Nanoparticles silica nanospheres

A mesoporous silica nanosphere-based carrier system with chemically removable CdS nanoparticle caps for stimuli-responsive controlled release of neurotransmitters and drag molecules. 

Figure 16.5 Design principle of nanoparticle gated mesoporous silica nanospheres. The nanoparticles cap the pores by covalent bonds trapping previously diffused guest molecules. The bonds are then broken under specific stimuli allowing the guest molecules to diffuse away.

S. Y., A mesoporous silica nanosphere-based carrier system with chemically removable CdS nanoparticle caps for stimuli-responsive controlled release of neurotransmitters and drug molecules. Journal of the American Chemical Society 125, (15), 4451 59, 2003. 

Wang Y, Biradar AV, Duncan CT, Asefa T (2010) Silica nanosphere-supported shaped Pd nanoparticles encapsulated with nanoporous silica shell efficient and recyclable nanocatalysts. J Mater Chem 20 7834-7841... 

Elsewhere, various other hollow mesoporous nanosilica have also been explored for their medical applications. Zhou et al. discussed the use of hollow silica nanospheres with magnetic nanoparticles (e.g. Fe304) within the pores to deliver ibu-profen. When the drug had been stored inside the pores, the openings were encapsulated [17]. As a consequence, the size of the nanospheres was of the order of a few hundred nanometers, while the magnetic Fe304 nanoparticles were about 5-10 nm. It should be noted here that these nanomaterials were used exclusively for delivery purposes. 

Figure 11.8 (a) A scheme for the preparation templated with 40 nm silica nanospheres, of monodispersed organosilica nanoparticles (Reproduced with permission from Ref. [49]. by templating with silica nanospheres, (b) TEM Copyright 2013, the Royal Society of and SEM (inset) images of the hollow particles Chemistry.)... 

The potential of hollow mesoporous silica nanoparticles as a drug carrier has been actively researched in vitro. For example, hollow mesoporous silica nanospheres with uniform sizes of 31-33 nm, prepared using PS-PVP-PEO triblock copolymer micelles, exhibited a higher storage capacity of a model drug (ibupro-fen) than the conventional mesoporous silica particles [111]. A more sustained release was achieved by propylamine functionalization, which is effective for controlled release of drug molecules. 

Koike, N., Ikuno, T., Okubo, T., and Shimojima, A. (2013) Synthesis of monodisperse organosilica nanoparticles with hollow interiors and porous shells using silica nanospheres as templates. Chem. Commun., 49, 4998-5000. 

Fig. 4.2 TEM images of fabricated nanoparticles, (a) Isolated composite core/shell submicron particles, (b) Hollow silica submicron particles prepared by removing the polystyrene core to demonstrate the high quality of the formed sol gel shell of the composite nanospheres employed to prepare sensing colloidal crystal films...

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