Publications by authors named "Chang Beom Kim"

Herein, we report the first study to create a three-dimensional (3D) bioprinted artificial larynx for whole-laryngeal replacement. Our 3D bio-printed larynx was generated using extrusion-based 3D bioprinter with rabbit's chondrocyte-laden gelatin methacryloyl (GelMA)/glycidyl-methacrylated hyaluronic acid (GMHA) hybrid bioink. We used a polycaprolactone (PCL) outer framework incorporated with pores to achieve the structural strength of printed constructs, as well as to provide a suitable microenvironment to support printed cells.

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The hyaluronic acid (HA) hydrogel array was employed for immobilization of 5-fluorouracil (5-FU), and the electrospun bilayer (hydrophilic: polyurethane/pluronic F-127 and hydrophobic: polyurethane) membrane was used to support the HA hydrogel array as a patch. To visualize the drug propagating phenomenon into tissues, we experimentally investigated how FITC-BSA diffused into the tissue by applying hydrogel patches to porcine tissue samples. The diffusive phenomenon basically depends on the FITC-BSA diffusion coefficient in the hydrogel, and the degree of diffusion of FITC-BSA may be affected by the concentration of HA hydrogel, which demonstrates that the high density of HA hydrogel inhibits the diffusive FITC-BSA migration toward the low concentration region.

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Objective: Poststroke insomnia is common and negatively affects stroke recovery. The objective of this study was to determine the effectiveness of bright light therapy for mild-to-moderate stroke patients with insomnia.

Methods: This study was randomized, double blind, and placebo controlled.

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In this work, a novel and simple bone morphogenetic protein (BMP)-2 carrier is developed, which enables localized and controlled release of BMP-2 and facilitates bone regeneration. BMP-2 is localized in the gelatin methacrylate (GelMA) micropatterns on hydrophilic semi-permeable membrane (SNM), and its controlled release is regulated by the concentration of GelMA hydrogel and BMP-2. The controlled release of BMP-2 is verified using computational analysis and quantified using fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) diffusion model.

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The magnetic particle imaging (MPI) is a technology that can image the concentrations of the superparamagnetic iron oxide nanoparticles (SPIONs) which can be used in biomedical diagnostics and therapeutics as non-radioactive tracers. We proposed a point-of-care testing MPI system (PoCT-MPI) that can be used for preclinical use for imaging small rodents (mice) injected with SPIONs not only in laboratories, but also at emergency sites far from laboratories. In particular, we applied a frequency mixing magnetic detection method to the PoCT-MPI, and proposed a hybrid field free line generator to reduce the power consumption, size and weight of the system.

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Occlusion of the major cerebral artery usually results in brain hypoxic-ischemic injury, which evokes neuroinflammation and microglial activation. Activated microglia are considered a source of multiple neurotoxic factors, such as reactive oxygen species (ROS), in the central nervous system (CNS). We herein present a 3D-rendering brain imaging technique in an experimental rodent model of cerebral ischemia based on 2D magnetic images of superparamagnetic iron oxide nanoparticles (SPIONs) using the planar frequency mixing magnetic detection (p-FMMD) technique.

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We represent the experimental results of our planar-frequency mixing magnetic detection (p-FMMD) technique to obtain 2D superparamagnetic images for magnetic immunoassay purpose. The imaging of magnetic beads is based on the nonlinear magnetic characteristics inherent in superparamagnetic materials. The p-FMMD records the sum-frequency components originating from both a high and a low frequency magnetic field incident on the magnetically nonlinear nanoparticles.

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[Purpose] This study was conducted to find out the effect of arm swing during treadmill training on the gait of stroke patients. [Subjects and Methods] This study subjects were 20 stroke subjects patients who were randomly assigned to either the experimental group (EG) or the control group (CG), 10 subjects in each group. Therapists induced arm swing of affected side of EG subjects using Nordic poles, while subjects in CG had the affected arm restricted to prevent arm swing.

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[Purpose] The aim of this study was to examine the effect of chest expansion resistance exercises (CERE) on chest expansion, maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) in elderly people with inspiratory muscle weakness. [Subjects] Thirty elderly people with inspiratory muscle weakness (MIP < 80% of the predicted value) were randomly and equally assigned to a chest expansion resistance exercise (CERE) group, core conditioning exercise (CCE) group, and control group. [Methods] The intervention was applied to the CERE group and CCE group five times per week, 30 minutes each time, for six weeks.

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[Purpose] The aim of this study was to examine the initial effects of chest expansion resistance exercise (CERE) applied to chronic stroke patients on their pulmonary functions, chest expansion, and functional gait ability. [Subjects] Forty chronic stroke patients without any respiration-related rehabilitation program experience (21 men and 19 women; times elapsed since occurrence of stroke: 21.8 ± 5.

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Alzheimer's disease (AD) is a neurodegenerative disorder that leads to a decline in cognitive and intellectual abilities and an irreversible mental deterioration. Based on multidisciplinary AD research, the most universally accepted hypotheses on AD pathogenesis are the intracerebral aggregate formation of beta-amyloid (Aβ) peptides. According to medical paradigmatic transition from medical treatment to early diagnostic prevention, scientists have considered physiological body fluid as a biomarker medium, in which the promising AD biomarkers could be verified.

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The existence of beta-amyloid [Aβ] peptides in the brain has been regarded as the most archetypal biomarker of Alzheimer's disease [AD]. Recently, an early clinical diagnosis has been considered a great importance in identifying people who are at high risk of AD. However, no microscale electronic sensing devices for the detection of Aβ peptides have been developed yet.

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A tunable process for polydimethylsiloxane (PDMS) nanoslit fabrication is developed for nanofluidic applications. A microcontact printing (μCP) of a laterally spreading self-assembled hexadecanethiol (HDT) layer, combined with in situ curing of a sliding SU-8 droplet, enables precise and independent tuning of a nanoslit-mold width and height using a single μCP master mold. The SU-8 nanoslit-mold is replicated using a hard-soft composite PDMS to prevent channel collapse at low (<0.

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We developed microfluidic-based pure chitosan microfibers (approximately 1 meter long, 70-150 microm diameter) for liver tissue engineering applications. Despite the potential of the chitosan for creating bio-artificial liver chips, its major limitation is the inability to fabricate pure chitosan-based microstructures with controlled shapes because of the mechanical weakness of the pure chitosan. Previous studies have shown that chitosan micro/nanofibers can be fabricated by using chemicals and electrospinning techniques.

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This review presents an application of micromixer technologies, which have driven a number of critical research trends over the past few decades, particularly for chemical and biological fields. Micromixer technologies in this review are categorized according to their applications: (1) chemical applications, including chemical synthesis, polymerization, and extraction; (2) biological applications, including DNA analysis, biological screening enzyme assays, protein folding; and (3) detection/analysis of chemical or biochemical content combined with NMR, FTIR, or Raman spectroscopies. In the chemical application, crystallization, extraction, polymerization, and organic synthesis have been reported, not only for laboratory studies, but also for industrial applications.

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A photon-to-thermal conversion nanosystem has been developed to rapidly elevate temperatures in poorly thermally conducting media using irradiation of gold nanorods. We first hypothesized that nanoparticles, especially gold nanorods, are capable of generating enough heat to lyse bacteria by heating sample solutions via laser irradiation. To test this, we synthesized Au nanorods (aspect ratio 3-4) and studied optothermal properties of these nanoparticles.

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To assess the role of the flagellum which was detected by immunoscreening of surface proteins of Vibrio vulnificus, an flgE-deleted mutant was constructed and tested for its pathogenicity. The ability of this nonmotile mutant to adhere to INT-407 cells and its role in biofilm were decreased, as was its lethality to mice.

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