Controlling mesoporous silica-coating of layered double hydroxide nanoparticles for drug control release

Layered double hydroxide (LDH) nanoparticles (NPs) have found various potential applications in control delivery of therapeutics, including many negatively charged drugs, oligonucleotides, genes, and peptides/proteins. The current study specifically investigated the surface coating with mesoporous silica (mSiO(2)) to make an LDH@mSiO(2) core/shell structure and precisely control the release of the payload. Mg2Al-LDH NPs were coated with mSiO(2) by varying the reagent concentration and the chain length of cationic surfactants in order to tailor the thickness and the pore size of the mSiO(2) shell. TEM images and FIIR spectra evidenced the successful mSiO(2) coating onto the surface of LDH NPs. Within the tested conditions, the thickness of the mSiO(2) shell can be tailored from 5 to 20 nm and the pore size from 1.9 to 33 nm. We further demonstrated that the exchanging property of Mg2Al-Cl-LDH NPs, combined with the diffusion control of the mSiO(2) shell, resulted in an effective controlled release of the payload. Thus we have established a foundation for the development of a multifunctional smart delivery platform. (C) 2016 Elsevier Inc. All rights reserved.