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

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