Publications by authors named "Young Bin Choy"

Delivery of secretomes, which includes growth factors, cytokines, and mRNA, is critical in regenerative medicine for cell-to-cell communication. However, the harsh in vivo environment presents significant challenges for secretome delivery. Proteolytic enzymes shorten secretomes' half-lives, and secretomes tend to rapidly diffuse at defect sites.

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We propose a hydrogel immobilized with manganese porphyrin (MnP), a biomimetic superoxide dismutase (SOD), and catalase (CAT) to modulate reactive oxygen species (ROS) and hypoxia that impede the repair of large bone defects. Our hydrogel synthesis involved thiolated chitosan and polyethylene glycol-maleimide conjugated with MnPs (MnP-PEG-MAL), which enabled gelation via a click reaction. Through optimization, a hydrogel with mechanical properties and catalytic effects favorable for bone repair was selected.

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Purpose: Transscleral ocular iontophoresis has been proposed to deliver charged particulate drugs to ocular tissues effectively by transmitting a weak electrical current through the sclera. The electric fields formed are influenced by the electrode conditions, thus affecting the amount of particulate drugs delivered to the ocular tissues via iontophoresis. Computational simulation is widely used to simulate drug concentrations in the eye; therefore, reflecting the characteristics of the drugs in living tissues to the simulations is important for a more precise estimation of drug concentration.

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Healing chronic diabetic wounds is challenging because of excessive reactive oxygen species (ROS) and hypoxia in the wound microenvironment. To address this issue, we propose a hydrogel wound dressing composed of polyethylene glycol (PEG) cross-linked with a biomimetic catalase, Fe-containing porphyrin (FeP) (i.e.

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Recipient site preparation using external volume expansion (EVE) increases graft survival in large-volume fat grafting. To improve patient compliance with using the device, we tested a new cyclic high negative-pressure (CHNP) mode that involves 1 h/day at -55 mm Hg, cycled between 1-second negative-pressure activation, followed by a 2-second deactivation period in an animal model. A miniaturized EVE device was applied to 30 8-week-old male Sprague-Dawley rats.

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Background: Noninvasive monitoring of tear glucose levels can be convenient for patients to manage their diabetes mellitus. However, there are issues with monitoring tear glucose levels, such as the invasiveness of some methods, the miniaturization, inaccuracy, or the high cost of wearable devices. To overcome the issues, we newly designed a sucking disk-type (SD) strip biosensor that can quickly suck tear fluid and contains cerium oxide nanoparticle (CNP) that causes a unique color change according to the glucose level of the tear without complicated electronic components.

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Adherence to medication plays a crucial role in the effective management of chronic diseases. However, patients often miss their scheduled drug administrations, resulting in suboptimal disease control. Therefore, we propose an implantable device enabled with automated and precisely timed drug administration.

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Background: Neutrophil extracellular traps (NETs) are observed in chronic rhinosinusitis (CRS), although their role remains unclear.

Objectives: This study aimed to investigate the influence of NETs on the CRS epithelium.

Methods: Forty-five sinonasal biopsy specimens were immunofluorescence-stained to identify NETs and p63 basal stem cells.

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A microneedle (MN) sensor coated with a sensing composite material was proposed for measuring glucose concentrations in interstitial fluid (ISF). The sensing composite material was prepared by blending a polymer containing glucose-responsive phenylboronic acid (PBA) moieties (i.e.

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Prompt administration of first-aid drugs can save lives during medical emergencies such as anaphylaxis and hypoglycemia. However, this is often performed by needle self-injection, which is not easy for patients under emergency conditions. Therefore, we propose an implantable device capable of on-demand administration of first-aid drugs (i.

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Chemodynamic therapy (CDT) is based on the production of cytotoxic reactive oxygen species, such as hydroxyl radicals (OH). Thus, CDT can be advantageous when it is cancer-specific, in terms of efficacy and safety. Therefore, we propose NH-MIL-101(Fe), a Fe-containing metal-organic framework (MOF), as a carrier of Cu (copper)-chelating agent, d-penicillamine (d-pen; i.

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Self-injectable therapy has several advantages in the treatment of metabolic disorders. However, frequent injections with needles impair patient compliance and medication adherence. Therefore, we develop a fully implantable device capable of on-demand administration of self-injection drugs via noninvasive manual button clicks on the outer skin.

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The potential therapeutic implications of nitric oxide (NO) have drawn a great deal of interest for reversing multidrug resistance (MDR) in cancer; however, previous strategies utilized unstable or toxic NO donors often oxidized by the excessive addition of reactive oxygen species, leading to unexpected side effects. Therefore, this study proposed a metal-organic framework (MOF), Porous coordination network (PCN)-223-Fe, to be loaded with a biocompatible NO donor, L-arginine (L-arg; i.e.

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Patients with high-risk non-metastatic renal cell carcinoma (RCC) are at risk of metastatic relapse following nephrectomy. Cabozantinib (CZ), a potent multitarget tyrosine kinase inhibitor, interferes with angiogenesis and immunosuppression associated with surgery-induced metastasis. Here, we explored the therapeutic potential of CZ-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (CZ-PLGA-NPs) as an adjuvant strategy for targeting post-nephrectomy metastasis.

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Cancer immunotherapy is a next-generation treatment strategy; however, its side effects limit its clinical translation. Here, a novel combination of a multi-functional nano-adjuvant (M-NA) prepared with an iron oxide/gold core and a cationic polymer shell via multilayer synthesis with CpG oligodeoxynucleotide (CpG-ODN) electrostatically complexed on its surface, and irreversible electroporation (IRE) technique was developed for effective image-guided in situ cancer vaccination. The M-NA can be retained long-term in the dense tumoral extracellular matrix after intratumoral injection and internalized by antigen-presenting cells (APCs).

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Background: A biological injectable material, paste-type micronized acellular dermal matrix (ADM), has been proven effective in wound healing by filling defects through tissue replacement. This study aimed to compare the efficacy of paste-type micronized ADM on soft tissue augmentation with that of the conventional fillers in animal experiments.

Methods: Two distinct paste-type micronized ADMs, which were mixed with distilled water (mADM) and gelatin (mADM+GEL), respectively, were compared with conventional fillers, hyaluronic acid (HA) and polymethyl methacrylate (COL+PMMA).

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Conventionally, macro-textured surfaces comprising several hundred micrometer-sized patterns are used to minimize silicone-based breast implant complications, including capsular contracture. However, because of the recent cases of breast implant-associated anaplastic large cell lymphoma from macro-textured implants, there is a strong demand for nano- or micro-textured silicone implants with dimensions smaller than sub-micrometers. Herein, we propose a simple and cost-effective topographical surface modification strategy for silicone-based implants.

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Prolonged drug efficacy to reduce the number of administrations is a key factor in the successful treatment of glaucoma through topical drug delivery to the eye. Therefore, we propose a new strategy for iontophoretic ocular delivery of drug-loaded nanoparticles. Considering safety and convenience, our strategy is involved with topical administration of the drug-loaded nanoparticles followed by their permeation into the eye tissues via noninvasive iontophoresis, using the skin-attached electrodes.

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A bolus of human growth hormone (hGH) is often prescribed for the treatment of growth hormone deficiency, which requires frequent injections in current clinical settings. This painful needle-involved delivery often results in poor patient compliance, leading to low medication adherence and poor clinical outcomes. Therefore, we propose a magnetically actuating implantable pump (MAP) that can infuse an accurate dose of hGH only at the time of non-invasive magnet application from the skin.

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For the prolonged, controlled delivery of systemic drugs, we propose an implantable drug-delivery chip (DDC) embedded with pairs of a microchannel and drug-reservoir serving as a drug diffusion barrier and depot, respectively. We pursued a DDC for dual drugs: a main-purpose drug, diclofenac (DF), for systemic exposure, and an antifibrotic drug, tranilast (TR), for local delivery. Thus, the problematic fibrotic tissue formation around the implanted device could be diminished, thereby less hindrance in systemic exposure of DF released from the DDC.

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Background: Due to the increasing aging of society, the number of patients suffering from senile diseases is increasing. Patients suffering from osteoporosis, which is a representative senile disease, take a long time to recover from fractures, and the resulting mortality rate is very high. Alendronate (Ald), which is widely used as a treatment for osteoporosis, alleviates osteoporosis by inhibiting osteoclasts.

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Precise estimation of electrical conductivity of the eyes is important for the accurate analysis of electric field distributions in the eyes during ocular iontophoresis. In this study, we estimated the tissue electrical conductivities of a rabbit eye, which has been widely employed for neuro-ophthalmological experiments, through an in vivo experiment for the first time. Electrical potentials were measured at multiple locations on the skin, while weak currents were transmitted into the skin via two surface electrodes attached to the skin around the eye.

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Cosmetic silicone implants for breast reconstruction often lead to medical complications, such as abnormally excessive fibrosis driven by foreign body granulomatous inflammation. The purpose of this study was to develop a silicone breast implant capable of local and controlled release of a glucocorticoid drug triamcinolone acetonide (TA) for the prevention of silicone-breast-implant-induced fibrosis in a Yorkshire pig model (in vivo). Implants were dip-coated in a TA solution to load 1.

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