Hyun Jung Chung

The ability to rapidly diagnose gram-positive pathogenic bacteria would have far reaching biomedical and technological applications. Here we describe the bioorthogonal modification of small molecule antibiotics (vancomycin and daptomycin), which bind to the cell wall of gram-positive bacteria. The bound antibiotics conjugates can be reacted orthogonally with tetrazine-modified nanoparticles, via an almost instantaneous cycloaddition, which subsequently renders the bacteria detectable by optical

Injectable cell therapy would provide a patient-friendly procedure for treatment of degenerated or wounded tissue. Biodegradable injectable porous microspheres were fabricated to use as dual-purpose microcarriers for cell culture and injectable scaffold for tissue regeneration. Gas foaming in a water-in-oil-in-water double emulsion was performed for fabricating the well-interconnected porous microcarriers using poly(lactic-co-glycolic acid) (PLGA). The gas foaming conditions were finely tuned to

Cellular aggregates were prepared using biodegradable porous microspheres for injectable reconstruction of soft tissues in vivo. Biodegradable porous microspheres with sizes of approximately 50 microm were prepared by a porogen leaching-phase separation process in an oil-in-water single-emulsion method using poly(D,L-lactide-co-glycolide). 3T3 L1 mouse preadipocyte cells were transformed into cellular aggregates by suspension cultivation in a spinner flask using the porous microspheres as effect

Currently available methods to stably disperse iron oxide nanoparticles (IONPs) in aqueous solution need to be improved due to potential aggregation, reduction of superparamagnetism, and the use of toxic reagents. Herein, we present a facile strategy for aqueous transfer and dispersion of organic-synthesized IONPs using only polyethylene glycol (PEG), a biocompatible polymer. A library of PEG derivatives was screened, and it was determined that amine-functionalized six-armed PEG, 6(PEG-NH(2)), w

Demands for ultrahigh strength in structural materials have been steadily increasing in response to environmental issues. Maraging alloys offer a high tensile strength and fracture toughness through a reduction of lattice defects and formation of intermetallic precipitates. The semi-coherent precipitates are crucial for exhibiting ultrahigh strength; however, they still result in limited work hardening and uniform ductility. Here, we demonstrate a strategy involving deformable semi-coherent prec

Effects of photosensitizers including riboflavin, chlorophyll b, or methylene blue on the stability of daidzein and genistein were studied in model systems by high-performance liquid chromatography (HPLC). Concentration of daidzein and genistein in 80% methanol with riboflavin under light for 7 h was significantly decreased with the apparent 1st-order rate constants of 0.234 and 0.193/h, respectively, (P < 0.05), while those without riboflavin under light did not change significantly (P > 0.05).

The high incidence of acute and chronic kidney injury due to various environmental factors such as heavy metals or chemicals has been a major problem in developing countries. However, the diagnosis of kidney injury in these areas can be more challenging due to the lack of highly sensitive and specific techniques that can be applied in point-of-care settings. To address this, we have developed a technique called 'micro-urine nanoparticle detection (μUNPD)', that allows the detection of trace amou

ABSTRACT: Relationships among headspace oxygen uptake, peroxide value, and conjugated dienes content in the oxidation of soybean oils in a gas‐tight bottle were studied for 24 h under light and 96 h in the dark at 55°C. The theoretical peroxide value determined by oxygen uptake continuously increased as storage time increased. The headspace oxygen method is simple and reproducible and may be the best analytical method to evaluate the oxidative stability of oils.