Silicification and Biosilicification

There has been some interest in generating silica-like particles using templates, as occurs naturally in biosilicification processes. - 3i6-32s Various particle shapes have been obtained. Platelet forms are of particular interest with regard to their ability to reinforce and decrease permeability. 

Additional novel particles, including nylon 66, alumina, gold, garnet, diamond, graphite, polyaniline, and boron nitride nanosheets, and nanoparticles of low molecular weight borate esters, have been introduced to increase ionic conductivities. Boron-doped PDMS has been used as scintillators for thermal neutron detection. Nanowires of ZnO have been inserted into PDMS to give tunable, flexible antireflection layers, and ZnO has also been introduced into such polymers as quantum dots. Similarly, color-tunable luminescent 

Other unusual additives include oxetanes, vinylic macromono-mers, silicon carbide, superconductive carbon blacks, silver-coated fly ash, metal oxides, Tb for green emission, antibacterial agents, and organic-inorganic hybrid copolymer fibers. In an interesting reversal, transition element acetylacetonate salts were decomposed in a PDMS matrix to give membranes with catalytic activity.  

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We demonstrated that a naturally derived polysaccharide, chitosan, is capable of forming composite nanoparticles with silica. For encapsulated particles, we used silicification and biosilicification to encapsulate curcumin and analyzed the physicochemical properties of curcumin nanoparticles. It proved that encapsulated curcumin nanoparticles enhanced stability toward ultraviolet (UV) irradiation, antioxidation and antitumor activity, enhanced/added function, solubility, bioactivities/ bioavailability, and control release and overcame the immunobarrier. We present an in vitro study that examined the cytotoxicity of amorphous and composite silica nanoparticles to different cell lines. These bioactives include curcumin mdAntrodia cinnamomea. It is hoped that by examining the response of multiple cell lines to silica nanoparticles more basic information regarding the cytotoxicity as well as potential functions of silica in future oncological applications could become available. 

Patwardhan, S. V. Clarson, S. J., Silicification and biosilicification - Part 7 Poly-L-arginine mediated bioinspired synthesis of silica. J. Inorg. Organomet. Polym. 2003,13, (4), 193-203. 

Patwardhan, S. V., Silicification and Biosilicification Role of Macromolecules in Bioinspired Silica Synthesis. Ph.D. Dissertation, University of Cincinnati 2003. 

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