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Peroxidase mimetic catalytic atom transfer radical polymerization (ATRP) was first used to install tertiary amine-functionalized polymer brushes on the surface of mesoporous silica nanoparticles (MSNs) in a facile and highly efficient manner. Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) brushes-grafted MSNs were fabricated by biocompatible deuterohemin-β-Ala-His-Thr-Val-Glu-Lys (DhHP-6)-catalyzed surface-initiated ATRP (SI-ATRP). The resulting organic-inorganic hybrid nanocarriers were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), SEM, TEM, Elemental analysis, Zeta-potential, and N2 adsorption-desorption isotherms, which demonstrated the successful coating of pH-responsive polymers on the MSN surface. Rhodamine 6G (Rh6G) dyes were further loaded within the mesopores of this nanocarrier, and the release of Rh6G out of MSNs in a controlled fashion was achieved upon lowing the solution pH. The electrostatic repulsion of positively-charged tertiary ammonium of PDMAEMAs in acidic environments induced the stretching out of polymer brushes on MSN surfaces, thus opening the gates to allow cargo diffusion out of the mesopores of MSNs. [ABSTRACT FROM AUTHOR]

The preparation of the ideal smart drug-delivery systems were successfully achieved by the in situ co -polymerization of a vinyl group-functionalized mesoporous silica nanoparticle (f-MSN) with 1-butyl-3-vinyl imidazolium bromide (BVIm) and N -isopropylacrylamide ( N IPAAm) monomers. The thickness of the capping copolymer layer, poly( N IPAAm- co -BVIm) ( p - N IBIm), was controlled at between 2.5 nm and 5 nm, depending on the monomers/f-MSN ratio in the reaction solution. The finally obtained smart drug-delivery systems are named as p-MSN2.5 and p-MSN5.0 (MSNs integrated by 2.5 nm and 5 nm p - N IBIm layer in thickness). The key roles of the mesoporous-silica-nanoparticle (MSN) core and the p - N IBIm shell are drug-carrying (or containing) and pore-capping, respectively, and the latter has an on/off function that operates in accordance with temperature changes. According to the swelling- or shrinking-responses of the smart capping copolymer to temperature changes between 10 °C and 40 °C, the loading and releasing patterns of the model drug cytochrome c were studied in vitro . The developed system showed interesting performances such as a cytochrome-c-loading profile (loading capacity for 3 h = 26.3% and 19.8% for p-MSN2.5 and p-MSN5.0, respectively) at 10 °C and a cytochrome-c-releasing profile (releasing efficiency = > 95% within 3 days and 4 days for p-MSN2.5 and p-MSN5.0, respectively) at 40 °C. The cytotoxicity of the drug delivery systems, p-MSN2.5 and p-MSN5.0 (in the concentration range of <0.125 mg/mL without drug), for human embryonic kidney (HEK 293) cells were minimal in vitro compared with that of a blank MSN. These results may be reasonably applied in the field of specified drug delivery. [ABSTRACT FROM AUTHOR]

Small-molecule drug combination therapies are an attractive approach to enhancing cancer chemotherapeutic responses. Therefore, this study aimed to investigate the potential of axitinib (AXT) and celastrol (CST) in targeting angiogenesis and mitochondrial-based apoptosis in cancer. Therefore, we prepared AXT/CST-loaded combination nanoparticles (ACML) with CST loaded in the mesoporous silica nanoparticles (MSN) and AXT in PEGylated lipidic bilayers. We showed that ACML effectively inhibited angiogenesis and mitochondrial function and was efficiently internalized in SCC-7, BT-474, and SH-SY5Y cells. Furthermore, hypoxia-inducible factor (HIF)-1α expression, which increased under hypoxic conditions in all cell lines exposed to ACML, markedly decreased, which may be critical for tumor inhibition. Western blotting showed the superior anticancer effect of combination nanoparticles in different cancer cells. Compared to the cocktail (AXT/CST), ACML induced synergistic cancer cell apoptosis. The AXT/CST-based combination nanoparticle synergism might be mediated by AXT, which controls vascular endothelial growth factor receptors while CST acts on target cell mitochondria. Importantly, ACML-treated mice showed remarkably higher tumor inhibition (64%) than other groups did in tumor xenograft models. Tumor xenograft immunohistochemistry revealed elevated caspase-3 and poly (ADP-ribose) polymerase and reduced CD31 and Ki-67 expression, clearly suggesting tumor apoptosis through mitochondrial and antiangiogenic effects. Overall, our results indicate that ACML potentially inhibited cell proliferation and induced apoptosis by blocking mitochondrial function, leading to enhanced antitumor efficacy. Statement of Significance In this research, we formulated an anticancer drug combination nanoparticle loaded with axitinib (AXT) in the lipidic bilayer of PEGylated liposomes and celastrol (CST) in mesoporous silica nanoparticles. The anticancer effects of the AXT/CST-loaded combination nanoparticle (ACML) were synergistic and superior to the other formulations and involved more efficient drug delivery to the tumor site with enhanced effects on angiogenesis and mitochondrial function. Therefore, our study demonstrated that the inhibition of cell proliferation and induction of apoptosis by ACML, which was mediated by blockade of mitochondrial function and anti-angiogenesis, led to enhanced antitumor efficacy, which may be potentially useful in the clinical treatment of cancer. [ABSTRACT FROM AUTHOR]

The enzymatic production of biodiesel by methanolysis of canola oil was studied using self-made biocatalysts. Mesoporous SBA-15 nanoparticles were prepared, characterized and functionalized by 3-glycidyloxypropyl trimethoxysilane. Lipases from Candida antarctica (CALB), Thermomyces lanuginosus (TLL) and Rhizomucor miehei (RML) were covalently immobilized onto SBA-epoxy. Thermal stability and the influence of methanol concentration on the catalytic activity were also evaluated. Higher thermal stability and methanol tolerance for immobilized derivatives were achieved compared to the free enzyme. In an optimization study, the effect of water, t -butanol and blue silica gel as water adsorbent on the yield of FAME was considered. For the SBA-RML catalysed reaction, water had little effect in increasing FAME yield, but when 20 wt% water by substrate weight was added to the SBA-TLL catalysed reaction, the methyl ester content reached nearly complete conversion (98% FAME). t -Butanol had a great effect on yield, with almost complete conversion for SBA-RML and SBA-TLL. The effect of blue silica gel also was investigated. The immobilized TLL was quite stable and can be reused for 20 cycles without significant loss in activity (6%). RML and CALB also presented a good reusability, keeping 95% of their initial activities after 7 and 15 cycles of the reaction. [ABSTRACT FROM AUTHOR]

Mesoporous silica nanoparticles with a three dimensionally ordered close-packing structure (3DOc-p MSNs) were confined synthesis through steam-assisted crystallization (SAC). With a perfect replication from the three dimensionally ordered mesoporous carbon template, the obtained 3DOc-p MSNs presented a unique assembly structure of colloidal crystals composed of uniform mesoporous silica spherical particles with a controllable particle size ranged from 10 to 160 nm and various mesopore morphologies of hollow, multicellar, disordered wormlike, and ordered structures with the increasing of the confined space provided by the carbon template. Moreover, sonication induced fragmentation of 10, 20, and 40 nm 3DOc-p MSNs resulted in the clear suspensions of highly monodispersed mesoporous silica nanoparticles. [ABSTRACT FROM AUTHOR]

Novel bilayer coated mesoporous silica nanoparticle (MCM-41) based on pH sensitive poly(acrylic acid-co-itaconic acid) and human serum albumin (HSA) was designed for controlled delivery of gemcitabine (anticancer drug) to cancer cells. The shell around the mesoporous silica has bilayer structure. Poly(acrylic acid-co-itaconic acid) was used as pH-sensitive inner shell and human serum albumin, HSA, was used as outer shell. The core–shell structure was formed due to electrostatic interaction between ammonium groups of modified MCM-41 and carboxylate groups of copolymer. Also, the albumin layer was wrapped around the copolymer coated nanoparticle by electrostatic interaction between ammonium groups from protein and carboxylate ions of copolymer shell. Moreover, the maximum release occurred at pH 5.5 (pH of endosomes) because the bilayer shell collapsed at this pH. The drug nanocarrier would be a good candidate for tumor therapy due to its biocompatibility, controlled release and pH responsive behavior. [ABSTRACT FROM AUTHOR]

Targeted delivery of anticancer agents by functional nanoparticles is an attractive strategy to increase their therapeutic efficacy while reducing toxicity. In this work, doxorubicin (DOX)-loaded mesoporous silica nanoparticles (MSNs) were modified with aptamer (Ap) against the epithelial cell adhesion molecule (EpCAM) for targeted delivery of DOX to colon cancer cells. These nanoparticles (Ap-MSN-DOX) were characterized by particle size, zeta potential, aptamer conjugation efficiency, drug encapsulation efficiency, and drug release properties. The in vitro cell recognition, cellular uptake, EpCAM protein inhibition efficiency, and cytotoxicity of Ap-MSN-DOX were also studied. Results demonstrated that EpCAM conjugation increased binding of Ap-MSN-DOX to EpCAM over-expressing SW620 colon cancer cells but not EpCAM-negative Ramos cells, resulting in enhanced cellular uptake and increased cytotoxicity of the DOX in SW620 cells when compared to non-Ap-modified nanoparticles (MSN-DOX). Additionally, Ap-MSN-DOX exhibited significant inhibition effects on the expression of EpCAM on SW620 cells. These results suggested that Ap-MSN-DOX has the potential for the targeted delivery of therapeutic agents into EpCAM positive colon cancer cells to improve therapeutic index while reducing side effects. [ABSTRACT FROM AUTHOR]

A strategy is described for the real time and selective monitoring of benzene, toluene and xylenes (BTX) in air. Rapid preconcentration and recovery have been achieved with films made of mesoporous silica nanoparticles assembled on a quartz plate. The resulting nanoparticle films displayed high transmittance and allowed the detection of toluene up to 1 ppm within a minute and a regeneration of the sensor in less than 30 s. The sensor response increased while increasing the concentration of benzene (detection at 252 nm), toluene (detection at 267 nm) or p-xylene (detection at 274 nm) in the polluted air from 1 to 100 ppm. The order of sensitivity, i.e. p-xylene > toluene > benzene, was correlated with their respective molar extinction coefficients. The BTX adsorption on mesoporous silica nanoparticle films has been analyzed with the Freundlich adsorption model. The repeatability of the detection was good in intraday (2%) and extra-day (4%) experiments with a given sensor. The ability to detect toluene in the presence of volatile compounds often encountered in working environments (i.e., methyl ethyl ketone, ethanol, acetone and cyclohexane) has been shown. The introduction of a gas dryer before the measurement cell allowed application of the sensor in humid atmosphere. This sensor could be used to alert if permissible values of exposure to toluene and xylenes have been reached during work. [ABSTRACT FROM AUTHOR]

In this paper, a multifunctional theranostic magnetic mesoporous silica nanoparticle (MMSN) with magnetic core was developed for magnetic-enhanced tumor-targeted MR imaging and precise therapy. The gatekeeper β-cyclodextrin (β-CD) was immobilized on the surface of mesoporous silica shell via platinum(IV) prodrug linking for reduction-triggered intracellular drug release. Then Arg-Gly-Asp (RGD) peptide ligand was further introduced onto the gatekeeper β-CD via host–guest interaction for cancer targeting purpose. After active-targeting endocytosis by cancer cells, platinum(IV) prodrug in MMSNs would be restored to active platinum(II) drug in response to the innative reducing microenvironment in cancer cells, resulting in the detachment of β-CD gatekeeper and thus simultaneously triggering the in situ release of anticancer drug doxorubicin (DOX) entrapped in the MMSNs to kill cancer cells. It was found that with the aid of an external magnetic field, drug loaded MMSNs showed high contrast in MR imaging in vivo and exhibited magnetically enhanced accumulation in the cancer site, leading to significant inhibition of cancer growth with minimal side effects. This multifunctional MMSN will find great potential as a theranostic nanoplatform for cancer treatment. [ABSTRACT FROM AUTHOR]

MCM-41-like mesoporous silica nanoparticles (MSNs) grafted with a thermoresponsive copolymer of N-isopropylacrylamide were synthesized, fully characterized and tested to assess their efficiency as drug delivery systems. The hybrid nanoparticles were prepared by carrying out the optimized copolymer synthesis within the mesopores of MSNs after infiltration of monomers and initiator. Polymerization and grafting of the thermoresponsive copolymer occurred simultaneously by exploiting the reactive sites of the 3-methacryloxypropyltrimethoxysilane comonomer which carries a polymerizable group and alkoxysilane groups prone to condensation with surface silanols on silica. The grafted copolymer through its coil-to-globule transition acts as a gatekeeper for the temperature-controlled release of ibuprofen molecules loaded inside the pores. Significant difference in the quantitative release of ibuprofen was observed at 25 and 40 °C, which are below and above the lower critical solution temperature of the thermoresponsive copolymer. Importantly, the ordered mesoporous structure of the MSNs remained intact in all synthetic steps, loading of drug and during the in vitro release tests. [ABSTRACT FROM AUTHOR]

The poor penetration of nanocarriers within tumor dense extracellular matrices (ECM) greatly restricts the access of anticancer drugs to the deep tumor cells, resulting in low therapeutic efficacy. Moreover, the high toxicity of the traditional chemotherapeutics inevitably causes undesirable side effects. Herein, taking the advantages of biosafe H 2 and small-sized nanoparticles in diffusion within tumor ECM, we develop a matrix metalloprotease 2 (MMP-2) responsive size-switchable nanoparticle (UAMSN@Gel-PEG) that is composed of ultrasmall amino-modified mesoporous silica nanoparticles (UAMSN) wrapped within a PEG-conjugated gelatin to deliver H 2 to the deep part of tumors for effective gas therapy. Ammonia borane (AB) is chosen as the H 2 prodrug that can be effectively loaded into UAMSN by hydrogen-bonding adsorption. Gelatin is used as the substrate of MMP-2 to trigger size change and block AB inside UAMSN during blood circulation. PEG is introduced to further increase the particle size and endow the nanoparticle with long blood circulation to achieve effective tumor accumulation via the EPR effect. After accumulation into the tumor site, MMP-2 promptly digests gelatin to expose UAMSN loading AB for deep tumor penetration. Upon stimulation by the acidic tumor microenvironment, AB decomposes into H 2 for further intratumor diffusion to achieve effective hydrogen therapy. Consequently, such a simultaneous deep tumor penetration of nanocarriers and H 2 results in an evident suppression on tumor growth in a 4T1 tumor-bearing model without any obvious toxicity on normal tissues. Our synthetic nanosystem provides a promising strategy for the development of nanomedicines with enhanced tumor permeability and good biosafety for efficient tumor treatment.

Integrating the versatility of synthetic nanoparticles to natural biomaterials, such as cells or cell membranes, has gained considerable attention as promising alternative cargo delivery platforms in recent years. Extracellular vesicles (EVs), natural nanomaterials composed of a protein-rich lipid bilayer secreted by cells, have also shown advantages and great potential as a nano delivery platform in combination with synthetic particles due to their specific natural properties in overcoming several biology hurdles possessed in the recipient cell. Therefore, the preservation of EV's origin properties is critical for their application as nanocarriers. This chapter will describe the encapsulation procedure of MSN encapsulated in EV membrane derived from mouse renal adenocarcinoma (Renca) cells through biogenesis. The FMSN-enclosed EVs produced through this approach still contain preserved EV's natural membrane properties., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

The human mutT homologue MTH1, a nucleotide pool sanitizing enzyme, represents a vulnerability factor and an attractive target for anticancer therapy. However, there is currently a lack of selective and effective platforms for the detection and inhibition of MTH1 in cells. Here, we demonstrate for the first time a gold nanoparticle (AuNP) flares-capped mesoporous silica nanoparticle (MSN) nanoplatform that is capable of detecting MTH1 mRNA and simultaneously suppressing MTH1 activity. The AuNP flares are made from AuNPs that are functionalized with a dense shell of MTH1 recognition sequences hybridized to short cyanine (Cy5)-labeled reporter sequences and employed to seal the pores of MSN to prevent the premature MTH1 inhibitors (S-crizotinib) release. Just like the pyrotechnic flares that produce brilliant light when activated, the resulting AuNP flares@MSN (S-crizotinib) undergo a significant burst of red fluorescence enhancement upon MTH1 mRNA binding. This hybridization event subsequently induces the opening of the pores and the release of S-crizotinib in an mRNA-dependent manner, leading to significant cytotoxicity in cancer cells and improved therapeutic response in mouse xenograft models. We anticipate that this nanoplatform may be an important step toward the development of MTH1-targeting theranostics and also be a useful tool for cancer phenotypic lethal anticancer therapy. [ABSTRACT FROM AUTHOR]

Can micelles be served as gating agents and fluorescent labels? Can a drug delivery system be constructed by combining two kinds of drug carriers, such as mesoporous silica nanoparticles and micelles? Will the combination be better or worse? To settle these questions, we designed and constructed a nanocarrier by cooperating two kinds of drug carriers (mesoporous silica nanoparticles and F127 micelles), providing a suitable method for the design of multifunctional stimuli-responsive drug delivery and self-fluorescent imaging systems. The system is fabricated using anticancer drug (curcumin) loaded micelles (CF127) as gating agents and fluorescent labels of mesoporous silica nanoparticles via Schiff base. Because of the pH-sensitive Schiff base, the gating micelles can achieve drug release under acidic condition, while preventing the drug release under natural condition. Moreover, due to the aggregation of CF127 micelles on the surface of mesoporous silica nanoparticles, the fluorescent intensity of CF127 micelles is significantly enhanced. Furthermore, CF127 micelles exhibit good anti-photobleaching property, indicating that the system here is promising for noninvasive in vivo tracking the delivery of therapeutic agents. The cooperation of two kinds of drugs in anti-cancer application and the easily further modification ability of the system is also be confirmed. These results indicate that this study paves the way for a generation of drug delivery systems and could provide a general route to prepare multifunctional biocompatible platforms for biomedical imaging diagnosis and simultaneous therapy for lesion sites such as cancers. [ABSTRACT FROM AUTHOR]

Surface modified mesoporous silica nanoparticles (MSNs) with reduced toxicity were prepared for light and pH dual triggerable drug delivery system. Both 413 nm light and acidic environment can activate the drug release process, improving the pharmacological action. By applying rhodamine B (RhB) as a model drug, the accumulative RhB release is as high as 95% in pH 5.0 and in irradiation of 413 nm light, compared to only 55% in pH 7.4 and in dark. The anti-cancer drug camptothecin (CPT) loaded nanoparticles can kill cancer cells with IC 50 value of 0.02 μg mL −1 in exposure of 413 nm light, which is much lower than free CPT (about 0.1 μg mL −1 ). Multimodal nonlinear optical imaging microscopy (NLOM) was employed to acquire in vitro coherent anti-Stokes Raman (CARS) and two-photon excited fluorescence (TPEF) images of live MCF-7 cells and showed that the nanoparticles can be taken up by breast tumor cell MCF-7 with high efficiency, indicating its great potential for anti-cancer drug delivery system. [ABSTRACT FROM AUTHOR]

Pomegranate‐structured composite microspheres composed of core mesoporous silica nanoparticles capped by a poly(l‐lactide) shell are prepared via one‐step electrospraying, which releases encapsulated model anti‐inflammatory drugs for up to 70 d and inhibits proliferation against macrophages over the long release period. [ABSTRACT FROM AUTHOR]

A facile method is described to prepare pH-sensitive and self-fluorescent drug delivery systems using mesoporous silica nanoparticles and PAMAM dendrimers, providing a general route to develop multifunctional and biocompatible platforms, which integrated increasing the number of reaction sites, retaining drug molecules, controlling drug delivery behaviour and fluorescent imaging into one carrier system, for biomedical imaging diagnosis and simultaneous therapy for lesion sites such as cancers. [ABSTRACT FROM AUTHOR]

A novel bone cement pellet, with sustained release of vancomycin (VAN), was prepared by mixing VAN loaded mesoporous silica nanoparticle (MSN) and calcium sulfate α-hemihydrate (CS) together. To improve the VAN loading ability, MSN was functionalized with aminopropyltriethoxysilane (APS) to give APS–MSN. The VAN loading content and entrapment efficiency of APS–MSN could reach up to 45.91 ± 0.81% and 84.88 ± 1.52%, respectively, much higher than those of MSN, which were only 3.91% and 4.07%, respectively. The nitrogen adsorption–desorption measurement results demonstrated that most of the VAN were in the pores of APS–MSN. The CS/VAN@APS–MSN composite pellet showed a strongly drug sustained release effect in comparison with CS control pellet. The in vitro cell assays demonstrated that CS/APS–MSN composite was highly biocompatible and suitable to use as bone cement. Furthermore, CS/VAN@APS–MSN pellet showed no pyrogenic effect and meet the clinical requirements on hemolytic reaction. These results imply that CS/VAN@APS–MSN was an ideal candidate to replace CS bone cement in the treatment of open fractures. [ABSTRACT FROM AUTHOR]

Unicellular bacterial cells exhibit diverse population behaviors (i.e., aggregation, dispersion, directed assembly, biofilm formation, etc.) to facilitate communication and cooperation. Suitable bacterial behaviors are required for efficient nutrient uptake, cell recycling, and stress response for environmental and industrial application of bacterial populations. However, it remains a great challenge to artificially control bacterial behaviors because of complicated genetic and biochemical mechanisms. In this study, we designed facile mesoporous silica nanoparticle (MSN)-based assemblies to intelligently regulate bacterial behaviors with the help of light and magnetic field. This system was composed of magnetic MSNs, i.e., MnFe 2 O 4 @CoFe 2 O 4 @MSN modified by photoactive spiropyran (SP), and the chitosan-based polymers ChiPSP, i.e., chitosan grafted by triphenylphosphine and SP. The assembly strongly bound bacterial cells, inducing reversible bacterial aggregation by visible-light irradiation and dark. Moreover, the formed bacterial aggregates could be further governed by a directed magnetic field (DMF) to form microfibers and by an alternating magnetic field (AMF) to form biofilms. This study realized stimulus-triggered regulation of bacterial behaviors by MSNs and implied the great power of chemical strategies in intelligent control of diverse biological processes for environmental and industrial applications.

• A dye-free fluorescent SiO2 porous nanoparticles is presented. • TEM & BET analysis confirmed the mesoporous structure of the SiO2 nanoparticles. • The porous dye-free SiO2 nanoparticles displayed strong visible light fluorescence. • Fluorescence intensities are modulated with varying calcination temperatures. • The visible light fluorescence is mainly attributed to carbon impurities. Synthesis of dye-free mesoporous silica nanoparticles and the effect of calcination on their photoluminescence properties are reported here. Mesoporous silica nanoparticles were synthesized using a modified Stöber method and calcined at different temperatures. Samples were characterized by transmission electron microscopy (TEM), BET surface area analyzer, thermogravimetry analyzer, Fourier Transform Infrared spectroscopy (FTIR), photoluminescence spectroscopy, and X-ray photoelectron spectroscopy (XPS). Silica nanoparticles calcined at 400 °C exhibited maximum porosity with highest specific surface area of 828 m2.g–1. Uncalcined porous nanoparticles exhibit broad visible light photoluminescence (from 400 nm to 600 nm), and its intensity varies significantly after calcination, mainly due to the creation of carbon impurities and oxygen defects within the silica lattice. Carbon impurities during calcination are formed from the remaining organic residue at the nanoparticle's surface and can be removed by calcining the particles above 400 °C and thereby, improving the visible light photoluminescence intensity of these nanoparticles. [Display omitted] [ABSTRACT FROM AUTHOR]

A significant bottleneck in the clinical translation of stem cells remains eliciting the desired stem cell behavior once transplanted in the body. In their natural environment, stem cell fate is regulated by their interaction with extracellular matrix (ECM), mainly through integrin-mediated cell adhesion. 2D biointerfaces that selectively present ECM-derived ligands can be used as valuable tools to study and improve our understanding on how stem cells interact with their environment. Here we developed a new type of biointerface based on mesoporous silica nanoparticles (MSN) which are interesting nanomaterials for biointerface engineering because they allow close control over surface physiochemical properties. To create the platform, DNA functionalized MSN (MSN-ssDNA) with varying PEG linker length were developed. Cell adhesion tripeptide RGD was conjugated to a complementary DNA strand, which could specifically bind to MSN-ssDNA to create MSN-dsDNA-RGD films. We showed that MSN-dsDNA-RGD films could promote hMSCs adhesion and spreading, whereas MSN-dsDNA films without RGD resulted in poor cell spreading with round morphology, and low cell adhesion. In addition, we showed that cell adhesion to the films is PEG length-dependent. The design of the platform allows easy incorporation of other and multiple ECM ligands, as well as soluble cues, making MSN-ssDNA based biointerfaces a novel tool to study ligand–stem cell interactions. [Display omitted] • A new 2-D biointerface based on DNA and PEG functionalized MSN was developed. • RGD-DNA conjugates could successfully bind to the MSN films. • RGD mediated hMSC adhesion was PEG length-dependent. • The biointerface allows incorporation of multiple ECM ligands, as well as soluble cues. [ABSTRACT FROM AUTHOR]

Synthesis of novel drug delivery system for targeted delivery of cuminaldehyde to breast cancer cells and the subsequent analyses of anti-neoplastic potential of the drug. 3-carboxy-phenyl boronic acid (PBA) conjugated and polyacrylic acid (PAA) gated mesoporous silica nanoparticles (MSNs) were synthesized for the targeted delivery of cuminaldehyde (CUM) to breast cancer cells. Enhancement of anti-neoplastic effects of cuminaldehyde (4-isopropylbenzaldehyde) by the nanoconjugates was assessed. The anti-cancer effects of non-targeted and targeted drug-nanoconjugates were examined in vitro and in vivo. The targeted drug-nanoconjugates caused cell cycle arrest and induced the intrinsic pathway of apoptosis in MCF-7 cells through mitochondrial damage. In vivo intravenous injection of the targeted drug-nanoconjugates led to effective reduction in growth of 4 T1 induced mammary pad tumor in female BALB/c mice via augmented accumulation of cuminaldehyde. The drug-nanoconjugates did not exhibit any systemic toxicity. Therefore, MSN-PBA-CUM-PAA represents a potent therapeutic model for breast cancer treatment. [Display omitted] • For the first time, PBA functionalized PAA coated MSNs have been synthesized. • Targeted delivery was achieved through the binding of PBA to poly-sialic acid residues on the surface of the cancer cells. • PAA gating on nanoformulations conferred pH-responsive release of cuminaldehyde in cancer cells. • MSN-PBA-CUM-PAA exhibited significant anti-neoplastic effects both in vitro and in vivo. • The nanocarriers did not exhibit any systemic toxicity. [ABSTRACT FROM AUTHOR]

Lung cancer is the leading cause of cancer-related death in the United States, and non-small cell lung cancer (NSCLC) the most common type. Platinum (Pt) anticancer agents, such as cisplatin, remain a mainstay in the clinic; however, these agents are not tumor-specific and, thus, the patient experiences negative side-effects. We here prepare trans , cis , cis -bis(heptanoato)amine(cyclohexylamine)dichloridoplatinum(IV) and demonstrate that it is greater than 50-fold more toxic toward NSCLC cells than is cisplatin. Furthermore, it has a much improved therapeutic index. This Pt(IV) complex binds to DNA in a manner similar to that of cisplatin, and can be incorporated into mesoporous silica nanoparticles for fine-controlled release and the targeting of tumors. [ABSTRACT FROM AUTHOR]

Superhydrophilic coatings with high transmittance were fabricated from solid and mesoporous silica nanoparticles (NPs) via layer-by-layer assembly followed by calcination. These porous silica coatings were highly transparent and superhydrophilic. The maximum transmittance reached as high as 96.1%, while that of the glass substrate was 91%. The time for a droplet to spread flat (water contact angle lower than 5°) is <1 s. Scanning and transmission electron microscopies were used to observe the morphology and structure of both NPs and coating surfaces. Transmission spectra and their changes after calcination were characterized by UV–vis spectrophotometry. The surface wettability was studied using a contact angle/interface system. [ABSTRACT FROM AUTHOR]

Abstract: Multidrug resistance (MDR) is a major impediment to the success of cancer chemotherapy. A polymer-lipid supported mesoporous silica nanoparticle (PLS-MSNs) is described here to facilitate intracellular delivery of anticancer drug and enhance the antitumor efficacy against MDR breast cancer cells. By coating MSNs with a synthetic dual-functional polymer-lipid material P123-DOPE, the supported membrane acted as an intact barrier against the escape of encapsulated drugs before reaching the target cells, leading to depolymerization and triggered storm release of loaded irinotecan (CPT-11) in acidic endosomal pH of tumor cells. In addition, P123-DOPE can inhibit breast cancer resistance protein (BCPR) mediated CPT-11 efflux in drug resistant MCF-7/BCRP breast cancer cells, thus acting as a “door blocker”. Compared to free CPT-11, PLS-MSNs resulted in a maximum increase in the intracellular CPT-11 concentration (12.9-fold), had 7.1-fold higher cytotoxicity and processed a stronger cell cycle arrest in MCF-7/BCRP cells. Moreover, CPT-11 loaded PLS-MSNs showed high therapeutic performance and low toxicity in BALB/c nude mice bearing drug resistant breast tumors, with an inhibition rate of 81.2% compared to free CPT-11 treatment group. The reported PLS-MSNs provide promising applicability in future preclinical and clinical MDR cancer treatment. [Copyright &y& Elsevier]

We synthesized pH-responsive chitosan-coated mesoporous silica nanoparticles. The morphological characterization conveyed that the mesoporous silica was encapsulated within pH-responsive cationic chitosan. Further, the average diameter of chitosan-coated mesoporous silica nanoparticles was approximately 230 nm. The doxorubicin, an anticancer drug, was loaded into the cavities of mesoporous chitosan-coated silica nanoparticles. pH played an important role in regulating the release of doxorubicin from chitosan-coated mesoporous silica nanoparticles, indicating that 53% and 90% doxorubicin were released from chitosan-coated mesoporous silica nanoparticles within 48 h at pH 7.4 and pH 4.4, respectively. We also demonstrated the endocytosis of chitosan-coated mesoporous silica nanoparticles in MCF-7 breast cancer cells. Therefore, this chitosan-coated mesoporous silica nanoparticle could be a powerful tool for pH-responsive controlled release of the anticancer drug. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This study reports the synthesis of mesoporous silica nanoparticle-encapsulated alginate microparticles (MSN@Alg) for sustained release and targeting therapy. The MSN@Alg was synthesized by air dynamical atomization, and the effects of several critical factors including concentration of alginate solution, flow rate of alginate solution, flow rate of air, the distance between nozzle and calcium bath, and stirring rate of calcium on the particle size of the synthesized MSN@Alg were investigated. For studying the sustained release properties of the MSN@Alg, rhodamine 6G (R6G) was used as a model drug, and we compared the release properties of R6G/MSN and R6G/MSN@Alg using different concentrations of alginate, concentrations and volumes of phosphate-buffered saline (PBS) buffer solutions. The sustained release behavior of the R6G/MSN@Alg system can be prolonged to 20 days with an optimal condition of 1 mg R6G/MSN@Alg to 2 mL PBS (10 m M). To achieve targeting therapy, an anticancer drug, doxorubicin (Dox), was loaded into MSN@Alg, and a arginine, glycine, and aspartic acid (RGD)-based peptide was functionalized onto the surface of MSN@Alg for the purpose of specific targeting. The results showed that the intracellular drug delivery efficiency was greatly enhanced (i.e., 3.5-folds) for the Dox/MSN@Alg-RGD drug delivery system. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 293-302, 2014. [ABSTRACT FROM AUTHOR]

Abstract: Fluoroboric acid (HBF4) adsorbed on mesoporous silica nanoparticles of 25–30nm dimension was synthesized and characterized by N2 adsorption, HRTEM, EDX, XPS, XRD, 29Si MAS NMR etc. The applicability of silica-HBF4 was probed through a library synthesis of tetraketones or their tautomeric enol forms. These tetraketones are further transformed into xanthenes. Synthesis using aqueous-ethanol is of paramount importance for its sustainable green impact. [Copyright &y& Elsevier]

The differential tumor environment guides various antitumor drug delivery strategies for efficient cancer treatment. Here, based on the special bacteria-enriched tumor environment, we report a different drug delivery strategy by targeting bacteria inhabiting tumor sites. With a tissue microarray analysis, it was found that bacteria amounts displayed significant differences between tumor and normal tissues. Bacteria-targeted mesoporous silica nanoparticles decorated with bacterial lipoteichoic acid (LTA) antibody (LTA-MSNs) could precisely target bacteria in tumors and deliver antitumor drugs. By the intravenous administration of bacteria-targeted nanoparticles, we showed in mice with colon cancer, lung cancer, and breast cancer that LTA-MSNs exhibited a high tumor-targeting ability. As a proof-of-concept study, tumor microbes as some of the characteristics of a tumor environment could be utilized as potential targets for tumor targeting. This bacteria-guided tumor-targeting strategy might have great potential in differential drug delivery and cancer treatment.

Traditional treatment of cancers such as chemotherapy still causes many side effects after the treatment even nowadays, therefore combination therapies by using drug delivery systems are valued by more and more scientists. However, loading multiple drugs in the nanoparticles for drug delivery system may cause insufficient drugs or functional groups, which might let the nanomaterial have fewer functions. Therefore, making the mesoporous silica nanoparticles (MSNs) have photodynamic therapy function by "doping " lanthanide ions into the material structure, can evade this problem. Moreover, with the doping of lanthanide metals, the MSNs can have not only dual imaging functions of both magnetic resonance imaging and fluorescence, but also achieve photodynamic function. To feature the material with more function, chemotherapeutic drug-doxorubicin was loaded into the pores of MSNs and then bonded hyaluronic acid which is the active target and a gatekeeper, on the surface of MSNs. Finally, an all-in-one drug delivery system" Hyaluronidase and pH-responsive mesoporous silica nanoparticles with dual-imaging activity for chemo-photodynamic therapy" is synthesized. The first part in this experiment was to confirm the physical properties of the lanthanides dopped MSN and its photodynamic treatment effect. The second part was to confirm that each organic molecule had been successfully bonded to the surface of the MSN and achieve pH and Hyaluronidase response drug release effect, The last part was to prove that the drug delivery system had a significant anticancer effect through cell experiments. The intracellular hyaluronidase will decompose hyaluronic acid on the surface of carrier to release doxorubicin and further released due to the lower pH in the cancer cell. Then, tumor is irradiated with near-infrared light so that the drug carrier produce Reactive oxygen species and increase the anticancer effect. [Display omitted] • This material successfully combines chemotherapy and photodynamic therapy. • The system has targeted, dual imaging and dual drug controlled release functions. • The drug will release due to the lower pH and higher hyaluronidase concentration. • The material demonstrating the fluorescent and magnetic imaging function. • Synergistic effect was performed in this drug delivery system. [ABSTRACT FROM AUTHOR]

In the present study, we have developed a new type of nanocomposite Ni-Co coating including mesoporous silica nanoparticles (MSNs) by electrodeposition for the corrosion protection of steel fasteners. The effects of the nanoparticles content in the bath on the microstructure, mechanical properties, and corrosion resistance of Ni-Co-MSNs nanocomposite coatings with and without silicone oil impregnation have been investigated comprehensively. It is found a significant improvement in corrosion resistance of the Ni-Co coating after adding 4 g/L of MSNs into the plating bath. The optimized Ni-Co-MSNs composite coating has MSNs both incorporated in the Ni-Co alloy matrix and dispersed on the coating surface. This nanocomposite coating infused with silicone oil decreases the surface wettability, friction coefficient, electrochemical activity at the scratch due to the dispersed mesoporous nanoparticles as oil reservoirs, showing a remarkable enhancement in corrosion resistance and lubricating performance of the composite coating system. [Display omitted] • Nanocomposite Ni-Co coating with mesoporous silica nanoparticles (MSNs) was prepared by co-electrodeposition. • Corrosion resistance of Ni-Co coating was improved significantly after adding 4 g/L MSNs into the plating bath. • Corrosion resistance and lubricating performance were enhanced remarkably with silicone oil infusion. • Oiled Ni-Co-MSNs nanocomposite coating is a good candidate of fastener coating. [ABSTRACT FROM AUTHOR]

Abstract: Breast cancer stem cells (BCSCs), which can fully recapitulate the tumor origin and are often resistant to chemotherapy and radiotherapy, are currently considered as a major obstacle for breast cancer treatment. To achieve the goal of both targeting BCSCs and bulk breast cancer cells, we developed 8-hydroxyquinoline-loaded hyaluronan modified mesoporous silica nanoparticles (MSN)-supported lipid bilayers (HA-MSS) and docetaxel-loaded MSS. The results showed that the size of all the nanoparticles was smaller than 200 nm. BCSCs were enriched from MCF-7 cells by a sphere formation method and identified with the CD44+/CD24− phenotype. Quantitative and qualitative analysis demonstrated that HA promotes the uptake of HA-MSS in CD44-overexpressing MCF-7 mammospheres, revealing the mechanism of receptor-mediated endocytosis. DTX or DTX-loaded MSS showed much enhanced cytotoxicity against MCF-7 cells compared with MCF-7 mammospheres, whereas 8-HQ or 8-HQ-loaded HA-MSS showed much enhanced cytotoxicity against MCF-7 mammospheres compared with MCF-7 cells. In the MCF-7 xenografts in mice, the combination therapy with DTX-loaded MSS plus 8-HQ-loaded HA-MSS produced the strongest antitumor efficacy, with little systemic toxicity (reflecting by loss of body weight) in mice. Thus, this combination therapy may provide a potential strategy to improve the therapy of breast cancer by eradication of breast cancer cells together with BCSCs. [Copyright &y& Elsevier]

Abstract: This paper describes the fabrication of a highly efficient, non-cytotoxic drug delivery platform designed for photodynamic therapy (PDT): phospholipid-capped, protoporphyrin IX–loaded and FITC-sensitized mesoporous silica nanocarriers (Lipo-FMSNs/PpIX). After derivatization with folate on the phospholipid-capped FMSNs (denoted fa-Lipo-FMSNs/PpIX, the so-called nanoPDT system), we confirmed the nanoPDT systems' selective targeting of and entry into the folic acid receptor-overexpressed HeLa cells by means of cell viability assessment and confocal microscopic analysis. The decrease in the unfavorable dark toxicity of fa-Lipo-FMSNs/PpIX enabled the delivery of high concentrations of PpIX into cells. Moreover, the cellular uptake of the nanoPDT systems was greater than that of free PpIX. Upon irradiation with visible light, the nanoPDT system generated singlet oxygen efficaciously in aqueous environments—a decisive factor affecting its therapeutic applicability in PDT, demonstrating enhanced in vitro photocytotoxicity. Furthermore, an in vivo study of subcutaneous melanoma in nude mice inoculated with B16F10 cells revealed the capability for the nanoPDT system to mitigate nearly 65% of tumor growth. [Copyright &y& Elsevier]

Abstract: A novel reduction-responsive drug delivery system was successfully constructed with mesoporous silica nanoparticle (MSN) core as a drug carrier and poly(acrylic acid) (PAA) shell crosslinked by disulfide linkages as a drug release switcher. To keep the pore structure of MSN intact, PAA was covalently attached to the exterior surface of MSN before removing structure-template via radical polymerization. After removing structure-template and loading doxorubicin (DOX), the PAA shell was crosslinked by cystamine dihydrochloride through amidation reaction. The loading content and the entrapment efficiency of DOX could reach up to 40.2% and 80.4%, respectively. Because that the dissociation of disulfide linkage is reduction-responsive, the release behavior of DOX could be controlled by varying the concentration of reductant, and the release rate was 49.4% after 24h with the existence of 2mM glutathione (simulated environment of cancer cells), about three times higher than that of without glutathione (corresponding to normal human cells), which was only 16.9%. The in vitro cell assays demonstrated that the disulfide linkages crosslinked MSN–PAA (MSN–PAA-crosslinked) was highly biocompatible and suitable to use as drug carrier, and the DOX loaded MSN–PAA-crosslinked showed remarkable cytotoxicity to HeLa cells (human cancer cells), and relatively lower cytotoxicity to 293 cells (human normal cells). These results imply that the MSN–PAA-crosslinked is a promising platform to construct reduction-responsive controlled drug delivery system for cancer therapy. [Copyright &y& Elsevier]