Surface Of Mesoporous Silica Nanoparticles Research Articles

DNA Nanoparticle Based 2D Biointerface to Study the Effect of Dynamic RGD Presentation on Stem Cell Adhesion and Migration.

The native extracellular matrix (ECM) undergoes constant remodeling, where adhesive ligand presentation changes over time and in space to control stem cell function. As such, it is of interest to develop 2D biointerfaces able to study these complex ligand stem-cell interactions. In this study, a novel dynamic bio interface based on DNA hybridization is developed, which can be employed to control ligand display kinetics and used to study dynamic cell-ligand interaction. In this approach, mesoporous silica nanoparticles (MSN) are functionalized with single-strand DNA (MSN-ssDNA) and spin-coated on a glass substrate to create the 2D bio interface. Cell adhesive tripeptide RGD is conjugated to complementary DNA strands (csDNA) of 9, 11, or 20 nucleotides in length, to form csDNA-RGD. The resulting 3 csDNA-RGD conjugates can hybridize with the ssDNA on the MSN surface, presenting RGD with increased ligand dissociation rates as DNA length is shortened. Slow RGD dissociation rates led to enhanced stem cell adhesion and spreading, resulting in elongated cell morphology. Cells on surfaces with slow RGD dissociation rates also exhibited higher motility, migrating in multiple directions compared to cells on surfaces with fast RGD dissociation rates. This study contributes to the existing body of knowledge on dynamic ligand-stem cell interactions.

PEGylation of Mesoporous Silica Nanoparticles for Drug Delivery Applications

Mesoporous silica nanoparticles (MSNs) and PEGylated mesoporous silica nanoparticles (PEG-MSNs) were synthesized and characterized for potential targeted drug delivery applications. In this study, MSNs were synthesized via a sol-gel process to investigate in vitro drug release efficacy and subsequently PEGylated to impart colloidal stability and biocompatibility for future mouse model experiment. Comprehensive characterization techniques, including Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) analysis, and zeta potential measurements were employed. SEM analysis revealed uniformly distributed spherical nanoparticles with smooth surfaces, while FTIR confirmed the successful PEGylation in the surface of MSNs. BET analysis also indicated a reduction in surface area, pore volume, and pore size upon PEGylation, suggesting that PEG chains influence the nanoparticle structure. Zeta potential measurements showed a shift from negative to positive surface charge post-PEGylation, indicating improved colloidal stability. Drug loading and release studies utilizing doxorubicin hydrochloride (DOX) demonstrated a controlled release profile, with MSNs exhibiting a higher cumulative release compared to PEG-MSNs over 24 h. These findings underscore the potential of PEG-MSNs for controlled drug delivery, offering advantages such as reduced systemic toxicity and enhanced therapeutic efficacy for PEG-MSNs nanocarrier in the animal studies due to their increased colloidal stability.

Towards the preparation of smart drug delivery platforms for colorectal cancer therapy: Biocompatible and targeted mesoporous silica nanoparticles with the deferiprone-copper complex gatekeeper

BackgroundAchieving smart drug release and preventing premature leakage throughout the delivery journey are two crucial factors that are essential to take into account in the design of nanocarriers. Mesoporous silica nanoparticles (MSNs) can be modified with gatekeeper molecules to achieve controlled release behavior, making them highly promising nanocarriers for smart drug delivery purposes. MethodsHerein, we introduced a novel gatekeeper in the form of an inverted umbrella, consisting of a deferiprone (DFP)-copper complex, which was strategically immobilized on the surface of MSNs to facilitate smart and controlled release of doxorubicin (DOX) within tumor cells. Polyethylene glycol (PEG) polymer and aptamer were further added onto the surface of the nanocarrier to enhance its biocompatibility, and targeting capabilities. The physicochemical characteristics of the targeted nanoplatform, Apt-PEG-DOX@GNP, were investigated, and its anti-cancer effect was evaluated against C26 cells and CHO cells to assess its specificity. In order to evaluate the anti-tumor efficacy, possible side effects, and biodistribution of the prepared nanocarriers, the in vivo experiment was carried out on BALB/c mice bearing colorectal tumors. ResultsThe substantial surface area of MSNs, measuring 339 m2/g, facilitated effective encapsulation of DOX with a maximum loading 23 % ± 2.05. Preparation of Apt-PEG-DOX@GNP yielded uniform particles with an average diameter of 144.73 ± 11.29 nm. The Apt-PEG-DOX@GNP demonstrated iron-dependent release behaviors, wherein the cleavage of DFP−COOH-Cu(II) bonds decorating the silica nanoparticles occurred asynchronously, leading to the formation of new DFP−COOH-Fe(II) bonds for the subsequent release of DOX. The in vivo experiments revealed that the biocompatible nanocarriers displayed targeted toxicity towards C26 tumor-bearing BALB/c mice, resulting in minimal side effects. ConclusionOur prepared novel nanoplatforms showed promising potential for targeted treatment of colorectal cancer and precise control over the drug release.

Precision drug delivery through methotrexate and tofacitinib citrate encapsulated mesoporous silica scaffold

Background: Advancements in drug delivery aim to enhance outcomes while reducing adverse effects. Mesoporous silica nanoparticles (MSN) offer potential for targeted delivery due to their unique properties, including ordered pore structure, large surface area, and biocompatibility. Methods: MSN were synthesized using tetraethyl orthosilicate (TEOS) and Pluronic F127, then amine-functionalized with 3-aminopropyltriethoxysilane. Methotrexate and tofacitinib citrate were loaded via incipient wetness impregnation. Characterization included FTIR, particle size analysis, TEM, SEM, DSC, XRD, and BET analysis. Results: FTIR confirmed surface modification. Particle size analysis showed nanoscale dimensions. TEM and SEM depicted ordered mesoporous structures. DSC indicated drug crystallinity and MSN amorphism. XRD revealed reduced drug crystallinity in MSN. BET analysis demonstrated high MSN surface area and pore volume. Drug-loading efficiency was 62.44%. Conclusion: Comprehensive synthesis and characterization of MSN for targeted drug delivery were achieved successfully, highlighting their potential in overcoming conventional therapy limitations.

Label-free fluorescent biosensor based on AuNPs etching releasing signal for miRNA-155 detection

Quantitative microRNA (miRNA) detection is crucial for early breast cancer diagnosis and prognosis. However, quick and stable fluorescence sensing for miRNA identification is still challenging. This work developed a novel label-free detection method based on AuNPs etching for quantitatively detecting miRNA-155. A layer of AuNPs was grown on the surface of mesoporous silica nanoparticles (MSN) loaded with Rhodamine 6G (R6G) using seed-mediated growth, followed by probe attachment. In the presence of miRNA-155, the MSN@R6G@AuNP surface loses the protection of the attached probe, rendering AuNPs susceptible to etching by hydrochloric acid. This results in a significant fluorescent signal being released in the free space. The encapsulation with AuNPs effectively reduces signal leakage, while the rapid etching process shortens detection time. This strategy enables sensitive and fast detection with a detection range of 100 fM to 100 nM, a detection limit of 2.18 fM, and a detection time of 30 min. The recovery rate in normal human serum ranges from 99.02 % to 106.34 %. This work presents a simple biosensing strategy with significant potential for application in tumor diagnosis.

Study of the anti-cancer activity of a mesoporous silica nanoparticle surface coated with polydopamine loaded with umbelliprenin

A mesoporous silica nanoparticle (MSN) coated with polydopamine (PDA) and loaded with umbelliprenin (UMB) was prepared and evaluated for its anti-cancer properties in this study. Then UMB-MSN-PDA was characterized by dynamic light scattering (DLS), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and FTIR methods. UV-visible spectrometry was employed to study the percentage of encapsulation efficiency (EE%). UMB-MSN-PDA mediated cell cytotoxicity and their ability to induce programmed cell death were evaluated by MTT, real-time qPCR, flow cytometry, and AO/PI double staining methods. The size of UMB-MSN-PDA was 196.7 with a size distribution of 0.21 and a surface charge of −41.07 mV. The EE% was 91.92%. FESEM and TEM showed the spherical morphology of the UMB-MSN-PDA. FTIR also indicated the successful interaction of the UMB and MSN and PDA coating. The release study showed an initial 20% release during the first 24 h of the study and less than 40% during 168 h. The lower cytotoxicity of the UMB-MSN-PDA against HFF normal cells compared to MCF-7 carcinoma cells suggested the safety of formulation on normal cells and tissues. The induction of apoptosis in MCF-7 cells was indicated by the upregulation of P53, caspase 8, and caspase 9 genes, enhanced Sub-G1 phase cells, and the AO/PI fluorescent staining. As a result of these studies, it may be feasible to conduct preclinical studies shortly to evaluate the formulation for its potential use in cancer treatment.

Conformation-Switchable Polypeptides as Molecular Gates for Controllable Drug Release.

The control over secondary structure has been widely studied to regulate the properties of polypeptide materials, which is used to change their functions in situ for various biomedical applications. Herein, we designed and constructed enzyme-responsive polypeptides as gating materials for mesoporous silica nanoparticles (MSNs), which underwent a distorted structure-to-helix transition to promote the release of encapsulated drugs. The polypeptide conjugated on the MSN surface adopted a negatively charged, distorted, flexible conformation, covering the pores of MSN to prevent drug leakage. Upon triggering by alkaline phosphatase (ALP) overproduced by tumor cells, the polypeptide transformed into positively charged, α-helical, rigid conformation with potent membrane-penetrating capabilities, which protruded from the MSN surface to uncover the pores. Such a transition thus enabled cancer-selective drug release and cellular internalization to efficiently kill tumor cells. This study highlights the important role of chain flexibility in modulating the biological function of polypeptides and provides a new application paradigm for synthetic polypeptides with secondary-structure transition.

Mesoporous silica-based pH/enzyme dual-response system: Nanoparticles for smart delivery of indoxacarb with improved insecticidal activity and biocompatibility

Mesoporous silica nanoparticles (MSN) are ideal carriers for agrochemical control release systems due to their smart environmental stimulus response by easy modification. Herein, MSN loaded with indoxacarb (IN) were successfully prepared using the hard template method. Dopamine (DA) and α-cyclohexapentylose (α-CD) were encapsulated around the MSN surface to obtain pH and enzyme dual-response nanoparticles (IN@MSN@PDA@α-CD). The prepared nanoparticles showed a spherical core-shell structure with a loading content of 22.5 %, and the polymer coating covering the surface of the nanoparticles effectively protected IN from photolysis. Moreover, different biostimuli associated with Spodoptera frugiperda can trigger the release of IN from nanoparticles. Compared with the commercial emulsifiable concentrate (14.93 mg L−1), IN@MSN@PDA@α-CD (8.89 mg L−1) extended the effective duration of IN against Spodoptera frugiperda, and considerably decreased the toxicity of IN to Eisenia fetida, zebrafish and human BEAS-2B cells. Thus, pH/enzyme dual-responsive nanoparticles have substantial potential for sustainable on-demand targeted delivery of agrochemicals and for improving their environmental safety.

Gint4.T-siHDGF chimera-capped mesoporous silica nanoparticles encapsulating temozolomide for synergistic glioblastoma therapy

Due to glioblastoma (GBM) being the most intractable brain tumor, the continuous improvement of effective treatment methods is indispensable. The combination of siRNA-based gene therapy and chemotherapy for GBM treatment has now manifested great promise. Herein, Gint4.T-siHDGF chimera-capped mesoporous silica nanoparticles (MSN) encapsulating chemotherapy drug temozolomide (TMZ), termed as TMSN@siHDGF-Gint4.T, is developed to co-deliver gene-drug siHDGF and TMZ for synergistic GBM therapy. TMSN@siHDGF-Gint4.T possesses spherical nucleic acid-like architecture that can improve the enzyme resistance of siHDGF and increase the blood-brain barrier (BBB) permeability of the nanovehicle. The aptamer Gint4.T of chimera endows the nanovehicle with GBM cell-specific binding ability. When administered systemically, TMSN@siHDGF-Gint4.T can traverse BBB and enter GBM cells. In the acidic lysosome environment, the cleavage of benzoic-imine bond on MSN surface leads to an initial rapid release of chimera, followed by a slow release of TMZ encapsulated in MSN. The sequential release of siHDGF and TMZ first allows siHDGF to exert its gene-silencing effect, and the downregulation of HDGF expression further enhances the cytotoxicity of TMZ. In vivo experimental results have demonstrated that TMSN@siHDGF-Gint4.T significantly inhibits tumor growth and extends the survival time of GBM-bearing mice. Thus, the as-developed TMSN@siHDGF-Gint4.T affords a potential approach for the combination treatment of GBM.

Albumin Hydrogel-Coated Mesoporous Silica Nanoparticle as a Carrier of Cationic Porphyrin and Ratiometric Fluorescence pH Sensor.

Here, we report that a mesoporous silica nanoparticle (MSN) coated with a fluoresceine-labeled bovine serum albumin (F-BSA) hydrogel layer works as a temperature-responsive nanocarrier for tetrakis-N-methylpyridyl porphyrin (TMPyP) and as a fluorescence ratiometric pH probe. F-BSA hydrogel-coated MSN containing TMPyP (F-BSA/MSN/TMPyP) was synthesized by thermal gelation of denatured F-BSA on the external surface of MSN. The F-BSA hydrogel layer was composed of an inner hard corona layer and an outer soft layer and was stable under physiological conditions. F-BSA/MSN/TMPyP exhibited temperature-dependent exponential release of TMPyP. In this release profile, the MSN was found to be a suitable host for stable encapsulation of tetracationic TMPyP by electrostatic interactions, and the F-BSA hydrogel layer mediated the diffusion of TMPyP from the MSN pore interior into the solution phase. Increasing temperature promoted partitioning of TMPyP from the pore interior to the F-BSA hydrogel layer, from where it was spontaneously released into the bulk solution phase by cation exchange. F-BSA/MSN/TMPyP also gave a linear ratiometric fluorescence response (1.3 per pH unit) in the pH range from 6.1 to 8.9.

Mesoporous silica-supported platinum nanocatalysts for colorimetric detection of glucose, cholesterol, and C-reactive protein.

Noble metal nanoparticles decorated on a catalyst support with a large specific surface area can exhibit enhanced catalytic activity. To this end, a synthetic method to heterogeneously and evenly nucleate platinum nanoparticles (Pt NPs) onto mesoporous silica nanoparticles (MSNs) is developed. The obtained Pt NP-modified MSNs (Pt-MSNs) are characterized as a thin layer of 3 nm-sized Pt NPs densely assembled on the MSN surface, by which the throughput of the peroxidase-like activity of Pt-MSNs is greatly improved. The utility of Pt-MSNs in colorimetric detection of analytes is validated for two different assay schemes. Firstly, colloidally dispersed Pt-MSNs are employed as a peroxidase-mimic in a two-step cascade reaction to quantitate glucose/cholesterol based on the amount of H2O2 produced by glucose/cholesterol oxidase. Secondly, detection of C-reactive protein (CRP) is conducted on a solid substrate by adopting a sandwich immunoassay format. Detection limits are estimated to be 20 μM, 55 μM, and 3.9 pM for glucose, cholesterol, and CRP, respectively.

Formulation development and characterization of luliconazole loaded−mesoporous silica nanoparticles (MCM−48) as topical hydrogel for the treatment of cutaneous candidiasis

The conventional formulation of luliconazole (LCZ) faces challenges such as poor solubility and limited skin retention upon application. Therefore, the focus of this research was to develop and characterize mesoporous silica nanoparticles (MSN) that can effectively deliver luliconazole for the treatment of cutaneous candidiasis fungal infection.The MSNs were optimized by central composite design and synthesized using the sol−gel method. Factors such as stirring time and surfactant ratio were varied to investigate their impact on particle size and Polydispersity index (PDI). Subsequently, the MSN surface was functionalized with both amine (positively charged) and phosphonate groups (negatively charged) using 3-aminopropyltriethoxysilane (APTES) and 3trihydroxysilyl propyl methylphosphonate (THMP).The efficacy of the optimized luliconazole−loaded MSNs was evaluated through various comparative studies, including in-vitro and in-vivo antifungal assessments, ex-vivo permeation and skin retention experiments, acute dermal irritation tests, and histopathological analysis. These evaluations were compared with the pure drug and a commercially available formulation.The optimized MSNs exhibited high porosity and spherical particle sizes ranging from 300 to 400 nm. They demonstrated excellent physical and chemical stability, indicating compatibility between the drug and the MSN structure. The successful loading of luliconazole into the nanopores of the MSNs was confirmed through Brunauer Emmett Teller (BET) analysis.The luliconazole−loaded MSN (LCZ−MSN) gel exhibited a controlled release profile, sustaining drug release for up to 24 h. The solubility of the drug was 12 times higher compared to the free form, and the MSNs enhanced skin retention by six−fold compared to the pure drug. In an in-vivo cutaneous candidiasis rat model, the enhanced efficacy of the MSNs was evident, highlighting the potential of this innovative approach for controlled release and solubility enhancement of poorly soluble drugs, with no observed skin irritation.Overall, this research showcases the potential of mesoporous silica nanoparticles as a promising approach for controlled delivery and improved solubility of poorly soluble drugs like luliconazole, thereby addressing the challenges associated with conventional formulations and offering a novel strategy for treating cutaneous candidiasis fungal infection.

High dispersibility ratiometric fluorescence sensor designed by functionalized mesoporous silica nanopraticles for sensing and imaging of hydrogen peroxide

Herein, a mesoporous silica nanoparticle (MSN) based ratiometric fluorescence nanosensor (MSN-BA-SiCD) with improved performance was designed for monitoring hydrogen peroxide (H2O2). Specifically, H2O2 response molecule (BA) with AIE feature was synthesized and encapsulated into MSN channel as the fluoresent recognition site. Afterwards, silane-modified carbon dot (SiCD) was covalently connected to the MSN surface which can effectively prevent the leakage of BA and improve the water dispersibility of the nanosensor. The presence of H2O2 could result in a “turn-on” fluorescence of BA as well as concurrent variation in the fluorescence resonance energy transfer (FRET) signal between SiCD and BA. MSN-BA-SiCD displays a specific blue-to-green resolved emission change in response to H2O2 and the detection limit can be as low as 4.78 × 10−6 M. In addition, the nanosensor exhibited enhanced photostability due to the protection of the material framework. Moreover, the nanosensing system was successfully applied to detect H2O2 in beer, orange juice and living cells. The excellent water dispersibility and photostability of the nanosensor, together with high specificity and biocompatibility, constituted an advanced set of characteristics among existing MSNs, which was expected to further promote the development of H2O2 sensors in the environmental and biological fields.

Surface Functionalized Mesoporous Silica Nanoparticles for Enhanced Removal of Heavy Metals: A Review

Human health and environmental sustainability are strongly influenced by the contamination of water resources with hazardous heavy metal ions due to the accumulation in human body via food chains. Thereby, researchers’ attention has been paid on effective methods for heavy metal ion scavenging to prevent them releasing to environment. Notably, Mesoporous Silica Nanoparticles (MSNPs) with high surface area, massive surface area to volume ratio, large pore volume and uniform pore distribution play a crucial role in addressing this challenge. Additionally, researchers focus on novel surface functionalization methods of MSNPs with suitable organic and inorganic moieties to amplify the adsorption efficiency of heavy metals. MSNPs possess easily functionalizable surface which facilitates the modifications and enhanced removal of heavy metals. The review article summarizes the different moieties used for functionalization of MSNPs such as amino, thio, carboxyl, phenyl, cyano groups, different types of polymers, inorganic functional groups. Further, a comparison has been made between functional and unmodified MSNPs to elaborate how these modifications have enhanced the removal performance of heavy metals in water. Further, this review provides an overview on different synthesis routes and structure directing agent used in synthesis of MSNPs. Moreover, pH effect on adsorption andreusability of modified NPs, while illustrating the mechanism of adsorption on to modified MSNPs surface has also been elaborated. Maximum adsorption capacity of each functional moiety has been taken into consideration with the aim of supporting future advancements.
 Keywords: Adsorption, Mesoporous silica nanoparticles, Heavy metals, Functionalization, Maximum adsorption capacity

A Novel Fluorescent Aptasensor Based on Mesoporous Silica Nanoparticles for Selective and Sensitive Detection of Saxitoxin in Shellfish

Background: Saxitoxin (STX) stands as one of the most potent marine biotoxins, exhibiting high lethality. Despite its severity, current treatments remain ineffective, and existing detection techniques are limited due to ethical concerns and technical constraints. Methods: Herein, an innovative approach was constructed for STX detection, utilizing mesoporous silica nanoparticles (MSN) as a foundation. This innovative, easy, and label-free aptamer (Apt)- sensor was fabricated. Apts were employed as molecular identification probes and "gated molecules," while rhodamine 6G was encapsulated within particles to serve as a signal probe. In a lack of STX, Apts immobilized on an MSN surface kept a "gate" closed, preventing signal probe leakage. Upon the presence of STX, the "gate" opened, allowing a particular binding of Apts to STX and a subsequent release of a signal probe. Results: Experimental results demonstrated a positive correlation between fluorescence intensity and concentrations of STX within a range of 1 to 80 nM, with an exceptional limit of detection of 0.12 nM. Furthermore, the selectivity and stability of a biosensor were rigorously evaluated, validating its reliability. Conclusion: This newly developed sensing strategy exhibits remarkable performance in STX detection. Its success holds significant promise for advancing portable STX detection equipment, thereby addressing a pressing need for efficient and ethical detection methods in combating marine biotoxin contamination.

Matrix metalloproteinase degradable, in situ photocrosslinked nanocomposite bioinks for bioprinting applications

The development of suitable bioinks with high printability, mechanical strength, biodegradability, and biocompatibility is a key challenge for the clinical translation of 3D constructs produced with bioprinting technologies. In this work, we developed a new type of nanocomposite bioinks containing thiolated mesoporous silica nanoparticles (MSN) that act as active fillers within norbornene-functionalized hydrogels. The MSNs could rapidly covalently crosslink the hydrogels upon exposure to UV light. The mechanical properties of the gels could be modulated from 9.3 to 19.7 kPa with increasing concentrations of MSN. The ability of the MSN to covalently crosslink polymeric networks was, however, significantly influenced by polymer architecture and the number of functional groups. Modification of the outer surface of MSNs with matrix metalloproteinase (MMP) sensitive peptides (MSN-MMPs) resulted in proteinase K and MMP-9 enzyme responsive biodegradable bioinks. Additional cysteine modified RGD peptide incorporation enhanced cell-matrix interactions and reduced the gelation time for bioprinting. The nanocomposite bioinks could be printed by using extrusion-based bioprinting. Our nanocomposite bioinks preserved their shape during in vitro studies and encapsulated MG63 cells preserved their viability and proliferated within the bioinks. As such, our nanocomposite bioinks are promising bioinks for creating bioprinted constructs with tunable mechanical and degradation properties.

Enhancing of anticancer efficiency of curcumin by functionalization of phosphonate functional group on surface of mesoporous nanosilica

The functionalization of the surface of silica-based nanoparticles with targeting ligands has demonstrated remarkable efficacy in enhancing their activity. In this study, the surface of mesoporous silica nanoparticles (MSN) was functionalized with the phosphonate group (-PO3) to facilitate the adsorption and targeted delivery of curcumin to cancer cells, concurrently significantly enhancing the stability of the nanomaterial. Methodologies including scanning electron microscopy, Fourier transform infrared spectroscopy, N2 adsorption isotherms, and thermal gravimetric analysis were systematically employed to characterize the features of the nanomaterials. The assessment of curcumin loading efficiency within both MSN and phosphonate-functionalized MSN (MSN-PO3) was conducted, predicated upon interactions with the loading solvent and the material's stability. Notably, stability assays revealed that unmodified particles exhibited agglomeration within a 96-h period, while their modified counterparts maintained their structural integrity. Moreover, discerning outcomes from in vitro cytotoxicity assays unveiled the potent efficacy of curcumin-loaded materials against colorectal cancer cells (C-26), with minimal impact on fibroblast cells (L929). These collective results substantiate the role of these materials as efficacious nanocarriers for delivering anticancer drugs.

DPP-Cu2+ Complexes Gated Mesoporous Silica Nanoparticles For pH and Redox Dual Stimuli-Responsive Drug Delivery.

A simple pH and redox dual stimuli-responsive diketopyrrolopyrrole (DPP)-Cu2+ complexes gated mesoporous silica nanoparticles (MSN) were prepared for precise drug delivery and controlled drug release. MSN was prepared by sol-gel method and then laminated. Carboxylic acid (CA)-Pyrrolo[3,4-c] pyrrole-1,4-dione, 2,5-dihydro-3,6-di-2-pyridinyl (PyDPP) was grafted onto the surface of amino-functionalized MSN (MSN-NH2) through a simple amide reaction and then complexed with Cu2+ to form gated molecules after doxorubicin (DOX) loading. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Low-angle X-ray diffraction (XRD) showed that MSN with uniform particle size (100 nm) and porous structure was successfully prepared. The prepared MSN, MSN- NH2, and MSN-DPP were fully characterized by Zeta potential, Fourier transforms infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption- desorption. High DOX-loading capacity (18.22%) and encapsulation efficiency (89.16%) were achieved by optimizing the mass ratio of MSN to DOX. Release studies showed that the gated molecules of our designed DPP-Cu2+ complexes had a good blocking effect under physiological conditions (the cumulative release rate of drugs within 24 hours was only 4.18%) and responded well to the pH and redox glutathione (GSH) dual stimuli. In vitro cytotoxicity assay showed that MSN-DPP-Cu2+ had good biocompatibility in both Hep G2 cells and L02 cells (the relative cell viability of both cells within 48 hours was above 97%), and the MSN-DPP-Cu2+@DOX could be triggered for efficient drug release in Hep G2 cells. The MSN-DPP-Cu2+ described in this research may be a good delivery system for the controlled release of antitumor drugs and can provide a potential possibility for clinical application in the future.

In Vitro Antimicrobial Studies of Mesoporous Silica Nanoparticles Comprising Anionic Ciprofloxacin Ionic Liquids and Organic Salts.

The combination of active pharmaceutical ingredients in the form of ionic liquids or organic salts (API-OSILs) with mesoporous silica nanoparticles (MSNs) as drug carriers can provide a useful tool in enhancing the capabilities of current antibiotics, especially against resistant strains of bacteria. In this publication, the preparation of a set of three nanomaterials based on the modification of a MSN surface with cholinium ([MSN-Chol][Cip]), 1-methylimidazolium ([MSN-1-MiM][Cip]) and 3-picolinium ([MSN-3-Pic][Cip]) ionic liquids coupled with anionic ciprofloxacin have been reported. All ionic liquids and functionalized nanomaterials were prepared through sustainable protocols, using microwave-assisted heating as an alternative to conventional methods. All materials were characterized through FTIR, solution 1H NMR, elemental analysis, XRD and N2 adsorption at 77 K. The prepared materials showed no in vitro cytotoxicity in fibroblasts viability assays. The minimum inhibitory concentration (MIC) for all materials was tested against Gram-negative K. pneumoniae and Gram-positive Enterococcus spp., both with resistant and sensitive strains. All sets of nanomaterials containing the anionic antibiotic outperformed free ciprofloxacin against resistant and sensitive forms of K. pneumoniae, with the prominent case of [MSN-Chol][Cip] suggesting a tenfold decrease in the MIC against sensitive strains. Against resistant K. pneumoniae, a five-fold decrease in the MIC was observed for all sets of nanomaterials compared with neutral ciprofloxacin. Against Enterococcus spp., only [MSN-1-MiM][Cip] was able to demonstrate a slight improvement over the free antibiotic.

Ultrasound-assisted synthesis of MSNs/PS nanocomposite membranes for effective removal of Cd2+ and Pb2+ ions from aqueous solutions

Contamination of heavy metal (Cd2+ & Pb2+) ions in drinking water is producing major impacts on the environment and public health and is considered one of the greatest dangers to humanity. Membrane technology has been chosen over other processing methods due to its simplicity and high capacity for more effective removal of hazardous heavy metals. In the current study, amine, thiol, and bi-thiol functional groups were used to functionalize mesoporous silica nanoparticles (MSNs) to improve the efficiency of the silica nanoparticle. The morphology of the MSNs as well as the existence of amine and thiol on the surface of MSNs was demonstrated by a variety of characterization techniques, including FTIR, TEM, and SEM examination. The impact of surface-modified MSNs on the morphology, properties, and performance of polysulfone (PS) nanofiltration (NF) membranes was also evaluated. The membrane that incorporated amine with thiol-based MSNs (DiMP-MSNs/PS-NF membrane) had the highest pure water permeability (6.7 LMH bar−1). As a result of the functional groups, the surface-modified MSNs/PS nanofiltration are extremely effective at removing heavy metal ions from aqueous solutions. The surface-modified MSNs/PS nano-filtration membranes exhibit unprecedented Cd2+ and Pb2+ removal rates of approximately 82% and 99%, respectively. This research indicates the possible application of the surface-modified MSNs/PS nanofiltration membrane as a promising platform to remove heavy metal ions from polluted water.