Biomimetic coat enables the use of sonoporation to assist delivery of silica nanoparticle-cargoes into human cells

Due to their biocompatibility and high adsorption properties, mesoporous silica nanoparticles (MSN) represent one of the most promising systems for drug delivery. Previous investigations have shown that both surface functionalization and external stimuli may act in a synergistic way to deliver drugs from nanoparticles. One such stimulus is underwater shock wave-induced sonoporation, a physical method known to transiently permeabilize cell membranes. However, there are some concerns regarding the feasibility to apply shock waves in the presence of dense nanoparticles. In this work, bioinspired supramolecular MSN were prepared by self-assembly of cationic liposomes with 200nm MCM-41 type silica nanoparticles. The effects of the biomimetic coat on cargo stability, adherence to HEK-293 cells, and shock wave-mediated delivery of plasmid deoxyribonucleic acid were addressed. Compared to bare MSN, structures displaying a lipid coat showed higher cargo retention. Adherence to cell surface was only achieved with a cationic lipid surface, which was related to higher efficient delivery of MSN cargoes, including the release of a green fluorescent protein-codifying transgene. Unexpectedly, MSN covered with a biomimetic coat were found to protect cells from the exacerbated mortality observed after exposure of cells to shock waves in the presence of bare MSN. Further research will be required to understand the mechanisms involved in this combined strategy, which paves the way for the exploration of dense nanoparticles in the field of shock wave-mediated drug delivery. (C) 2016 American Vacuum Society.