Curcumin-loaded food-grade nano-silica hybrid material exhibiting improved photodynamic effect and its application for the preservation of small yellow croaker (Larimichthys polyactis).

Two types of curcumin-loaded food-grade nano-silica (F-SiO2) hybrid materials were successfully synthesized using the rotary evaporation method (F-SiO2@Cur) and the adsorption method (Cur@F-SiO2). The microstructure and spectral analyses confirmed that the curcumin in F-SiO2@Cur was loaded within the nanopores in a non-aggregate form rather than being adsorbed onto the surface (Cur@F-SiO2). Additionally, F-SiO2@Cur exhibited remarkable water solubility (1510 ± 50.33 µg/mL) and photostability (a photodegradation ratio of only 59.22 %). Importantly, F-SiO2@Cur obtained a higher capacity for the generation of singlet oxygen (1O2) compared to control groups. Consequently, F-SiO2@Cur-mediated photodynamic inactivation (PDI) group attained the highest score in sensory evaluation and the best color protection effect in PDI experiment of small yellow croaker (Larimichthys polyactis) at 4 °C. Moreover, F-SiO2@Cur could effectively controlled total volatile basic nitrogen (TVB-N) content, pH, and total viable count (TVC), thereby prolonging the shelf life. Therefore, F-SiO2@Cur-mediated PDI is an effective fresh-keeping technology for aquatic products.

Fabrication of mesoporous silica nanoparticles for releasable delivery of licorice polysaccharide at the acne site in topical application.

Glycyrrhizae Radix et rhizome/licorice is a precious herb in traditional Chinese medicine (TCM). TCM's polysaccharides are medicinally active. But herbal polysaccharides pose some limitations for topical applications. Therefore, this study aimed to utilize licorice polysaccharide via mesoporous silica nanoparticles (MSN) for anti-acne efficacy in topical delivery. The polysaccharide (GGP) was extracted with a 10 % NaOH solution. Chemical characterization suggested that GGP possesses an Mw of 267.9 kDa, comprised primarily of Glc (54.1 %) and Ara (19.12 %), and probably 1,4-linked Glc as a backbone. Then, MSN and amino-functionalized MSN were synthesized, GGP entrapped, and coated with polydopamine (PDA) to produce nanoparticle cargo. The resulted product exhibited 76 % entrapment efficiency and an in vitro release of 89 % at pH 5, which is usually an acne-prone skin's pH. Moreover, it significantly increased Sebocytes' cellular uptake. GGP effectively acted as an anti-acne agent and preserved its efficacy in synthesized nanoparticles. In vivo, the results showed that a 20 % gel of MSN-NH2-GGP@PDA could mediate an inflammatory response via inhibiting pro-inflammatory cytokines and regulating anti-inflammatory cytokines. The MSN-NH2-GGP@PDA inhibited TLR2-activated-MAPK and NF-κB pathway triggered by heat-killed P. acnes. In conclusion, fabricated MSN entrapped GGP for biomimetic anti-acne efficacy in topical application.

Tuning quantum dots emission on DNA tetrahedron/silica nanosphere/graphene oxide nanointerface for ratiometric fluorescence assay of Pb2+ in multiplex samples.

BACKGROUND: Assembling framework nucleic acid (FNA) nanoarchitectures and tuning luminescent quantum dots (QDs) for fluorescence assays represent a versatile strategy in analytical territory. Rationally, FNA constructs could offer a preferential orientation to efficiently recognize the target and improve detection sensitivity, meanwhile, regulating size-dependent multicolor emissions of QDs in one analytical setting for ratiometric fluorescence assay would greatly simplify operation procedures. Nonetheless, such FNA/QDs-based ratiometric fluorescence nanoprobes remain rarely explored. RESULTS: We designed a sensitive and signal amplification-free fluorescence aptasensor for lead ions (Pb2+) that potentially cause extensive contamination to environment, cosmetic, food and pharmaceuticals. Red and green emission CdTe quantum dots (rQDs and gQDs) were facilely prepared. Moreover, silica nanosphere encapsulating rQDs served as quantitative internal reference and scaffold to anchor a predesigned FNA and DNA sandwich containing Pb2+ binding aptamer and gQD modified DNA signal reporter. On binding of Pb2+, the gQD-DNA signal reporter was set free, resulting in fluorescence quenching at graphene oxide (GO) interface. Owing to the rigid structure of FNA, the fluorescence signal reporter orderly arranged at the silica nanosphere could sensitively respond to Pb2+ stimulation. The dose-dependent fluorescence signal-off mode enabled ratiometric analysis of Pb2+ without cumbersome signal amplification. Linear relationship was established between fluorescence intensity ratio (I555/I720) and Pb2+ concentration from 10 nM to 2 µM, with detection limit of 1.7 nM (0.43 ppb), well addressing the need for Pb2+ routine monitoring. The designed nanoprobe was applied to detection of Pb2+ in soil, cosmetic, milk, drug, and serum samples, with the sensitivity comparable to conventional ICP-MS technique. SIGNIFICANCE: Given the programmable design of FNA and efficient recognition of target, flexible tuning of QDs emission, and signal amplification-free strategy, the present fluorescence nanoprobe could be a technical criterion for other heavy metal ions detection in a straightforward manner.

Unlocking the potential of SiO2 and CeO2 nanoparticles for arsenic mitigation in Vigna mungo L. Hepper (Blackgram).

In this study, the interaction effects of NaAsO2 (1 and 5 µM), SiO2 NPs (10 and 100 mg/L) and CeO2 NPs (10 and 100 mg/L) were assessed in Vigna mungo (Blackgram). The treatment of NaAsO2, SiO2, CeO2-NPs and combinations of NPs & As were applied to blackgram plants under hydroponic conditions. After its application, the morpho-physiological, antioxidant activity, and phytochemical study were evaluated. At 10 and 100 mg/L of SiO2 and CeO2-NPs, there was an increase in antioxidative enzymatic activity (p < 0.05) and reactive oxygen species (ROS). However, substantial ROS accumulation was observed at 1 and 5 µM NaAsO2 and 100 mg/L SiO2 NPs (p < 0.05). Additionally, at such concentrations, there is a substantial reduction in photosynthetic pigments, nitrogen fixation, chlorosis, and plant development when compared to controls (p < 0.05). The combination of SiO2 and CeO2 NPs (10 and 100 mg/L) with NaAsO2 decreased superoxide radical and hydrogen peroxide and improved SOD, CAT, APX, GR, and chlorophyll pigments (p < 0.05). Further FTIR results were evaluated for documenting elemental and phytochemical analysis.

Retention mechanisms of amitriptyline and its impurities on amide, amino, diol, and silica columns in hydrophilic interaction liquid chromatography.

Hydrophilic interaction liquid chromatography (HILIC) has been widely applied to challenging analysis in biomedical and pharmaceutical fields, bridging the gap between normal-phase high-performance liquid chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC). This paper comprehensively explores the retention mechanisms of amitriptyline and its impurities A, B, C, D, F, and G on amide, amino, diol, and silica columns. Dual HILIC/RP-HPLC retention mechanisms were developed, and transitional points between HILIC and RP-HPLC mechanisms were calculated on amide, diol, and silica columns. Adsorption and partition contributions to overall retention mechanisms were evaluated using Python software in HILIC and RP-HPLC regions. The cation exchange mechanism dominates overall retention for ionized analytes in the silica column (R2 > 0.995), whereas the retention of ionized analytes increases with pH. Impacts of acetonitrile content, buffer ionic strength, and pH, along with their interactions on the retention of ionized analytes in the silica column, were determined using the chemometric approach. Acetonitrile content showed the most significant impact on the retention mechanisms. These findings highlight that a detailed investigation into retention mechanisms provides notable insights into factors influencing analyte retention and separation, promising valuable guidance for future analysis.

A highly sensitive point-of-care detection platform for Salmonella typhimurium by integrating magnetic enrichment and fluorescent CsPbBr3@SiO2.

A platform was designed based on Fe3O4 and CsPbBr3@SiO2 for integrated magnetic enrichment-fluorescence detection of Salmonella typhimurium, which significantly simplifies the detection process and enhances the working efficiency. Fe3O4 served as a magnetic enrichment unit for the capture of S. typhimurium. CsPbBr3@SiO2 was employed as a fluorescence-sensing unit for quantitative signal output, where SiO2 was introduced to strengthen the stability of CsPbBr3, improve its biomodificability, and prevent lead leakage. More importantly, the SiO2 shell shows neglectable absorption or scattering towards fluorescence, making the CsPbBr3@SiO2 exhibit a high quantum yield of 74.4%. After magnetic enrichment, the decreasing rate of the fluorescence emission intensity of the CsPbBr3@SiO2 supernatant at 527 nm under excitation light at UV 365 nm showed a strong linear correlation with S. typhimurium concentration of 1 × 102~1 × 108 CFU∙mL-1, and the limit of detection (LOD) reached 12.72 CFU∙mL-1. This platform has demonstrated outstanding stability, reproducibility, and resistance to interference, which provides an alternative for convenient and quantitative detection of S. typhimurium.

Synthetic silica fibers of different length, diameter and shape: synthesis and interaction with rat (NR8383) and human (THP-1) macrophages in vitro, including chemotaxis and gene expression profile.

BACKGROUND: Inhalation of biopersistent fibers like asbestos can cause strong chronic inflammatory effects, often resulting in fibrosis or even cancer. The interplay between fiber shape, fiber size and the resulting biological effects is still poorly understood due to the lack of reference materials. RESULTS: We investigated how length, diameter, aspect ratio, and shape of synthetic silica fibers influence inflammatory effects at doses up to 250 µg cm-2. Silica nanofibers were prepared with different diameter and shape. Straight (length ca. 6 to 8 µm, thickness ca. 0.25 to 0.35 µm, aspect ratio ca. 17:1 to 32:1) and curly fibers (length ca. 9 µm, thickness ca. 0.13 µm, radius of curvature ca. 0.5 µm, aspect ratio ca. 70:1) were dispersed in water with no apparent change in the fiber shape during up to 28 days. Upon immersion in aqueous saline (DPBS), the fibers released about 5 wt% silica after 7 days irrespectively of their shape. The uptake of the fibers by macrophages (human THP-1 and rat NR8383) was studied by scanning electron microscopy and confocal laser scanning microscopy. Some fibers were completely taken up whereas others were only partially internalized, leading to visual damage of the cell wall. The biological effects were assessed by determining cell toxicity, particle-induced chemotaxis, and the induction of gene expression of inflammatory mediators. CONCLUSIONS: Straight fibers were only slightly cytotoxic and caused weak cell migration, regardless of their thickness, while the curly fibers were more toxic and caused significantly stronger chemotaxis. Curly fibers also had the strongest effect on the expression of cytokines and chemokines. This may be due to the different aspect ratio or its twisted shape.

Adhesive Cementation of CAD/CAM Silica-based Ceramics: Effect of Adhesive Type and Long-term Aging on the Bond Strength to Composite Cement.

PURPOSE: To investigate the effect of adhesive type and long-term aging on the shear bond strength (SBS) between silica-based ceramics and composite cement (CC). MATERIALS AND METHODS: Lithium-silicate (LS), feldspathic (FD) and polymer-infiltrated ceramic (PIC) blocks were sectioned (10 x 12 x 2 mm) and divided into 24 groups considering the factors: "ceramics" (LS, FD, and PIC), "adhesive" (Ctrl: without adhesive; 2SC: 2-step conventional; 3SC: 3-step conventional; 1SU: 1-step universal), and "aging" (non-aged or aged [A]). After the surface treatments, CC cylinders (n = 15, Ø = 2 mm; height = 2 mm) were made and half of the samples were subjected to thermocycling (10,000) and stored in water at 37°C for 18 months. The samples were submitted to SBS testing (100 kgf, 1 mm/min) and failure analysis. Extra samples were prepared for microscopic analysis of the adhesive interface. SBS (MPa) data was analyzed by 3-way ANOVA and Tukey's test (5%). Weibull analysis was performed on the SBS data. RESULTS: All factors and interactions were significant for SBS (p<0.05). Before aging, there was no significant difference between the tested groups and the respective control groups. After aging, the LS_1SU (22.18 ± 7.74) and LS_2SC (17.32 ± 5.86) groups exhibited significantly lower SBS than did the LS_Ctrl (30.30 ± 6.11). Only the LS_1SU group showed a significant decrease in SBS after aging vs without aging. The LS_1SU (12.20) group showed the highest Weibull modulus, which was significantly higher than LS_2SC_A (2.82) and LS_1SU_A (3.15) groups. CONCLUSION: No type of adhesive applied after silane benefitted the long-term adhesion of silica-based ceramics to CC in comparison to the groups without adhesive.

Multifunctional Hierarchical Nanoplatform with Anisotropic Bimodal Mesopores for Effective Neural Circuit Reconstruction after Spinal Cord Injury.

A persistent inflammatory response, intrinsic limitations in axonal regenerative capacity, and widespread presence of extrinsic axonal inhibitors impede the restoration of motor function after a spinal cord injury (SCI). A versatile treatment platform is urgently needed to address diverse clinical manifestations of SCI. Herein, we present a multifunctional nanoplatform with anisotropic bimodal mesopores for effective neural circuit reconstruction after SCI. The hierarchical nanoplatform features of a Janus structure consist of dual compartments of hydrophilic mesoporous silica (mSiO2) and hydrophobic periodic mesoporous organosilica (PMO), each possessing distinct pore sizes of 12 and 3 nm, respectively. Unlike traditional hierarchical mesoporous nanomaterials with dual-mesopores interlaced with each other, the two sets of mesopores in this Janus nanoplatform are spatially independent and possess completely distinct chemical properties. The Janus mesopores facilitate controllable codelivery of dual drugs with distinct properties: the hydrophilic macromolecular enoxaparin (ENO) and the hydrophobic small molecular paclitaxel (PTX). Anchoring with CeO2, the resulting mSiO2&PMO-CeO2-PTX&ENO nanoformulation not only effectively alleviates ROS-induced neuronal apoptosis but also enhances microtubule stability to promote intrinsic axonal regeneration and facilitates axonal extension by diminishing the inhibitory effect of extracellular chondroitin sulfate proteoglycans. We believe that this functional dual-mesoporous nanoplatform holds significant potential for combination therapy in treating severe multifaceted diseases.

Antiepileptic drug-loaded and multifunctional iron oxide@silica@gelatin nanoparticles for acid-triggered drug delivery.

The current study developed an innovative design for the production of smart multifunctional core-double shell superparamagnetic nanoparticles (NPs) with a focus on the development of a pH-responsive drug delivery system tailored for the controlled release of Phenytoin, accompanied by real-time monitoring capabilities. In this regard, the ultra-small superparamagnetic iron oxide@silica NPs (IO@Si MNPs) were synthesized and then coated with a layer of gelatin containing Phenytoin as an antiepileptic drug. The precise saturation magnetization value for the resultant NPs was established at 26 emu g-1. The polymeric shell showed a pH-sensitive behavior with the capacity to regulate the release of encapsulated drug under neutral pH conditions, simultaneously, releasing more amount of the drug in a simulated tumorous-epileptic acidic condition. The NPs showed an average size of 41.04 nm, which is in the desired size range facilitating entry through the blood-brain barrier. The values of drug loading and encapsulation efficiency were determined to be 2.01 and 10.05%, respectively. Moreover, kinetic studies revealed a Fickian diffusion process of Phenytoin release, and diffusional exponent values based on the Korsmeyer-Peppas equation were achieved at pH 7.4 and pH 6.3. The synthesized NPs did not show any cytotoxicity. Consequently, this new design offers a faster release of PHT at the site of a tumor in response to a change in pH, which is essential to prevent epileptic attacks.

Targeting c-Myc with decoy oligodeoxynucleotide-loaded polycationic nanoparticles inhibits cell growth and induces apoptosis in cancer stem-like cells (NTERA-2).

BACKGROUND: An increase in cancer stem cell (CSC) populations and their resistance to common treatments could be a result of c-Myc dysregulations in certain cancer cells. In the current study, we investigated anticancer effects of c-Myc decoy ODNs loaded-poly (methacrylic acid-co-diallyl dimethyl ammonium chloride) (PMA-DDA)-coated silica nanoparticles as carriers on cancer-like stem cells (NTERA-2). METHODS AND RESULTS: The physicochemical characteristics of the synthesized nanocomposites (SiO2@PMA-DDA-DEC) were analyzed using FT-IR, DLS, and SEM techniques. UV-Vis spectrophotometer was applied to analyze the release pattern of decoy ODNs from the nanocomposite. Furthermore, uptake, cell viability, apoptosis, and cell cycle assays were used to investigate the anticancer effects of nanocomposites loaded with c-Myc decoy ODNs on NTERA-2 cancer cells. The results of physicochemical analytics demonstrated that SiO2@PMA-DDA-DEC nanocomposites were successfully synthesized. The prepared nanocomposites were taken up by NTERA-2 cells with high efficiency, and could effectively inhibit cell growth and increase apoptosis rate in the treated cells compared to the control group. Moreover, SiO2@PMA-DDA nanocomposites loaded with c-Myc decoy ODNs induced cell cycle arrest at the G0/G1 phase in the treated cells. CONCLUSIONS: The conclusion drawn from this study is that c-Myc decoy ODN-loaded SiO2@PMA-DDA nanocomposites can effectively inhibit cell growth and induce apoptosis in NTERA-2 cancer cells. Moreover, given that a metal core is incorporated into this synthetic nanocomposite, it could potentially be used in conjunction with irradiation as part of a decoy-radiotherapy combinational therapy in future investigations.

Composite Aerogel Scaffolds Containing Flexible Silica Nanofiber and Tricalcium Phosphate Enable Skin Regeneration.

Poor hemostatic ability and less vascularization at the injury site could hinder wound healing as well as adversely affect the quality of life (QOL). An ideal wound dressing should exhibit certain characteristics: (a) good hemostatic ability, (b) rapid wound healing, and (c) skin appendage formation. This necessitates the advent of innovative dressings to facilitate skin regeneration. Therapeutic ions, such as silicon ions (Si4+) and calcium ions (Ca2+), have been shown to assist in wound repair. The Si4+ released from silica (SiO2) can upregulate the expression of proteins, including the vascular endothelial growth factor (VEGF) and alpha smooth muscle actin (α-SMA), which is conducive to vascularization; Ca2+ released from tricalcium phosphate (TCP) can promote the coagulation alongside upregulating the expression of cell migration and cell differentiation related proteins, thereby facilitating the wound repair. The overarching objective of this study was to exploit short SiO2 nanofibers along with the TCP to prepare TCPx@SSF aerogels and assess their wound healing ability. Short SiO2 nanofibers were prepared by electrospinning and blended with varying proportions of TCP to afford TCPx@SSF aerogel scaffolds. The TCPx@SSF aerogels exhibited good cytocompatibility in a subcutaneous implantation model and manifested a rapid hemostatic effect (hemostatic time 75 s) in a liver trauma model in the rabbit. These aerogel scaffolds also promoted skin regeneration and exhibited rapid wound closure, epithelial tissue regeneration, and collagen deposition. Taken together, TCPx@SSF aerogels may be valuable for wound healing.

"Three Musketeers" Enhances Photodynamic Effects by Reducing Tumor Reactive Oxygen Species Resistance.

Photodynamic therapy (PDT) based on upconversion nanoparticles (UCNPs) has been widely used in the treatment of a variety of tumors. Compared with other therapeutic methods, this treatment has the advantages of high efficiency, strong penetration, and controllable treatment range. PDT kills tumors by generating a large amount of reactive oxygen species (ROS), which causes oxidative stress in the tumor. However, this killing effect is significantly inhibited by the tumor's own resistance to ROS. This is because tumors can either deplete ROS by high concentration of glutathione (GSH) or stimulate autophagy to eliminate ROS-generated damage. Furthermore, the tumor can also consume ROS through the lactic acid metabolic pathway, ultimately hindering therapeutic progress. To address this conundrum, we developed a UCNP-based nanocomposite for enhanced PDT by reducing tumor ROS resistance. First, Ce6-doped SiO2 encapsulated UCNPs to ensure the efficient energy transfer between UCNPs and Ce6. Then, the biodegradable tetrasulfide bond-bridged mesoporous organosilicon (MON) was coated on the outer layer to load chloroquine (CQ) and α-cyano4-hydroxycinnamic acid (CHCA). Finally, hyaluronic acid was utilized to modify the nanomaterials to realize an active-targeting ability. The obtained final product was abbreviated as UCNPs@MON@CQ/CHCA@HA. Under 980 nm laser irradiation, upconverted red light from UCNPs excited Ce6 to produce a large amount of singlet oxygen (1O2), thus achieving efficient PDT. The loaded CQ and CHCA in MON achieved multichannel enhancement of PDT. Specifically, CQ blocked the autophagy process of tumor cells, and CHCA inhibited the uptake of lactic acid by tumor cells. In addition, the coated MON consumed a high level of intracellular GSH. In this way, these three functions complemented each other, just as the "three musketeers" punctured ROS resistance in tumors from multiple angles, and both in vitro and in vivo experiments had demonstrated the elevated PDT efficacy of nanomaterials.

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.

The influence of Zircos-E® etchant, silica coating, and alumina air-particle abrasion on the debonding resistance of endocrowns with three different preparation designs.

OBJECTIVES: The study aimed to evaluate the debonding resistance of three different endocrown designs on molar teeth, using three different zirconia surface pretreatments. MATERIAL AND METHOD: Ninety human mandibular first molars were divided into three main groups: endocrowns without ferrule, with 1 mm ferrule, and with 2 mm ferrule. The subgroups were defined by their surface pretreatment method used (n = 15): 50 µm alumina air-particle abrasion, silica coating using 30 µm Cojet™ particles, and Zircos-E® etching. The endocrowns were fabricated using multilayer zirconia ceramic, cemented with self-adhesive resin cement, and subjected to 5000 thermocycles (5-55°C) before debonding. The data obtained were analyzed using a two-way ANOVA. RESULTS: All test specimens survived the thermocyclic aging. The results indicated that both the preparation design and the surface treatment had a significant impact on the resistance to debonding of the endocrowns (p < .001). The 2 mm ferrule followed by the 1 mm ferrule designs exhibited the highest debonding resistance, both were superior to the endocrown without ferrule. Zircos-E® etching and silica coating yielded comparable debonding resistance, which were significantly higher than alumina air-particle abrasion. All endocrowns demonstrated a favorable failure mode. CONCLUSIONS: All designs and surface treatments showed high debonding resistance for a single restoration. However, ferrule designs with Zircos-E® etching or silica coating may represent better clinical options compared to the nonferrule design or alumina airborne-particle abrasion. Nonetheless, further research, including fatigue testing and evaluations with different luting agents is recommended.

Loading cinnamon oil into pH-sensitive chitosan grafted mesoporous silica nanoparticles via supercritical carbon dioxide.

Stimulus-responsive mesoporous silica nanoparticles (MSNs) have displayed great potentiality for controlled-release and targeted drug delivery. In the current work, a supercritical fluid method was utilized to successfully prepare cinnamon oil loaded into chitosan grafted MSNs (CO@CS-MSNs). The influencing factors of drug loads, such as pressure, temperature, impregnation time and depressure time, were investigated. The structure of CO@CS-MSNs was demonstrated with Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetry (TG) as well as X-ray diffraction (XRD). The drug release assays in vitro at various pH conditions displayed that CO@CS-MSNs had an excellent pH-responsive release behavior, which confirmed that CO was loaded successfully into the CO@CS-MSNs. The findings indicated that the supercritical fluid approach is a non-destructive and efficient approach for stimulus-responsive MSNs, which is expected to further expand its application range.

Comparing the Potential of Silicon Nanoparticles and Conventional Silicon for Salinity Stress Alleviation in Soybean (Glycine max L.): Growth and Physiological Traits and Rhizosphere/Endophytic Bacterial Communities.

In this study, 20-day-old soybean plants were watered with 100 mL of 100 mM NaCl solution and sprayed with silica nanoparticles (SiO2 NPs) or potassium silicate every 3 days over 15 days, with a final dosage of 12 mg of SiO2 per plant. We assessed the alterations in the plant's growth and physiological traits, and the responses of bacterial microbiome within the leaf endosphere, rhizosphere, and root endosphere. The result showed that the type of silicon did not significantly impact most of the plant parameters. However, the bacterial communities within the leaf and root endospheres had a stronger response to SiO2 NPs treatment, showing enrichment of 24 and 13 microbial taxa, respectively, compared with the silicate treatment, which led to the enrichment of 9 and 8 taxonomic taxa, respectively. The rhizosphere bacterial communities were less sensitive to SiO2 NPs, enriching only 2 microbial clades, compared to the 8 clades enriched by silicate treatment. Furthermore, SiO2 NPs treatment enriched beneficial genera, such as Pseudomonas, Bacillus, and Variovorax in the leaf and root endosphere, likely enhancing plant growth and salinity stress resistance. These findings highlight the potential of SiO2 NPs for foliar application in sustainable farming by enhancing plant-microbe interactions to improve salinity tolerance.

Dental biomaterials redefined: molecular docking and dynamics-driven dental resin composite optimization.

BACKGROUND: Dental resin-based composites are widely recognized for their aesthetic appeal and adhesive properties, which make them integral to modern restorative dentistry. Despite their advantages, adhesion and biomechanical performance challenges persist, necessitating innovative strategies for improvement. This study addressed the challenges associated with adhesion and biomechanical properties in dental resin-based composites by employing molecular docking and dynamics simulation. METHODS: Molecular docking assesses the binding energies and provides valuable insights into the interactions between monomers, fillers, and coupling agents. This investigation prioritizes SiO2 and TRIS, considering their consistent influence. Molecular dynamics simulations, executed with the Forcite module and COMPASS II force field, extend the analysis to the mechanical properties of dental composite complexes. The simulations encompassed energy minimization, controlled NVT and NPT ensemble simulations, and equilibration stages. Notably, the molecular dynamics simulations spanned a duration of 50 ns. RESULTS: SiO2 and TRIS consistently emerged as influential components, showcasing their versatility in promoting solid interactions. A correlation matrix underscores the significant roles of van der Waals and desolvation energies in determining the overall binding energy. Molecular dynamics simulations provide in-depth insights into the mechanical properties of dental composite complexes. HEMA-SiO2-TRIS excelled in stiffness, BisGMA-SiO2-TRIS prevailed in terms of flexural strength, and EBPADMA-SiO2-TRIS offered a balanced combination of mechanical properties. CONCLUSION: These findings provide valuable insights into optimizing dental composites tailored to diverse clinical requirements. While EBPADMA-SiO2-TRIS demonstrates distinct strengths, this study emphasizes the need for further research. Future investigations should validate the computational findings experimentally and assess the material's response to dynamic environmental factors.

Arginine-Functional Methacrylic Block Copolymer Nanoparticles: Synthesis, Characterization, and Adsorption onto a Model Planar Substrate.

Recently, we reported the synthesis of a hydrophilic aldehyde-functional methacrylic polymer (Angew. Chem., 2021, 60, 12032-12037). Herein we demonstrate that such polymers can be reacted with arginine in aqueous solution to produce arginine-functional methacrylic polymers without recourse to protecting group chemistry. Careful control of the solution pH is essential to ensure regioselective imine bond formation; subsequent reductive amination leads to a hydrolytically stable amide linkage. This new protocol was used to prepare a series of arginine-functionalized diblock copolymer nanoparticles of varying size via polymerization-induced self-assembly in aqueous media. Adsorption of these cationic nanoparticles onto silica was monitored using a quartz crystal microbalance. Strong electrostatic adsorption occurred at pH 7 (Γ = 14.7 mg m-2), whereas much weaker adsorption occurred at pH 3 (Γ = 1.9 mg m-2). These findings were corroborated by electron microscopy, which indicated a surface coverage of 42% at pH 7 but only 5% at pH 3.

Nucleic acid vaccine candidates encapsulated with mesoporous silica nanoparticles against MERS-CoV.

Middle East respiratory coronavirus (MERS-CoV) is a newly emergent, highly pathogenic coronavirus that is associated with 34% mortality rate. MERS-CoV remains listed as priority pathogen by the WHO. Since its discovery in 2012 and despite the efforts to develop coronaviruses vaccines to fight against SARS-CoV-2, there are currently no MERS-CoV vaccine that has been approved. Therefore, there is high demand to continue on the development of prophylactic vaccines against MERS-CoV. Current advancements in vaccine developments can be adapted for the development of improved MERS-CoV vaccines candidates. Nucleic acid-based vaccines, including pDNA and mRNA, are relatively new class of vaccine platforms. In this work, we developed pDNA and mRNA vaccine candidates expressing S.FL gene of MERS-CoV. Further, we synthesized a silane functionalized hierarchical aluminosilicate to encapsulate each vaccine candidates. We tested the nucleic acid vaccine candidates in mice and evaluated humoral antibodies response. Interestingly, we determined that the non-encapsulated, codon optimized S.FL pDNA vaccine candidate elicited the highest level of antibody responses against S.FL and S1 of MERS-CoV. Encapsulation of mRNA with nanoporous aluminosilicate increased the humoral antibody responses, whereas encapsulation of pDNA did not. These findings suggests that MERS-CoV S.FL pDNA vaccine candidate induced the highest level of humoral responses. This study will enhance further optimization of nanosilica as potential carrier for mRNA vaccines. In conclusion, this study suggests MERS-CoV pDNA vaccine candidate as a suitable vaccine platform for further pivotal preclinical testings.