Preparation of ORMOSIL nanoparticles conjugated with vitamin D3 analogues and their biological evaluation

Abstract

Dye-doped, 90 nm diameter, multifunctional organically modified silica (ORMOSIL) nanoparticles were prepared by condensation of vinyltriethoxysilane within surfactant-stabilized microemulsions and conjugated with several vitamin D₃ derivatives. For this, vitamin D analogues possessing at least one hydroxyl group derivatized as vinylcarbonate have been synthesized. These analogues were conjugated to ORMOSIL nanoparticles through the carbonate function, forming carbamate derivatives of vitamin D nanoparticles. The interaction between these nanoparticles and human serum albumin, which is one of the serum transporters of the insoluble vitamin D₃, was investigated by surface plasmon resonance. The results obtained revealed that this approach allows obtaining water-soluble vitamin D₃ derivatives, which maintain their full protein binding ability.