Mesoporous Silica Nanoparticle Materials Research Articles

Facile Hydrothermal Assisted Basic Catalyzed Sol Gel Synthesis for Mesoporous Silica Nanoparticle from Alkali Silicate Solutions Using Dual Structural Templates.

This work presents a novel hydrothermally aided sol-gel method for preparation of mesoporous silica nanoparticles (MSNs) with a narrow particle size distribution and varied pore sizes. The method was carried out in alkaline media in presence of polyethylene glycol (PEG) and cetyltrimethylammonium chloride (CTAC) as dual templates and permitted the synthesis of spherical mesoporous silica with a high surface area (1011.42 m2/g). The MSN materials were characterized by FTIR, Thermogravimetric (TG), Nitrogen adsorption and desorption and Field emission scanning electron microscopic analysis (FESEM). The materials feasibility as solid phase adsorbent has been demonstrated using cationic dyes; Rhodamine B (RB) and methylene blue (MB) as models. Due to the large surface area and variable pore width, the adsorption behaviors toward cationic dyes showed outstanding removal efficiency and a rapid sorption rate. The adsorption isotherms of RB and MB were well-fitted to the Langmuir and Freundlich models, while the kinetic behaviours adhered closely to the pseudo-second-order pattern. The maximum adsorption capacities were determined to be 256 mg/g for MB and 110.3 mg/g for RB. The findings suggest that MSNs hold significant potential as solid-phase nanosorbents for the extraction and purification of dye pollutants, particularly in the analysis and treatment of effluents containing cationic dyes.

Turn Hood into Good: Recycling Silicon from Mesoporous Silica Nanoparticles through Magnesium Modification to Lower Toxicity and Promote Tissue Regeneration.

Mesoporous silica nanoparticles (MSNs) have gained wide application as excellent carrier materials; however, their limited degradation in the biological system and potential chronic toxicity pose challenges to their clinical applications. Previous studies have focused on optimizing the elimination performance of MSNs; interestingly, silicon has been well-documented as an essential body component. Therefore, converting MSNs into a form readily utilizable by the organism is a way to turn waste into a valuable resource. However, the recycling and utilization of MSNs are associated with significant hurdles. This study proposes an approach to impede the formation of siloxane, the crucial core in MSNs, by introducing a gradient concentration of Mg2+. The invasion of Mg2+ significantly reduces the stability of Si-O-Si bonds by substituting silicon ions while preserving the functional three-dimensional structure. Recycling the increased release of Mg and Si ions enhances cellular antioxidant capacity, reduces oxidative stress reactions, improves mitochondrial function, and regulates macrophage inflammatory states. The proposed approach to converting MSN materials shows significant advantages for tissue regeneration in the periodontal defect model. This study opens an insight for applying MSNs in clinical applications in regenerative medicine.

Mesoporous Silica Nanoparticles-Based Nanoplatforms: Basic Construction, Current State, and Emerging Applications in Anticancer Therapeutics.

In recent years, researchers are developing novel nanoparticles for diagnostic applications using imaging techniques and for therapeutic purposes through drug delivery techniques. The unique physical and chemical properties of mesoporous silica nanoparticles (MSNs) make it possible to integrate a variety of commonly used therapeutic and imaging agents to construct a multimodal synergistic anticancer drug delivery system. Herein, recent advances in MSNs synthesis for drug delivery and smart response applications are reviewed. First, synthetic strategies for the fabrication of ordered MSNs, hollow MSNs, core-shell structured MSNs, dendritic MSNs, and biodegradable MSNs are outlined. Then, the recent research progress in designing functional MSN materials with various controlled release mechanisms in anticancer therapy is discussed, and new properties are introduced to suggest the latest design requirements as drug delivery materials. The review also highlights significant achievements in bioimaging using MSNs and their multifunctional counterparts as delivery vehicles. Finally, personal views on key directions for future work in this area are presented.

Encapsulation of Volatile Monoterpene Fragrances in Mesoporous Organosilica Nanoparticles and Potential Application in Fruit Preservation.

In this work, we synthesized mesoporous silica nanoparticles (MSNs) and periodic mesoporous organosilica nanoparticles containing bridging groups of ethylene (E-PMO) and phenylene (P-PMO) and compared their adsorption properties using D-limonene (Lim), myrcene (Myr), and cymene (Cym) as model guest molecules. For the selected nanoparticles of ~100 nm in diameter, the loading capacity to the volatile fragrances was in the order of P-PMO < E-PMO < MSN, consistent with the trend of increasing total pore volume. For example, P-PMO, E-PMO, and MSN had a Lim uptake of 42.2 wt%, 47.3 wt%, and 62.7 wt%, respectively, which was close to their theoretical adsorption capacity. Under isothermal thermogravimetric analysis conditions (30 °C, a N2 flow of 1 mL min−1), the lowest fragrance release of ~56% over 24 h was observed for P-PMO, followed by E-PMO (74−80%), and MSN (~89%). The release kinetics of the fragrant molecules from MSN and PMO materials can be well described by first-order and Weibull models, respectively. Moreover, the incorporation of Lim-loaded P-PMO NPs in an aqueous solution of regenerated silk fibroin provided a composite coating material suitable for perishable fruit preservation. The active layer deposited on fruit peels using dip coating showed good preservation efficacy, enabling the shelf-life of mangoes in a highly humid and hot atmosphere (30−35 °C, 75−85% RH) to be extended to 6 days.

Study of cancer cell cytotoxicity, internalization and modulation of growth factors induced by transferrin-conjugated formulations of metallodrug-functionalized mesoporous silica nanoparticles

Nano-sized materials have shown to have very high potential in anticancer therapy by an adequate tuning of their functionalization and physico-chemical properties. This study is focused on the synthesis and characterization of mesoporous silica nanoparticles (MSN) functionalized with a titanium(IV) or an organotin(IV) compound (therapeutic agents), fluorescein isothiocyanate (image agent) and transferrin (targeting molecule). The analysis of the biological activity of the metallodrug-functionalized systems with and without transferrin has been evaluated and the cell internalization with respect to the presence of the protein has been assessed. The biological results show, as expected, that Sn-based materials are more active than the Ti-based systems with some of the tin-functionalized nanoparticles being almost 50 times more active than carboplatin. In contrast, the cellular uptake seems to be higher in Ti-based materials, which take advantage of the stronger interaction with transferrin to internalize the cells with more effectivity. Finally, a study of vascular endothelial growth factor A (VEGF-A), human fibroblast growth factor 2 (FGF-2) and nuclear factor κβ transcription factor (NF-κβ) show that, specially the Sn-based MSNs, were able to modulate these factors in A2780 cells showing anti-angiogenic effects through VEGF-A and FGF-2, probably due to interaction of the materials with transferrin. • MSN have been functionalized with Sn or Ti metallodrugs and FITC and formulated with transferrin. • Transferrin assists in the internalization of all the functionalized mesoporous nanoparticles. • Transferrin does not increase the cytotoxicity of the functionalized mesoporous systems. • Transferrin-functionalized MSN materials modulate and downregulate growth and transcription factors.

Mesoporous Silica and Organosilica Nanomaterials as UV-Blocking Agents.

Mesoporous silica nanoparticles (MSN) and periodic mesoporous organosilica nanoparticles containing bridging benzene (PMOBTB) and ethane (PMOBTE) moieties are synthesized, characterized, and evaluated for application in skin protection from UVA/UVB sun irradiation. Furthermore, the influence of surface functionalization with chelating 3-(2-aminoethylamino)propylsilane and Zn2+ ions on the UV-blocking ability of MSN is evaluated, along with the photostability and capability of the synthesized nanomaterials to carry avobenzone, a known UV-absorbing agent. The obtained results reveal promising characteristics of MSN and PMO materials with regard to their potential for sunscreen applications, which could be beneficial in terms of alleviating concerns about health and environmental hazards of sunscreen ingredients.

Controlled release and intracellular protein delivery from mesoporous silica nanoparticles.

Protein therapeutics are promising candidates for disease treatment due to their high specificity and minimal adverse side effects; however, targeted protein delivery to specific sites has proven challenging. Mesoporous silica nanoparticles (MSN) have demonstrated to be ideal candidates for this application, given their high loading capacity, biocompatibility, and ability to protect host molecules from degradation. These materials exhibit tunable pore sizes, shapes and volumes, and surfaces which can be easily functionalized. This serves to control the movement of molecules in and out of the pores, thus entrapping guest molecules until a specific stimulus triggers release. In this review, we will cover the benefits of using MSN as protein therapeutic carriers, demonstrating that there is great diversity in the ways MSN can be used to service proteins. Methods for controlling the physical dimensions of pores via synthetic conditions, applications of therapeutic protein loaded MSN materials in cancer therapies, delivering protein loaded MSN materials to plant cells using biolistic methods, and common stimuli-responsive functionalities will be discussed. New and exciting strategies for controlled release and manipulation of proteins are also covered in this review. While research in this area has advanced substantially, we conclude this review with future challenges to be tackled by the scientific community.

Mesoporous Silica Nanoparticles Loaded with Cisplatin and Phthalocyanine for Combination Chemotherapy and Photodynamic Therapy in vitro.

Mesoporous silica nanoparticles (MSNs) have been synthesized and loaded with both aluminum chloride phthalocyanine (AlClPc) and cisplatin as combinatorial therapeutics for treating cancer. The structural and photophysical properties of the MSN materials were characterized by different spectroscopic and microscopic techniques. Intracellular uptake and cytotoxicity were evaluated in human cervical cancer (HeLa) cells by confocal laser scanning microscopy (CLSM) and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays, respectively. The CLSM experiments showed that the MSN materials can be readily internalized in HeLa cells. The cytotoxic experiments demonstrated that, after light exposure, the combination of both AlClPc and cisplatin compounds in the same MSN platform potentiate the toxic effect against HeLa cells in comparison to the control AlClPc-MSN and cisplatin-MSN materials. These results show the potential of using MSN platforms as nanocarriers for combination photodynamic and chemotherapies to treat cancer.

A Review on Application of Multifunctional Mesoporous Nanoparticles in Controlled Release of Drug Delivery

In the early 1990s the discovery of the MCM-41 and the M41S family of mesoporous materials had open new era in the chemistry and biology. They have prominent application inbiotechnological, biomedical and heterogeneous catalysts. Mesoporous silica nanoparticles (MSNs) exhibit unique structural features like as their large surface areas, tunable pore sizes in nanometer and well-defined surface properties. MSN materials which are comprised of a honeycomb-like porous structure with hundreds of empty mesoporous channel that are able to encapsulate relatively large amounts of biomolecules. They are ideal candidate for constructing multifunctional materials that encapsulate a variety of functional nanostructured materials. Multifunctional MSN materials have become one of the most attractive areas in nanobiotechnology and nanomedicine for various disease diagnosis and therapy. Multifunctional MSN have been successfully developed as a multifunctional platform to deliver therapeutic and diagnostic agents. Multifunctional MSNs are a highly promising platform for intracellular controlled release of drugs. In this review we discuss the recent developments in design and fabrication of multifunctional mesoporous silica nanoparticles in as efficient drug delivery applications such as the site-specific delivery and intracellular controlled release of drugs.Abbreviations;APTES; 3-aminopropyl triethoxy sialne, ATP; Adenosine triphospahate, CD; cyclodextrinCPT; camptothecin, CS; Chitosan,CTAB; cyltrimethylammonium bromide,DNA; Deoxyribonucleic acid,DOX; doxorubicin,EDC; 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide,FD; fluorescein disodium,FSP;Fluroscent particle ,IBU;ibuprofen,MCM; mobil composition material, MPS; 3-trimethoxylsilyl propyl methacrylate, MS; mesoporous silica,MSN; mesoporous silica nanoparticle, MSNs; mesoporous silica nanoparticles,MSNP; mesoporous silica nanoparticle,NPS; nanoparticles;PFDTES;perfluorodecyltriethoxysilane, PAA; polyacrylic acid,PR;photo responsive,PMAA; polymethyl methacrylate,SBF; simulated body fluid,TEOS;tetraethyl orthosilicate,TUNA;Thio undecyl-tetraethyleneglycoestero-nitrobenzylethyldimethyl ammonium bromide.

Surface-functionalized mesoporous silica nanoparticles as sorbents for BTEX

A series of octyl-functionalized and surfactant-containing mesoporous silica nanoparticle (MSN) materials were synthesized via a co-condensation method. The authors investigated the feasibility of the MSN materials as adsorbents for BTEX (benzene, toluene, ethylbenzene, and xylenes) in groundwater. Octyl group functionalization up to 1.5 mol octyl/kg MSN improved BTEX adsorption capacity, while the mesoporous structure was still maintained. The following trend in adsorption equilibrium and kinetics of each BTEX compound onto MSN was observed: p-xylene > ethylbenzene > = toluene > benzene. Pseudo-second-order rate constant for p-xylene adsorption onto MSN was 0.907 g/mmol.min, significantly higher than that of activated carbon (0.043 g/mol.min). Desorption/regeneration with methanol was completed in 2 h, and the regenerated MSN showed the adsorption capability equivalent to the original. We envision that the MSN material could serve as an efficient adsorbent for the removal of BTEX from aqueous phase.

Ligand Conformation Dictates Membrane and Endosomal Trafficking of Arginine‐Glycine‐Aspartate (RGD)‐Functionalized Mesoporous Silica Nanoparticles

Recent breakthrough research on mesoporous silica nanoparticle (MSN) materials has illustrated their significant potential in biological applications due to their excellent drug delivery and endocytotic behavior. We set out to determine if MSN, covalently functionalized with conformation specific bioactive molecules (either linear or cyclic RGD ligands), behave towards mammalian cells in a similar manner as the free ligands. We discovered that RGD immobilized on the MSN surface did not influence the integrity of the porous matrix and improved the endocytosis efficiency of the MSN materials. Through competition experiments with free RGD ligands, we also discovered a conformation specific receptor-integrin association. The interaction between RGD immobilized on the MSN surface and integrins plays an important role in endosome trafficking, specifically dictating the kinetics of endosomal escape. Thus, covalent functionalization of biomolecules on MSN assists in the design of a system for controlling the interface with cancer cells.

Parameters Affecting the Efficient Delivery of Mesoporous Silica Nanoparticle Materials and Gold Nanorods into Plant Tissues by the Biolistic Method

Applying nanotechnology to plant science requires efficient systems for the delivery of nanoparticles (NPs) to plant cells and tissues. The presence of a cell wall in plant cells makes it challenging to extend the NP delivery methods available for animal research. In this work, research is presented which establishes an efficient NP delivery system for plant tissues using the biolistic method. It is shown that the biolistic delivery of mesoporous silica nanoparticle (MSN) materials can be improved by increasing the density of MSNs through gold plating. Additionally, a DNA-coating protocol is used based on calcium chloride and spermidine for MSN and gold nanorods to enhance the NP-mediated DNA delivery. Furthermore, the drastic improvement of NP delivery is demonstrated when the particles are combined with 0.6 μm gold particles during bombardment. The methodology described provides a system for the efficient delivery of NPs into plant cells using the biolistic method.

Tuning the Release of Anticancer Drugs from Magnetic Iron Oxide/Mesoporous Silica Core/Shell Nanoparticles

AbstractA series of core/shell, iron oxide nanoparticle embedded magnetic mesoporous silica nanoparticle materials with radial (MMSN‐r) and hexagonal (MMSN‐h) porous structures are synthesized and their capacity to load and release the anticancer drugs, 9‐aminoacridine (9AA) and camptothecin (CPT) are investigated. Although effective release of 9AA is observed for nonfunctionalized MMSN, its release from the phenylethyl‐functionalized hexagonal MMSN material (Ph‐MMSN‐h) was hindered. Conversely, the loading and release of CPT is promoted by the presence of the phenylethyl functionality inside the mesopores of MMSN, whereas very low release of CPT was observed from nonfunctionalized MMSN material. Controlled‐release properties of the drug‐loaded magnetic materials were confirmed by viability studies on Chinese hamster ovarian (CHO) cells, which revealed efficient cytotoxic activity of CPT‐loaded Ph‐MMSN‐h and 9AA‐loaded MMSN‐h materials. In addition, it was demonstrated that applying an external magnetic field to induce agitation of the drug leaded materials promoted the release of anticancer drugs from the magnetic materials. It is envisioned that the MMSN materials could be effectively applied for externally controlled, selective drug delivery to tumor tissues.

Effect of size on the cellular endocytosis and controlled release of mesoporous silica nanoparticles for intracellular delivery

Due to the unique physicochemical properties and membrane-permeable capacity, mesoporous silica nanoparticles (MSNs) are considered as an ideal carrier for intracellular delivery. Herein, we endeavored to address the size effect of MSNs on the cellular uptake, endosomal escape and controlled release, the key steps for the intracellular delivery. The well-ordered MSNs in the range from 55-nm to 440-nm with similar pore texture were prepared by modified base-catalyzed sol-gel method. With MC3T3-E1 model cell line, the in vitro results indicated that after 12h cultivation, MSNs within 55 ~ 440nm could all be internalized into the cells, and further escaped out of the endosomal compartment. The efficiency of the cellular uptake and endosomal escape strongly depended on the particle size, with the best efficiencies from 100-nm MSNs. Furthermore, the MTT results indicated that these MSNs materials were all biocompatible. The controlled release experiments with hydrophobic dexamethasone and hydrophilic vitamin C as models showed that for these small-molecular drugs, the loading amount all mainly determined by the surface area of the MSNs, and the subsequent release of the drug dramatically decreased with the increasing of the particle size. By contrast, the release rate of vitamin C was much quicker than that of the dexamethasone. These findings presented here could provide new means to tailor the size of MSNs and thus to guide the design of MSNs-based intracellular delivery system. Due to the good cell biocompatibility, high cellular uptake and endosomal escape, we conjectured that the 100-nm MSNs are more favorable for the intracellular delivery of drugs in live cells.

Luciferase and Luciferin Co-immobilized Mesoporous Silica Nanoparticle Materials for Intracellular Biocatalysis

We report a gold nanoparticle (AuNP)-capped mesoporous silica nanoparticle (Au-MSN) platform for intracellular codelivery of an enzyme and a substrate with retention of bioactivity. As a proof-of-concept demonstration, Au-MSNs are shown to release luciferin from the interior pores of MSN upon AuNP uncapping in response to disulfide-reducing antioxidants and codeliver bioactive luciferase from the PEGylated exterior surface of Au-MSN to Hela cells. The effectiveness of luciferase-catalyzed luciferin oxidation and luminescence emission in the presence of intracellular ATP was measured by a luminometer. Overall, the chemical tailorability of the Au-MSN platform to retain enzyme bioactivity, the ability to codeliver enzyme and substrate, and the potential for imaging tumor growth and metastasis afforded by intracellular ATP- and glutathione-dependent bioluminescence make this platform appealing for intracellular controlled catalysis and tumor imaging.

Capped mesoporous silica nanoparticles as stimuli-responsive controlled release systems for intracellular drug/gene delivery

Importance of the field: The incorporation of stimuli-responsive properties into nanostructured systems has recently attracted significant attention in the research of intracellular drug/gene delivery. In particular, numerous surface-functionalized, end-capped mesoporous silica nanoparticle (MSN) materials have been designed as efficient stimuli-responsive controlled release systems with the advantageous ‘zero premature release’ property.Areas covered in this review: Herein, the most recent research progress on the design of biocompatible, capped MSN materials for stimuli-responsive intracellular controlled release of therapeutics and genes is reviewed. A series of hard and soft caps for drug encapsulation and a variety of internal and external stimuli for controlled release of different cargoes are summarized. Recent investigations on the biocompatibility of MSN both in vitro and in vivo are also discussed.What the reader will gain: The reader will gain an understanding of the challenges for the future exploration of biocompatible stimuli-responsive MSN devices.Take home message: With a better understanding of the unique features of capped MSN and its behaviors in biological environment, these multifunctional materials will find a wide variety of applications in the field of drug/gene delivery.

Lipid coated mesoporous silica nanoparticles as photosensitive drug carriers

This paper presents a strategy for the biofunctionalization of novel photosensitizer carriers, mesoporous silica nanoparticles (MSNs). After being calcined and absorbed with photosensitizers (hypocrellin B, HB), MSNs can be coated with a lipid layer. Transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) results proved that HB molecules can be loaded into MSN porous and lipid can coated on the surface of the nanoparticles. When co-cultured with cancer cells (MCF-7), MSNs can transport HB molecules into cells and present low cytotoxicity. With the introduction of a lipid layer, the efficiency of MSN uptake by cells can be improved. These intracellular HB-loaded MSN materials also present cytotoxicity to MCF-7 cells after light irradiation which indicates the materials can be used as good photosensitizer carriers in photodynamic therapy.

Tuning the cellular uptake and cytotoxicity properties of oligonucleotide intercalator-functionalized mesoporous silica nanoparticles with human cervical cancer cells HeLa

A series of organically functionalized, MCM-41 type mesoporous silica nanoparticle materials (PAP-LP-MSN and AP-PAP-MSN) with different pore sizes (5.7 nm and 2.5 nm, respectively) were synthesized and characterized. We selectively decorated the exterior particle surface of PAP-LP-MSN and the interior pore surface of AP-PAP-MSN with an oligonucleotide intercalating phenanthridinium functionality. While phenanthridinium itself is a cell membrane impermeable molecule, we demonstrated that both phenanthridinium-immobilized PAP-LP-MSN and AP-PAP-MSN materials could indeed be internalized by live human cervical cancer cells (HeLa). We discovered that the PAP-LP-MSN nanoparticles with the phenanthridium groups located on the exterior surface were able to bind to cytoplasmic oligonucleotides, such as messenger RNAs, of HeLa cells resulting in severe cell growth inhibition. In contrast, the cytotoxicity of AP-PAP-MSN, where the same oligonucleotide intercalating molecules were anchored inside the pores, was significantly lowered upon the endocytosis by HeLa cells. We envision that this approach of combining the selective functionalization of the two different surfaces (exterior particle and interior pore surfaces) with morphology control of mesoporous silica nanoparticles would lead to a new generation of nanodevices with tunable biocompatibility and cell membrane trafficking properties for many biomedical applications.

Temperature Responsive Solution Partition of Organic–Inorganic Hybrid Poly(N‐isopropylacrylamide)‐Coated Mesoporous Silica Nanospheres

AbstractA series of poly(N‐isopropylacrylamide)‐coated mesoporous silica nanoparticle materials (PNiPAm‐MSNs) has been synthesized by a surface‐initiated living radical polymerization with a reversible addition–fragmentation chain transfer (RAFT) reaction. The structure and the degree of polymerization of the PNiPAm‐MSNs has been characterized by a variety of techniques, including nitrogen sorption analysis, 29Si and 13C solid‐state NMR spectroscopy, transmission electron microscopy (TEM), and powder X‐ray diffraction (XRD). The thermally induced changes of the surface properties of these polymer‐coated core–shell nanoparticles have been determined by examining their partition activities in a biphasic solution (water/toluene) at different temperatures.

Mesoporous Silica Nanoparticles for Drug Delivery and Biosensing Applications

AbstractRecent 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.