Yong Jun Lim

Su Hwan Jin

Yu Jin Kim

In Young Cho

Dong Min Shin

Hyun Kyo Roh

Ji Won Byun

Hye Won Kim

So Jung Oh

Jeong Yeon Kim

Young Hee Kim

Seok Joon Mun

Do Yeon Kim

Jun Beom Kim

Su Hyeon Bae

Se Myung Jung

Jun Ho Lee

Ji Yeon Eom

Ju Yeon Kim

Yoon Ho Roh

Hyeon Ung Kim

Nak Jun Lee

Hyun Jee Lee

Hyun June Moon

Ju-Yeon Moon

Ji Sun Kim

Seong Hwan Kim

Jin Hyun Hwang

Hye Jin Kim

So Young Lee

Ji Hee Moon

Na Young Kim

Houng Sub Lee

The Bong Research Group is a research team dedicated to developing innovative technologies in microfluidics and biopolymer area. Especially, we focus on the synthesis, assembly, and analysis of 3D soft matter architectures. Using advanced micro/nanofabrication methods, We want to build complex 3D structures for use within vitrodiagnostics andinvivotherapeutics. We are constantly immersed in these researches to advance modern science.

본 연구 그룹은 마이크로fluidics 및 바이오폴리머 분야에서 혁신적인 기술 개발에 전념하는 연구팀입니다. 특히, 3D 연성 물질 아키텍처의 합성, 조립 및 분석에 중점을 둡니다. 고급 마이크로/나노 제작 방법을 사용하여 체외 진단 및 생체 내 치료제에 사용하기 위한 복잡한 3D 구조를 구축하고자 합니다. 우리는 현대 과학을 발전시키기 위해 이러한 연구에 끊임없이 몰두하고 있습니다.

Amplification-Free and Label-Free Multiplexed Profiling of Extracellular Vesicle-Derived MicroRNA via Micropore Sensing Based on PNA-Functionalized Hydrogel Barcodes

MIDAS: rapid, multiplexed molecular profiling for integrated host–pathogen analysis

Oxygen-free discontinuous dewetting in a degassed mold for anisotropic colloidal hydrogel microparticle synthesis

Magnetically controlled microgelbots with stem cells for the treatment of interstitial cystitis

Modulating oxygen release via manipulated microspheres embedded in thermoresponsive hydrogels for enhanced stem cell survival under hypoxia

Using encoded hydrogel microparticles in a 96-well filter plate system for enhanced rinsing efficiency in multiplexed nucleic acid detection

Enhancement of low-temperature ammonia decomposition over potassium-promoted Ru/MgAl2O4 catalyst for clean hydrogen production

Meso–macroporous hydrogel for direct litre-scale isolation of extracellular vesicles

Combining Microfluidic Assessment with Encoded Hydrogel Microparticle-Based Immunoassay for Anti-Interleukin Drug Repurposing of Pulmonary Fibrosis Therapy

Recent advances in suspension microarray-based multiplexed biosensing technologies integrated with fluorescence signal amplification

Multiplexed and streamlined DNA methylation detection of colorectal cancer-related genes using graphically encoded hydrogel microparticles and rolling circle amplification

Thermo-responsive Bioink for Personalized 3D Printed Scaffolds with Antioxidant and Fibroblast Delivery to Accelerate Diabetic Wound Healing

Polyethylene Glycol Nanofiller for Robust Lyophilization of Graphically Encoded Hydrogel Microparticles

Thermo-responsive hydrogel via sustained Co-delivery of TA and PDGF to modulate the diabetic microenvironment and accelerate diabetic wound healing

Mechanically robust and recyclable CO 2 -derived poly(carbonate) vitrimers: The role of crosslinking density in mechanical and rheological properties

Tyramide Signal Amplification for Highly Sensitive Multiplex Immunoassay based on Encoded Hydrogel Microparticles

Hydrogel-Based In Situ DNA Extension Assay for Multiplexed and Rapid Detection of MicroRNA

Fibrosis Drug Efficacy Assessment based on Microfluidic Mechanical Property Evaluation of Spheroid Models

Label-free multiplexed protein quantification in clinical samples using encodable hydrogel barcode and low-aspect-ratio micropore

Cube-shaped metal foam catalyst for natural gas pre-reforming in solid oxide fuel cell systems

Air-through-Precursor Suction-Augmented Replica Molding for Fabrication of Anisotropic Microparticles in Gas-impermeable Molds

Efficient isolation of encoded microparticles in a degassed micromold for highly sensitive and multiplex immunoassay with signal amplification

Real-Time Signal Analysis with Wider Dynamic Range and Enhanced Sensitivity in Multiplex Colorimetric Immunoassays Using Encoded Hydrogel Microparticles

Oxygen-Supplying Piezocatalytic Therapy of Hypoxic Tumors by Intratumoral Delivery of pH-Responsive Multicompartmental Carriers with Sequential Drug Release Capability

Multiplex Genotyping of SNPs in Genomic DNA via Hydrogel-based Assay Mediated with MutS and Polyethylene Glycol

Highly flexible deep-learning-based automatic analysis for graphically encoded hydrogel microparticles

The Detection of Urinary Exosomal miRNAs for Cancer Diagnostics and Prognostics

Label-free multiplex detection of miRNA-assayed hydrogel barcode using a low-aspect-ratio micropore device

Controlled growth factor delivery via a degradable poly(lactic acid) hydrogel microcarrier synthesized using degassed micromolding lithography

Optimization of particle rinsing process in linker-free post-synthesis functionalization for sensitive encoded hydrogel microparticle-based immunoassay

Multiplex assay for rapid detection and analysis of nucleic acid using Barcode Receptor Encoding Particle (BREP)

Normally Off WSe2 Nanosheet-Based Field-Effect Transistors with Self-Aligned Contact Doping

High-Resolution Surface Replication of Living Organisms using Air-through-Precursor Suction-augmented Replica Molding

Optimizing reduced capture antibody conjugation to encoded hydrogel microparticles for enhanced multiplex immunoassays

Encoded Hydrogel Microparticles with Universal Mismatch-Incorporated DNA Probes for Highly Specific Multiplex Detection of SNPs

Direct functionalization of cell-adhesion promoters to hydrogel microparticles synthesized by stop-flow lithography

Rapid colorimetric analysis of multiple microRNAs using encoded hydrogel microparticles

Highly Magnetized Encoded Hydrogel Microparticles with Enhanced Rinsing Capabilities for Efficient microRNA Detection

Hydrogel-based hybridization chain reaction (HCR) for detection of urinary exosomal miRNAs as a diagnostic tool of prostate cancer

Gold Nanorods-encapsulated Thermosensitive Drug Carriers for NIR Light-Responsive Anticancer Therapy

Discontinuous Dewetting in Degassed Mold for Fabrication of Homogeneous Polymeric Microparticles

Photopolymerization-based Synthesis of Uniform Magnetic Hydrogels and Colorimetric Glucose Detection

Phosphorylcholine-based Encoded Hydrogel Microparticles with Enhanced Fouling Resistance for Multiplex Immunoassays

Precipitation-based Colorimetric Multiplex Immunoassay in Hydrogel Particles

Direct Conjugation of Streptavidin to Encoded Hydrogel Microparticles for Multiplex Biomolecule Detection with Rapid Probe-Set Modification

Elimination of Unreacted Acrylate Double Bonds in the Polymer Networks of Microparticles Synthesized via Flow Lithography

Affinity‐Enhanced CTC‐Capturing Hydrogel Microparticles Fabricated by Degassed Mold Lithography

Inertio-elastic focusing of bioparticles in microchannels at high throughput

Three-Dimensional Blood-Brain Barrier Model for in vitro Studies of Neurovascular Pathology

Synthesis of Nonspherical Superparamagnetic Particles: In Situ Coprecipitation of Magnetic Nanoparticles in Microgels Prepared by Stop-Flow Lithography

Reduction of cogging torque in flux-reversal machine by rotor teeth pairing

Nitrogen-doped graphene-wrapped iron nanofragments for high-performance oxygen reduction electrocatalysts

A conformal nano-adhesive via initiated chemical vapor deposition for microfluidic devices

Lock release lithography for 3D and composite microparticles

Hydrodynamic focusing lithography

Patterning nanodomains with orthogonal functionalities: solventless synthesis of self-sorting surfaces

Compressed-air flow control system

Magnetic barcoded hydrogel microparticles for multiplexed detection

Porous microwells for geometry-selective, large-scale microparticle arrays

Non-polydimethylsiloxane devices for oxygen-free flow lithography

Tissue beads: tissue‐specific extracellular matrix microbeads to potentiate reprogrammed cell‐based therapy

Oxygen‐supplying piezocatalytic therapy of hypoxic tumors by intratumoral delivery of pH‐responsive multicompartmental carriers with sequential drug release capability

Multiplexed immunoassay using post-synthesis functionalized hydrogel microparticles

Using stop-flow lithography to produce opaque microparticles: Synthesis and modeling

Stop flow lithography in perfluoropolyether (PFPE) microfluidic channels

Microdroplet photobioreactor for the photoautotrophic culture of microalgal cells

Ki Wan Bong

Controlled manipulation of particles from very large volumes of fluid at high throughput is critical for many biomedical, environmental and industrial applications. One promising approach is to use microfluidic technologies that rely on fluid inertia or elasticity to drive lateral migration of particles to stable equilibrium positions in a microchannel. Here, we report on a hydrodynamic approach that enables deterministic focusing of beads, mammalian cells and anisotropic hydrogel particles in a microchannel at extremely high flow rates. We show that on addition of micromolar concentrations of hyaluronic acid, the resulting fluid viscoelasticity can be used to control the focal position of particles at Reynolds numbers up to Re ≈10,000 with corresponding flow rates and particle velocities up to 50 ml min −1 and 130 m s −1 . This study explores a previously unattained regime of inertio-elastic fluid flow and demonstrates …

Blood–brain barrier (BBB) pathology leads to neurovascular disorders and is an important target for therapies. However, the study of BBB pathology is difficult in the absence of models that are simple and relevant. In vivo animal models are highly relevant, however they are hampered by complex, multi-cellular interactions that are difficult to decouple. In vitro models of BBB are simpler, however they have limited functionality and relevance to disease processes. To address these limitations, we developed a 3-dimensional (3D) model of BBB on a microfluidic platform. We verified the tightness of the BBB by showing its ability to reduce the leakage of dyes and to block the transmigration of immune cells towards chemoattractants. Moreover, we verified the localization at endothelial cell boundaries of ZO-1 and VE-Cadherin, two components of tight and adherens junctions. To validate the functionality of the BBB model …

We present the synthesis of nonspherical magnetic microparticles with multiple functionalities, shapes, and chemistries. Particle synthesis was performed in two steps: polymeric microparticles functionalized homogenously with carboxyl groups were generated using stop-flow lithography, and then in situ coprecipitation was used to grow magnetic nanoparticles at these carboxyl sites. With successive growth of magnetic nanoparticles, we obtained polymeric particles with saturation magnetizations of up to 42 emu/g microparticle. The growth in the magnetic nanoparticle mean size and polydispersity was determined from the magnetization curves obtained following each growth cycle; nanoparticle sizes were limited by the physical constraint of the effective mesh within the hosting gel microparticle. Particles with spatially segregated domains of varying magnetic properties (e.g., Janus particles, particles with step …

The cogging torque of the flux-reversal machine (FRM) may cause some problems like noise and vibration of the motor. By FEM analysis of the cogging torque of FRM, a noticeable feature was found that the rotor teeth width increases, phase and magnitude of the cogging torque varies. So, the rotor teeth pairing method is proposed for reducing the cogging torque of FRM. In this method, we made a rotor which has two different tooth widths and measured the cogging torque of the motor. From the result, we can see that the simulation result is well matched with the measured result and the proposed method is feasible.

Transition metals, such as iron (Fe)- or cobalt (Co)-based nanomaterials, are promising electrocatalysts for oxygen reduction reactions (ORR) in fuel cells due to their high theoretical activity and low cost. However, a major challenge to using these metals in place of precious metal catalysts for ORR is their low efficiency and poor stability, thus new concepts and strategies should be needed to address this issue. Here, we report a hybrid aciniform nanostructures of Fe nanofragments embedded in thin nitrogen (N)-doped graphene (Fe@N-G) layers via a heat treatment of graphene oxide-wrapped iron oxide (Fe 2 O 3 ) microparticles with melamine. The heat treatment leads to transformation of Fe 2 O 3 microparticles to nanosized zero-valent Fe fragments and formation of core-shell structures of Fe nanofragments and N-doped graphene layers. Thin N-doped graphene layers massively promote electron transfer from the …

A novel high-strength nano-adhesive is demonstrated for fabricating nano- and microfluidic devices. While the traditional plasma sealing methods are specific for sealing glass to poly(dimethylsiloxane) (PDMS), the new method is compatible with a wide variety of polymeric and inorganic materials, including flexible substrates. Additionally, the traditional method requires that sealing occur within minutes after the plasma treatment. In contrast, the individual parts treated with the nano-adhesive could be aged for at least three months prior to joining with no measurable deterioration of post-cure adhesive strength. The nano-adhesive is comprised of a complementary pair of polymeric nanolayers. An epoxy-containing polymer, poly(glycidyl methacrylate) (PGMA) was grown via initiated chemical vapor deposition (iCVD) on the substrate containing the channels. A plasma polymerized polyallylamine (PAAm) layer was …

We present a method called “Lock Release Lithography (LRL)” that utilizes a combination of channel topography, mask design, and pressure-induced channel deformation to form and release particles in a cycled fashion. This technique provides a means for the high-throughput production of particles with complex 3D morphologies and composite particles with spatially configurable chemistries. In this work, we demonstrate a diverse set of functional particles including those displaying heterogeneous swelling characteristics and containing functional entities such as nucleic acids, proteins and beads.

Anisotropic multifunctional particles hold great promise for drug delivery,[1] imaging,[2] and construction of building blocks [3, 4] for dynamic mesostructures such as self-assembled tissues [4, 5] and 3-D electrical circuits.[6] Of particular interest, multifunctional particles with unique barcodes have been suggested as diagnosis tools for rapid screening of biomolecules.[7] For these applications, particle design is at least as important as size [3, 7–10] and requires a fabrication technique with precise control over shape and chemical patchiness. Methods currently used to generate multifunctional particles include microcutting,[11] co-jetting,[12] core–shell systems,[13] photo resist-based lithography,[14] and the PRINT method (particle replication in non-wetting templates).[15] The morphology of particles prepared by co-jetting, microcutting, and core–shell systems has been limited to spheres and cylinders.[11–13 …

A simple method to fabricate a multifunctional patterned platform on the nanometer scale is demonstrated. The platform contains two reactive functional groups on the surface: one is an acetylene group which can be functionalized via click chemistry, and the other is an amine group which can also be functionalized by classic carbodiimide chemistry with N -hydroxysuccinimide (NHS). The click-active and amine surface could be obtained from polymer coating of poly(propargyl methacrylate) (PPMA) via initiated chemical vapor deposition (iCVD) and poly(allylamine) (PAAm) via a plasma polymerization process, respectively, utilizing commercially available monomers. A capillary force lithography (CFL) process was applied on a stacked film of a PPMA layer on PAAm, and CFL could selectively pattern PPMA maintaining the bottom PAAm layer intact, which completes the multifunctional nanopatterns. The minimum …

Although urinary exosomal microRNAs (miRNAs) have recently emerged as potential biomarkers, clinical applications are still limited due to their low concentration in small volumes of clinical samples. Therefore, the development of a non-invasive, specific diagnostic tool, along with profiling exosomal miRNA markers from urine, remains a significant challenge. Here, we present hydrogel-based hybridization chain reaction (HCR) for multiplex signal amplification to detect urinary exosomal miRNAs from human clinical samples. We succeeded in identifying small amounts (~amol) of exosomal miRNAs from 600 μL of urine with up to ~35-fold amplification and enhanced detection limits by over an order of magnitude for two miRNA biomarker candidates, hsa-miR-6090 and hsa-miR-3665. Furthermore, we proposed ratiometric analysis without requiring normalization to a reference miRNA and validated the clinical …

We present the construction and operation of a compressed-air driven flow system that can be used for a variety of microfluidic applications that require rapid dynamic response and precise control of multiple inlet streams. With the use of inexpensive and readily available parts, we describe how to assemble this versatile control system and further explore its utility in continuous- and pulsed-flow microfluidic procedures for the synthesis and analysis of microparticles.

Magnetic polymer particles have been used in a wide variety of applications ranging from targeting and separation to diagnostics and imaging. Current synthesis methods have limited these particles to spherical or deformations of spherical morphologies. In this paper, we report the use of stop flow lithography to produce magnetic hydrogel microparticles with a graphical code region, a probe region, and a magnetic tail region. These anisotropic multifunctional magnetic polymer particles are an enhanced version of previously synthesized “barcoded” particles (Science, 2007, 315, 1393−1396) developed for the sensitive and rapid multiplexed sensing of nucleic acids. The newly added magnetic region has acquired dipole moments in the presence of weak homogeneous magnetic fields, allowing the particles to align along the applied field direction. The novel magnetic properties have led to practical applications in …

Large-scale microparticle arrays (LSMAs) are key for material science and bioengineering applications. However, previous approaches suffer from trade-offs between scalability, precision, specificity and versatility. Here, we present a porous microwell-based approach to create large-scale microparticle arrays with complex motifs. Microparticles are guided to and pushed into microwells by fluid flow through small open pores at the bottom of the porous well arrays. A scaling theory allows for the rational design of LSMAs to sort and array particles on the basis of their size, shape, or modulus. Sequential particle assembly allows for proximal and nested particle arrangements, as well as particle recollection and pattern transfer. We demonstrate the capabilities of the approach by means of three applications: high-throughput single-cell arrays; microenvironment fabrication for neutrophil chemotaxis; and complex, covert …

Flow lithography has become a powerful particle synthesis technique. Currently, flow lithography relies on the use of polydimethylsiloxane microchannels, because the process requires local inhibition of polymerization, near channel interfaces, via oxygen permeation. The dependence on polydimethylsiloxane devices greatly limits the range of precursor materials that can be processed in flow lithography. Here we present oxygen-free flow lithography via inert fluid-lubrication layers for the synthesis of new classes of complex microparticles. We use an initiated chemical vapour deposition nano-adhesive bonding technique to create non-polydimethylsiloxane-based devices. We successfully synthesize microparticles with a sub-second residence time and demonstrate on-the-fly alteration of particle height. This technique greatly expands the synthesis capabilities of flow lithography, enabling particle synthesis, using …

Microbeads have been utilized as efficient cell culture carriers and injectable scaffolds for cell transplantation. However, various polymers currently used to generate microbeads have limited applicability due to loss of biological functions and tissue‐specific effects. Here, a tissue bead platform is reported that can provide a tissue‐specific microenvironment to facilitate cell culture and potentiate cell therapy. Using a flow‐focusing microfluidic device, uniform‐sized tissue microbeads are fabricated with extracellular matrix (ECM) from various decellularized tissues. The tissue microbeads are tested for tissue‐specific encapsulation of induced hepatic (iHep), induced cardiac (iCar), and induced myogenic (iMyo) cells, which are directly reprogrammed from mouse primary fibroblasts. Tissue‐specific microbeads significantly enhanced the viability, lineage‐specific maturation, and functionality of each type of …

Piezocatalytic cancer therapy, in which piezoelectric nanomaterials generate reactive oxygen species (ROS) via piezocatalytic redox reactions under mechanical stress, has emerged as an effective strategy for cancer treatment. However, the inherent hypoxia in tumor microenvironments enormously restricts its efficacy. To address this issue, acid‐degradable Janus‐type multicompartmental carriers able to separately encapsulate piezocatalytic gold nanoparticle‐coated poly(ethylene glycol)‐modified zinc oxide nanorods (Au@P‐ZnO NRs) and O 2 ‐generating catalase (CAT) are fabricated in this study using stop‐flow lithography (SFL). The CAT and Au@P‐ZnO NRs are sequentially released by modulating the composition ratios of acid‐cleavable monomers in the precursor solution during the SFL. The sequential release by the Janus carriers significantly increased the intracellular ROS levels under hypoxia …

In response to a growing demand for simultaneous detection of multiple proteins in a single sample, multiplex immunoassay platforms have emerged at the forefront of proteomic analysis. In particular, detections using graphically encoded hydrogel microparticles synthesized via flow lithography have received attention for integrating a hydrogel, a substrate that can provide enhanced kinetics and high loading capacity, into the bead-based multiplex platform. Currently, the method of microparticle functionalization involves copolymerization of antibodies with the gel during particle synthesis. However, its practical operation is too precarious to be adopted because antibodies are susceptible to aggregation due to incompatibility with hydrophobic photoinitiators used in the photo-induced gel polymerization. In this work, we present a multiplex immunoassay platform that uses encoded hydrogel microparticles that are …

We report on modeling and experimental studies of the synthesis of opaque microparticles made via stop-flow lithography. Opaque magnetic beads and UV-absorbing dyes incorporated into hydrogel microparticles during synthesis changed the height and the degree of cross-linking of the polymer matrices formed. The effect of the concentration of these opaque materials on the particle height was determined experimentally and agreed well with model predictions based on the photopolymerization process over a wide range of UV absorbance. We also created particles with two independent anisotropies, magnetic and geometric, by applying magnetic fields during particle synthesis. Our work provides a platform for rational design of lithographic patterned opaque particles and also a new class of structured magnetic microparticles.

Stop Flow Lithography (SFL) is a microfluidic-based particle synthesis method for creating anisotropic multifunctional particles with applications that range from MEMS to biomedical engineering. Polydimethylsiloxane (PDMS) has been typically used to construct SFL devices as the material enables rapid prototyping of channels with complex geometries, optical transparency, and oxygen permeability. However, PDMS is not compatible with most organic solvents which limit the current range of materials that can be synthesized with SFL. Here, we demonstrate that a fluorinated elastomer, called perfluoropolyether (PFPE), can be an alternative oxygen permeable elastomer for SFL microfluidic flow channels. We fabricate PFPE microfluidic devices with soft lithography and synthesize anisotropic multifunctional particles in the devices via the SFL process – this is the first demonstration of SFL with oxygen lubrication …

Microalgae, unicellular photoautotrophic microorganisms, have attracted great attention for the production of biofuel and high-value products, but the commercial use of microalgae has been limited by low photosynthetic productivity. To overcome this limitation, it is required to develop an efficient platform for the rapid evaluation of photoautotrophic growth performance and productivity of microalgal strains. Here we describe a droplet-based photobioreactor for high-throughput analysis of the photoautotrophic growth of microalgal cells. By integrating micropillar arrays and adjusting the height of the microchamber, we could accurately monitor the growth kinetics of microalgae in an immobilized microdroplet and improve the transfer rate of CO2 into the microdroplet photobioreactor with an increased contact area between the microdroplet and PDMS surface. The improvement of CO2 transfer into the microdroplet was …

Bong Research Group

교수님 소개

봉기완

연구실 소개

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

Amplification-Free and Label-Free Multiplexed Profiling of Extracellular Vesicle-Derived MicroRNA via Micropore Sensing Based on PNA-Functionalized Hydrogel Barcodes

MIDAS: rapid, multiplexed molecular profiling for integrated host–pathogen analysis

Oxygen-free discontinuous dewetting in a degassed mold for anisotropic colloidal hydrogel microparticle synthesis

연구실 보유 특허

대학별 입시끈

우리 연구실 모집

교수님 소개

봉기완

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

Amplification-Free and Label-Free Multiplexed Profiling of Extracellular Vesicle-Derived MicroRNA via Micropore Sensing Based on PNA-Functionalized Hydrogel Barcodes

MIDAS: rapid, multiplexed molecular profiling for integrated host–pathogen analysis

Oxygen-free discontinuous dewetting in a degassed mold for anisotropic colloidal hydrogel microparticle synthesis

연구실 보유 특허

최근 3년간 연구실적 높은 연구실

대학별 입시끈

우리 연구실 모집