Dendritic Mesoporous Silica Research Articles

Dendritic mesoporous silica loaded with gold nanoclusters and their application in immunochromatographic assay.

Novel green-emitting fluorescent microspheres (GreFMPs) were assembled by loading highly luminescent gold nanoclusters (Arg/ATT/AuNCs) ondendritic mesoporous silica nanoparticles (DMSNs) via PEI-mediated electrostatic adsorption. The fluorescence microspheres exhibit excellent monodispersion with average diameters about (254.5 ± 34.6nm). Compared with free Arg/ATT/AuNCs, the GreFMPs have similar fluorescent properties and biocompatibility but superior environmental tolerance. Subsequently, an immunochromatographic assay based on GreFMPs (GreFMP-ICA) has been successfully developed, which is highly selective toward alphafetoprotein (AFP) in human serum. Under the optimal parameters, there is a good linear range between 0.5 and 160.0ng/mL, the limit of detection was found to be about 0.5ng/mL, and the recovery and relative standard deviation are 81.0 ~ 100.6% and 3.5 ~ 16.6%, respectively. These results manifested that the GreFMPs are beneficial for the rational design of the ICA platform, and the proposed GreFMP-ICA has the potential to screen AFP in clinical applications.

Fabrication of composite RGD-tagged poly(lactic acid)-graphene oxide nanofiber containing bone-forming peptide-3 loaded-dendritic silica nanoparticles for bone regeneration in rabbit

In the current study, polylactic acid (PLA)/graphene oxide (GO) based composite scaffolds were fabricated by electrospinning method and then covalently modified with bone-forming peptide-3 (BFP-3)-loaded thiol-functionalized dendritic mesoporous silica nanoparticles (BFP-3@HS-DMSNs) and RGD. In this regard, PLA electrospinning nanofibers and composite of PLA/GO electrospinning nanofibers containing 0.02, 0.01, 0.04, 0.1, 0.2 % of GO were prepared and characterized in terms of mechanical strength, nanofibers diameter, thermal stability, crystallinity, specific surface area, total pore volume and cell adhesion properties. Among the prepared composites, PLA nanofibers containing 0.02 % GO demonstrated superior mechanical and morphological characteristics along with better cell adhesion for mesenchymal stem cell. Then, the PLA/0.02 %GO nanofiber was treated with plasma and consequently modified with N-(2-aminoethyl)maleimide linker which was applied for Cys-RGD and BFP-3@HS-DMSNs conjugation. The obtained results showed desirable adhesion of PLA/0.02 %GO nanofiber after incorporation of RGD (5 % of maleimide groups of the linker) and DMSNs which significantly increase cell adhesion potency (1.53 folds). By incorporation of BFP-3@HS-DMSNs (equivalent to 0.1 µg of BFP-3) to the RGD-tagged PLA/0.02 %GO nanofiber, the scaffold demonstrated better cytocompatibility and MSC differentiation to osteoblast based on biomineralization assay via alizarin red (4.2 folds) and alkaline phosphatase activity (1.7 folds) tests. In preclinical stage, after skull defect creation in rabbits, 5 treatments groups comprising PLA/0.02 %GO nanofiber, PLA/0.02 %GO/DMSNs, PLA/0.02 %GO/DMSNs/Cys-RGD, PLA/0.02 %GO/BFP-3@DMSNs and PLA/0.02%GO/BFP-3@DMSNs/Cys-RGD were used for bone regeneration in skull defects. After 3 months, the implantation of PLA/0.02GO/BFP-3@DMSNs/Cys-RGD showed higher bone regeneration based on CBCT imaging (18.875 mm2 bone formed area) in comparison with other treatment groups. This hybrid multimodal platform is purposely organized interactive processes which lead to potential bone regeneration.

Adsorption removal of copper(II) from water by zero valent iron loaded dendritic mesoporous silica

The object of research is synthesized dendritic mesoporous nanoscale silica (DMSN) modified with zero-valent iron (Fe0@DMSN). This material exhibits a high adsorption capacity for heavy metal ions, in particular copper, whose increased content in the aquatic environment poses a threat to living organisms. In this regard, the main physicochemical features of the removal of copper cations from the aqueous medium using the obtained sample were investigated. The morphology of the obtained dendritic silicas was studied by electron microscopy and the presence of a layer of zero-valent iron was confirmed by X-ray diffraction analysis and infrared spectroscopy. The parameters of the porous structure of the synthesized materials were determined. It was found that after modification of mesoporous silica with particles of zero-valent iron, the value of its specific surface area decreased from 504 m2/g to 312 m2/g. This may be due to the formation of a Fe0 layer not only on their surface but also in the channels of the inorganic matrix, which has a unique dendritic structure characteristic of this type of particles. At the same time, the number of active centers increases due to the enrichment of the silica surface with functional modifier groups that show a high affinity for metal cations. The adsorption capacity of Fe0@DMSN towards Cu2+ ions has been studied and it has been shown that the maximum adsorption value is 39.8 mg/g, which is significantly higher than that of the initial synthesized DMSN sample (0.7 mg/g). The experimental data obtained indicate that the obtained sorption material based on dendritic mesoporous silica nanoparticles with a layer of reactive zero-valent iron can be used for the purification of water contaminated with metal ions. In addition, the magnetic properties of such materials, known and proven by various scientists, will make it easy to separate the solid phase in the processes of sorption water purification using magnetic separation.

Optimized Fabrication of Dendritic Mesoporous Silica Nanoparticles as Efficient Delivery System for Cancer Immunotherapy.

In the past decade, cancer immunotherapy has revolutionized the field of oncology. Major immunotherapy approaches such as immune checkpoint inhibitors, cancer vaccines, adoptive cell therapy, cytokines, and immunomodulators have shown great promise in preclinical and clinical settings. Among them, immunomodulatory agents including cancer vaccines are particularly appealing; however, they face limitations, notably the absence of efficient and precise targeted delivery of immune-modulatory agents to specific immune cells and the potential for off-target toxicity. Nanomaterials can play a pivotal role in addressing targeting and other challenges in cancer immunotherapy. Dendritic mesoporous silica nanoparticles (DMSNs) can enhance the efficacy of cancer vaccines by enhancing the effective loading of immune modulatory agents owing to their tunable pore sizes. In this work, an emulsion-based method is optimized to customize the pore size of DMSNs and loaded DMSNs with ovalbumin (OVA) and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (CpG-OVA-DMSNs). The immunotherapeutic effect of DMSNs is achieved through controlled chemical release of OVA and CpG in antigen-presenting cells (APCs). The results demonstrated that CpG-OVA-DMSNs efficiently activated the immune response in APCs and reduced tumor growth in the murine B16-OVA tumor model.

Signal-Boosted Electrochemical Lateral Flow Immunoassay for Early Point-of-Care Detection of Liver Cancer Biomarker.

The early diagnosis of cancer in a point-of-need manner is of great significance, yet it remains challenging to achieve the necessary sensitivity and speed. Traditional lateral flow immunoassay (LFIA) methods are limited in accuracy and quantification, restricting their suitability for home-based applications. Thus, we explored a new and user-friendly electrochemical LFIA (e-LFIA) test strip to detect α-fetoprotein (AFP), a diagnostic marker for liver cancer. The specific electrochemical immunoprobe utilized in this e-LFIA test strip is characterized by significant signal boosting, resulted from the loading Ag shell into a gold nanoparticle (AuNP)-coated dendritic mesoporous silica nanoscaffold (DMSN). Leveraging the distinct electrochemical characteristics of Ag anodic stripping and the high volume-to-surface area ratio of DMSNs, the developed DMSNs/AuNPs@Ag-based e-LFIA test strip is capable of detecting AFP at a low concentration of 0.85 ng/mL within a rapid 20 min timespan, both of these values are smaller than those in current clinical testing. Furthermore, we utilized homemade screen-printed electrodes in this sensing prototype and demonstrated the high versatility and reliability of this e-LFIA device. We envision that this DMSNs/AuNPs@Ag-based e-LFIA holds substantial potential for the early diagnosis of liver cancer and household health monitoring.

Kiwi-Inspired Rational Nanoarchitecture with Intensified and Discrete Magneto-Fluorescent Functionalities for Ultrasensitive Point-of-Care Immunoassay.

Fluorescent lateral flow immunoassays (FLFIA) is a well-established rapid detection technique for quantitative analysis. However, achieving accurate analysis of biomarkers at the pg mL-1 level using FLFIA still poses challenges. Herein, an ultrasensitive FLFIA platform is reported utilizing a kiwi-type magneto-fluorescent silica nanohybrid (designated as MFS) that serves as both a target-enrichment substrate and an optical signal enhancement label. The spatially-layered architecture comprises a Fe3O4 core, an endocarp-fibers like dendritic mesoporous silica, seed-like quantum dots, and a kiwi-flesh like silica matrix. The MFS demonstrates heightened fluorescence brightness, swift magnetic response, excellent size uniformity, and dispersibility in water. Through liquid-phase capturing and fluorescence-enhanced signal amplification, as well as magnetic-enrichment sample amplification and magnetic-separation noise reduction, the MFS-based FLFIA is successfully applied to the detection of cardiac troponin I that achieved a limit of detection at 8.4 pg mL-1, tens of times lower than those of previously published fluorescent and colorimetric lateral flow immunoassays. This work offers insights into the strategic design of magneto-fluorescent synergetic signal amplification on LFIA platform and underscores their prospects in high-sensitive rapid and on-site diagnosis of biomarkers.

Bimetallic clusterzymes-loaded dendritic mesoporous silica particle regulate arthritis microenvironment via ROS scavenging and YAP1 stabilization

Clusterzymes are synthetic enzymes exhibiting substantial catalytic activity and selectivity, which are uniquely driven by single-atom constructs. A dramatic increase in antioxidant capacity, 158 times more than natural trolox, is noted when single-atom copper is incorporated into gold-based clusterzymes to form Au24Cu1. Considering the inflammatory and mildly acidic microenvironment characteristic of osteoarthritis (OA), pH-dependent dendritic mesoporous silica nanoparticles (DMSNs) coupled with PEG have been employed as a delivery system for the spatial-temporal release of clusterzymes within active articular regions, thereby enhancing the duration of effectiveness. Nonetheless, achieving high therapeutic efficacy remains a significant challenge. Herein, we describe the construction of a Clusterzymes-DMSNs-PEG complex (CDP) which remarkably diminishes reactive oxygen species (ROS) and stabilizes the chondroprotective protein YAP by inhibiting the Hippo pathway. In the rabbit ACLT (anterior cruciate ligament transection) model, the CDP complex demonstrated inhibition of matrix metalloproteinase activity, preservation of type II collagen and aggregation protein secretion, thus prolonging the clusterzymes' protective influence on joint cartilage structure. Our research underscores the efficacy of the CDP complex in ROS-scavenging, enabled by the release of clusterzymes in response to an inflammatory and slightly acidic environment, leading to the obstruction of the Hippo pathway and downstream NF-κB signaling pathway. This study illuminates the design, composition, and use of DMSNs and clusterzymes in biomedicine, thus charting a promising course for the development of novel therapeutic strategies in alleviating OA.

Mediated self-assembled gold nanoclusters with mesoporous silica particles to boost fluorescence for enhanced on-site monitoring of organophosphate pesticides

Accurate detection of organophosphate pesticides (OPs) is paramount for ensuring food safety. Dendritic mesoporous silica sphere was employed to confine gold nanoclusters (AuNCs@dmSiO2) to ameliorate fluorescent property of AuNCs. A AuNCs@dmSiO2-based fluorescent method was developed for OPs sensing. Identification of Cu2+ by AuNCs quenched AuNCs@dmSiO2 fluorescence. Interaction between Cu2+ and generated thiocholine in catalysis of acetylcholinesterase (AChE) caused fluorescence enhancement. OPs, an inhibitor of AChE, suppressed thiocholine production to cause fluorescence quenching. Based on fluorescent variation, a fluorescent method was proposed for OPs by selecting paraoxon as a model within range of 0.05–25.0 ng/mL with a limit of detection (LOD) of 0.032 ng/mL. Besides, a portable test swab was prepared for on-site monitoring OP paraoxon with a smartphone-based 3D-printing portable device with a LOD of 0.65 ng/mL. This work is highlighted by the inspiration of designing highly fluorescent AuNCs, and the provision of a viable avenue for OPs-related food analysis.

Fabrication of acorn-shaped Janus C-SiO2 carrier and their application in DOX release

Asymmetric nanocarriers with different functions can achieve synergistic effect in cancer treatment. In this study, asymmetric carbon-silica (C-SiO2) carriers were prepared for drug delivery and combining therapy. The C-SiO2 carriers presented acorn-like structure with dendritic mesoporous silica hat and carbon body. The carbon body render the carriers photothermal effect. The prepared C-SiO2 carriers with size around 130 nm have improving cell uptake efficiency, and excellent biocompatibility. After loading doxorubicin hydrochloride (DOX), menthol (LM) was used to seal the loaded drug (DOX@C-SiO2-LM). LM coating can melt above the phase transition temperature, leading to the release of loaded cargo. The DOX@C-SiO2-LM displayed temperature/NIR-triggered drug release.

Ultrastable NAC-Capped CdZnTe Quantum Dots Encapsulated within Dendritic Mesoporous Silica As an Exceptional Tag for Anti-Interference Fluorescence Aptasensor with Signal Amplification.

In this work, we explored the potential of thiol-capped CdZnTe quantum dots (QDs) as an exceptional signal tag for fluorescence aptasensing applications. Employing a one-pot hydrothermal approach, we modulated the terminal functional groups of CdZnTe QDs using l-cysteine (Lcys), 3-mercaptopropionic acid (MPA), and N-acetyl-l-cysteine (NAC) as ligands. Our comparative analysis revealed that NAC-capped CdZnTe QDs (NAC-CdZnTe QDs) exhibited superior anti-interference capabilities and storage stability across various temperatures, pH levels, and storage durations. Encouraged by these promising results, we further optimized the use of ultrastable NAC-CdZnTe QDs encapsulated in dendritic mesoporous silica nanoparticles (DMSN@QDs) as an exceptional tag for the development of an advanced anti-interference fluorescence aptasensor for aflatoxin B1 (AFB1) detection. The developed aptasensor using DMSN@QDs as signal tags achieved a remarkable signal amplification of approximately 10.2 fold compared to the NAC-CdZnTe QDs coated silica (SiO2@QDs) labeled fluorescence aptasensor. This aptasensor was able to detect AFB1 within a wide range of 1 pg mL-1 to 200 ng mL-1, achieving a limit of detection as low as 0.41 pg mL-1 (S/N = 3). Crucially, the specific binding affinity between the aptamer and the target enabled the aptasensor to be easily customized for various targets by simply replacing the aptamer sequence with the desired one. The exceptional potential of NAC-CdZnTe QDs, particularly when encapsulated in DMSNs, leads to the development of highly sensitive and selective anti-interference fluorescence aptasensors for various targets, thereby, paving the way for advancements in a diverse range of applications.

Fe-doped biodegradable dendritic mesoporous silica nanoparticles for starvation therapy and photothermal-enhanced cascade catalysis in tumor therapy

Combination therapies have attracted significant attention because they address the limitations of monotherapy while improving overall efficacy. In this study, we designed a novel nanoplatform, named GOx@Fe-DMSN@PDA (GFDP), by integrating Fe2+ into dendritic mesoporous silica nanoparticles (DMSN) and selecting glucose oxidase (GOx) as the model drug loaded into the DMSN pores. Additionally, we coated the surface of the DMSN with polydopamine (PDA) to confer pH/near infrared (NIR) light-responsive controlled-release behavior and photothermal therapy (PTT). The introduction of Fe2+ into the DMSN framework greatly improved biodegradability and enhanced the peroxidase (POD)-like activity of GFDP. In addition, GOx could consume glucose and generate hydrogen peroxide (H2O2) within tumor cells to facilitate starvation therapy and enhance cascade catalysis. The PDA coating provided the DMSN with an intelligent response release ability, promoting efficient photothermal conversion and achieving the PTT effect. Cellular tests showed that under NIR light irradiation, GFDP exhibited a synergistic effect of PTT-enhanced starvation therapy and cascade catalysis, with a half-maximal inhibitory concentration (IC50) of 2.89 μg/mL, which was significantly lower than that of GFDP without NIR light irradiation (18.29 μg/mL). The in vivo anti-tumor effect indicated that GFDP could effectively accumulate at the tumor site for thermal imaging and showed remarkable synergistic therapeutic effects. In summary, GFDP is a promising nanoplatform for multi-modal combination therapy that integrates starvation therapy, PTT, and cascade catalysis.

Electrochemiluminescence Lateral Flow Immunoassay Using Ruthenium(II) Complex‐Loaded Dendritic Mesoporous Silica Nanospheres for Highly Sensitive and Quantitative Detection of SARS‐CoV‐2 Nucleocapsid Protein

AbstractLateral flow immunoassays (LFIA) are widely used for the cost‐effective and rapid detection of diverse analytes. However, traditional LFIA suffers from difficulties in providing quantitative results and has low sensitivity. Herein, LFIA is combined with electrochemiluminescence (ECL), a leading transduction technique with high sensitivity and wide dynamic range, to achieve highly sensitive and quantitative detection of severe acute respiratory syndrome coronavirus nucleocapsid protein (SARS‐CoV‐2 N protein). Ruthenium(II)‐based complexes are synthesized and loaded into dendritic mesoporous silica nanospheres (PEI‐Ru/dSiO2), which possessed central‐radial pore channels and served as tags for ECL‐LFIA. The electrodes are fabricated on a nitrocellulose (NC) membrane, which simplifies the structure of the ECL‐LFIA. PEI‐Ru/dSiO2 is captured on the electrode surface via a sandwich immunoreaction, which enhances the ECL signal by decreasing the distance between PEI‐Ru/dSiO2 and the electrode surface. Using 2,2‐bis(hydroxymethyl)‐2,2′,2′'‐nitrilotriethanol (BIS‐TRIS) as coreactant, the ECL‐LFIA is used for detecting SARS‐CoV‐2 N protein, with a linear range of 1–104 ng mL−1 and a limit of detection (LOD) of 0.52 ng mL−1. ECL‐LFIA can also be used to detect analytes in complex matrices. These results demonstrate that the prepared ECL‐LFIA has great potential as a point‐of‐care testing platform for the rapid and quantitative detection of disease biomarkers.

PtCo with oxidase-like activity and laccase for synergistic catalytic degradation of phthalic acid esters

Phthalic acid esters (PAEs) as common plasticizers, providing convenience to humans. However, they also present a potential threat to ecosystems and human health as emerging contaminants. In this study, co-immobilization of nanozyme (PtCo) and laccase (Lac) into dendritic mesoporous silica (DMSN) constitutes nanomaterials (Lac@PtCo@DMSN). PtCo with an atomic ratio of 3:1 has the highest oxidizing activity. DMSN exhibited a maximum Lac loading capacity of 365 mg/g and activity of Lac@PtCo@DMSN exhibits excellent pH, temperature, and storage stability and reusability, and demonstrated greater recoverability. Remarkably, Lac@PtCo@DMSN (50 mg) achieved 81.83% degradation of total PAEs within 72 h and maintained 72.44% degradation of dimethyl phthalate (DMP) in the fifth cycle. Electron transfer between Pt, Co and adsorbed oxygen (O2ads) in PtCo can generate •OH and •O2−, which were the dominant reactants for PAEs degradation. •OH could degrade PAEs to phthalic acid via H-abstration and •OH addition. •OH effectively enhanced Lac activity, and promoted the synergistic catalytic performance of nanozymes and natural enzymes. The degradation of phthalic acid by Lac accelerated the release of PtCo@DMSN reaction sites, resulting in significantly enhanced PAEs degradation. Thus, artificial/natural enzymes can degrade PAEs without exogenous additives to solve the limitation of Lac application, providing a new strategy for degrading contaminants in water.

One-Pot Synthesis of Silicon Quantum Dots-Based Fluorescent Nanomaterial and Its Application.

Conventionally obtained silicon quantum dots (Si QDs) generally suffer from the disadvantages of a cumbersome preparation process, large fluctuation in the quality of Si QDs, poor water solubility, and aggregation-caused quenching (ACQ) phenomenon. Here we report a facile one-pot strategy to synthesize a novel Si QDs-based fluorescent nanomaterial in which Si QDs are confined into dendritic mesoporous silica, named as SiQDs@DMSNs. The prepared SiQDs@DMSNs, with adjustable particle sizes ranging from 140 to 300 nm, emit blue fluorescence around 410 nm upon excitation by ultraviolet light at a wavelength of 300 nm. It is found that the addition of sodium salicylate (NaSAL) plays a crucial role in the in situ generation of Si QDs. The obtained SiQDs@DMSNs exhibit excellent fluorescence intensity, water solubility, and stability, facilitating easy surface modification, without being limited by the ACQ phenomenon. It is expected to be widely used in many fields such as biosensors, nanomedicines, in vivo imaging, fingerprint identification, and anticounterfeiting labels.

Pore analysis of dendritic mesoporous silica nanoparticles by STEM tomography and nitrogen sorption

Dendritic mesoporous silica nanoparticles (DMSN) provide a high diversity and complexity regarding their pore structure. Herein, we present results related to electron tomographic reconstruction and nitrogen sorption analysis of DMSNs with different pore structures obtained through variation of the surfactant concentration in the synthesis. The tomograms revealed that at all DMSNs exhibit a highly porous shell structure and a denser porous core with smaller pores. The shell generally consists of dendritic silica walls forming a disordered pore system of center radially aligned mesopores. At the highest surfactant concentration these mesopores had a roughly conical geometry, providing a highly accessible pore network. Nitrogen sorption revealed a broad pore size distribution, in agreement with this conical mesopore shape. The mesopore dimensions obtained through reconstruction were in good agreement with the pore size distribution obtained by nitrogen sorption. For intermediate and low surfactant concentrations, different pore geometries were observed in the reconstruction with increasing restriction of the pore volume towards the outer surface of the particles by branching of large pores into smaller ones. Nitrogen sorption analyses support these observations by featuring an increasing hysteresis with decreasing surfactant concentration in the synthesis, which indicates that the accessible pore volume is restricted by smaller mesopores towards the rim of the particles.

Morphological and structural control of dendritic mesoporous silica&titania nanospheres by the one-pot co-condensation approach

Morphological and structural control of dendritic mesoporous silica&titania nanospheres by the one-pot co-condensation approach

Dual‐Responsive Nanoreactor Initiates In Situ Generation of Copper Complex for Paraptosis‐Mediated Tumor Chemo‐Immunotherapy

AbstractParaptosis is a non‐apoptotic and caspase‐independent programmed cell death that can trigger immunogenic cell death (ICD) in tumor cells, representing a potent tactic to overcome immune tolerance to apoptosis. Here, this study demonstrates the construction of a dual‐responsive nanoreactor (MCGDH) to achieve paraptosis‐mediated ICD for chemo‐immunotherapy. Specifically, by doping Cu2+ into glutathione (GSH)‐responsive dendritic mesoporous silica nanoparticles, the platform (CGDMSN) is endowed with partial acid‐sensitivity. After loaded with 8‐hydroxyquinoline (8‐HQ), cell membrane fragments are coated onto the ammoniated CGDMSN surface to construct MCGDH. Upon internalization by tumor cells, the release of Cu2+ and 8‐HQ from MCGDH in response to the acidic pH and high concentration of GSH in the tumor microenvironment stimulates in situ generation of Cu(8‐HQ)2, inducing tumor cells paraptosis at a low copper dose. Moreover, MCGDH‐mediated paraptosis amplifies the immunogenicity of tumor cells, facilitating antigen presentation to dendritic cells and activating CD8+/CD4+ T cells immune responses. Furthermore, the combination of MCGDH and anti‐PD‐1 antibodies (αPD‐1) promotes the systemic anti‐tumor immune responses and long‐term immunological effect to vastly inhibit the primary/distant tumor growth and prevent tumor metastasis. This GSH/pH dual‐responsive nanoreactor serves as a selective platform for accelerating the development of chemo‐immunotherapy.

Development of Ce/Cu co-doped dendritic mesoporous silica nanoparticles (DMSNs) as novel abrasive systems toward high-performance chemical mechanical polishing

Development of novel abrasive systems with functional activities and physicochemical properties are of great significance in the reactive oxygen species (ROS)-enhanced chemical mechanical polishing. In this work, Ce single-doped and Ce/Cu co-doped dendritic mesoporous silica nanoparticles (DMSNs), namely Ce−DMSNs and Ce/Cu−DMSNs, were produced via a simple impregnation and thermolysis procedure. The Ce and/or Cu species involved in DMSNs frameworks were characterized through X-ray diffractometry, infrared spectroscopy, scanning electron microscopy, energy dispersive spectrometry, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption/desorption techniques. We report the evolution of surface morphology and roughness, defects, peak-to-valley data, image surface area difference, and material removal efficiency during ROS-enhanced polishing experiments toward silica materials. All the pure, Ce single-doped, and Ce/Cu co-doped DMSNs abrasive systems offered nearly defect-free surfaces with close-to-atom scale roughness. It might be attributed to the “springlike effect” and “soft polishing/abrasion”, possibly originating from the low-modulus DMSNs carriers. Among these abrasives, the Ce/Cu co-doped DMSNs systems achieved an evident improvement in removal efficiency, especially under ultraviolet irradiation-assisted polishing conditions. The coexisted Ce(Ⅲ)/Ce(Ⅳ) and Cu(Ⅰ)/Cu(Ⅱ) couples might be responsible for the effective production of ROS in photocatalysis and Fenton-like processes, thereby contributing to the Si–OH and Ce(Ⅲ)−O–Si bonding formations. The role of the developed Ce/Cu co-doped DMSNs abrasive systems in ROS-enhanced polishing processes was discussed.

Construction and Evaluation of Paclitaxel Mn-Doped Dendritic Mesoporous Silica Coated with N-Succinyl Chitosan

Mesoporous silica, as a drug carrier, has become the new research focus in the field of nanodrug delivery system in recent years. In this study, Mn-doped mesoporous silicas are synthesized by template and in-situ doping method and physically characterized. The drug-loading performance of silica and its impact on drug release are studied. The Mn-doped mesoporous silicas show dendritic morphology (MDMS) with a loose wrinkle structure on the surface and a large number of pores. MDMS is used as a carrier to solve the problem of low water solubility of paclitaxel. In order to avoid leakage during drug transportation, the surface of Mn-doped mesoporous silica loaded with paclitaxel is coated with N-succinyl chitosan to construct a new type of nanodrug delivery system (MDMS-PTX-NSC). Compared to MDMS, MDMS-PTX-NSC shows an increase in particle size and smooth surface. The dissolution characteristics of manganese ions and swelling behavior of N-succinyl chitosan make MDMS-PTX-NSC delivery system exhibit a good pH-responsive release. And MDMS-PTX-NSC release curve can be well fitted by Ritger-Peppas equation. The cytotoxicity test shows that the MDMS-PTX-NSC has significant biocompatibility and enhanced cytotoxicity, which reveals that the MDMS-PTX-NSC is a promising nanodrug delivery system.

H2S-Powered Nanomotors for Active Therapy of Tumors by Inducing Ferroptosis and Lactate-Pyruvate Axis Disorders.

Disruption of the symbiosis of extra/intratumoral metabolism is a good strategy for treating tumors that shuttle resources from the tumor microenvironment. Here, we report a precision treatment strategy for enhancing pyruvic acid and intratumoral acidosis to destroy tumoral metabolic symbiosis to eliminate tumors; this approach is based on PEGylated gold and lactate oxidase-modified aminated dendritic mesoporous silica with lonidamine and ferrous sulfide loading (PEG-Au@DMSNs/FeS/LND@LOX). In the tumor microenvironment, LOX oxidizes lactic acid to produce pyruvate, which represses tumor cell proliferation by inhibiting histone gene expression and induces ferroptosis by partial histone monoubiquitination. In acidic tumor conditions, the nanoparticles release H2S gas and Fe2+ ions, which can inhibit catalase activity to promote the Fenton reaction of Fe2+, resulting in massive ·OH production and ferroptosis via Fe3+. More interestingly, the combination of H2S and LND (a monocarboxylic acid transporter inhibitor) can cause intracellular acidosis by lactate, and protons overaccumulate in cells. Multiple intracellular acidosis is caused by lactate-pyruvate axis disorders. Moreover, H2S provides motive power to intensify the shuttling of nanoparticles in the tumor region. The findings confirm that this nanomedicine system can enable precise antitumor effects by disrupting extra/intratumoral metabolic symbiosis and inducing ferroptosis and represents a promising active drug delivery system candidate for tumor treatment.