BACKGROUND Silica nanoparticles have been discovered to exert cytotoxicity and induce apoptosis in normal human cells. However, until now, few studies have investigated the cytotoxicity of silica nanoparticles in tumor cells. METHODS This study investigated the cytotoxicity of 7-50 nm silica nanoparticles in human HepG2 hepatoma cells, using normal human L-02 hepatocytes as a control. Cell nu...

The study of ordered mesoporous silica materials has exploded since their discovery by Mobil researchers 20 years ago. The ability to make uniformly sized, porous, and dispersible nanoparticles using colloidal chemistry and evaporation-induced self-assembly has led to many applications of mesoporous silica nanoparticles (MSNPs) as "nanocarriers" for delivery of drugs and other cargos to cells. ...

A significantly soft and tough nanocomposite gel was realized by a novel network formed using cyclodextrin-based polyrotaxanes. Covalent bond formation between the cyclic components of polyrotaxanes and the surface of silica nanoparticles (15 nm diameter) resulted in an infinite network structure without direct bonds between the main chain polymer and the silica. Small-angle X-ray scattering re...

Enzyme-responsive, hybrid, magnetic silica nanoparticles have been employed for multifunctional applications in selective drug delivery and intracellular tumor imaging. In this study, doxorubicin (Dox)-conjugated, enzyme-cleavable peptide precursors were covalently tethered onto the surface of uniform silica-coated magnetic nanoparticles through click chemistry. This enzyme-responsive nanoparti...

Spatiotemporal control over the delivery of therapeutic agents is an outstanding challenge to cancer treatment. By taking advantage of recent advances in DNA aptamer biology and mesoporous silica nanotechnology, we report a general approach to design and fabricate controlled release drug delivery systems that are able to effectively target cancer cells. Specifically, polyvalent mesoporous silic...

We report a facile one-pot synthesis of hierarchically porous scaffolds, with independent control over nanoparticle mesoporosity and scaffold macroporosity. Our technique combines the chemistry of mesoporous silica nanoparticles with the control afforded by dynamic templating of surfactant mesophases. These materials are readily functionalizable and allow controllable spatial variation in macro...

In order to elucidate the nanoparticle-induced cytotoxicity and its mechanism, the effects of 20 and 50 nm silica nanoparticles on cultured human embryonic kidney (HEK293) cells were investigated. Cell viability, mitochondrial function, cell morphology, reactive oxygen species (ROS), glutathione (GSH), thiobarbituric acid reactive substance (TBARS), cell cycle and apoptosis were assessed under ...

We show that germania nanoparticle self-assembly in basic aqueous solutions occurs at a critical aggregation concentration (CAC) corresponding to a 1:1 GeO2/OH- molar ratio. A combination of pH, conductivity, and small-angle X-ray scattering (SAXS) measurements was used to monitor the effect of incremental additions of germanium (IV) ethoxide to basic solutions of sodium hydroxide or tetraalkyl...

The investigation of nanoparticle interactions with tissues is complex. High levels of standardization, ideally testing of different material types in the same biological model, and combinations of sensitive imaging and detection methods are required. Here, we present our studies on nanoparticle interactions with skin, skin cells, and biological media. Silica, titanium dioxide and silver partic...

Silica nanoparticle supported cationic lipids can effectively bind plasmid DNAs and transfect mammalian cells with an efficiency that depends on both the particle size and lipid composition; here the gene delivery and expression process has been confirmed by confocal fluorescence microscopy.