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Scope: Silicon (Si) is an abundant element on earth. It is found naturally in water in the form of orthosilicic acid (OSA), however this form is not stable under certain conditions such as in highly concentrated and non-neutral pH solutions, which lead to its polymerization and reduced bioavailability. This study aimed to assess the bioavailability of Si from OSA stabilized by vanillin (OSA-VC)., Methods and Results: This was a single-center, double-blind, cross-over randomized controlled trial. Fourteen healthy subjects were recruited and consumed either OSA-VC or a placebo on two separate occasions. Blood and urine samples were collected during 6 h following ingestion and analyzed to determine Si absorption and excretion. Plasma Si area under the curve (0-6 h) was significantly higher after OSA-VC ingestion compared to placebo ingestion (p = 0.0002). Significantly higher urinary Si excretion was also reported over the 6-h period after OSA-VC ingestion compared to placebo (p<0.0001). Approximately 21% of ingested Si was excreted in urine during this period., Conclusion: Although many studies have investigated the metabolism and bioavailability of Si supplemented in foods or as a food ingredient, this was the first to investigate and demonstrate the digestibility of OSA administered in a complex form with vanillin., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The dual-labeled microcapsules via nanoparticle/polymer assembly based on polyamine-salt aggregates can be fabricated for the ratiometric intracellular pH sensing. After deposition of SiO2 nanoparticles on the poly(allylamine hydrochloride)/multivalent anionic salt aggregates followed by silicic acid treatment, the generated microcapsules are stable in a wide pH range (3.0 ∼ 8.0). pH sensitive dye and pH insensitive dye are simultaneously labeled on the capsules, which enable the ratiometric pH sensing. Due to the rough and positively charged surface, the microcapsules can be internalized by several kinds of cells naturally. Real-time measurement of intracellular pH in several living cells shows that the capsules are all located in acidic organelles after being taken up. Furthermore, the negatively charged DNA and dyes can be easily encapsulated into the capsules via charge interaction. The microcapsules with combination of localized pH sensing and drug loading abilities have many advantages, such as following the real-time transportation and processing of the carriers in cells., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Phage display experiments on industrially important calcium silicate hydrates (C-S-H), the main hydration product of ordinary Portland cement, suggest fundamentally different specific binding motifs compared to hitherto existing commercial cement additives. According to that, a strong and specific adsorbing additive on C-S-H should have three features which are a negative charge, H-bond formers (especially amide functions) and a hydrophobic part., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Micropatterns of silica were generated under biocompatible conditions by a combination of microcontact printing (muCP), layer-by-layer (LbL) self-assembly, and biomimetic silicification. Quaternary amine-containing poly(diallyl dimethyl ammonium chloride) induced polycondensation of silicic acid, resulting in spatioselective formation of silica micropatterns. Scale bar: 10 microm.

A nonenzymatic electrochemical method is described for the detection of glucose by using gold (Au) nanoparticles self-assembled on a three-dimensional (3D) silicate network obtained by using sol-gel processes. The nanosized Au particles have been self-assembled on the thiol tail groups of the silicate network and enlarged by hydroxylamine. The Au nanoparticles efficiently catalyze the oxidation of glucose at less-positive potential (0.16 V) in phosphate buffer solution (pH 9.2) in the absence of any enzymes or redox mediators. The Au nanoparticle-modified transducer (MPTS-nAuE) was successfully used for the amperometric sensing of glucose and it showed excellent sensitivity with a detection limit of 50 nM. The common interfering agent ascorbate (AA) does not interfere with the detection of glucose. The MPTS-nAuE transducer showed individual voltammetric responses for glucose and AA. This transducer responded linearly to glucose in the range of 0-8 mM and the sensitivity of the transducer was found to be 0.179 nA cm(-2) nM(-1). Excellent reproducibility, and long-term storage and operational stability was observed for this transducer.

Micropatterns of silica on a gold substrate were generated by a biomimetic approach, namely, the biosilicification of silicic acids. The procedure consists of three simple steps: pattern generation of a polymerization initiator, (BrC(CH(3))(2)COO(CH(2))(11)S)(2), by microcontact printing; surface-initiated, atom-transfer radical polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) from the patterned area; and polycondensation of silicic acids. The tertiary amine-containing polymer, pDMAEMA, aided in the spatially controlled polycondensation of silicic acids on surfaces in the presence of phosphate ions, and micropatterns of silica on a gold substrate were successfully generated in combination with the technique of microcontact printing. The procedure could be extended to the controlled fabrication of silica patterns with any size, shape, or thickness.