Preparation of multifunctional ceramic foams for sound absorption, waterproofing, and antibacterial applications.

Using porous materials for sound absorption is an effective approach to alleviating noise pollution, although their hydrophilic properties potentially cause concerns regarding public safety and health risks. This work provides a facile strategy for establishing a multifunctional ceramic system by using sponges as the sintering template, adjusting the pore structure of ceramic foams by varying the ceramic slurry weights and fluorinating the sintered ceramic foams via hydrolysis and condensation processes to provide low surface energy. The obtained porous ceramic foams demonstrate sound-absorbing, waterproof, and antibacterial properties. The results reveal that the increase in ceramic slurry weight decreases the pore size and porosity due to the formation of more compact structures, and the decrease in porosity compromises the sound absorption performance. In the middle-range sound frequency, the maximum sound absorption coefficient reached 0.92. In addition, the fluorination of the rough ceramic surfaces endows the ceramic foams with waterproof properties, which enables them to float on water and display the silver mirror phenomenon. In addition, due to the waterproof property reducing the contact area between the ceramic surface and the bacterial suspension, as well as the lipophilic fluorine chain disrupting the bacterial structures, these ceramic foams exhibited antibacterial rates above 95%. In addition, the mechanisms underlying the sound-absorbing, waterproof, and antibacterial properties of these porous ceramic foams are elucidated. Therefore, this work provides a facile approach to developing a multifunctional ceramic system. Their practical features make these ceramic foams more significant in the field of noise reduction.

Foliar application of glycine-functionalized nanopesticides for effective prevention and control of root-knot nematodes via a targeted delivery strategy.

BACKGROUND: Root-knot nematodes (RKNs) are the highly damaging pests for various crops, and the prevalence of RKNs has posed serious threats to worldwide agricultural harvest, severely affecting global food security and ecosystem health. Traditional pesticide systems on controlling RKNs generally cause environmental hazards and phytotoxicity due to the excessive use of pesticides resulted from low utilization efficiency. And effective approaches with biosafe and efficient features are highly demanded to break away from the dilemma caused by RKNs. RESULTS: In this research, a nanopesticide system with root-targeted delivery function was developed to achieve effective prevention and control of RKNs. The nanocarriers (MSN-KH560-Gly) and the obtained nanopesticides (EB@MSN-KH560-Gly) were proved to be biosafe. Also, this nanopesticide system demonstrated sustained release behavior. The grafting of glycine (Gly) significantly improved the pesticide contents translocating to cucumber roots (about 304.7%). Besides, such root-targeted delivery function resulted in no root nodule in cucumber plants after the foliar application of these nanopesticides (prevention rate of 100%). In addition, the root nodule numbers of the infected cucumber plants decreased by 71.67%. CONCLUSION: Foliar application of these Gly-functionalized nanopesticides achieved effective prevention and control of RKNs due to the root-targeted delivery property inherent in this nanopesticide system, and such root-targeted delivery strategy opens a novel and efficient method to protect crops from RKN invasion and thus facilitates the development of sustainable agriculture. © 2023 Society of Chemical Industry.

Preparation of Salicylic Acid-Functionalized Nanopesticides and Their Applications in Enhancing Salt Stress Resistance.

Soil salinization is one of the global ecological and environmental problems that are tremendously threatening to the sustainable development of agriculture and food supply. In this work, a facile strategy was proposed to enhance the salt stress resistance of plants by preparing salicylic acid (SA)-functionalized mesoporous silica nanocarriers loaded with emamectin benzoate (EB). The obtained nanopesticides demonstrated a particle size of less than 300 nm. As an endogenous plant hormone, the grafting of SA in this nanopesticide system improved the uptake and translocation of pesticides in cucumber plants by 145.06%, and the applications of such nanopesticides enhanced the salt stress resistance of plants. This phenomenon was accounted for by the SA-functionalized nanopesticides increasing the superoxide dismutase and peroxidase activities (640 and 175%, respectively) and reducing the malondialdehyde content (54.10%), correspondingly alleviating the accumulation of reactive oxygen species and cell damage in plants. The above results were also confirmed by Evans blue staining and NBT staining experiments on cucumber leaves. In addition, these nanopesticides exhibited high insecticidal toxicity, and they also demonstrated biosafety toward nontarget organisms due to their sustained release property. Therefore, this work developed a biosafe SA-functionalized nanopesticide system, and these newly developed nanopesticides have potential in the agricultural field for enhancing salt stress resistance of plants.

Preparation of mesoporous silica-based nanocomposites with synergistically antibacterial performance from nano-metal (oxide) and polydopamine.

In this work, a novel antibacterial nanocomposite system was developed using mesoporous silica (MSN) as an effective nanocarrier, and the resultant nanocomposites demonstrated remarkable antibacterial performance due to the synergistic effect among nano zinc oxides, silver nanoparticles, and polydopamine (PDA). The successful synthesis of MSN/ZnO@PDA/Ag nanocomposites was confirmed. The physicochemical properties and the morphologies of these nanocomposites were investigated. It was found that the particle size increased along with the evolution of these nanocomposites. Besides, nano zinc oxides were formed in the nanochannels of mesoporous silica with a particle size about 2 nm, and that of silver nanoparticle was less than 50 nm. In addition, the results revealed that the presence of mesoporous silica could effectively prevent the formation of large-size silver nanoparticles and facilitate their well dispersion. Due to the synergistic effect among nano zinc oxides, silver nanoparticles, and polydopamine, these nanocomposites exhibited remarkable antibacterial performance even at a low concentration of 313 ppm, and the antibacterial mechanism was also elucidated. Therefore, this work provides a facile and controllable approach to preparing synergistically antibacterial nanocomposites, and the remarkable antibacterial performance make them suitable for practical applications.

Functionalization of mesoporous silica as an effective composite carrier for essential oils with improved sustained release behavior and long-term antibacterial performance.

In this work, a novel composite carrier system for loading essential oils was developed by using tetraethyl orthosilicate (TEOS) and (3-aminopropyl) triethoxysilane (APTES) as silica precursors and cetyl trimethyl ammonium bromide (CTAB) as a template, and the resultant aminated mesoporous silica was further chemically modified by polyacrylic acid (PAA). The obtained composite carriers exhibited a high loading capability toward tea tree oil (TTO), and they also significantly improved the release behavior of TTO due to the steric hindrance of silica mesopore and the polymer restriction. Besides, it was found that the release behavior followed the First-Order kinetic model, revealing that the release of TTO was driven by the concentration gradient. In addition, these composite carriers with essential oil-loaded demonstrated remarkable antibacterial performance againstE. coliandS. aureus, and they could retain antibacterial performance even after 50 d. Moreover, the antibacterial mechanism was also elucidated with the assistance of nucleic acid and conductivity measurements. Therefore, this work provides a facile and environmentally friendly approach to preparing effective composite carriers for improving the sustained release of essential oils, and the long-term antibacterial performance of these essential oil-loaded composite carriers makes them tremendously potential for practical applications.

Rosin modified aminated mesoporous silica adsorbed tea tree oil sustained-release system for improve synergistic antibacterial and long-term antibacterial effects.

Tea tree oil, a natural antibacterial compound, cannot be used effectively because of its volatile nature. In this work, a biocompatible carrier was prepared and loaded with tea tree essential oil. The carrier was prepared via the electrostatic or chemical action of aminated mesoporous silica and sodium rosin for achieving a low volatilization rate of tea tree essential oil. A synergistic antibacterial effect was observed between sodium rosin and tea tree essential oil. This method utilized the positive charge of the amino group and the condensation reaction with the carboxyl group to achieve physical and chemical interactions with sodium rosin. Fourier Transform Infrared, Brunauer-Emmet-Teller, Zeta potential, SEM, TEM, and TG were performed to characterize the structure and properties of the samples. Compared to the electrostatic effect, the chemically modified system exhibited a longer sustained release, and the sustained release curve followed the Korsmeyer-Peppas release model. Also, the antibacterial properties of the chemically modified system exhibited better minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) respectively, the MIC and MBC forE. coliwere 0.3 mg ml-1and 0.6 mg ml-1respectively, forS. aureuswere 0.15 mg ml-1and 0.3 mg ml-1respectively. More strikingly, the sample also demonstrated long-term antibacterial performance. Therefore, this work provides a new way for the delivery of volatile antibacterial drugs to achieve sustained-release and long-lasting antibacterial effects.

Fabrication of Magnetically Inorganic/Organic Superhydrophobic Fabrics and Their Applications.

In order to solve the problem caused by oil spills and organic solvent contamination, novel magnetically inorganic/organic superhydrophobic fabrics are fabricated via a facile method. Cotton fabrics are immersed in a mixture of functionalized Co0.2Mg0.8Fe2O4 (FCMFO) nanoparticles, vinyl-terminated polydimethylsiloxane (VPDMS), trimethylolpropane triacrylate, and 2-hydroxy-2-methylpropiophenone before UV irradiation for 100 s to obtain the multifunctional superhydrophobic fabrics with magnetic property. The coated fabrics show excellent superhydrophobicity, and the water contact angle is 157.1° when the mass ratio of FCMFO nanoparticles to VPDMS is 0.3. These superhydrophobic fabrics have high oil/water separation efficiency (98.7% for dichloromethane/water) and high oil flux (71,506 L·m-2·h-1 for dichloromethane/water). Even after 20 separation cycles, oil/water separation efficiency and oil flux maintain 96.4% and 64,012 L·m-2·h-1, respectively. Furthermore, the magnetic property of these superhydrophobic fabrics could be used in the separation of oil from water. Moreover, the superhydrophobic fabrics possess exceptional self-cleaning performance, mechanical durability, chemical stability, and flame retardancy. These multifunctional superhydrophobic fabrics are potential for wide applications.

Robust Hyperbranched Polyester-Based Anti-Smudge Coatings for Self-Cleaning, Anti-Graffiti, and Chemical Shielding.

In this work, a novel anti-smudge coating system was developed by using hydroxyl-terminated hyperbranched polyester as a coating precursor, mono-hydroxyl-terminated poly(dimethylsiloxane) (PDMS) as an anti-smudge agent, and hexamethylene diisocyanate trimer as a curing agent. The resultant coatings with 0.5 wt % PDMS content incorporated are highly transparent and liquid repellent. They exhibit striking repellency against various liquids and display remarkable self-cleaning performance. Water, hexadecane, salt solution, strong alkali solution, strong acid solution, pump oil, and crude oil could slide off the coated surface without leaving any traces, and the dirt on the coated surface could be readily removed by water or oil. Besides, these coatings show potential application for anti-fingerprint and anti-graffiti due to the exceptional repellency of coated surface against artificial fingerprint liquid, oil-based ink, paint, and water-based smudge. Furthermore, they also possess superb chemical shielding ability and thus endow substrates with remarkable protection against exposure to harsh chemical conditions. Moreover, these coatings are mechanically robust against extensive abrasion, impact, and bending without compromising anti-smudge properties, and they also exhibit excellent adhesion to various substrates. Therefore, these newly developed coatings have tremendous potential for widespread applications.

Self-Cleaning, Chemically Stable, Reshapeable, Highly Conductive Nanocomposites for Electrical Circuits and Flexible Electronic Devices.

Materials with multiple functions are highly desirable in practical applications. Developing multifunctional nanocomposites by a straightforward process is still a challenge. Here, a versatile nanocomposite has been developed by simple blending and pressing of multiwalled carbon nanotubes (MWCNTs) and modified polydimethylsiloxane (MPDMS). Because of the synergistic effect of MWCNTs and MPDMS, this nanocomposite exhibits outstanding hydrophobic property, striking self-cleaning capability, and excellent chemical stability against strong acid and strong base, which makes it possible to work under wet and even extreme chemical conditions. Besides, because of its flexibility, this nanocomposite can be reshaped, bended, twisted, and molded into on-demand patterns for special applications. Owing to the good distribution of MWCNTs, the nanocomposite shows high conductivity (with a sheet resistance of 86.33 Ω sq-1) and high healing efficiency (above 96.53%) in an electrical field, and it also exhibits outstanding performance in various electrical circuits and flexible electroluminescent devices. Furthermore, the inherent portability, recyclability, and reusability of this nanocomposite make it more convenient and environmentally friendly for practical applications. Thus, our work provides a new strategy to develop a multifunctional nanocomposite, and it shows tremendous potential in flexible electronics.

Down-regulation of WT1/+17AA gene expression using RNAi and modulating leukemia cell chemotherapy resistance.

We have shown that inhibition of WT1/+17AA protein expression following transfection with a vector-based small interfering RNA expression construct in K562 cell lines, leads to a decrease in MDR1 and P-glycoprotein levels, accumulation of Rh123, and enhancement of the doxorubicin cytotoxicity. Our findings suggest that WT1/+17AA exerts its oncogenic function by modulating multidrug resistance in leukemia cells.

[Inhibition of vascular endothelial growth factor gene expression and proliferation of leukemia cells by RNA interference].

OBJECTIVE: To explore the feasibility of selective inhibiting VEGF expression using VEGF short hairpin RNA (shRNA) interference, and observe the effects of VEGF gene silencing on NB4 cells growth. METHODS: Three 19 bp reverse repeated motifs targeting exons 3, 4, 5 respectively of VEGF gene were synthesized and cloned into eukaryotic expression plasmid pGenesil-1 containing U6 shRNA promoter and termination signal of RNA polymerase. The recombinant plasmids pGenesil-VR1, pGenesil-VR2, pGenesil-VR3 and pGenesil-con (plasmid containing random DNA fragment) were transfected into NB4 cells respectively through lipofectamine reagent. The alteration of VEGF expression was examined by fluorescent real time RT-PCR and Western blot. The proliferation capacity of leukemia cells was measured by trypan blue exclusion, MTT assay, colony formation assay and cell cycles analysis. RESULTS: Recombinant plasmids containing three shRNAs and random fragment were successfully constructed and transfected into NB4 cells respectively by liposome-mediated gene transfer method. shRNA in pGenesil-VR3 cells knocked down the expression of VEGF mRNA and protein dramatically in a sequence-specific manner when compared with that of pGenesil-VR1, Genesil-VR2 and pGenesil-con. The NB4 cells transfected with pGenesil-VR3 (NB4-VR3) had a more significant decrease in proliferation ability than NB4 and that transfected with pGenesil-con (NB4-con). The colony forming efficiencies of NB4-VR3, NB4-con and NB4 cell were (13.3 +/- 3.8)%, (21.3 +/- 6.4)% and (24.5 +/- 5.2)%, respectively (P < 0.05). Higher G(1) and lower S proportion were found in cell cycle distribution in comparison with the control groups by FCM. CONCLUSIONS: The shRNA can efficiently suppress VEGF expression in NB4 cells. Selective VEGF gene silence can inhibit the malignant proliferation of leukemia cells.