Insung S. Choi 교수

We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy and at a macroscopic level with the us

Abstract In this paper, we report a facile and efficient method for fabricating gecko‐inspired, hairy hard poly(dimethylsiloxane) (h‐PDMS) structures, composed of nanopillars with controllable lengths. The structures are generated by utilizing an anodic aluminum oxide (AAO) membrane as a replication template. For easy handling of the replicated h‐PDMS films, the vinyl‐terminated glass substrate is used. The cross‐linking between the vinyl moieties on the glass surface and methylhydrosiloxanes, o

The cytoprotective coating of physicochemically labile mammalian cells with a durable material has potential applications in cell-based sensors, cell therapy, and regenerative medicine, as well as providing a platform for fundamental single-cell studies in cell biology. In this work, HeLa cells in suspension were individually coated with silica in a cytocompatible fashion through bioinspired silicification. The silica coating greatly enhanced the resistance of the HeLa cells to enzymatic attack

Abstract Summary: We investigated the formation of thermoresponsive gold nanoparticle/poly( N ‐isopropylacrylamide) (AuNP/PNIPAAm) core/shell hybrid structures by surface‐initiated, atom transfer radical polymerization (SI‐ATRP) in aqueous media and the effect of cross‐linking on the thermoresponsiveness of the AuNP/PNIPAAm hybrids. The disulfide containing an ATRP initiator was attached onto AuNPs and the monomer, NIPAAm, was polymerized from the surface of AuNPs in the absence or presence of a

A cytocompatible method of surface-initiated, activator regenerated by electron transfer, atom transfer radical polymerization (SI-ARGET ATRP) is developed for engineering cell surfaces with synthetic polymers. Dopamine-based ATRP initiators are used for both introducing the ATRP initiator onto chemically complex cell surfaces uniformly (by the material-independent coating property of polydopamine) and protecting the cells from radical attack during polymerization (by the radical-scavenging prop

Single-cell nanoencapsulation is an emerging field in cell-surface engineering, emphasizing the protection of living cells against external harmful stresses in vitro and in vivo. Inspired by the cryptobiotic state found in nature, cell-in-shell structures are formed, which are called artificial spores and which show suppression or retardation in cell growth and division and enhanced cell survival under harsh conditions. The property requirements of the shells suggested for realization of artific

Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-Fe(III) nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradatio

Cells are encapsulated individually within thin and tough shells in a cytocompatible way, by mimicking the structure of bacterial endospores that survive under hostile conditions. The 3D 'cell-in-shell' structures-coined as 'artificial spores'-enable modulation and control over cellular metabolism, such as control of cell division, resistance to external stresses, and surface-functionalizability, providing a useful platform for applications, including cell-based sensors, cell therapy, regenerati

We designed a perfluorinated dopamine derivative, which, upon oxidative polymerization, formed a structurally rough film of extremely low surface energy on various substrates. The static water contact angles larger than 150° and the low water sliding angles less than 7° confirmed the formation of superhydrophobic, self-cleaning surfaces.

Tough shell: Living yeast cells can be simultaneously silica-encapsulated and thiol-functionalized by polycondensation of silicic acid and (3-mercaptopropyl)trimethoxysilane under mild conditions. Various functions such as fluorescent dyes (see picture; green: fluorescein, red: rhodamine), chemical moieties, or proteins, can be introduced to the artificial shell by using maleimide-based coupling reactions. Detailed facts of importance to specialist readers are published as ”Supporting Informatio

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSurface-Initiated Polymerization of l-Lactide: Coating of Solid Substrates with a Biodegradable PolymerInsung S. Choi and Robert LangerView Author Information Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Cite this: Macromolecules 2001, 34, 16, 5361–5363Publication Date (Web):July 3, 2001Publication History Received24 January 2001Published online3 Jul