Fabrication of mesoporous silica nanoparticle to target mitochondria

Abstract

Over the past decade, mesoporous silica nanoparticles (MSNPs) have been gaining much attention in many applications such as for therapeutic drug delivery systems. However, not much research has been done to target subcellular organelles. Mitochondria are known as the powerhouse of cancer cells, thus it will be a target site for drug delivery systems. In this experiment, (4-carboxybutyl) triphenyl-phosphorium bromide (PPH3-COOH) was used as the targeting ligand. It was then attached to the surface of MSNPs, to target the mitochondria. In this report, more information will be given on the ways whereby MSNPs can be used to target the mitochondria. Firstly, MSNPs with average diameter of 80 nm was synthesized and characterized with the use of a Transmission Electron Microscope (TEM) and a Scanning Electron Microscope (SEM). MSNPs were then mixed with PPH3-COOH ligands,1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-Hydroxysuccinimide (NHS) to activate the targeting group. Next, Infrared Spectroscopy was used to test for the functionalization of the targeting ligand. Two types of MSNPs were made – one whereby Fluorescein (FITC) was functionalized, and one which did not have FITC. FITC is a fluorescent molecule that can be observed under the confocal laser scanning microscope (CLSM). The presence of fluorescence will indicate that the MSNPs had been successfully incorporated by HeLa cells. The mitochondria targeting effect was demonstrated using confocal study. Mitochondria isolation was then performed to further confirm the presence of MSNPs in the mitochondria. Lastly, to test for the absence of cytotoxicity of MSNPs nanoparticles, MTT assay was carried out on the MSNPs. Positive results obtained further proved the many advantages of MSNPs particles in targeting the mitochondria.