Synthesis, structural properties, biosafety and applications of chiral mesoporous silica nanostructures

Chiral mesoporous silica nanoparticles (CMSNs) are important members of mesoporous silica nanoparticles (MSNs) family. They not only exhibit prominent physicochemical properties as MSNs, being effective and tunable for drug loading and releasing, but also have specific functions and unique biological behavior advantages due to the presence of helical architectures at both the molecular and macroscopic scale. Accordingly, CMSNs show extensive and promising applications in several fields (e.g., chiral catalysis, chiral selectivity, chiral recognition, separation and drug delivery). Moreover, they have turned out to be a hotspot in medical research. For the past two decades, considerable studies on CMSNs have been conducted, and synthesis, chirality origination mechanisms, structural properties, as well as practical applications have been substantially progressed. In the present study, the experimental and theoretical studies on synthesizing strategies and chirality origination mechanisms of CMSNs are summarized and assessed, especially the synthesizing methods and mechanisms of surfactants as templates. Furthermore, the typical applications of CMSNs, especially in drug delivery system are elaborated. In view of the in vivo utilization of CMSNs, we also evaluate the biosafety of CMSNs. Thus, this study also discusses the research status, development prospects and future challenges of CMSNs. Undoubtedly, CMSNs with unique functionalities are capable of facilitating the application of nanoporous silica and presenting novel insights into the development of pharmaceutical science and other relevant fields.