Mesoporous organic-inorganic hybrid materials, a new class of materials characterized by large specific surface areas and pore sizes between 2 and 15 nm, have been obtained through the coupling of inorganic and organic components by template synthesis. The incorporation of functionalities can be achieved in three ways: by subsequent attachment of organic components onto a pure silica matrix (grafting), by simultaneous reaction of condensable inorganic silica species and silylated organic compounds (co-condensation, one-pot synthesis), and by the use of bissilylated organic precursors that lead to periodic mesoporous organosilicas (PMOs). This Review gives an overview of the preparation, properties, and potential applications of these materials in the areas of catalysis, sorption, chromatography, and the construction of systems for controlled release of active compounds, as well as molecular switches, with the main focus being on PMOs.

Silica-based mesoporous organic-inorganic hybrid materials.

Mesoporous silica nanoparticles as controlled release drug delivery and gene transfection carriers

In the past decade, mesoporous silica nanoparticles (MSNs) have attracted more and more attention for their potential biomedical applications. With their tailored mesoporous structure and high surface area, MSNs as drug delivery systems (DDSs) show significant advantages over traditional drug nanocarriers. In this review, we overview the recent progress in the synthesis of MSNs for drug delivery applications. First, we provide an overview of synthesis strategies for fabricating ordered MSNs and hollow/rattle-type MSNs. Then, the in vitro and in vivo biocompatibility and biotranslocation of MSNs are discussed in relation to their chemophysical properties including particle size, surface properties, shape, and structure. The review also highlights the significant achievements in drug delivery using mesoporous silica nanoparticles and their multifunctional counterparts as drug carriers. In particular, the biological barriers for nano-based targeted cancer therapy and MSN-based targeting strategies are discussed. We conclude with our personal perspectives on the directions in which future work in this field might be focused.

Mesoporous Silica Nanoparticles: Synthesis, Biocompatibility and Drug Delivery

Recent advancements in morphology control and surface functionalization of mesoporous silica nanoparticles (MSNs) have enhanced the biocompatibility of these materials with high surface areas and pore volumes. Several recent reports have demonstrated that the MSNs can be efficiently internalized by animal and plant cells. The functionalization of MSNs with organic moieties or other nanostructures brings controlled release and molecular recognition capabilities to these mesoporous materials for drug/gene delivery and sensing applications, respectively. Herein, we review recent research progress on the design of functional MSN materials with various mechanisms of controlled release, along with the ability to achieve zero release in the absence of stimuli, and the introduction of new characteristics to enable the use of nonselective molecules as screens for the construction of highly selective sensor systems.

Mesoporous silica nanoparticles for drug delivery and biosensing applications

Silicate mesoporous materials have received widespread interest because of their potential applications as supports for catalysis, separation, selective adsorption, novel functional materials, and use as hosts to confine guest molecules, due to their extremely high surface areas combined with large and uniform pore sizes. Over time a constant demand has developed for larger pores with well-defined pore structures. Silicate materials, with well-defined pore sizes of about 2.0–10.0 nm, surpass the pore-size constraint ( 700 m2 g−1) and narrow pore size distributions. Instead of using small organic molecules as templating compounds, as in the case of zeolites, long chain surfactant molecules were employed as the structure-directing agent during the synthesis of these highly ordered materials. The structure, composition, and pore size of these materials can be tailored during synthesis by variation of the reactant stoichiometry, the nature of the surfactant molecule, the auxiliary chemicals, the reaction conditions, or by post-synthesis functionalization techniques. This review focuses mainly on a concise overview of silicate mesoporous materials together with their applications. Perusal of the review will enable researchers to obtain succinct information about microporous and mesoporous materials.

https://www.mdpi.com/1996-1944/5/12/2874/pdf

A Review: Fundamental Aspects of Silicate Mesoporous Materials

A series of new mesoporous silica materials with MCM-41 type of structure containing a homogeneous layer of organic functional groups inside the pores was prepared using a co-condensation method under low surfactant concentration condition. This reproducible synthetic approach resulted in high surface coverage with several functional groups such as a primary amine, secondary amine, urea, isocyanate, vinyl, and nitrile. In addition, the presence of organoalkoxysilane precursors during the base catalyzed condensation greatly influenced the final particle shape. By changing the precursor or its concentration, the particle morphology was tuned to various shapes, including spheres, tubes, and rods of various dimensions. The synthetic procedures that gave rise to the specific particle morphologies were investigated and the mechanism responsible for shape control was postulated. The structure and functionality of these materials were characterized by field-emission scanning electron microscopy, transmission elec...

and Marek Pruski

Papers

Organic Functionalization and Morphology Control of Mesoporous Silicas via a Co-Condensation Synthesis Method