Multifunctional, CD44v6-Targeted ORMOSIL Nanoparticles Enhance Drugs Toxicity in Cancer Cells

Drug-loaded, PEGylated, organic-modified silica (ORMOSIL) nanoparticles prepared by microemulsion condensation of vinyltriethoxysilane (VTES) were investigated as potential nanovectors for cancer therapy. To target cancer stem cells, anti-CD44v6 antibody and hyaluronic acid (HA) were conjugated to amine-functionalized PEGylated ORMOSIL nanoparticles through thiol-maleimide and amide coupling chemistries, respectively. Specific binding and uptake of conjugated nanoparticles were studied on cells overexpressing the CD44v6 receptor. Cytotoxicity was subsequently evaluated in the same cells after the uptake of the nanoparticles. Internalization of nanocarriers loaded with the anticancer drug 3N-cyclopropylmethyl-7-phenyl-pyrrolo- quinolinone (MG2477) into cells resulted in a substantial increase of the cytotoxicity with respect to the free formulation. Targeting with anti-CD44v6 antibodies or HA yielded nanoparticles with similar effectiveness, in their optimized formulation.

Gold Nanoparticle-Enhanced Photodynamic Therapy from Photosensitiser-Entrapped Ormosil Nanoparticles

Herein, we investigate the effect of the surface attachment of gold nanoparticles (AuNPs) on photosensitiser-entrapped organically modified silica (ormosil) nanoparticles for enhanced photodynamic therapy (PDT). Photosensitiser methylene blue (MB)-entrapped ormosil nanoparticles of three different diameters (30/55/80 nm) were synthesised, and AuNPs were attached to their surface. Subsequent light irradiation with a 630 nm laser resulted in the production of singlet oxygen (1O2), with different amounts depending on the diameter of the ormosil nanoparticle. Enhancement in 1O2 production was observed upon the AuNP attachment on the ormosil surface. In vitro studies in pancreatic cancer (Panc-1) cells have demonstrated that cellular uptake and photodynamic cytotoxicity are also dependent on the size of ormosil nanoparticles and AuNP attachment. These studies pave the way for designing ormosil nanoparticles with suitable size and surface attachment for PDT applications.

Endosomal/lysosomal location of organically modified silica nanoparticles following caveolae-mediated endocytosis

Organically modified silica (ORMOSIL) nanoparticles (NPs) are widely used in biomedicine.

Preparation of ORMOSIL nanoparticles conjugated with vitamin D3analogues and their biological evaluation

Dye-doped multifunctional organically modified silica (ORMOSIL) nanoparticles were prepared within surfactant stabilized microemulsions and conjugated with several vitamin D3derivatives.

Development of organically modified silica nanoparticles for monitoring the intracellular level of oxygen using a frequency-domain FLIM platform

The dynamic quenching of luminescence derived from Ru(dpp3)2+-doped ORMOSIL nanoparticles is used for monitoring of the intracellular oxygen concentration.

Ormosil nanoparticles as a sustained-release drug delivery vehicle

Tem images (above) and release profiles (below) of encapsulated drug from ormosil nanoparticles with small (orm-s), medium (orm-m) and large (orm-l) sizes.