Tailored Covalent Organic Framework Platform: From Multistimuli, Targeted Dual Drug Delivery by Architecturally Engineering to Enhance Photothermal Tumor Therapy.

Engineering bulk covalent organic frameworks (COFs) to access specific morphological structures holds paramount significance in boosting their functions in cancer treatment; nevertheless, scant effort has been dedicated to exploring this realm. Herein, silica core-shell templates and multifunctional COF-based reticulated hollow nanospheres (HCOFs) are novelly designed as a versatile nanoplatform to investigate the simultaneous effect of dual-drug chemotherapy and photothermal ablation. Taking advantage of the distinct structural properties of the template, the resulting two-dimensional (2D) HCOF, featuring large internal voids and a peripheral interconnected mesoporous shell, presents intriguing benefits over its bulk counterparts for cancer treatment, including a well-defined morphology, an outstanding drug loading capability (99.6%) attributed to its ultrahigh surface area (2087 m2/g), great crystallinity, improved tumor accumulation, and an adjustable drug release profile. After being loaded with hydrophilic doxorubicin with a remarkable loading capacity, the obtained drug-loaded HCOFs were coated with gold nanoparticles (Au NPs) to confer them with three properties, including pore entrance blockage, active-targeting capability, and improved biocompatibility via secondary modification, besides high near infrared (NIR) absorption for efficient photothermal hyperthermia cancer suppression. The resultant structure was functionalized with mono-6-thio-ß-cyclodextrin (ß-CD) as a second pocket to load docetaxel as the hydrophobic anticancer agent (combination index = 0.33). The dual-drug-loaded HCOF displayed both pH- and near-infrared-responsive on-demand drug release. In vitro and in vivo evaluations unveiled the prominent synergistic performance of coloaded HCOF in cancer elimination upon NIR light irradiation. This work opens up a new avenue for exciting applications of structurally engineered HCOFs as hydrophobic/hydrophilic drug carriers as well as multimodal treatment agents.

Meta-Phenylenediamine-Derived Silver-Containing Nanoporous Hyper-Cross-Linked Polymer: An Innovative Fluorescence Probe for S2O32- ion Detection in Aqueous Media.

The meta-phenylenediamine polymer, when hyper-cross-linked, exhibits a minimal fluorescence intensity. However, the introduction of silver ions induces a significant increase in intensity, attributed to the plasmonic effect. This heightened intensity is selectively increased more upon the addition of thiosulfate ions. Capitalizing on this property, a fluorescence probe was developed. The correlation between fluorescence intensity reduction and S2O32- concentration follows a linear and consistent pattern. The precursor's response to diverse anions such as SO42-, CO32-, HPO42-, Cr2O72-, F-, Cl-, Br-, I-, H2PO4-, CH3COO-, NO3-, ClO-, and HCO3- was also examined. Under optimal conditions, the probe exhibited a linear range of 0.5-3 µM with a detection limit of 0.01 µM. Its effectiveness was demonstrated in measuring thiosulfate concentrations in aqueous media.

Coumarin derivative-functionalized nanoporous silica as an on-off fluorescent sensor for detecting Fe3+ and Hg2+ ions: a circuit logic gate.

A highly efficient fluorescent sensor (S-DAC) was easily created by functionalizing the SBA-15 surface with N-(2-Aminoethyl)-3-Aminopropyltrimethoxysilane followed by the covalent attachment of 7-diethylamino 3-acetyl coumarin (DAC). This chemosensor (S-DAC) demonstrates selective and sensitive recognition of Fe3+ and Hg2+ in water-based solutions, with detection limits of 0.28 × 10-9 M and 0.2 × 10-9 M for Hg2+ and Fe3+, respectively. The sensor's fluorescence characteristics were examined in the presence of various metal ions, revealing a decrease in fluorescence intensity upon adding Fe3+ or Hg2+ ions at an emission wavelength of 400 nm. This sensor was also able to detect ferric and mercury ions in spinach and tuna fish. The quenching mechanism of S-DAC was investigated using UV-vis spectroscopy, which confirmed a static-type mechanism for fluorescence quenching. Moreovre, the decrease in fluorescence intensity caused by mercury and ferric ions can be reversed using trisodium citrate dihydrate and EDTA as masking agents, respectively. As a result, a circuit logic gate was designed using Hg2+, Fe3+, trisodium citrate dihydrate, and EDTA as inputs and the quenched fluorescence emission as the output.

Chitosan-derived mesoporous N-doped carbon catalyst embedded with NiO for highly selective benzyl alcohol oxidation.

MOF-derived heteroatom-doped mesoporous carbons have gained the significant consideration in heterogenous catalytic reactions because of their multipurpose features. Especially, the high Specific Surface Area (SSA) of these materials provides abundant activated sites for the catalytic reactions, while the mesoporous structure allows for the effective mass transfer, enhancing the overall capability of the catalytic process. Herein, the efficient NiO/CN-T (T referred to the pyrolysis temperature) was prepared by facile pyrolysis of MOF/CS composite (Ni-MOF (74), Chitosan) in the presence of excess amount of starch as the carbon precursor. The NiO/CN-T as heterogenous catalyst has desired SSA varied from 1094 to 491 m2.g-1. The optimized catalyst (NiO/CN-600) possesses the superior catalytic activity toward the oxidation of the BnOHs due to its high SSA (1094 m2.g-1), which can notably rectify the mass transfer proficiency. Additionally, the NiO/CN-600 heterogenous catalyst also represents the acceptable chemical stability. So, it was demonstrated that such an innovative strategy can provide several versatile tunability insights for the preparation of MOF/biopolymer-derived heterogenous catalysts.

Nitrogen-contained Nanoporous Hyper-cross-linked Polymer: A New Turn-on Fluorescence Probe for Detection of Ag+ Ions in Aqueous Media.

A fluorescence probe was designed using a nitrogen-contained mesoporous hyper-cross-linked polymer precursor (NH2-HCP) in order to selectively detect silver (Ag+) ions. NH2-HCP exhibits fluorescence intensity, but upon the addition of Ag+, a significant enhancement in fluorescence signal is observed. The relationship between fluorescence intensity enhancement and Ag+ concentration shows a linear and monotonic trend. The probe's response to various other cations such as Al3+, Fe3+, Cd2+, Ni2+, Cu2+, Fe2+, Hg2+, Mg2+, Zn2+, Pb2+, Mn2+, Co2+, Ca2+, Na+, and K+, as well as halogen anions like F-, Cl-, Br-, and I- was also investigated. Under optimal conditions, the probe demonstrated a linear range of 0.1-3 µM and a detection limit of 0.01 µM.

Fumed-Si-Pr-PNS as a Photoluminescence sensor for the Detection of Hg2+ in Aqueous Media.

Fumed silica was functionalized by piperazine followed by the reaction with 2- naphthalenesulfonyl chloride to prepare Fumed-Si-Pr-Piperazine-Naphthalenesulfonyl chloride (Fumed-Si-Pr-PNS), which was characterized to demonstrate the effective attachment on the surface of fumed silica. The optical sensing ability of Fumed-Si-Pr-PNS was studied via diverse metal ions in H2O solution by photoluminescence spectroscopy. The results showed that Fumed-Si-Pr-PNS detected selectively Hg2+ ions. The prepared sensor showed almost high absorption at different pH for Hg ion. After drawing various diagrams, The detection limits were calculated at about 12.45 × 10-6 M for Hg2+.

ZnO/black phosphorus/C3N4 composite: An effective photocatalyst for Cr (VI) reduction and degradation of rhodamine B.

The utilization of photocatalysts offers a promising approach for the removal of Cr (VI) and rhodamine dyes. Through the generation of reactive species and subsequent degradation reactions, photocatalysis provides an efficient and environmentally friendly method for the remediation of wastewater. In this study, we have synthesized an n-p-n heterojunction of carbon nitride (C3N4), zinc oxide (ZnO), and black phosphorus (BP) through the sonication-stirring method. The photocatalytic ability of this composite was examined for the decomposition rhodamine B (RhB) and detoxification of hexavalent chromium ion (up to 97% during 80 min) under Xenon irradiation. The results of trapper experiments indicated that the active species were hydroxyl radical (˙OH), electron (e-), and superoxide anion radical (˙O2-). Based on the obtained potential of the lowest unoccupied molecular orbitals (LUMO) and the highest occupied molecular orbital (HOMO) for the mentioned semiconductors, through Mutt-Schottky results, the double Z-scheme mechanism was proposed for the studied process. The electrochemical impedance spectroscopy data exhibited good charge transfer for the evaluated composite versus the pure compounds. The impressive separation of holes and electrons along with the low recombination were confirmed by the responses of photocurrent and quenching the photoluminescence (pl) intensity for the composite, respectively. The current density of the composite recorded 66.6%, 87.3%, and 92% higher than those of BP, C3N4, and ZnO, indicating an excellent electron-hole separation for the ternary composite compared to the pure semiconductors. Diffuse reflectance spectra (DRS) data revealed 2.9, 3.17, 1.15, and 2.63 eV as the band gap values for C3N4, ZnO, BP, and composite. The rate constant of the new composite to remove RhB and reduce hexavalent chromium were about 4.79 and 2.64 times higher than that of C3N4, respectively.

Black Phosphorus-based Photocatalysts: Synthesis, Properties, and Applications.

Photocatalysis is considered as an eco-friendly and sustainable strategy, since it uses abundant light for the advancement of the reaction, which is freely accessible and is devoid of environmental pollution. During the last decades, (nano)photocatalysts have gained broad industrial applications in terms of purification and detoxification of water as well as production of green fuels and hydrogen gas due to their special attributes. The degradation or remediation of toxic and hazardous compounds from the environment or changing them into non-toxic entities is a significant endeavor and necessary for the safety of humans, animals, and the environment. Black phosphorus (BP), a two-dimensional single-element material, has a marvelous structure, tunable bandgap, changeable morphology from bulk to nanosheet/quantum dot, and unique physicochemical properties, which makes it attractive material for photocatalytic applications, especially for sustainable development purposes. Since it can serve as a photocatalyst with or without coupling with other semiconductors, various aspects for multidimensional exploitation of BP are deliberated including their preparation via solvothermal, ball milling, calcination, and sonication methods to obtain BP from red phosphorus. The techniques for improving the photocatalytic and stability of BP-based composites are discussed along with their multifaceted applications for environmental remediation, pollution degradation, water splitting, N2 fixation, CO2 reduction, bacterial disinfection, H2 generation, and photodynamic therapy. Herein, most recent advancements pertaining to the photocatalytic applications of BP-based photocatalyst are cogitated, with a focus on their synthesis and properties as well as crucial challenges and future perspectives.

A miniaturized analytical system with packed epoxy-functionalized mesoporous organosilica for copper determination using a customized Android-based software.

A smartphone-assisted determination of copper ions is introduced by using a down-scaled microfluidic mixer. The system was coupled with a micro-column packed with a periodic mesoporous organosilica (PMO) material for preconcentration of copper ions. Copper ions were reduced to Cu(I) on-chip to selectively form an orange-colored complex with neocuproine. A novel Android-based software was made to determine the color change of the adsorbent by analyzing red-green-blue (RGB) components of images from the packed PMO material. Four porous framework materials with high porosity and chemical stability were synthesized and compared for the extraction of the Cu-neocuproine complex. The main parameters influencing the complex extraction efficiency were optimized. The analytical performance of the method showed limit of detection and quantification of 0.2 µg L-1 and 0.5 µg L-1, respectively. The accuracy and precision of the method were determined as recovery > 92% and relative standard deviations < 5.2% at medium concentration level (n = 5). Due to accumulation of the retained analyte in a single point and elimination of the stripping step, the RGB-based method showed sensitivity and precision higher than inductively coupled plasma-atomic emission spectrometry (ICP-AES) for determination of copper ions. To investigate the applicability of the method, six different water samples were analyzed. The t-test on the data showed that the method has no significant difference when compared with ICP-AES determination.

The role of hydrogen sulfide in the retina.

The discovery of the hydrogen sulfide (H2S) and the transsulfuration pathway (TSP) responsible for its synthesis in the mammalian retina has highlighted this molecule's wide range of physiological processes that influence cellular signaling, redox homeostasis, and cellular metabolism. The multi-level regulatory program that influences H2S levels in the retina depends on the relative expression and activity of TSP enzymes, which regulate the abundance of competitive substrates that support or abrogate H2S synthesis. In addition, and apart from TSP, intracellular H2S levels are regulated by mitochondrial sulfide oxidizing pathways. Retinal layers natively express differing levels of TSP enzymes, which highlight the differences in the metabolite and substrate requirement. Recent studies indicate that these systems are susceptible to pathophysiologies affecting the retina. Dysregulation at any level can upset the balance of redox and signaling processes and possibly upset oxidative stress, apoptotic signaling, ion channels, and immune response within this sensitive tissue. H2S donors are a potential therapeutic in such cases and have been demonstrated to bridge the gap, positively impacting the damaged retina. Here, we review the recent findings of H2S, how its multi-level regulation impacts the retina, and how its dysregulation is implicated in retinal pathologies.

Enhanced photocatalytic activity of modified black phosphorus-incorporated PANi/PAN nanofibers.

Enhancement of the photocatalytic activity of black phosphorus (BP) is a highly challenging proposition. The fabrication of electrospun composite nanofibers (NFs) through the incorporation of modified BP nanosheets (BPNs) into conductive polymeric NFs has been recently introduced as a newer strategy not only to enhance the photocatalytic activity of BPNs but also to overcome their drawbacks including ambient instability, aggregation, and hard recycling, which exist in their nanoscale powdered forms. The proposed composite NFs were prepared through the incorporation of silver (Ag)-modified BPNs, gold (Au)-modified BPNs, and graphene oxide (GO)-modified BPNs into polyaniline/polyacrylonitrile (PANi/PAN) NFs by an electrospinning process. The successful preparation of the modified BPNs and electrospun NFs was confirmed by the characterization techniques of Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis), powder X-ray diffraction (PXRD), and Raman spectroscopy. The pure PANi/PAN NFs exhibited high thermal stability with a main weight loss of ∼23% for the temperature range of 390-500 °C, and the thermal stability of NFs was enhanced after their incorporation with the modified BPNs. The BPNs@GO-incorporated PANi/PAN NFs indicated improved mechanical properties compared to the pure PANi/PAN NFs with tensile strength (TS) of 1.83 MPa and elongation at break (EAB) of 24.91%. The wettability of the composite NFs was measured in the range of 35-36°, which exhibited their good hydrophilicity. The photodegradation performance was found in the sequence of BPNs@GO > BPNs@Au > BPNs@Ag > bulk BP ∼BPNs > red phosphorus (RP) for methyl orange (MO) and in the sequence of BPNs@GO > BPNs@Ag > BPNs@Au > bulk BP > BPNs > RP for methylene blue (MB), accordingly. The composite NFs degraded the MO and MB dyes more efficiently relative to the modified BPNs and pure PANi/PAN NFs.

Glucose Transporter Glut1-Dependent Metabolic Reprogramming Regulates Lipopolysaccharide-Induced Inflammation in RAW264.7 Macrophages.

This study investigated the critical role of Glut1-mediated glucose metabolism in the inflammatory response of macrophages, which are energy-intensive cells within the innate immune system. Inflammation leads to increased Glut1 expression, ensuring sufficient glucose uptake to support macrophage functions. We demonstrated that using siRNA to knock down Glut1 reduces the expression of various pro-inflammatory cytokines and markers, such as IL-6, iNOS, MHC II/CD40, reactive oxygen species, and the hydrogen sulfide (H2S)-producing enzyme cystathionine γ-lyase (CSE). Glut1 activates a pro-inflammatory profile through a nuclear factor (NF)-κB, while silencing Glut1 can prevent lipopolysaccharide (LPS)-induced IκB degradation, blocking NF-κB activation. Glut1's role in autophagy, an essential process for macrophage functions such as antigen presentation, phagocytosis, and cytokine secretion, was also measured. The findings show that LPS stimulation decreases autophagosome formation, but Glut1 knockdown reverses this effect, increasing autophagy beyond control levels. The study highlights Glut1's importance in macrophage immune responses and its regulation of apoptosis during LPS stimulation. Knocking down Glut1 negatively impacts cell viability and mitochondrial intrinsic pathway signaling. These findings collectively suggest that targeting macrophage glucose metabolism through Glut1 could potentially serve as a target for controlling inflammation.

From Gasotransmitter to Immunomodulator: The Emerging Role of Hydrogen Sulfide in Macrophage Biology.

Hydrogen sulfide (H2S) has been increasingly recognized as a crucial inflammatory mediator in immune cells, particularly macrophages, due to its direct and indirect effects on cellular signaling, redox homeostasis, and energy metabolism. The intricate regulation of endogenous H2S production and metabolism involves the coordination of transsulfuration pathway (TSP) enzymes and sulfide oxidizing enzymes, with TSP's role at the intersection of the methionine pathway and glutathione synthesis reactions. Additionally, H2S oxidation mediated by sulfide quinone oxidoreductase (SQR) in mammalian cells may partially control cellular concentrations of this gasotransmitter to induce signaling. H2S is hypothesized to signal through the posttranslational modification known as persulfidation, with recent research highlighting the significance of reactive polysulfides, a derivative of sulfide metabolism. Overall, sulfides have been identified as having promising therapeutic potential to alleviate proinflammatory macrophage phenotypes, which are linked to the exacerbation of disease outcomes in various inflammatory conditions. H2S is now acknowledged to have a significant influence on cellular energy metabolism by affecting the redox environment, gene expression, and transcription factor activity, resulting in changes to both mitochondrial and cytosolic energy metabolism processes. This review covers recent discoveries pertaining to the involvement of H2S in macrophage cellular energy metabolism and redox regulation, and the potential implications for the inflammatory response of these cells in the broader framework of inflammatory diseases.

Recent advances in covalent organic frameworks (COFs) for wound healing and antimicrobial applications.

Covalent organic frameworks (COFs) are crystal-like organic structures such as cartography buildings prepared from appropriately pre-designed construction block precursors. Moreover, after the expansion of the first COF in 2005, numerous researchers have been developing different materials for versatile applications such as sensing/imaging, cancer theranostics, drug delivery, tissue engineering, wound healing, and antimicrobials. COFs have harmonious pore size, enduring porosity, thermal stability, and low density. In addition, a wide variety of functional groups could be implanted during their construction to provide desired constituents, including antibodies and enzymes. The reticular organic frameworks comprising porous hybrid materials connected via a covalent bond have been studied for improving wound healing and dressing applications due to their long-standing antibacterial properties. Several COF-based systems have been planned for controlled drug delivery with wound healing purposes, targeting drugs to efficiently inhibit the growth of pathogenic microorganisms at the wound spot. In addition, COFs can be deployed for combinational therapy using photodynamic and photothermal antibacterial therapy along with drug delivery for healing chronic wounds and bacterial infections. Herein, the most recent advancements pertaining to the applications of COF-based systems against bacterial infections and for wound healing are considered, concentrating on challenges and future guidelines.

MOF-based composites as photoluminescence sensing platforms for pesticides: Applications and mechanisms.

Metal-organic frameworks (MOFs) have recently garnered considerable attention among reticular compounds due to their unique physicochemical properties and applications in sensing toxic compounds. On the other hand, fluorometric sensing has been widely studied for food safety and environmental protection among the various sensing methods. Thus, designing MOF-based fluorescence sensors for specific detection of hazardous compounds, especially pesticides, are incessantly needed to keep up with the continuous demands for monitoring these environmental pollution. Herein, recent MOF-based platforms for pesticide fluorescence detection are deliberated owing to sensors' emission origins and in terms of their structural properties. The influences of different guest incorporation in MOFs on pesticide fluorescence detection are summarized, and the future developments of novel MOF composites such as polyoxometalate@MOFs (POMOF), carbon quantum dots@MOFs (CDs@MOF), and organic dye@MOF are prospected for fluorescence sensing of assorted pesticides with a focus on mechanistic insights of specific detection techniques in food safety and environmental protection.

Selective detection of aspartic acid in human serum by a fluorescent probe based on CuInS2@ZnS quantum dots.

The importance of amino acids identification in biological systems has created expectation to develop a sensitive method for their detection. In this work, an efficient core-shell fluorescent quantum dots (QDs) probe based on CuInS2 (CIS) core and ZnS shell with the formula of CIS@ZnS QDs were synthesised and characterised by FT-IR, UV-Vis, TEM and DLS techniques. The probe was used for detection of Aspartic Acid (Asp) in an aqueous media. The probe shows a remarkable fluorescence response toward Asp over the other amino acids such as valine (Val), glycine (Gly), phenylalanine (Phe), leucine (Leu), alanine (Ala), serine (Ser), isoleucine (Iso), threonine (Thr), methionine (Met), Glutamic acid (Glu), histidine (His), arginine (Arg), cysteine (Cys), asparagine (Asn), glutamine (Gln), citrolline (Cit), sarcosine (Sar) and ornithine (Orn) the fluorescence intensity quenches significantly upon addition of Asp in an aqueous media. The CIS@ZnS QDs probe showed a selective and sensitive response by fluorescence quenching toward Asp in the concentration range of 8.3 × 10-7 M to 3.3 × 10-4 M with the detection limit of 7.8 × 10-8 M. The application of the sensor in determination of Asp in real human serum sample was also investigated. Based on our library search, the all reported fluorescent sensors for detection of Asp, either show a remarkable sensitivity to Glu acid. Luckily, this is the first presented optical probe able to detect just Asp from the solutions containing various amino acids.

MXene-Carbon Nanotube Composites: Properties and Applications.

Today, MXenes and their composites have shown attractive capabilities in numerous fields of electronics, co-catalysis/photocatalysis, sensing/imaging, batteries/supercapacitors, electromagnetic interference (EMI) shielding, tissue engineering/regenerative medicine, drug delivery, cancer theranostics, and soft robotics. In this aspect, MXene-carbon nanotube (CNT) composites have been widely constructed with improved environmental stability, excellent electrical conductivity, and robust mechanical properties, providing great opportunities for designing modern and intelligent systems with diagnostic/therapeutic, electronic, and environmental applications. MXenes with unique architectures, large specific surface areas, ease of functionalization, and high electrical conductivity have been employed for hybridization with CNTs with superb heat conductivity, electrical conductivity, and fascinating mechanical features. However, most of the studies have centered around their electronic, EMI shielding, catalytic, and sensing applications; thus, the need for research on biomedical and diagnostic/therapeutic applications of these materials ought to be given more attention. The photothermal conversion efficiency, selectivity/sensitivity, environmental stability/recyclability, biocompatibility/toxicity, long-term biosafety, stimuli-responsiveness features, and clinical translation studies are among the most crucial research aspects that still need to be comprehensively investigated. Although limited explorations have focused on MXene-CNT composites, future studies should be planned on the optimization of reaction/synthesis conditions, surface functionalization, and toxicological evaluations. Herein, most recent advancements pertaining to the applications of MXene-CNT composites in sensing, catalysis, supercapacitors/batteries, EMI shielding, water treatment/pollutants removal are highlighted, focusing on current trends, challenges, and future outlooks.

N-doped carbon nanospheres as selective fluorescent probes for mercury detection in contaminated aqueous media: chemistry, fluorescence probing, cell line patterning, and liver tissue interaction.

A precise nano-scale biosensor was developed here to detect Hg2+ in aqueous media. Nitrogen-doped carbon nanospheres (NCS) created from the pyrolysis of melamine-formaldehyde resin were characterized by FESEM, XRD, Raman spectra, EDS, PL, UV-vis spectra, and N2 adsorption-desorption, and were used as a highly selective and sensitive probe for detecting Hg2+ in aqueous media. The sensitivity of NCS to Hg2+ was evaluated by photoluminescence intensity fluctuations under fluorescence emission in the vicinity of 390 nm with a λexc of 350 nm. The fluorescence intensity of the NCS probe weakened in the presence of Hg2+ owing to the effective fluorescence quenching by that, which is not corresponding to the special covalent liking between the ligand and the metal. The effects of the fluorescence nanoprobe concentration, pH, and sensing time were monitored to acquire the best conditions for determining Hg2+. Surprisingly, NCS revealed excellent selectivity and sensitivity towards Hg2+ in the samples containing Co2+, Na+, K+, Fe2+, Mn2+, Al3+, Pb2+, Ni2+, Ca2+, Cu2+, Mg2+, Cd2+, Cr3+, Li+, Cs+, and Ba2+. The fluorescence response was linearly proportional to Hg2+ concentration in 0.013-0.046 µM with a limit of detection of 9.58 nM. The in vitro and in vivo toxicological analyses confirmed the completely safe and biocompatible features of NCS, which provides promise for use for water, fruit, vegetable, and/or other forms of natural-connected materials exposed to Hg2+, with no significant toxicity noticed toward different cells/organs/tissues.

Evaluation of the cell viability and antimicrobial effects of orthodontic bands coated with silver or zinc oxide nanoparticles: An in vitro study.

Objective: We aimed to evaluate the cell viability and antimicrobial effects of orthodontic bands coated with silver or zinc oxide nanoparticles (nano-Ag and nano-ZnO, respectively). Methods: In this experimental study, 30 orthodontic bands were divided into three groups (n = 10 each): control (uncoated band), Ag (silver-coated band), and ZnO (zinc oxide-coated band). The electrostatic spray-assisted vapor deposition method was used to coat orthodontic bands with nano-Ag or nano-ZnO. The biofilm inhibition test was used to assess the antimicrobial effectiveness of nano-Ag and nano-ZnO against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. Biocompatibility tests were conducted using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The groups were compared using oneway analysis of variance with a post-hoc test. Results: The Ag group showed a significantly higher reduction in the number of L. acidophilus, C. albicans, and S. mutans colonies than the ZnO group (p = 0.015, 0.003, and 0.005, respectively). Compared with the control group, the Ag group showed a 2-log10 reduction in all the microorganisms' replication ability, but only S. mutants showed a 2-log10 reduction in replication ability in the ZnO group. The lowest mean cell viability was observed in the Ag group, but the difference between the groups was insignificant (p > 0.05). Conclusions: Coating orthodontic bands with nano-ZnO or nano-Ag induced antimicrobial effects against oral pathogens. Among the nanoparticles, nano-Ag showed the best antimicrobial activity and nano-ZnO showed the highest biocompatibility.

Removal of mercury ions from aqueous by functionalized LUS-1 with Bis [3-(triethoxysilyl) propyl] tetrasulfide as an effective nanocomposite using response surface methodology (RSM).

In this study, LUS-1, as a mesoporous silica material, was functionalized using sulfur-containing ligand (Bis [3-(triethoxysilyl) propyl] tetrasulfide, TESPT) and used for mercury removal from the aqueous solution. Different characterizations such as N2 adsorption-desorption (BET), TGA, XRD, FT-IR, and SEM were used to verify the nanocomposite synthesis. In addition, the effects of several independent parameters like pH, the contact time of reaction, and adsorbent dose on the removal efficiency of mercury from aqueous in a batch system were studied using response surface methodology (RSM). Based on the results and after both theoretical and experimental studies, the optimum conditions using the LUS-1-TESPT were contact time of reaction of 23.16 min, sorbent dose of 51.12 mg, and pH of 4.5. The kinetic and isotherm models for the adsorption process showed a maximum adsorption capacity of adsorbent which was 136.73 mg g-1 with 99% removal of Hg(II) via the Langmuir model. Meanwhile, the sorbent's reusability and efficiency verified that the sorbent could be used five times after recovery with 99% efficiency.