rapidly concentrates pathogens in 1-ml samples of undiluted urine by more than 100-fold for the on-device colorimetric detection of bacterial load and pathogen identification. The device enabled the on-site detection of infection with the naked eye within 50 min in urine samples from 39 patients suspected of having a urinary tract infection. We also show that, in 30 clinical samples of urinary tract infection, the device can be used to perform an antimicrobial susceptibility test for the antimicrobial drugs ciprofloxacin and cefazolin within 120 min. The fidget spinner could be used in low-resource settings as an inexpensive handheld point-of-care device for the rapid concentration and detection of pathogens in urine samples.
 Diagnostics, 2020, Article
Circulating Tumor Cells Enumerated by a Centrifugal Microfluidic Device as a Predictive Marker for Monitoring Ovarian Cancer Treatment: A Pilot Study
Hyera Kim , Minji Lim, Jin Young Kim, So-Jin Shin, Yoon-Kyoung Cho* and Chi Heum Cho*
This pilot study of 13 patients with ovarian cancer aimed to investigate a strategy for the enumeration and detection of CTCs based on a newly-developed centrifugal microfluidic device equipped with a fluid-assisted separation technology (FAST) disc and to demonstrate the correlations among CTC counts from the new device, CA125 concentrations, and clinical course of the disease.
 Angewandte Chemie International Edition, 2020, in press
Nanocatalosomes as Plasmonic Bilayer Shells with Interlayer Catalytic Hot Nanospaces for Solar‐Light‐Induced Reactions
Amit Kumar, Nitee Kumari, Sateesh Dubbu, Sumit Kumar, Taewan Kwon, Jung Hun Koo, Jongwon Lim, Inki Kim, Yoon-Kyoung Cho, Junsuk Rho, and In Su Lee*
Paramount interest and challenges remain in designing and synthesizing catalysts with nature‐like complexities at few‐nm scale to harness unprecedented functionalities by using sustainable solar light. We introduce “nanocatalosomes”— bio‐inspired bilayer‐vesicular design of nanoreactor with metallic bilayer hollow shell‐in‐shell structure, having numerous controllable confined cavities within few‐nm interlayer space, customizable with different noble metals. This work paves the way towards next‐generation nanoreactors, craftable at few‐nm scale to maximize their functionality and customizable to carry out diverse chemical transformations efficiently with green solar energy.
 Anaytical Chemistry, 2020, Advanced article
EV-Ident: Identifying tumor-specific extracellular vesicles by size fractionation and single-vesicle analysis
Dongyoung Kim,# Hyun-Kyung Woo,# Chaeeun Lee, Yoohong Min, Sumit Kumar, Vijaya Sunkara, 4 Hwi-Gyeong Jo, Young Joo Lee, Jisun Kim, Hong Koo Ha, and Yoon-Kyoung Cho*
Here, we introduce EV-Ident for preparation of subpopulations of EVs in three different size fractions: large EVs (EV200 nm; 200−1,000 nm), medium EVs (EV100 nm; 100−200 nm), and small EVs (EV20 nm; 20−100 nm). As a proof-of-concept, we analyzed the presence of human epidermal growth factor receptor 2 (HER2) and prostate-specific membrane antigen (PSMA) in breast cancer and prostate cancer cell-derived EVs, respectively, using three different size fractions at the single-EV level. By reducing the complexity of EV heterogeneity in each size fraction, we found that HER2-positive breast cancer cells showed the greatest expression of HER2 in EV20 nm, whereas PSMA expression was the highest in EV200 nm derived from PSMA expressing prostate cancer cells. This increase in HER2 expression in EV20 nm and PSMA expression in EV200 nm was further confirmed in plasma-derived nanoparticles (PNPs) obtained from breast and prostate cancer patients, respectively.
 Nature Nanotechnology, 2020, Advance Article
Targeted crystallization of mixed-charge nanoparticles in lysosomes induces selective death of cancer cells
Magdalena Borkowska, Marta Siek, Diana V. Kolygina, Yaroslav I. Sobolev, Slawomir Lach, Sumit Kumar, Yoon-Kyoung Cho, Kristiana Kandere-Grzybowska & Bartosz A. Grzybowski
Here, we show that mixed-charge nanoparticles covered with certain ratios of positively and negatively charged ligands can selectively target lysosomes in cancerous cells while exhibiting only marginal cytotoxicity towards normal cells. This selectivity results from distinct pH-dependent aggregation events, starting from the formation of small, endocytosis-prone clusters at cell surfaces and ending with the formation of large and well-ordered nanoparticle assemblies and crystals inside cancer lysosomes. These assemblies cannot be cleared by exocytosis and cause lysosome swelling, which gradually disrupts the integrity of lysosomal membranes, ultimately impairing lysosomal functions and triggering cell death.
A Lab-on-a-Disc platform enables serial monitoring of Individual CTCs associated with tumor progression during EGFR-targeted therapy for patients with NSCLC
Minji Lim‡, Juhee Park‡, Alarice C. Lowe, Hyoung-oh Jeong, Semin Lee, Hee Chul Park, Kyusang Lee, Gwang Ha Kim, Mi-Hyun Kim*, and Yoon-Kyoung Cho*
The change ratio of the CTC counts was associated with tumor response, detected by CT scan, while the baseline CTC counts did not show association with progression-free survival or overall survival. We achieved a 100% concordance rate for the detection of EGFR mutation, including the emergence of T790M, between tumor tissue and CTCs. More importantly, our data revealed the importance of the analysis of the epithelial/mesenchymal signature of individual pretreatment CTCs to predict drug responsiveness in patients. The fluid-assisted separation technology disc platform enables serial monitoring of CTC counts, DNA mutations, as well as unbiased molecular characterization of individual CTCs associated with tumor progression during targeted therapy.
 BJU International, 2020, Advance Article
The combination of size‐based separation and selection‐free technology provides higher circulating tumor cells detection sensitivity than either method alone in patients with metastatic prostate cancer
Liang Dong, Zhongyuan Zhang, Kimberly Smith, Morgan Kuczler, Diane Reyes, Sarah R. Amend, Yoon‐Kyoung Cho, Wei Xue*, and Kenneth J. Pienta*
Here, we investigate the CTC capture abilities of two technologies that are not dependent on cell‐surface marker expression: a selection‐free platform, the AccuCyte®‐CyteFinder® system (Rarecyte) and a size‐based platform, the fluid‐assisted separation technology (FAST). The combination of the two systems to more completely assess CTCs was investigated.
 Lab Chip, 2020,20, 949-957
Fully automated platelet isolation on a centrifugal microfluidic device for molecular diagnostics
Chi-Ju Kim‡, Dong Yeob Ki‡, Juhee Park, Vijaya Sunkara, Tae-Hyeong Kim, YooHong Min and Yoon-Kyoung Cho*
Herein, we describe a fully automated lab-on-a-disc-based method of platelet isolation from a small volume of blood (<1 mL). This method provides higher yields (>4 folds) and purity (>99%) and lower platelet activation than the conventional method. Moreover, it was also superior in the detection of platelet-related RNAs CD41, PF4, and P2Y12 due to lower contamination with white blood cells.
 Nano Letters, 2020, 20, 1, 441-448
Near-Field Electrospinning for Three-Dimensional Stacked Nanoarchitectures with High Aspect Ratios
Yang-Seok Park†, Junyoung Kim†, Jung Min Oh, Seungyoung Park, Seungse Cho, Hyunhyub Ko, Yoon-Kyoung Cho*
Herein, we report on a direct-write 3D NFES technique to construct self-aligned, template-free, 3D stacked nanoarchitectures by simply adding salt to the polymer solution. Numerical simulations suggested that the electric field could be tuned to achieve self-aligned nanofibers by adjusting the conductivity of the polymer solution. We demonstrate the 3D printing of nanoskyscrapers with various designs, such as curved “nanowall arrays”, nano “jungle gyms,” and “nanobridges”. Further, we present an application of the 3D stacked nanofiber arrays by preparing transparent and flexible polydimethylsiloxane films embedded with Ag-sputtered nanowalls as 3D nanoelectrodes. The conductivity of the nanoelectrodes can be precisely tuned by adjusting the number of 3D printed layers, without sacrificing transmittance. The current NFES approach provides a simple, reliable route to build 3D stacked nanoarchitectures with high-aspect ratios for potential applications in smart materials, energy devices, and biomedical applications.
AI-powered transmitted light microscopy for functional analysis of live cells
Dongyoung Kim, Yoohong Min, Jung Min Oh, and Yoon-Kyoung Cho*
Transmitted light microscopy can readily visualize the morphology of living cells. Here, we introduce artificial-intelligence-powered transmitted light microscopy (AIM) for subcellular structure identification and labeling-free functional analysis of live cells. AIM provides accurate images of subcellular organelles; allows identification of cellular and functional characteristics (cell type, viability, and maturation stage); and facilitates live cell tracking and multimodality analysis of immune cells in their native form without labeling.
 Biosensors and Bioelectronics, Available online 26 November 2019, 111927
Highly sensitive detection of hydrazine by a disposable, Poly(Tannic Acid)-Coated carbon electrode
Monsur Jiaul Haque‡, Sumit Kumar‡, Jonathan Sabaté del Río‡, and Yoon-Kyoung Cho*
We propose an electrochemical sensor based on the enhanced electrocatalytic oxidation exhibited on a functionalized poly(tannic acid) coating to detect hydrazine. Tannic acid, a naturally abundant and low-cost polyphenol, was enzymatically polymerized with horseradish peroxidase and subsequently adsorbed on a disposable, screen-printed carbon electrode with a short incubation time (30 min). The fabrication method proved to be reproducible (4.2% relative standard deviation), with the sensors displaying high sensitivity (7 × 10-3 µA·mm-2·µM-1) and selectivity even in the presence of various common interfering agents. The low detection limit (100 nM) and robustness of the sensor demonstrated its suitability for environmental applications. It can be used to quantify hydrazine in tap and river water samples.
Human Platelet Membrane Functionalized Microchips with Plasmonic Codes for Cancer Detection
Sumit Kumar, Jae‐A Han, Issac J. Michael, Dongyeob Ki , Vijaya Sunkara, Juhee Park , Shreedhar Gautam, Hong Koo Ha, Liangfang Zhang, Yoon-Kyoung Cho*
The possibility of functional roles played by platelets in close alliance with cancer cells has inspired the design of new biomimetic systems that exploit platelet–cancer cell interactions. Here, the role of platelets in cancer diagnostics is leveraged to design a microfluidic platform capable of detecting cancer‐derived extracellular vesicles (EVs) from ultrasmall volumes (1 µL) of human plasma samples. Further, the captured EVs are counted by direct optical coding of plasmonic nanoprobes modified with EV‐specific antibodies. Owing to the diverse function proteins associated with human platelets that can bind to the wide spectrum of cancer cell-derived extracellular vesicles, the resulting microdevice is capable for sensitive and accurate detection of cancer from ultra-small volumes of patient’s plasma samples
 Soft Matter, 2019,15, 6127-6133
Effects of poly(ethylene glycol) on the wetting behavior and director configuration of lyotropic chromonic liquid crystals confined in cylinders
Hyesong Lee, Vijaya Sunkara, Yoon-Kyoung Cho and Joonwoo Jeong*
We investigate the effects of poly(ethylene glycol) (PEG) doping on nematic lyotropic chromonic liquid crystals (LCLCs) confined in a cylindrical cavity. We also confirm that the grafting of PEG to bare glass surfaces changes them from nemato-philic to nemato-phobic. Additionally, we observe that PEG-doped nematic SSY retains the double-twist director configuration as in the PEG-free case. However, the PEG-doped nematic SSY is accompanied by unprecedented domain-wall-like defects and heterogeneity in the director configuration. We propose multiple hypotheses on how PEG changes the director configuration, including the formation of meta-stable director configurations.
 Clinical and Translational Gastroenterology, 2019, Jul;10(7):e00055.
Clinical Potential of Circulating Tumor Cells in Colorectal Cancer: A Prospective Study
Dong Hoon Baek, Gwang Ha Kim, Geun Am Song, In Sub Han, Eun Young Park, Hyun Sung Kim, Hong Jae Jo, Sang Hwa Ko, Do Youn Park, and Yoon-Kyoung Cho
Circulating tumor cells (CTCs) in the blood have been used as diagnostic markers in patients with colorectal cancer (CRC). In this study, we evaluated a CTC detection system based on cell size to assess CTCs and their potential as early diagnostic and prognostic biomarkers for CRC