Mesoporous System Research Articles

Construction of multifunctional mesoporous silicon nano-drug delivery system and study of dual sensitization of chemo-photodynamic therapy in vitro and in vivo

This study was conducted to construct a multifunctional nanodrug delivery system (NDDS) to deplete glutathione (GSH) in tumor cells and amplify oxidative stress, enhancing the synergistic effect of chemotherapy and photodynamic therapy (PDT). l-Buthionine-sulfoximine (BSO) and chlorin e6 (Ce6) were loaded into mesoporous silicon nanoparticles (MSN), and then MSN were modified with oxidized hyaluronic acid (OHA) as a pore-blocking agent. Cisplatin (Pt(II)) was further loaded by a coordination reaction with carboxyl groups in OHA to yield a multifunctional NDDS (denoted as MSN@OHA-Ce6/BSO/Pt). The physicochemical properties and antitumor activity of the prepared nanoparticles were characterized in detail. In vitro and in vivo experiments demonstrated that OHA was shed from MSN@OHA-Ce6/BSO/Pt under acidic conditions in tumors, resulting in the release of free BSO, Ce6, and Pt(II). The released BSO could reduce intracellular GSH expression by 48.8 %, effectively enhancing the PDT effect of Ce6 and the chemotherapy effect of Pt(II). Finally, the tumor inhibitory rate (vs saline) reached 73.8 % ± 2.5 % for MSN@OHA-Ce6/BSO/Pt in A549/DDP tumor-bearing nude mice. Therefore, the multifunctional NDDS significantly enhanced the synergistic effect of PDT and chemotherapy.

Synthesis of mesoporous TiO2‐MCM‐41 photocatalyst for quinolone antibiotics removal from aqueous solution

AbstractIn this paper, a significant aspect of using TiO2 photocatalyst immobilized on MCM‐41 mesoporous material by sol‐gel method for ciprofloxacin (CIP) and norfloxacin (NOR) antibiotics removals was studied. The structure and morphology of the materials were evaluated by X‐ray diffraction (XRD), energy‐dispersive X‐ray spectrometer analysis combined with field‐emission scanning electron microscopy (FESEM‐EDX), fourier transform infrared spectroscopy (FTIR), transmission electron microscopes (TEM), and N2 adsorption‐desorption isotherms (BET) methods. Characterization results indicated that the presence of TiO2 anatase phase with relatively high TiO2 content (up to 60 % by weight) did not destroy the mesopore system of MCM‐41 substrate. Photoactivity of the catalyst was tested through the degradation of two quinolone antibiotics, CIP, and NOR. In this study, the factors affecting the decomposition efficiency of the above pharmaceutical antibiotics such as, the immobilized content of TiO2 and the concentrations of antibiotics as and catalyst were also evaluated using Langmuir‐Hinshelwood (LH) model. The TiO2 immobilized on MCM‐41 material showed a better ability to remove CIP and NOR antibiotics than the commercial TiO2 nanoparticles (P25) due to the high dispersion of active sites on an MCM‐41 high specific surface area mesoporous substrate.

Development of Pore Morphology During Nitrate Group Removal by Calcination of Mesoporous CexZr1-x-y-zYyLazO2-δ Powders.

Here, we present a study of the development of the micro- and mesoporosity of a CexZr1-x-y-zYyLazO2-δ oxygen storage material upon treatment at temperatures up to 1050 °C. The investigated powder, obtained from nitrate-based metal oxide precursors in a specially developed hydrothermal synthesis, is highly crystalline, features a high surface area and does not show phase segregation at high temperatures. By employing an advanced methodology, consisting of state-of-the-art argon physisorption, thermogravimetric analysis coupled with mass spectrometry (TG-MS) and X-ray powder diffraction (XRD) along with Raman spectroscopy, we correlate the stability of the mesopore system to the presence of surface-bound nitrate groups introduced during synthesis, which prevent sintering up to a temperature of 600 °C. In addition, the connectivity of mesopores was further studied by hysteresis scanning within the argon physisorption measurements. These advanced physisorption experiments suggest a three-dimensionally interconnected pore system and, in turn, a 3D network of the material itself on the nanometer scale which appears to be beneficial to endow the mesopore space with enhanced stability against sintering and mesopore collapse once the removal of nitrate groups is completed.

Conversion of cellulose to glucose and further transformation into fuels over solid acid catalysts: A mini review

The abundant of cellulose biomass resources and the projected global market escalations for allied chemicals and fuels inferred that large-scale valorization would benefit the global energy and chemical industries. In line with this strategy, the paper carefully reviewed and examined resourceful literature on the potentials of solid acids for cellulose-to-glucose reaction and the transformation into fuels/chemicals. It initially evaluated the cellulose to glucose path by considering ionic liquids as the media for hydrolysis. The influence of employing sulfonated mesoporous carbon systems was adequately explored. In addition to critical analysis of the cellulose to sugar alcohols, the paper also analyzed the role of Fe-modified zeolites for glucose upgrading. It simultaneously discussed the parameters necessary for process upgrade and addressing catalyst-stability challenges. We have also provided new directions for further investigations in line with the findings established.

Functionalized Mesoporous MCM-41 for the Adsorption of Various Pharmaceutical Compounds

This study aims to evaluate the adsorption performance of an amine-functionalized MCM–41 mesoporous silica nanoparticles system (MCM–41–NH2) as an adsorbent for the removal of different pharmaceutical pollutants from aqueous solutions. The modification of MCM-41 was achieved through post-synthesis treatment in the presence du 3-Aminopropyltriethoxysilane (APTES). Surface and structural characteristics of MCM-41 and MCM–41–NH2 were examined using N2 adsorption–desorption analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and point of zero charge analysis. In addition, thermal stability was investigated by thermogravimetric analysis. The kinetics study shows that adsorption on MCM–41–NH2 follows pseudo-second-order rate expression. Isotherm study showed that the experimental data fitted well with the Langmuir equation. Moreover, the maximum adsorption capacities of MCM–41–NH2 were: (129.8, 272.0, 233.2 and 318.6) mg/g for Diclofenac, Ibuprofen, Oxacillin and Trihydrated Amoxicillin respectively). The adsorption is controlled by the surface charges of the adsorbent and the adsorbate. Compared with other adsorbents, MCM–41–NH2 was more effective for the different pharmaceutical removal.

Chemiluminescence sensing of adenosine using DNA cross-linked hydrogel-capped magnetic mesoporous silica nanoparticles

At present, a host of high-sensitivity and selective tumor marker detection methods play a central role in various research fields and assay platforms. Here, a method for DNA cross-linked hydrogel-capped magnetic core-shell structure mesoporous silica nanoparticles (Fe3O4@nSiO2@mSiO2) based on target stimulus was proposed. Specifically, Fe3O4@nSiO2@mSiO2 nanoparticles with nucleic acid promoter units were prepared. The promoter induces the predesigned modified polyacrylamide DNA strand to carry out hybridization chain reaction on the surface of Fe3O4@nSiO2@mSiO2 nanoparticles, forming a hydrogel coating on the surface of Fe3O4@nSiO2@mSiO2 nanoparticles. Under the stimulation of adenosine, Fe3O4@nSiO2@mSiO2 released the signal molecule luminol. Simultaneously, the MIL-101（Fe）material, a signal amplification molecule, was released from the DNA hydrogel. Compared with the traditional gated mesoporous silica system, the DNA hydrogel-coated Fe3O4@nSiO2@mSiO2 is not easy to leak and has a higher loading capacity. In addition, the optical background of DNA hydrogels is low, combined with MOFs materials, even about 1.4 × 10−10 M adenosine can be detected in this biosensor. Based on the combination of DNA hydrogels, MOFs conjugates and gating systems, the construction of biosensors will be more eye-catching, which will expand new ideas for biosensor platform manufacturing.

Study on the structure and properties of Fe3O4@HMPDA@HA magnetic hollow mesoporous submicron drug-carrying system

In this study, Fe 3 O 4 @HMPDA@HA core-shell submicron particles with a large specific surface area and total pore volumes were prepared. A large cavity structure was constructed between the core and the shell, so the core-shell particles as drug carriers have a large loading capacity. The adsorption properties and mechanism of organic dyes RhB and MB on particles were studied. The results showed that the adsorption capacities of the particles to RhB and MB were 830.65 mg/g and 380.66 mg/g respectively. And doxorubicin (DOX) was used as a targeted drug to research the delivery and sustained-release properties of the particles, the results showed that the loading capacity of DOX was up to 624.75 mg/g. In addition, Hyaluronic acid (HA) can specifically recognize the cancer cells, so the above prepared particles combined magnetic targeting and receptor-mediated targeting. In vitro experiments, the DOX loaded particles had a significant inhibitory effect on HeLa cells. • A large cavity structure between core and shell endowed the drug carriers a large loading capacity. • HA can specifically recognize the cancer cells. • Fe 3 O 4 nanoparticles endowed the drug carriers a magnetic targeting performance. • The DOX release rate was significantly higher under acidic conditions. • In vitro experiment, the DOX-loaded Fe 3 O 4 @MPDA nanospheres can evidently inhibit the growth of cancer cells.

A pH-responsive mesoporous silica nanoparticle-based drug delivery system for targeted breast cancer therapy.

In order to make the drug specifically aggregate at the tumor site, we had developed a targeted drug delivery system based on pH responsive mesoporous silica nanoparticles. Mesoporous silica nanoparticles (MSN-COOH) were prepared and doxorubicin (DOX) was loaded into the pores of MSN-COOH, and then polyethyleneimine (PEI) and anisamide (AA) were modified on the surface of mesoporous silica, named DOX@MSN-PEI-AA(DMPA). DMPA specifically entered tumor cells through AA-mediated receptor endocytosis; PEI dissociated from the surface of the MSN in the acidic environment of cellular lysosomes/endosomes due to protonation of PEI, resulting in steady release of the encapsulated DOX from the pores of MSN in the cytoplasm of the target cells. In vitro and in vivo anti-tumor experiments and hemolytic experiments indicated that DMPA can accurately target breast cancer cells and show excellent safety at the same time, showing great potential for tumor therapy.

The Role of Transmission Electron Microscopy in the Early Development of Mesoporous Materials for Tissue Regeneration and Drug Delivery Applications.

For the last 20 years, silica-based mesoporous materials have provided a sound platform for the development of biomedical technology applied to tissue engineering and drug delivery. Their unique structural and textural characteristics, chiefly, the ordered distribution of homogeneous and tunable pores with high surface areas and large pore volume, and their excellent biocompatibility provide an excellent starting point for bone tissue regeneration on the mesoporous surface, and also to load species of interest inside the pores. Adequate control of the synthesis conditions and functionalization of the mesoporous surface are critical factors in the design of new systems that are suitable for use in specific medical applications. Simultaneously, the use of appropriate characterization techniques in the several stages of design and manufacture of mesoporous particles allows us to ascertain the textural, structural and compositional modifications induced during the synthesis, functionalization and post-in vitro assays processes. In this scenario, the present paper shows, through several examples, the role of transmission electron microscopy and associated spectroscopic techniques in the search for useful information in the early design stages of mesoporous systems, with application in the fields of tissue regeneration and drug delivery systems.

Improving the supercapacitor performance of activated carbon materials derived from pretreated rice husk

In this study, the application of high specific surface area activated carbon prepared from rice husk (RHAC) as a supercapacitor electrode was reported. To enhance the pore-making efficiency of activator, pretreatment using NaOH solution or K2CO3 solution was adopted. Seven samples of RHAC were prepared at different pretreatment conditions and characterized with their specific surface area, pore structure and electrochemical performance. The alkaline solution pretreatment of rice husk developed a more advanced mesopore system, which greatly increased the RHAC specific surface area and electrochemical performance when applied to the supercapacitor electrode. The maximum specific capacitance (up to 325 F g−1) and outstanding cycling stability (up to 285 F g−1 after 10,000 cycles) were obtained by the RHAC-b sample (specific surface area of 2556.8 m2 g−1) which was prepared with 10% K2CO3 pretreatment.

Progressive regulation of Al sites and Cu distribution to increase hydrothermal stability of hierarchical SSZ-13 for the selective catalytic reduction reaction

As a commercial catalyst for selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3), hydrothermal stability is critical to the lifetime of copper-based SSZ-13. Adjusting the appropriate distribution of framework Al sites and the active copper ions can improve the hydrothermal stability of Cu-SSZ-13. Here we present a hierarchical SSZ-13 catalyst that prepared by the collaborative effect of two organic templates. The employ of C16H33-[N+-methylpiperidine] (C16MPBr) successfully introduced the hydrophobic mesoporous system into the catalyst. Detailed characterizations illustrate that the density of paired Al in the SSZ-13 framework increased with increasing content of C16MPBr in the crystalline gels. The increase in the content of paired Al conversely promotes the generation of more hydrothermally stable Cu2+-2Z species in the six-membered rings sites. This effectively suppresses the loss of active copper ions and dealumination of the framework during the hydrothermal aging, therefore, the hydrothermal stability of the catalyst is remarkably improved.

An intelligent responsive macrophage cell membrane-camouflaged mesoporous silicon nanorod drug delivery system for precise targeted therapy of tumors

Macrophage cell membrane-camouflaged nanocarriers can effectively reduce immune cell clearance and actively target tumors. In this study, a macrophage cell membrane-camouflaged mesoporous silica nanorod (MSNR)-based antitumor drug carrier equipped with a cationic polymer layer was developed. As drug carriers, these MSNRs were loaded with the thermosensitive phase change material L-menthol (LM), the chemotherapy drug doxorubicin (DOX) and the fluorescent molecule indocyanine green (ICG). The rod-like shape of the MSNRs was shown to enhance the penetration of the drug carriers to tumors. In the weakly acidic tumor microenvironment, the cationic polymer exhibited a proton sponge effect to trigger macrophage cell membrane coating detachment, promoting tumor cell uptake. Following nanocarrier uptake, ICG is heated by near-infrared (NIR) irradiation to make LM undergo a phase transition to release DOX and generate a synergistic effect of thermochemotherapy which kills tumor cells and inhibits tumor growth together with reactive oxygen species (ROS) produced by ICG. Overall, this nanohybrid drug delivery system demonstrates an intelligent cascade response, leads to tissue-cell specific targeting and improves drug release accuracy, thus proving to be an effective cancer therapy.Graphical

Theoretical and experimental insights into electron-induced efficient defluorination of perfluorooctanoic acid and perfluorooctane sulfonate by mesoporous plasma

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are global environmental pollutants and pose significant threats to environmental safety and human health. Defluorination of PFOA and PFOS was investigated theoretically and practically in a mesoporous plasma system in this study. Rapid and highly efficient defluorination was realized, and 98% and 65% defluorination rate for PFOA and PFOS, respectively, were obtained within 60 min of treatment. Electrons generated in the mesoporous plasma system played a decisive role in PFOA and PFOS defluorination; other species, including 1O2 and ·OH, also contributed to defluorination. C-F, C-C, and C-S bonds were broken by plasma oxidation; various shorter-chain perfluorocarboxylic acids, polyfluoroalkyl substances, and alcohols were produced. PFOA and PFOS decomposition mechanisms involved electron transfer, defluorination, decarboxylation, and hydroxylation reactions. Desulfonation reactions were also involved in PFOS decomposition. Density functional theory calculations identified sites susceptible to be attacked and the main degradation pathways. Effective defluorination of PFOA and PFOS reduced their toxicities. Furthermore, its potential for actual surface water treatment was also determined.

In vivo study of light-driven naproxen release from gated mesoporous silica drug delivery system

A drug delivery system based on mesoporous particles MCM-41 was post-synthetically modified by photo-sensitive ligand, methyl-(2E)-3-(4-(triethoxysilyl)-propoxyphenyl)-2-propenoate (CA) and the pores of MCM-41 particles were loaded with Naproxen sodium salt (NAP). The CA was used as a photoactive molecule that can undergo a reversible photo-dimerization by [2π + 2π] cycloaddition when irradiated with UV light of specific wavelengths. Thus, it has a function of gate-keeper that is responsible for opening/closing the pores and minimizing premature release of NAP. The physicochemical properties of the prepared system were studied by infrared spectroscopy (IR), nitrogen adsorption measurements, thermogravimetric analysis (TGA), scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDX). The mechanism of the opening/closing pores was confirmed by UV measurements. In vitro and in vivo drug release experiments and the concentration of released NAP was determined by UV spectroscopy and high-performance liquid chromatography (HPLC). In vivo drug release in the blood circulatory system of rats has demonstrated the effective photo-cleavage reaction of CA molecules after UV-light stimulation. The localization and morphological changes of the particles were studied in the blood and liver of rats at different time intervals. The particles in the blood have been shown to retain their original rod-like shape, and the particles in the liver have been hydrolysed, which has resulted in spherical shape with a reduced size.

Insights on a Hierarchical MFI Zeolite: A Combined Spectroscopic and Catalytic Approach for Exploring the Multilevel Porous System Down to the Active Sites.

The hierarchization of zeolites to overcome the major drawbacks related to molecular diffusion limitation in micropores is a popular concept in heterogeneous catalysis. Despite the constant increase of new synthesis strategies to produce such hierarchical systems, the deep knowledge of their structural arrangement and how the zeolitic lattice is organized in a multilevel porous system is often missing. This information is essential to design a structure, tuning the porosity and the distribution of easily accessible active sites, and successively controlling the catalytic properties. In the present work, the synthesis of one of the most sophisticated forms of the hierarchical ZSM-5 zeolite has been reproduced, obtaining two multilevel porous materials with different crystallinity degrees, with the final aim of investigating and clarifying the finest features of their active sites. For this purpose, an extended characterization step by means of a unique multitechnique approach has been performed, thus revealing the active site nature, abundance, and distribution. IR spectroscopy with different molecular probes and a targeted catalytic test based on the hydroconversion reaction of n-decane were the toolbox for disclosing how the MFI lattice takes part in the hierarchical structure and how it, working in synergy with the mesoporous system, confers to this material a totally new shape–size selectivity. Merging the information obtained for the synthesized hierarchical zeolite with the characterization results of two reference materials (a mesoporous aluminum-containing MCM-41 and a microporous commercial ZSM-5), it was possible to define an internal and external map of the pore network of this complex and unique molecular sieve, where strong Brønsted acidic sites are located at the mouth of the MFI micropores and, at the same time, exposed at the surface of the mesoporous channels. Hence, the possibility of easily releasing bulky products is ensured and the application possibilities of the MFI lattice are expanded beyond cracking reactions.

An injectable mesoporous silica-based analgesic delivery system prolongs the duration of sciatic nerve block in mice with minimal toxicity

The major limitation of traditional local anesthetics is the finite duration of a single injection. The present study developed two kinds of novel injectable anesthetic nanocomposites based on mesoporous silica, and evaluated their long-lasting analgesic effect and biosafety. The nanoparticulate carriers, mesoporous silica nanoparticles (MSNs) and mesoporous silica-coated gold nanorods (GNR@MSN), were firstly constructed using the oil-water biphase reaction approach and then ropivacaine (RPC), a local anesthetic, was loaded into the mesoporous carriers by vacuum suction. Transmission electron microscopic images showed the well-ordered mesoporous structure for drug loading. RPC-loaded MSNs and RPC-loaded GNR@MSN exhibited a sustained-release pattern in vitro, and the latter also showed a controlled-release manner triggered by near-infrared (NIR) irradiation. RPC-loaded MSNs and RPC-loaded GNR@MSN caused an initial sensory blockade in mice that lasted for 6 h, almost 2.5 folds of that from free RPC solution. Furthermore, upon NIR irradiation, the latter induced three additional periods of the blockade. Neither of them showed motor nerve block, which may be due to the sustained release manner. The low myotoxicity and low neurotoxicity of the two nanocomposites were presented both in vitro and in vivo. These results demonstrate the potential of the mesoporous silica-based analgesic nanocomposites in effectively controlling postoperative pain, maybe RPC-loaded MSNs for moderate pain and RPC-loaded GNR@MSN for severe pain. Statement of significanceAdequate postoperative analgesia helps early functional exercise after surgery and accelerates rapid recovery, while uncontrolled postoperative pain probably develops chronic post-surgical pain that impacts the life quality of patients for a long time. However, postoperative pain management is still a challenge. The current treatment drugs are always accompanied by some side effects due to their systemic effect. Opioids have risks of addiction and respiratory depression, and nonsteroidal anti-inflammatory drugs can lead to gastrointestinal reaction. Therefore, the long-lasting local anesthetic formulation with good biocompatibility is the most promising solution to manage post-surgical pain. The present study developed novel injectable anesthetic nanocomposites based on mesoporous silica, providing long-lasting pain relief in mice with minimal toxicity.

A dual-sensitive poly(amino acid)/hollow mesoporous silica nanoparticle-based anticancer drug delivery system with a rapid charge-reversal property

The negative-to-positive surface charge-reversal capability introduced can reduce the nonspecific cellular uptake of the nanosized anticancer drug delivery systems (DDSs) and enhance the endocytosis capability by cancer cells. In this article, a novel dual-sensitive anticancer DDS with a rapid charge-reversal property was reported. Hollow mesoporous silica nanoparticle (HMSN) with a high drug loading capacity was applied as the “nanocontainer” to package the drug doxorubicin hydrochloride (DOX), then was coated by poly(aspartic acid)-graft-1-(3-aminopropyl) imidazole (PASP-g-API) through the redox-sensitive disulfide bond to obtain the DDS DOX@HMSN–SS–PASP-API. The imidazole group was not ionized at pH 7.4, resulting in a negatively charged surface of the DDS. But in the slightly acidic tumor microenvironment, the ionization of the imidazole group rapidly reversed the surface charge of the carriers for better uptake by cancer cells. After the endocytosis, the disulfide bond linking PASP-g-API and HMSN could be interrupted in the reducing environment intercellular, leading to the DOX release. The rapid charge-reversal property of the carriers was demonstrated by the in vitro studies, and the cell experiments proved that the carriers could enter the cancer cells much easier in the weakly acidic environment. Drug release studies indicated that DOX@HMSN–SS–PASP-API could release ~97% loaded DOX within 5 days with the glutathione concentration of 10 mM, demonstrating its sensitivity to redox. Also, DOX@HMSN–SS–PASP-API at pH 6.5 showed the best therapeutic effect among all the DDS groups. This dual-sensitive system with a rapid charge-reversal property should be a good complement to the researches of anticancer DDSs.

Hierarchical Zeolites-confined Metal Catalysts and Their Enhanced Catalytic Performances.

The confinement of metal species within hierarchical zeolites combines the acidic/basic sites of zeolites, the enhanced mass transfer of mesoporous system, and the inside active metal sites, leading to high activity, unique selectivity, and superior stability in chemicals synthesis, energy and environment catalysis. To date, review on this emerging topic is rarely reported. Herein, we classify five metals-hierarchical zeolites composite (metal@hierarchical zeolites) according to the location of metals on hierarchical structure, including metals located on micropores, intercrystalline mesopores, intracrystalline mesopores, hollow nanobox and mesoporous shells. The synthesis and catalysis applications of metal@hierarchical zeolites composite are provided, highlighting the rational design of catalyst preparation, the improved catalytic efficiency and stability of metal species. Finally, we discuss the current limitations and future opportunities for this emerging field. This Review is expected to inspire more developments and applications of metal@hierarchical zeolites.

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.

Adsorption performance of an amine-functionalized MCM–41 mesoporous silica nanoparticle system for ciprofloxacin removal

Antibiotic pollutants discharged from pharmaceutical industries are often present in the aquatic environment due to ineffective treatment of pharmaceutical wastewater and are hazardous to human and aquatic life. Therefore, effective treatment of antibiotic-containing wastewater is of utmost importance in the field of environmental protection. This study aims to evaluate the adsorption performance of an amine-functionalized MCM–41 mesoporous silica nanoparticles system (MCM–41–NH2) as an adsorbent for the removal of ciprofloxacin (CIP) antibiotic from aqueous solution. Surface and structural characteristics of MCM–41–NH2 were examined using scanning electron microscopy, X-ray diffraction, N2 adsorption–desorption analysis, Fourier transform infrared spectroscopy, and point of zero charge analysis. In addition, thermal stability was investigated by thermogravimetric analysis. Via the proposed treatment, 99.25% CIP removal was achieved under the following conditions: pH = 7; MCM–41–NH2 dose = 0.8 g/L; CIP concentration = 10 mg/L; adsorption time = 120 min; and shaking speed = 200 rpm. Isotherm study showed that the experimental data fitted well with the Langmuir equation. Moreover, the maximum adsorption capacity of MCM–41–NH2 for CIP was 164.3 mg/g. Thermodynamic parameters showed that the adsorption process of CIP on MCM–41–NH2 was endothermic and spontaneous. Additionally, the increase in solution temperature had a positive impact on the removal of CIP. The kinetic data obtained at different CIP concentrations (10, 25, 50, and 100 mg/L) were consistent with the pseudo-second-order model. MCM–41–NH2 could be recycled eight times in the proposed adsorption process, with a slight loss in its adsorption capacity. Compared with other adsorbents, MCM–41–NH2 was more effective for CIP removal.