UCLA

This thesis involves synthesis, derivatization and biomedical applications of mesoporous silica nanopartilces (MSNs) and Fe3O4@SiO2 core/shell nanoparticles. Chapter 1 introduces the development of MSNs including the mesopores formation mechanism, synthesis conditions and their capability to act as stimuli responsive drug delivery platforms. In chapter 2, the synthesis optimization of different kinds of particles and their surface derivatization are introduced. Chapter 3 & 4 give specific examples of successful optimization and in vitro and in vivo application of MSNs enabled with pH-sensitive nanovalves and disulfide snap-tops for delivering the antibiotic moxifloxacin. It is shown that a high release capacity is necessary to reach a high efficacy ratio, compared with free drug. Chapter 5 discusses the uptake and release capacities of Fe3O4@SiO2 core/shell nanoparticles when modified with a pH-sensitive nanovalves, and its thermally cargo release behavior when surrounding temperature increases or an oscillating magnetic field is applied. In Chapter 6, successful distribution of Fe3O4@SiO2 core/shell nanoparticles in biofilms and on-command release of cargo inside biofilms are shown. Overall, these chapters demonstrate the ability of modifying both the outer surface and interior of MSNs, and their capability to act as a biocompatible controlled release platform that is more effective than equivalent amount of free drug.