Effect of Surface Functionalization and Pore Structure Type on the Release Performance of Mesoporous Silica Nanoparticles

Abstract

Based on the excellent physicochemical properties of mesoporous silica nanoparticles (MSN), the application of MSN in drug delivery has become a popular strategy. However, a wide variety of MSN structures and surface modification affect the drug loading and release, thus affecting the effectiveness of drug delivery system. Therefore, the effects of MSN type, pore structure and modified functional groups on drug release properties were investigated in this paper. A series of MSN was synthesized by sol-gel method, and the mesopore type and pore size were adjusted. Their surfaces were modified by amino groups (NH 2 ) and polydopamine (PDA) to change the surface charge. Anticancer Doxorubicin (DOX) was used as a model drug to study effects of different types of MSN on drug loading and release. MSN with hollow structure had a large inner cavity for DOX loading and tiny pore shell to prevent DOX loss, leading to higher loading capacity. MSN with surface-modified amine was positively charged and processed good pH responsiveness and accelerated DOX release. Thus hexagonal pore MSN-NH 2 and MSN-PDA were the anticancer DOX delivery carriers with better combined release performance in terms of pH-responsive performance and sustained release effect. Finally, several kinetic models were measured to fit the in vitro DOX release data and the results showed that release behaviors of different MSNs were more consistent with Korsmeyer-Peppas release kinetic model. All of them were Fick diffusion-controlled except for the second release stage of hollow MSN at pH 7.4, which was non-Fick diffusion release. • A series of MSNs with diverse structures and modification were studied. • Specific surface area, pore volume/type and surface charge affected drug loading. • Diverse kinetic models were employed to investigate mechanism of drug release. • MSNs with modification were drug delivery systems with better release performance.