Sei Kwang Hahn

A smart contact lens can be used as an excellent interface between the human body and an electronic device for wearable healthcare applications. Despite wide investigations of smart contact lenses for diagnostic applications, there has been no report on electrically controlled drug delivery in combination with real-time biometric analysis. Here, we developed smart contact lenses for both continuous glucose monitoring and treatment of diabetic retinopathy. The smart contact lens device, built on

Optimization was carried out for the recovery of microbiol poly(3-hydroxybutyrate) (PHB) from Alcaligenes eutrophus. This process involved the use of a dispersion made of sodium hypochlorite solution and chloroform. The dispersion enabled us to take advantage of both differential digestion by hypochlorite and solvent extraction by chloroform. The PHB recovery (%) from cell powder was maximized using a 30% hypochlorite concentration, a 90-min treatment time, and a 1:1 (v/v) chloroform-to-aqueous-

A facile in situ supramolecular assembly and modular modification of biocompatible hydrogels were demonstrated using cucurbit[6]uril-conjugated hyaluronic acid (CB[6]-HA), diaminohexane-conjugated HA (DAH-HA), and tags-CB[6] for cellular engineering applications. The strong and selective host-guest interaction between CB[6] and DAH made possible the supramolecular assembly of CB[6]/DAH-HA hydrogels in the presence of cells. Then, the 3D environment of CB[6]/DAH-HA hydrogels was modularly modifie

Melanoma skin cancer is one of the most dangerous skin cancers and the main cause of skin-cancer-related mortality. Hyaluronic acid (HA) has been used as an effective transdermal delivery carrier of chemical drugs and biopharmaceuticals. In this work, a nanographene oxide-HA conjugate (NGO-HA) was synthesized for photothermal ablation therapy of melanoma skin cancer using a near-infrared (NIR) laser. Confocal microscopy and ex vivo bioimaging clearly visualized the remarkable transdermal deliver

Rheumatoid arthritis (RA) is a chronic inflammatory immune disease causing the inflammation of synovial membrane and the articular cartilage destruction. In this work, hyaluronate-gold nanoparticle/Tocilizumab (HA-AuNP/TCZ) complex was prepared for the treatment of RA. AuNP was used as a drug carrier with antiangiogenic effect. TCZ is a humanized monoclonal antibody against the interleukin-6 (IL-6) receptor and used as an immunosuppressive drug by interfering IL-6 in the pathogenesis of RA. HA i

A new drug delivery device using cylindrical block copolymer nanochannels was successfully developed for controlled protein drug delivery applications. Depending on the hydrodynamic diameter of the protein drugs, the pore size in cylindrical nanochannels could be controlled precisely down to 6 nm by Au deposition. Zero-order release of bovine serum albumin (BSA) and human growth hormone (hGH) by single-file diffusion, which has been observed for gas diffusion through zeolite pores, was realized

Fluorescent nanosized carbon dots (Cdots) are an emerging bioimaging agent with excellent chemical inertness and marginal cytotoxicity in comparison to widely used semiconductor quantum dots. In this work, we report the application of Cdots for real time bioimaging of target specific delivery of hyaluronic acid (HA) derivatives. Polyethylene glycol (PEG) diamine-capped Cdots were synthesized by the pyrolysis of citric acid in a hot solvent. The synthesized Cdots showed strong fluorescence under

The last decade has seen dramatic progress in the principle, design, and fabrication of photonic nanomaterials with various optical properties and functionalities. Light-emitting and light-responsive nanomaterials, such as semiconductor quantum dots, plasmonic metal nanoparticles, organic carbon, and polymeric nanomaterials, offer promising approaches to low-cost and effective diagnostic, therapeutic, and theranostic applications. Reasonable endeavors have begun to translate some of the promisin

Smart contact lenses for continuous glucose monitoring (CGM) have great potential for huge clinical impact. To date, their development has been limited by challenges in accurate detection of glucose without hysteresis for tear glucose monitoring to track the blood glucose levels. Here, long-term robust CGM in diabetic rabbits is demonstrated by using bimetallic nanocatalysts immobilized in nanoporous hydrogels in smart contact lenses. After redox reaction of glucose oxidase, the nanocatalysts fa

Gold nanoparticles (AuNPs) have been extensively investigated as an emerging delivery carrier of various biopharmaceuticals. Instead of nonspecific polyethylene glycol (PEG) conjugated interferon α (IFNα) for the clinical treatment of hepatitis C virus (HCV) infection, in this work, a target-specific long-acting delivery system of IFNα was successfully developed using the hybrid materials of AuNP and hyaluronic acid (HA). The HA-AuNP/IFNα complex was prepared by chemical binding of thiolated HA

We studied recovery of poly(3-hydroxybutyric acid) (PHB) from Alcaligenes eutrophus and a recombinant Escherichia coli strain harboring the A. eutrophus poly(3-hydroxyalkanoic acid) biosynthesis genes. The amount of PHB degraded to a lower-molecular-weight compound in A. eutrophus during the recovery process was significant when sodium hypochlorite was used, but the amount degraded in the recombinant E. coli strain was negligible. However, there was no difference between the two microorganisms i

Hyaluronic acid (HA) plays important biological roles in tissue integrity, angiogenesis, wound healing, and cell motility through the interaction with receptors on cell membranes. In this work, we investigated the effect of HA modification on the receptor-mediated endocytosis labeling HA derivatives with quantum dots (QDots). HA-QDot conjugates with a degree of modification less than ca. 25 mol % appeared to be more efficiently taken up to B16F1 cells by HA receptor mediated endocytosis than QDo