Controlled drug release systems based on mesoporous silica capped by gold nanoparticles

Abstract

Nanotechnology, with many advantages to engineer new organized nanomaterials, has attracted much attention in recent decades. Smart drug delivery and controlled release system can enhance the effectiveness of chemotherapy at diseased body parts and reduce its side effects of drugs on normal tissues and cells. With high rigidity and surface area, tailored mesoporous structure, and good biocompatibility, mesoporous silica nanoparticles (MSNs) have been proven to be excellent nanocarriers and delivery vehicle. In the mean time, gold nanoparticles (AuNPs) possess a number of advantages of gold-based nanomaterials that make them appealing for controlled drug delivery applications. The novel nanovalve systems based on MSNs (acting as nanocontainers or reservoirs)-AuNPs (acting as gates or switches), combining the good characteristics of the two kinds of nanoparticles in one system, has captured research interests in the fields of chemistry, biomaterials, nanoscience and clinical medicine. This review article introduces important research progress on the single and multiple functions of controllable drug release systems based on MSN-AuNPs hybrids, which will be illustrated from stimulus and applications points of view. In the section of single responsive systems, we introduce the adaptability and responsiveness of the hybrid systems to external environmental stimuli, such as light (UV and NIR), pH, competitive binding, aptamers, and biological signals. In the section of multiple responsive systems, we focus on the design principle and release effect of dual responsive systems and reversible systems. In addition, the challenges and development direction of this type of nanovalve-based drug delivery systems are systematically discussed. Although the nanogate systems based on MSNs capped by AuNPs, employing many different functions, have made tremendous progress in recent years, collaborations between chemists, material scientists, engineers and medical doctors are in urgent need to further advance this research field and realize their final practical applications in the near future.