Recent advancements in drug delivery technologies utilizing a variety of carriers have resulted in a path-breaking revolution in the approach towards diagnosis and therapy alike in the current times. Need for materials with high thermal, chemical and mechanical properties have led to the development of mesoporous silica nanoparticles (MSNs). These ordered porous materials have garnered immense attention as drug carriers owing to their distinctive features over the others. They can be synthesized using a relatively simple process, thus making it cost effective. Moreover, by controlling the parameters during the synthesis; the morphology, pore size and volume and particle size can be transformed accordingly. Over the last few years, a rapid increase in research on MSNs as drug carriers for the treatment of various diseases has been observed indicating its potential benefits in drug delivery. Their widespread application for the loading of small molecules as well as macromolecules such as proteins, siRNA and so forth, has made it a versatile carrier. In the recent times, researchers have sorted to several modifications in the framework of MSNs to explore its potential in drug resistant chemotherapy, antimicrobial therapy. In this review, we have discussed the synthesis of these multitalented nanoparticles and the factors influencing the size and morphology of this wonder carrier. The second part of this review emphasizes on the applications and the advances made in the MSNs to broaden the spectrum of its use especially in the field of biomedicine. We have also touched upon the lacunae in the thorough understanding of its interaction with a biological system which poses a major hurdle in the passage of this carrier to the clinical level. In the final part of this review, we have discussed some of the major patents filed in the field of MSNs for therapeutic purpose.

https://www.mdpi.com/1999-4923/10/3/118/pdf/1

Mesoporous Silica Nanoparticles: A Comprehensive Review on Synthesis and Recent Advances

The integration of reactive oxygen species (ROS)-involved photodynamic therapy (PDT) and chemodynamic therapy (CDT) holds great promise for enhanced anticancer effects. Herein, we report biodegradable cancer cell membrane-coated mesoporous copper/manganese silicate nanospheres (mCMSNs) with homotypic targeting ability to the cancer cell lines and enhanced ROS generation through singlet oxygen (1O2) production and glutathione (GSH)-activated Fenton reaction, showing excellent CDT/PDT synergistic therapeutic effects. We demonstrate that mCMSNs are able to relieve the tumor hypoxia microenvironment by catalytic decomposition of endogenous H2O2 to O2 and further react with O2 to produce toxic 1O2 with a 635 nm laser irradiation. GSH-triggered mCMSNs biodegradation can simultaneously generate Fenton-like Cu+ and Mn2+ ions and deplete GSH for efficient hydroxyl radical (•OH) production. The specific recognition and homotypic targeting ability to the cancer cells were also revealed. Notably, relieving hypoxia an...

Biodegradable Biomimic Copper/Manganese Silicate Nanospheres for Chemodynamic/Photodynamic Synergistic Therapy with Simultaneous Glutathione Depletion and Hypoxia Relief.

Mesoporous silica materials: From physico-chemical properties to enhanced dissolution of poorly water-soluble drugs

Morphology-controlled nanomaterials such as silica play a crucial role in the development of technologies for addressing challenges in the fields of energy, environment, and health. After the discovery of Stober silica, followed by that of mesoporous silica materials, such as MCM-41 and SBA-15, a significant surge in the design and synthesis of nanosilica with various sizes, shapes, morphologies, and textural properties has been observed in recent years. One notable invention is dendritic fibrous nanosilica, also known as KCC-1. This material possesses a unique fibrous morphology, unlike the tubular porous structure of various conventional silica materials. It has a high surface area with improved accessibility to the internal surface, tunable pore size and pore volume, controllable particle size, and, importantly, improved stability. Since its discovery, a large number of studies have been reported concerning its use in applications such as catalysis, solar-energy harvesting, energy storage, self-cleaning antireflective coatings, surface plasmon resonance-based ultrasensitive sensors, CO2 capture, and biomedical applications. These reports indicate that dendritic fibrous nanosilica has excellent potential as an alternative to popular silica materials such as MCM-41, SBA-15, Stober silica, and mesoporous silica nanoparticles. This Review provides a critical survey of the dendritic fibrous nanosilica family of materials, and the discussion includes the synthesis and formation mechanism, applications in catalysis and photocatalysis, applications in energy harvesting and storage, applications in magnetic and composite materials, applications in CO2 mitigation, biomedical applications, and analytical applications.

Dendritic Fibrous Nanosilica for Catalysis, Energy Harvesting, Carbon Dioxide Mitigation, Drug Delivery, and Sensing

Recently, metal nanoclusters (MNCs) emerged as a new class of luminescent materials and have attracted tremendous interest in the area of luminescence-related applications due to their excellent luminous properties (good photostability, large Stokes shift) and inherent good biocompatibility. However, the origin of photoluminescence (PL) of MNCs is still not fully understood, which has limited their practical application. In this mini-review, focusing on the origin of the photoemission emission of MNCs, we simply review the evolution of luminescent mechanism models of MNCs, from the pure metal-centered quantum confinement mechanics to ligand-centered p band intermediate state (PBIS) model via a transitional ligand-to-metal charge transfer (LMCT or LMMCT) mechanism as a compromise model.

https://www.mdpi.com/2079-4991/10/2/261/pdf

Origin of the Photoluminescence of Metal Nanoclusters: From Metal-Centered Emission to Ligand-Centered Emission

The synthesis of highly uniform mesoporous silica nanospheres (MSNs) with dendritic pore channels, particularly ones with particle sizes below 200 nm, is extremely difficult and remains a grand challenge. By a combined synthetic strategy using imidazolium ionic liquids (ILs) with different alkyl lengths as cosurfactants and Pluronic F127 nonionic surfactants as inhibitors of particle growth, the preparation of dendritic MSNs with controlled diameter between 40 and 300 nm was successfully realized. An investigation of dendritic MSNs using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen physisorption revealed that the synthesis of dendritic MSNs at larger size (100–300 nm) strongly depends on the alkyl lengths of cationic imidazolium ILs; while the average size of dendritic MSNs can be controlled within the range of 40–100 nm by varying the amount of Pluronic F127. The Au@MSNs can be used as a catalyst for the reduction of 4-nitrophenol by NaBH4 into 4-aminophenol an...

Facile synthesis of size controllable dendritic mesoporous silica nanoparticles.

The invention discloses a method for synthesizing mesoporous silicon dioxide nanoparticles by using an alkali-free method. According to the method, the mesoporous silicon dioxide nanoparticles are synthesized in the presence or absence of a hetero-metal atomic compound under the condition of not additionally introducing an alkali source by using a cationic surfactant as a template agent, using dicarboxylate with different carbon chains as a cosurfactant, using tetra-alkyl silicate as a silicon source and using deionized water as a water source, wherein the mole composition ratio of the silicon source to the cationic surfactant to dicarboxylate with different carbon chains to water to the hetero-metal atomic compound is 1: (0.003-0.3): (0.001-0.2): (40-200): (0-0.1). Compared with the prior art, the method has the most remarkable advantages that synthesis is carried out under the condition that the pH value of a reaction system is close to neutral, additional inorganic and organic alkali sources which cause relatively high pollution to environment are not used, and the synthesis method is simple and is short in cycle, low in cost, good in repeatability and easy in large-scale production, thereby being an environment-friendly synthesis strategy.

Jun-Ling Pang

Papers

Facile synthesis of size controllable dendritic mesoporous silica nanoparticles.

Method for synthesizing mesoporous silicon dioxide nanoparticles by using alkali-free method

Genome-wide association study and metabolic pathway prediction of barrenness in maize as a response to high planting density

One-pot pseudomorphic crystallization of mesoporous porous silica to hierarchical porous zeolites