Nanosized mesoporous silica particles with high colloidal stability attract growing attention as drug delivery systems for targeted cancer treatment and as bioimaging devices. This Perspective describes recent breakthroughs in mesoporous silica nanoparticle design to demonstrate their high potential as multifunctional drug delivery nanocarriers. These types of nanoparticles can feature a well-defined and tunable porosity at the nanometer scale, high loading capacity, and multiple functionality for targeting and entering different types of cells. We focus on the requirements for an efficient stimuli-responsive and thus controllable release of cargo into cancer cells and discuss design principles for smart and autonomous nanocarrier systems. Mesoporous silica nanoparticles are viewed as a promising and flexible platform for numerous biomedical applications.

Multifunctional Mesoporous Silica Nanoparticles as a Universal Platform for Drug Delivery

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.

Predetermining the physico-chemical properties, biosafety, and stimuli-responsiveness of nanomaterials in biological environments is essential for safe and effective biomedical applications. At the forefront of biomedical research, mesoporous silica nanoparticles and mesoporous organosilica nanoparticles are increasingly investigated to predict their biological outcome by materials design. In this review, it is first chronicled that how the nanomaterial design of pure silica, partially hybridized organosilica, and fully hybridized organosilica (periodic mesoporous organosilicas) governs not only the physico-chemical properties but also the biosafety of the nanoparticles. The impact of the hybridization on the biocompatibility, protein corona, biodistribution, biodegradability, and clearance of the silica-based particles is described. Then, the influence of the surface engineering, the framework hybridization, as well as the morphology of the particles, on the ability to load and controllably deliver drugs under internal biological stimuli (e.g., pH, redox, enzymes) and external noninvasive stimuli (e.g., light, magnetic, ultrasound) are presented. To conclude, trends in the biomedical applications of silica and organosilica nanovectors are delineated, such as unconventional bioimaging techniques, large cargo delivery, combination therapy, gaseous molecule delivery, antimicrobial protection, and Alzheimer's disease therapy.

Mesoporous Silica and Organosilica Nanoparticles: Physical Chemistry, Biosafety, Delivery Strategies, and Biomedical Applications.

Poly(dopamine) has emerged in recent years as a readily accessible synthetic analogue of the naturally occurring melanins. However, the polymer's structure has proved difficult to unambiguously elucidate and a variety of models have been proposed. Despite these challenges, poly(dopamine) has found extraordinary utility in a range of applications including surface coatings, biotechnology and biomedicine, and water purification membranes. Most of these applications take advantage of the robust polymer films that deposit onto a wide range of surfaces, as well as its inertness to harsh chemical environments. In view of the expansion of interest in poly(dopamine), we provide perspective on this material, focusing on its history, chemical relationship to melanins, recent applications, and potential areas for future study.

Perspectives on poly(dopamine)

The therapeutic effect of reactive oxygen species (ROS)-involved cancer therapies is significantly limited by shortage of oxy-substrates, such as hypoxia in photodynamic therapy (PDT) and insufficient hydrogen peroxide (H2O2) in chemodynamic therapy (CDT). Here, we report a H2O2/O2 self-supplying nanoagent, (MSNs@CaO2-ICG)@LA, which consists of manganese silicate (MSN)-supported calcium peroxide (CaO2) and indocyanine green (ICG) with further surface modification of phase-change material lauric acid (LA). Under laser irradiation, ICG simultaneously generates singlet oxygen and emits heat to melt the LA. The exposed CaO2 reacts with water to produce O2 and H2O2 for hypoxia-relieved ICG-mediated PDT and H2O2-supplying MSN-based CDT, acting as an open source strategy for ROS production. Additionally, the MSNs-induced glutathione depletion protects ROS from scavenging, termed reduce expenditure. This open source and reduce expenditure strategy is effective in inhibiting tumor growth both in vitro and in vivo, and significantly improves ROS generation efficiency from multi-level for ROS-involved cancer therapies.

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An open source and reduce expenditure ROS generation strategy for chemodynamic/photodynamic synergistic therapy.

Mesoporous silica nanoparticles (MSNs) are experiencing rapid development in the biomedical field for imaging and for use in heterogeneous catalysis. Although the synthesis of MSNs with various morphologies and particle sizes has been reported, synthesis of a pore network with monodispersion control below 200 nm is still challenging. We achieved this goal using mild conditions. The reaction occurred at atmospheric pressure with a templating sol–gel technique using cetyltrimethylammonium (CTA+) as the templating surfactant and small organic amines (SOAs) as the mineralizing agent. Production of small pore sizes was performed for the first time, using pure and redispersible monodispersed porous nanophases with either stellate (ST) or raspberry-like (RB) channel morphologies. Tosylate (Tos–) counterions favored ST and bromide (Br–) RB morphologies at ultralow SOA concentrations. Both anions yielded a worm-like (WO) morphology at high SOA concentrations. A three-step formation mechanism based on self-assembly...

http://or.nsfc.gov.cn/bitstream/00001903-5/97758/1/1000007638737.pdf

Facile Large-Scale Synthesis of Monodisperse Mesoporous Silica Nanospheres with Tunable Pore Structure

Ultrastable MCM-48 silica with Ia3d cubic structure was synthesized by using only the surfactant cetyltrimethylammonium tosylate (CTATos) as template at extremely low surfactant concentration (CTATos/SiO2 = 0.068). Characterization by small-angle X-ray diffraction (XRD), nitrogen adsorption, and high-resolution transmission electron microscopy (HRTEM) clearly shows that the obtained MCM-48 silica has a highly ordered structure and large surface area (ca. 1281 m2/g) and pore volume (ca. 1.07 cm3/g). The regular cubic arrays were well retained even after this material was calcined at a high temperature of 900 °C for 3 h or heated at reflux in boiling water for 12 h. The Fourier transform infrared (FTIR) spectrum, thermogravimetric analysis (TG), and chemical analysis provide strong evidence that the formation of MCM-48 is attributed to the retention of tosylate (Tos–) counteranions of the surfactant in the interface between surfactant and silicate. The current synthetic strategy is suitable for routine and large-scale preparations of mesoporous silica with different topological structures.

Preparation of High‐Quality MCM‐48 Mesoporous Silica and the Mode of Action of the Template

Preparation method for mordenite with high Si/Al ratio and small crystal particle

Method for preparing mordenite molecular sieve

The invention relates to a method for synthesizing a mobil composition of matters-41(MCM-41) mesoporous molecular sieve. The method comprises the following steps of: dissolving SiO2 filter cakes obtained by recovering MCM-48 synthetic mother liquor in an alkali solution, and stirring at constant temperature of 60 DEG C for 1 hour; dripping the solution into an aqueous solution containing a surfactant, stirring at the constant temperature of 60 DEG C for 2 hours, cooling to the room temperature, transferring the mixture to a closed reactor, and crystallizing at the temperature of between 80 and 130 DEG C for 15 to 24 hours; and filtering, washing and drying a crystallized product to obtain the MCM-41 mesoporous molecular sieve, wherein a molar ratio of SiO2 to cetyltrimethylammonium tosylate (CTATos) to NaOH or KOH to H2O in the MCM-41 mesoporous molecular sieve is 1:(0.015-0.06):(0.15-0.35):(40-200). Compared with the prior art, the method has the obvious advantages that: a silicon source which is left in the synthetic mother liquor of a mesoporous material can be recycled, the using amount of the surfactant is low, the utilization rate of the silicon source is high, and the quality and purity of products are high; and in addition, and the method is short in synthetic period, low in cost and high in repeatability, the products are easy to synthesize on a large scale, so the method is an environment-friendly synthetic process.

Xu Langlang

Papers

Facile Large-Scale Synthesis of Monodisperse Mesoporous Silica Nanospheres with Tunable Pore Structure

Preparation of High‐Quality MCM‐48 Mesoporous Silica and the Mode of Action of the Template

Preparation method for mordenite with high Si/Al ratio and small crystal particle

Method for preparing mordenite molecular sieve

Method for synthesizing mobil composition of matters-41(MCM-41) mesoporous molecular sieve