Diatoms and glass sponges are able to construct their siliceous bodies from small amounts of dissolved silicic acid. The enzymatic synthesis of silica found in silicatein (a silica-forming protein in glass sponges) devoted attention to designing chemical strategies for the formation of organized and functional silica structures with synthetic analogues to silicatein. For example, cysteamine, containing thiol and amine functional groups at the terminal ends, was utilized as a catalyst for bioinspired silicification, and generated discrete silica spheres, hollow silica spheres, and worm-like silica structures under benign conditions. In particular, hollow silica spheres would be the promising material for programmed release of useful ingredients in conjunction with the selective surface modification by silane chemistry.

References: Small 2009, 5(17), 1947-1951; Bull. Korean Chem. Soc. 2010, 31(7), 1831-1832; Chem. Asian J. 2011, 6(8), 1939-1942; Chem. Asian J. 2014, 9(3), 764-768; Bull. Korean Chem. Sci. 2014, 35(11), 3336-3338; Angew. Chem. Int. Ed. 2014, 53(31), 8056-8059; Chem. Commun. 2015, 51(25), 5523-5525.

Living cells are composed of soft and dynamic materials that respond to external chemical environments. In particular, cell surface is the outermost platform for controlling cellular activities, with characteristic properties, such as selective permeation, biomolecular recognition, and molecular transportation. To achieve the artificial manipulation of cellular activities and functions, biocompatible strategis maintaining cell viability, for example, metal-polyphenol nanofilm, have been utilized. The cell growth of coated cell was controlled by the degradation of the metal-polyphenol nanofilm. Furthermore, the nanocoating endowed individual cells with the protective abilities against UV irradiation, lytic enzymes, and silver nanoparticle, thereby being applicable further to other functional cells. Currently, the interest lies in the fabrication of functional cells integrated with hybrid nanomaterials for customized cell-based applications and also the translation of nanotechnology to practical applications in daily life exemplified by the enhanced shelf-life of agricultural products.

References: Angew. Chem. Int. Ed. 2013, 52(47), 12279-12282; Adv. Mater. 2014, 26(13), 2001-2010; Angew. Chem. Int. Ed. 2014, 53(46), 12420-12425; Nanoscale 2015, 7(45), 18918-18922; Acc. Chem. Res. 2016, 49(5), 792-800; Polymers 2017, 9(4), 140; Sci. Rep. 2017, 7, 6980