Sepideh Taghavi - Department of Pharmaceutical Engineering, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran
Mostafa Shahnani - Department of Pharmaceutical Engineering, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran
Hasan Rafati - Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran

Objective(s): Controlled drug delivery using nanotechnology enhances drug targeting at the site of interest and prevents drug dispersal throughout the body. This study focused on loading a poorly water-soluble drug Tamoxifen (TMX) into silica nanoparticles (SNPs) and amine-functionalized mesoporous silica nanoparticles (NH۲-SBA-۱۵). Materials and Methods: SNPs were prepared according to the Stöber method and functionalized with an amine group using ۳-aminopropyl triethoxysilane (APTES) through a one-pot synthesis method to produce amine-functionalized mesoporous silica nanoparticles (NH۲-SBA-۱۵). Characterization of both nanoparticles was performed using FT-IR, FE-SEM, CHN analysis, porosity tests (BET), and dynamic light scattering (DLS). Results: The results showed an average particle size of ۱۰۳.۷ nm for SNPs and ۲۲۵.۹ nm for NH۲-SBA-۱۵. Based on the BET results, the pore size of NH۲-SBA-۱۵ was about ۵.۴ nm. In both silica nanoparticles, drug release at pH=۵.۷ was greater than that of pH=۷.۴. However, Tamoxifen-loaded NH۲-SBA-۱۵ (TMX@NH۲-SBA-۱۵) indicated the highest drug release in the acidic medium among TMX-loaded SNPs (TMX@SNPs), perhaps due to the high columbic repulsion in the functionalized NH۲-SBA-۱۵ nanoparticles. Regarding cytotoxicity results against MCF-۷ breast cancer cell lines, both TMX@SNPs and TMX@NH۲-SBA-۱۵ nanoparticles exhibited greater cytotoxicity compared to the free TMX as a positive control. Although TMX@SNPs had a small size and high loading capacity, the cytotoxic effects were higher than those of TMX@NH۲-SBA-۱۵.Conclusion: Amine functionalization of SNPs can improve the potential activity of these nanoparticles for target therapy.

Amine-functionalized mesoporous silica nanoparticles (NH۲-SBA-۱۵), Breast Cancer, Drug Delivery, MCF-۷ cells, Silica Nanoparticles, Tamoxifen