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Polymer dielectrics with excellent capacitive performance are urgently needed in advanced electrical and electronic systems. However, due to the dramatic increase in the conduction loss, the energy density and efficiency of polymers degrade severely at elevated temperatures, limiting their application in harsh environments up to 150 °C. Herein, an all-organic polyurea (PU)/polyetherimide (PEI) blend film is designed to prepare high-temperature polymer dielectric. It is found that carrier traps can be introduced by blending, and the hydrogen bond between PU and PEI increases the trap depth, leading to suppressed leakage current and enhanced breakdown strength, thus improving the energy storage performance. PU/30%PEI exhibits a high discharged energy density of ∼3.74 J/cm3 with an efficiency higher than 90% at 150 °C, which is 78% and 70% higher than pristine PU and PEI, respectively. This work provides a facile strategy to improve the energy storage performance of polymer dielectrics by introducing deep traps through blending. [ABSTRACT FROM AUTHOR]

Helium nanodroplets ("HNDs") are widely used for forming tailor-made clusters and molecular complexes in a cold, transparent, and weakly interacting matrix. The characterization of embedded species by mass spectrometry is often complicated by the fragmentation and trapping of ions in the HNDs. Here, we systematically study fragment ion mass spectra of HND-aggregated water and oxygen clusters following their ionization by charge transfer ionization ("CTI") and Penning ionization ("PEI"). While the efficiency of PEI of embedded clusters is lower than for CTI by about factor 10, both the mean sizes of detected water clusters and the relative yields of unprotonated cluster ions are significantly larger, making PEI a "soft ionization" scheme. However, the tendency of ions to remain bound to HNDs leads to a reduced detection efficiency for large HNDs containing > 1 0 4 helium atoms. These results are instrumental in determining optimal conditions for mass spectrometry and photoionization spectroscopy of molecular complexes and clusters aggregated in HNDs. [ABSTRACT FROM AUTHOR]

Biomass three‐dimensional composite aerogels have garnered significant attention in the realm of wearable electronic skin owing to their favorable properties, including excellent human compatibility, environmentally benign degradability, and continuous porous architecture. However, conventional biomass aerogels suffer from inadequate mechanical flexibility, susceptibility to irreversible deformation under high compressive stress, and limited reusability, thereby constraining their applicability in sensing technologies. To address these limitations, this study presents the development of porous CCS/KH560/PEI/CNT‐COOH (CKPC) composite aerogels through a freeze–drying process. Chemical crosslinking was achieved using silane coupling agent (KH560) with carboxymethyl chitosan (CCS) and polyethyleneimine (PEI), while carboxylated carbon nanotubes (CNT‐COOH) were incorporated as conductive fillers. This approach successfully overcame the issues of poor mechanical properties, low elasticity, and unbalanced sensitivity‐sensing range trade‐off in chitosan‐based aerogel sensors. The results revealed that the porous CKPC aerogels exhibited a remarkable mechanical compressive strain of 86.3% while maintaining structural integrity post‐unloading. The CKPC composite aerogel‐based sensor demonstrated a high sensitivity of 42.9 within a wide strain range of 60%–76.3%, accompanied by a stable and repeatable electrical signal response across varying strains. The porous structure of the CKPC conductive aerogel sensor holds promising applications in human motion monitoring and flexible electronics. [ABSTRACT FROM AUTHOR]

The basis of most neurological syndromes is the accumulation of free radical molecules. Quercetin is a polyphenolic bioflavonoid molecule and it has a very strong antioxidant effect by maintaining oxidative balance. There are many difficulties in the clinical use of quercetin due to its hydrophobic structure, low solubility, instability, poor oral bioavailability, and limited tissue-barrier penetration. Its synergistic use in complex with gold nanoparticles (AuNPs) could overcome these problems. AuNPs have recently emerged as an attractive candidate for delivery applications of various biomolecules and drugs. The aim of this study was to synthesize two different sized gold nanoparticles (AuNP 20 and AuNP 50) modified with polyethyleneimine (PEI) and quercetin, evaluate their potential neuroprotective effects on the in vitro oxidative stress model using DRG primary sensory neurons. It was shown that the antioxidant and anti-apoptotic ability of the bioflavonoid was preserved after exposure to the designed quercetin modified AuNPs. The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. It also potentially enables additional surface functionalization. This study indicates that designed nanoparticles (AuNP-Q-PEI) with different sizes could be a useful potential platform for the treatment of neurodegenerative syndromes or cancer diseases. Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. Designed nanoplatform (AuNPs-Q-PEI) increased stability and biocompatibility. After nanomaterial exposure in the oxidative stress model of the DRG sensory neurons, the level of ROS and apoptosis was significantly reduced. [Display omitted] • Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. • The antioxidant property of the bioflavonoid was preserved after exposure to designed Q-coated AuNPs in the DRG neurons. • The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. • The designed gold nanoconjugates could be a useful potential nanoplatform for the treatment of neurodegenerative syndromes. [ABSTRACT FROM AUTHOR]

Rising anthropogenic carbon emissions have dire environmental consequences, necessitating remediative approaches, which includes use of solid sorbents. Here, aminopolymers (poly(ethylene imine) (PEI) and poly(propylene imine) (PPI)) are supported within solid mesoporous MIL‐101(Cr) to examine effects of support defect density on aminopolymer‐MOF interactions for CO2 uptake and stability during uptake‐regeneration cycles. Using simulated flue gas (10 % CO2 in He), MIL‐101(Cr)‐ρhigh (higher defect density) shows 33 % higher uptake capacity per gram adsorbent than MIL‐101(Cr)‐ρlow (lower defect density) at 308 K, consistent with increased availability of undercoordinated Cr adsorption sites at missing linker defects. Increasing aminopolymer weight loadings (10–50 wt.%) within MIL‐101(Cr)‐ρlow and MIL‐101(Cr)‐ρhigh increases amine efficiencies and CO2 uptake capacities relative to bare MOFs, though both incur CO2 diffusion limitations through confined, viscous polymer phases at higher (40–50 wt.%) loadings. Benchmarked against SBA‐15, lower polymer packing densities (PPI>PEI), weaker and less abundant van der Waals interactions between aminopolymers and pore walls, and open framework topology increase amine efficiencies. Interactions between amines and Cr defect sites incur amine efficiency losses but grant higher thermal and oxidative stability during uptake‐regeneration cycling. Finally, >25 % higher CO2 uptake capacities are achieved for aminopolymer/MIL‐101(Cr)‐ρhigh under humid conditions, demonstrating promise for realistic applications. [ABSTRACT FROM AUTHOR]

As global demand for renewable energy and electric vehicles increases, the need for lithium has surged significantly. Extracting lithium from salt lake brine has become a cutting-edge technology in lithium resource production. In this study, two-dimensional (2D) GO/MXene composite membranes were fabricated using pressure-assisted filtration with a polyethyleneimine (PEI) coating, resulting in positively charged PEI-GO/MXene membranes. These innovative membranes, taking advantage of the synergistic effects of interlayer channel sieving and the Donnan effect, demonstrated excellent performance in Mg2+/Li+ separation with a mass ratio of 20 (Mg2+ rejection = 85.3%, Li+ rejection = 16.7%, SLi,Mg = 5.7) in simulated saline lake brine. Testing on actual salt lake brine in Tibet, China, confirmed the composite membrane's potential for effective Mg2+/Li+ separation. In the actual brine test with high concentration, Mg2+/Li+ after membrane separation is 2.2, which indicates that the membrane can significantly reduce the concentration of Mg2+ in the brine. Additionally, the PEI-GO/MXene composite membrane demonstrated strong anti-swelling properties and effective divalent ion rejection. This research presents an innovative approach to advance the development of 2D membranes for the selective removal of Mg2+ and Li+ from salt lake brine. [ABSTRACT FROM AUTHOR]

Microgel particles can play a key role, e.g., in drug delivery systems, tissue engineering, advanced (bio)sensors or (bio)catalysis. Amine-functionalized microgels are particularly interesting in many applications since they can provide pH responsiveness, chemical functionalities for, e.g., bioconjugation, unique binding characteristics for pollutants and interactions with cell surfaces. Since the incorporation of amine functionalities in controlled amounts with predefined architectures is still a challenge, here, we present a novel method for the synthesis of responsive core–shell nanogels (dh < 100 nm) with a poly(N-isopropylacrylamide) (pNIPAm) core and a polyamine shell. To achieve this goal, a surface-functionalized pNIPAm nanogel was first prepared in a semi-batch precipitation polymerization reaction. Surface functionalization was achieved by adding acrylic acid to the reaction mixture in the final stage of the precipitation polymerization. Under these conditions, the carboxyl functionalities were confined to the outer shell of the nanogel particles, preserving the core's temperature-responsive behavior and providing reactive functionalities on the nanogel surface. The polyamine shell was prepared by the chemical coupling of polyethyleneimine to the nanogel's carboxyl functionalities using a water-soluble carbodiimide (EDC) to facilitate the coupling reaction. The efficiency of the coupling was assessed by varying the EDC concentration and reaction temperature. The molecular weight of PEI was also varied in a wide range (Mw = 0.6 to 750 kDa), and we found that it had a profound effect on how many polyamine repeat units could be immobilized in the nanogel shell. The swelling and the electrophoretic mobility of the prepared core–shell nanogels were also studied as a function of pH and temperature, demonstrating the successful formation of the polyamine shell on the nanogel core and its effect on the nanogel characteristics. This study provides a general framework for the controlled synthesis of core–shell nanogels with tunable surface properties, which can be applied in many potential applications. [ABSTRACT FROM AUTHOR]

Ramie fibers have poor flame-retardant properties, which limits their application. To improve the flame-retardant properties of ramie fabric (RF), a durable flame-retardant coating was successfully realized on RF by combining covalent bonding and electrostatic adsorption. Si/P/N flame-retardant coatings were constructed on RF using cationic polyethyleneimine (PEI) and anionic sodium hexametaphosphate (PSP) via the layer-by-layer (LBL) assembly approach with the introduction of 3-glycidoxypropyltrimethoxysilane (GPTMS) as an organic cross-linker. Compared with the untreated RF samples, the fabrics treated with the flame-retardant coating PEI/PSP via the LBL method presented reductions of 51.06%, 48.30%, and 40.05% in the fire growth rate, peak heat release rate, and total heat release, respectively, in the cone calorimeter test. In addition, at a weight gain of 31.57%, the fabric self-extinguished in the UL-94 test within 10 s after leaving the ignition source, resulting in a damaged length of 6.13 cm. G-3 retained the limiting oxygen index (LOI) of 26.40% after 6 laundering cycles (LCs). The TG results revealed that the char residue of G-3 at 800 °C reached 30.34 wt%. The surface of the flame-retardant coating of GPTMS-PEI/PSP had good char formation. This study provides a feasible method for realizing durable flame-retardant RFs. [ABSTRACT FROM AUTHOR]

The present study aims to improve the mechanical, thermal and dielectric properties of polyetherimide (PEI) nanocomposite via simplified method, involving the creation of a nanocomposite using PEI incorporated with exfoliated‐chemical functionalization induced hexagonal boron nitride nanosheets (BNNS). XRD, FTIR and Raman elucidated the chemical structure of functionalized BNNS and indicated the success preparation of functionalized BNNS. Functionalization effectively improved the compatibility of nanocomposites and contributed to the property improvements. Morphological analysis unveiled a compact and dense microstructure within the nanocomposites in correlation with functionalized BNNS. Broad band dielectric spectroscopy revealed excellent dielectric properties of produced PEI nanocomposite. DMA testing verified a noteworthy enhancement in both Tg and storage modulus upon incorporating of BNNS. In summary, this comprehensive investigation highlights the impact of functionalized BNNS on mechanical, thermal and dielectric properties of developed PEI dielectric nanocomposite and is expected to expand the application of PEI in the field of high‐temperature energy storage. Highlights: Polyetherimide (PEI) was used as polymer matrix and boron nitride derivatives as dielectric fillers to prepare PEI dielectric nanocomposite.Due to the influences of dielectric properties by interface polarization effect and the local distribution of electric field of the fillers in PEI matrix, the dielectric constant, breakdown strength and energy storage density of PEI nanocomposites were obviously improved compared with pure PEI.The effects of interfacial interactions between PBNNS and PEI contributes to the uniform dispersion and comprehensive property improvements of PEI dielectric nanocomposites.This work presents a systematic investigation into the fabrication of PEI/BNNS nanocomposite using a one‐step solution blending method, inspiring the research and development of PEI in the energy storage applications areas in the future. [ABSTRACT FROM AUTHOR]

Chemical grafting is commonly employed to functionalize carbon fiber (CF) surface to enhance the interfacial properties of CF reinforced polymer composites (CFRP) by forming a robust interface. However, an overly rigid interface layer can result in relatively poor interface toughness. To balance interfacial strength and toughness, this paper proposes an effective method to simultaneously strengthen and toughen the interface of CF/epoxy composites by grafting branched polyethyleneimine (PEI) on CF surface using hexachlorophosphazene (HCCP) as active intermediate, which features a rigid ring structure and six active P‐Cl groups. The introduction of PEI provided a large number of amine and imine groups on CF surfaces, which were contributive to improving surface wettability and reactivity of CF, thus resulting in strong chemical bonding between CF and epoxy matrix. Additionally, the long and flexible molecular skeleton of PEI constructed a rigid‐flexible composite interface, which could effectively reduce stress concentration and absorb impact energy. After surface modification with PEI, the interfacial shear strength and fracture toughness of CF/epoxy composite were increased to 89.9 MPa and 200.3 J m−2, by 64.3% and 149.7%, respectively, in compared with desized CF reinforced epoxy composites. Highlights: A rigid‐flexible interface was constructed between CF and epoxy resin.The interfacial strength and toughness of CFRP were synergistically improved.IFSS and interfacial toughness increased by 64.3% and 149.7%, respectively. [ABSTRACT FROM AUTHOR]

In this work, four kinds of silica with similar textural properties but different particle size (PS) from 6 to 60 μm were selected as support to prepare silyl‐chromate/VOx/silica bimetallic catalysts for ethylene polymerization, thus making it possible to conduct convincing investigation on the effects of catalyst PS over catalytic behaviors and polymer properties. It is found, owing to mass‐ and heat‐transfer limitations, the catalysts with smaller PS showed higher initial activity, while the deactivation in the later stage was more remarkable. Meanwhile, catalysts with smaller PS synthesized bimodal ultrahigh molecular weight polyethylene/high‐density polyethylene in‐reactor blends (UHMWPE/HDPE IRBs) with higher molecular weight (MW) and narrower molecular weight distribution (MWD). Four PE sample couples with MW increasing from 5 × 105 to 10 × 105 g mol−1 and PS from 40 to 460 μm were selected for tensile and rheological tests. For each couple with similar MW and MWD, the sample with smaller PS always had larger tensile strength and breaking elongation. The cryogenically fractured surface of the samples made by smaller PE particles showed fewer delamination defects and unfused small particles. The rheological results indicate that higher homogeneity was achieved for the sample with smaller PS, which was reflected by the unexpected higher viscosity and storage modulus. [ABSTRACT FROM AUTHOR]

Synchronous boosting adsorption and desorption efficiency is a great challenge for CO2 adsorption capture, especially for metal–organic frameworks (MOFs) having high adsorption uptakes. Herein, a novel "self‐supporting foam" strategy is proposed to fabricate a thermally conductive MOFs@boron nitride nanosheets (BNNS) composite foam (MOFs@BNNS‐PEI) via polyethyleneimine (PEI) cross‐linkage. The "rebar" BNNS and the "aggregate" MOFs are packed against each other to form a self‐supporting structure, effectively reducing the reliance on polymers to maintain high MOFs loading. Furthermore, this approach enables the successful fabrication of three different types of typical MOFs, including HKUST‐1, MIL‐100(Fe), and ZIF‐8. This unique design maintains a high specific surface area (SSA) of the MOFs foam and generates nitrogen‐rich microporosity contributing to CO2 adsorption. Additionally, PEI serves as a thermal bridge to reduce the interfacial thermal resistance between BNNS and MOFs, accelerating the thermal desorption of CO2 within the MOFs foam. Benefiting from these advantages, the MOFs@BNNS‐PEI exhibits a higher CO2 adsorption capacity (1.35–1.42 times that of pure MOFs) and a significant increase in the desorption rate for CO2 (5.0–5.7 times that of pure MOFs). Thus, the thermally conductive MOFs foam can be a viable option for efficient CO2 capture in practical applications. [ABSTRACT FROM AUTHOR]

High molecular weight polyethylenimine (HMW PEI; branched 25 kDa PEI) has been widely investigated for gene delivery due to its high transfection efficiency. However, the toxicity and lack of targeting to specific cells have limited its clinical application. In the present investigation, L-3, 4‐dihydroxyphenylalanine (L-DOPA) was conjugated on HMW PEI in order to target L-type amino acid transporter 1 (LAT-1) and modulate positive charge density on the surface of polymer/plasmid complexes (polyplexes). The results of biophysical characterization revealed that the PEI conjugates are able to form nanoparticles ≤ 180 nm with the zeta potential ranging from + 9.5–12.4 mV. These polyplexes could condense plasmid DNA and protect it against nuclease digestion at the carrier to plasmid ratios higher than 4. L-DOPA conjugated PEI derivatives were complexed with a plasmid encoding human interleukin-12 (hIL-12). Targeted polyplexes showed up to 2.5 fold higher transfection efficiency in 4T1 murine mammary cancer cell line, which expresses LAT-1, than 25 kDa PEI polyplexes prepared in the same manner. The cytotoxicity of these polyplexes was also substantially lower than the unmodified parent HMW PEI. These results support the use of L-3, 4‐dihydroxyphenylalanine derivatives of PEI in any attempt to develop a LAT-1 targeted gene carrier. [ABSTRACT FROM AUTHOR]

Electrospun sponges with electrical conductivity are promising materials for electrodes with applications in pressure sensors, flexible wearable sensors, and supercapacitors. However, electrospun sponges display poor electric conductivity, which can be increased by the addition of silver nanowire (AgNW). The resulting electric conductivity may depend strongly on the distribution of the AgNW in and on the sponges. A straightforward assembly method for an elastic conductive sponge, composed of 3D structures and metal nanowires, using a synergistic strategy which involves modified impregnation and deposition processes assisted by polyethyleneimine (PEI) impregnation, is presented. The resulting changes in the material properties are also explored, and it is under specific conditions, that percolation, leading to significantly enhanced electrical conductivity in the sponges, is achieved. [ABSTRACT FROM AUTHOR]

Drug-eluting stents are commonly utilized for the treatment of coronary artery disease, where they maintain vessel patency and prevent restenosis. However, problems with prolonged vascular healing, late thrombosis, and neoatherosclerosis persist; these could potentially be addressed via the local generation of nitric oxide (NO) from endogenous substrates. Herein, we develop amine-functionalized graphene as a NO-generating coating on polylactic acid (PLA)-based bioresorbable stent materials. A novel catalyst was synthesized consisting of polyethyleneimine and polyethylene glycol bonded to graphene oxide (PEI-PEG@GO), with physicochemical characterization using x-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. In the presence of 10 μM S-nitrosoglutathione (GSNO) or S-nitroso-N-acetylpenicillamine (SNAP), PEI-PEG@GO catalyzed the generation of 62% and 91% of the available NO, respectively. Furthermore, PEI-PEG@GO enhanced and prolonged real-time NO generation from GSNO and SNAP under physiological conditions. The uniform coating of PEI-PEG@GO onto stent material is demonstrated via an optimized simple dip-coating method. The coated PLA maintains good biodegradability under accelerated degradation testing, while the PEI-PEG@GO coating remains largely intact. Finally, the stability of the coating was demonstrated at room temperature over 60 days. In conclusion, the innovative conjugation of polymeric amines with graphene can catalyze the generation of NO from S-nitrosothiols at physiologically relevant concentrations. This approach paves the way for the development of controlled NO-generating coatings on bioresorbable stents in order to improve outcomes in coronary artery disease. [ABSTRACT FROM AUTHOR]

Successful gene therapy relies on carriers to transfer genetic materials with high efficiency and low toxicity in a targeted manner. To enhance targeted cell binding and uptake, we developed and synthesized a new gene delivery vector based on graphene oxide (GO) modified by branched polyethyleneimine (BPEI) and folic acid (FA). The GO‐PEI‐FA nanocarriers exhibit lower toxicity compared to unmodified PEI, as well as having the potential to efficiently condense and protect pDNA. Interestingly, increasing the polymer content in the polyplex formulation improved plasmid transfer ability. Substituting graphene oxide for PEI at an N/P ratio of 10 in the HepG2 and THP1 cell lines improved hIL‐12 expression by up to approximately eightfold compared to simple PEI, which is twice as high as GO‐PEI‐FA in Hek293 at the same N/P ratio. Therefore, the GO‐PEI‐FA described in this study may serve as a targeting nanocarrier for the delivery of the hIL‐12 plasmid into cells overexpressing folic acid receptors, such as those found in hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

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Porous silica-based adsorbents for hexavalent chromium (Cr(VI)) ion removal were prepared by the combined use of functionalization with (3-glycidyloxypropyl)trimethoxysilane and the grafting of branched and linear polyethyleneimine (BPEI and LPEI). LPEI was prepared from polyethyloxazolin by hydrolysis with HCl. The preparation of LPEI was identified by NMR measurements and the grafting of BPEI and LPEI on the silica beads was confirmed by an XPS analysis. The Cr(VI) ion adsorption of the obtained BPEI-grafted silica beads (BPEI–silica beads) was investigated as a function of the pH value, the content of amino groups, the temperature, the Cr(VI) ion concentration, and the molecular mass of the grafted BPEI chains. The Cr(VI) ion adsorption at pH 3.0 increased with an increase in the content of amino groups, and the maximum adsorption capacity of 1.06 mmol/g was obtained when the content of amino groups was at 2.17 mmol/g. This value corresponds to 589 mg/g−1.8KPEI, and the adsorption ratio of about 0.5 is a noteworthy result. The data fit to the pseudo-second-order kinetic model, and the suitability of this fitting was supported by the results that the adsorption capacity and initial rate of adsorption increased with the temperature. In addition, the equilibrium data followed the Langmuir isotherm model. These results clearly demonstrate that the Cr(VI) adsorption occurred chemically, or through the electrostatic interaction of protonated amino groups on the grafted BPEI chains with hydrochromate ( H C r O 4 − ) ions. A higher adsorption capacity was obtained for the silica beads grafted with shorter BPEI chains, and the adsorption capacity of BPEI–silica beads is a little higher than that of linear PEI-grafted silica beads, suggesting that the Cr(VI) ion adsorption is affected by the chain isomerism of PEI (linear and branched) as well as the molecular mass of the grafted PEI chains, in addition to the content of amino groups. The experimental and analytical results derived from this study emphasize that the BPEI–silica beads can be used as an adsorbent for the removal of Cr(VI) ions from an aqueous medium. [ABSTRACT FROM AUTHOR]

Polymer gel was widely used as water shutoff agent in mature oil fields. And the results of single-phase plugging experiments show that the plugging rate of the polymer gel to the oil phase is lower than that of the water phase. However, the disproportionate permeability reduction (DPR) mechanism of polymer gels still remains controversial. In this paper, we used four gel formulations including polyethyleneimine (PEI) and phenol-formaldehyde crosslinked gel with and without adding laponite to investigate the effect of gel elastic property on the water shutoff mechanism. The result of sand pack flooding experiments shown that the gel with higher elastic modulus has better effects on decreasing water cut and increasing oil recovery. After adding laponite, the elastic modulus of phenol-formaldehyde crosslinked gel increased from 64.2 Pa to 192 Pa, and the elastic modulus of PEI crosslinked gel increased from 27.4 Pa to 36.5 Pa. Compared to the phenol-formaldehyde-HAPM gel, the oil recovery of laponite-phenol-formaldehydeHPAM gel increased by 5.2% and the maximum water cut decreased by 8.3%. Besides, comparing with PEI-HPAM gel, the oil recovery of laponite-PEI-HPAM gel increased by 2.7% and the water cut dropped by 27.8%. In the meanwhile, the laponite-phenol-formaldehyde-HPAM gel with higher elastic modulus obviously swells in the formation water but almost remains constant in oil at 105(C. The mass of gel soaked in the formation water increased from 42 g to 96 g and the gel volume increased by 300% within 48 hours. This study improves the understanding of the DPR mechanism of polymer gel for water shutoff. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2), one of the primary greenhouse gases, plays a key role in global warming and is one of the culprits in the climate change crisis. Therefore, the use of appropriate CO2 capture and storage technologies is of significant importance for the future of planet Earth due to atmospheric, climate, and environmental concerns. A cleaner and more sustainable approach to CO2 capture and storage using porous materials, membranes, and amine-based sorbents could offer excellent possibilities. Here, sucrose-derived porous carbon particles (PCPs) were synthesized as adsorbents for CO2 capture. Next, these PCPs were modified with branched- and linear-polyethyleneimine (B-PEI and L-PEI) as B-PEI-PCP and L-PEI-PCP, respectively. These PCPs and their PEI-modified forms were then used to prepare metal nanoparticles such as Co, Cu, and Ni in situ as M@PCP and M@L/B-PEI-PCP (M: Ni, Co, and Cu). The presence of PEI on the PCP surface enables new amine functional groups, known for high CO2 capture ability. The presence of metal nanoparticles in the structure may be used as a catalyst to convert the captured CO2 into useful products, e.g., fuels or other chemical compounds, at high temperatures. It was found that B-PEI-PCP has a larger surface area and higher CO2 capture capacity with a surface area of 32.84 m2/g and a CO2 capture capacity of 1.05 mmol CO2/g adsorbent compared to L-PEI-PCP. Amongst metal-nanoparticle-embedded PEI-PCPs (M@PEI-PCPs, M: Ni, Co, Cu), Ni@L-PEI-PCP was found to have higher CO2 capture capacity, 0.81 mmol CO2/g adsorbent, and a surface area of 225 m2/g. These data are significant as they will steer future studies for the conversion of captured CO2 into useful fuels/chemicals. [ABSTRACT FROM AUTHOR]

Polyethyleneimine (PEI), a cationic hydrophilic polymer, and (phenylthio)acrylic acid (PTAA), a hydrophobic counter ion, were used to prepare ion pair self-assembly (IPSAM), which is sensitive to temperature and oxidation. The IPSAM was spontaneously formed when the amino group to carboxylic group molar ratio was 5/5 to 7/3. On the TEM micrograph, PEI/PTAA IPSAM was discovered as sphere-shaped nanoparticles with a diameter of tens of nanometers. The upper critical solution temperature (UCST) of the ion pair increased as the PTAA content increased and decreased when H2O2 oxidized the PTAA of the ion pair. The ion pair was interface active due to its amphiphilic property and the interface activity was decreased upon the PTAA oxidation. FT-IR and 1H NMR spectroscopy were used to verify the ionic interaction among PEI and PTAA, and X-ray photoelectron microscopy was used to confirm the oxidation of PTAA. The release of a payload (i.e. Nile red) in IPSAM was limited when the medium temperature was lower than the UCST but it was triggered above the phase transition temperature possibly due to the disintegration of the IPSAM. Upon oxidation, the UCST would decrease below the release medium temperature due to the PTAA oxidation causing promoted release and the release degree could occur readily in proportion to the H2O2 concentration. Schematic diagram of temperature and oxidation-responsive of PEI/PTAA self-assembly ion pairs (IPSAM) [ABSTRACT FROM AUTHOR]

This study introduces an innovative approach by modifying a commonly used filler with a natural compound, PEI. Fine aggregates within the filler were treated with different contents of PEI solutions. This research thoroughly examined the filler's pore structure, mineral composition, physical characteristics, and surface morphology. Additionally, this study explored the effects of PEI-treated fine aggregates on the macroscopic features of recycled cement mortar, focusing on aspects like flowability, compressive strength, capillary water absorption, and chloride ion permeability. The findings revealed that treating the fine aggregates with PEI decreased the pore volume by up to 28.2% compared to untreated samples. This improvement in the microstructure may originate from the formation of calcite and its by-products, which occupy the pores with nanoparticles generated in situ. Furthermore, the modification with polyethyleneimine resulted in a wavy, plate-like structure that not only enhanced the surface morphology but also improved the compressive strength and chloride ion permeability. Furthermore, it significantly reduced capillary water absorption by 32% to 51%, thereby enhancing the material's durability. The present study underscores the superior advantages of PEI modification as a promising strategy to enhance the viability of public fine aggregates. [ABSTRACT FROM AUTHOR]

Ditch irrigation is an important route that potentially discharges microplastics (MPs) into environment. Samiran ditch irrigation is the largest urban irrigation in Pamekasan City, Indonesia. Water and sediment samples were collected in Samiran ditch irrigation to identify MPs including their color, shape, size, and number of MPs. From all sampling locations, MPs were found in both the water and sediments of the Samiran ditch irrigation with sizes ranging from 0.1 mm to 2.9 mm. The abundance of MPs in water ranged from 0.5 to 0.9 items/L, while MPs in sediments 0.14 to 0.23 items/g with colors of black, blue, and yellow. The polymer types of polyethyleneimine (PEI) and polypropylene (PP) were found both in surface water and sediment sample. MPs such as fragments, filament, fiber, and pellet were found in Samiran ditch irrigation with fiber was dominant found in the surface water (40%) and fragment was dominant in sediment (25%). [ABSTRACT FROM AUTHOR]

Current diabetic retinopathy (DR) treatment involves blood glucose regulation combined with laser photocoagulation or intravitreal injection of vascular endothelial growth factor (VEGF) antibodies. However, due to the complex pathogenesis and cross‐interference of multiple biochemical pathways, these interventions cannot block disease progression. Recognizing the critical role of the retinal microenvironment (RME) in DR, it is hypothesized that reshaping the RME by simultaneously inhibiting primary and secondary blood–retinal barrier (BRB) injury can attenuate DR. For this, a glucose‐responsive hydrogel named Cu‐PEI/siMyD88@GEMA‐Con A (CSGC) is developed that effectively delivers Cu‐PEI/siMyD88 nanoparticles (NPs) to the retinal pigment epithelium (RPE). The Cu‐PEI NPs act as antioxidant enzymes, scavenging ROS and inhibiting RPE pyroptosis, ultimately blocking primary BRB injury by reducing microglial activation and Th1 differentiation. Simultaneously, MyD88 expression silence in combination with the Cu‐PEI NPs decreases IL‐18 production, synergistically reduces VEGF levels, and enhances tight junction proteins expression, thus blocking secondary BRB injury. In summary, via remodeling the RME, the CSGC hydrogel has the potential to disrupt the detrimental cycle of cross‐interference between primary and secondary BRB injury, providing a promising therapeutic strategy for DR. [ABSTRACT FROM AUTHOR]

Acoustic graphene plasmons (GPs) exhibit an exceptional density of electromagnetic states within the mid-infrared (MIR) and terahertz frequency ranges, leading to a pronounced near-field amplification and localization at the nanometer scale. This characteristic renders them highly promising for the development of ultra-sensitive plasmon-enhanced MIR sensing and spectroscopic applications. However, the tight spatial confinement inherent to acoustic GPs results in a significant momentum mismatch, which in turn leads to poor coupling efficiency with light in free space. To overcome this limitation, we leverage numerical simulations to show that GPs can act as an intermediary to facilitate efficient excitation of acoustic GPs by incident MIR radiation, achieving an extinction spectrum peak value of approximately 0.9. The proposed gas sensor based on the acoustic GP resonator is composed of pristine, large-area graphene, an array of periodic metal nanocubes, and a slender polyethylenimine (PEI) layer that adsorbs CO2, situated between the nanocubes and the graphene sheet. The sensing performance of the proposed sensor is numerically investigated. It is demonstrated that by incorporating a CO2-absorbing material into the acoustic GPs, we can perform highly sensitive assessments of the absorption bands within the PEI layer upon CO2 adsorption. The observed behavior of the acoustic GPs indicates a weakening and broadening with increasing CO2 concentrations, a phenomenon attributed to the alteration in the permittivity of the PEI in the interstitial layer due to CO2 adsorption. Numerical simulation results indicate that the sensitivity of the proposed hybrid gas sensor can reach up to 0.0183% ppm−1, which offers a remarkable 95-fold enhancement over the gas sensor based on graphene nanoribbons. Our findings underscore the potential of acoustic GP nanoresonators as a transformative platform for ultrasensitive plasmon-enhanced sensing applications, particularly when integrated with various gas adsorption layers or molecular agents. [ABSTRACT FROM AUTHOR]

Highlights Interfacial adhesion properties are a key factor affecting the mechanical properties of composites. It is a very effective way to improve the low‐velocity impact resistance of composites by improving the interfacial adhesion properties. To improve the fiber/matrix interfacial adhesion properties of GF/PA6 (glass‐fiber/polyamide 6) composites, polyethyleneimine (PEI) and γ‐aminopropyltriethoxysilane (KH550) were used to co‐modify GF together in this study. The GF/PA6 composites with different modifications of glass‐fiber (GF) were also prepared using a hot pressing process, and then their flexural strength, shear strength, pendulum impact strength, and low‐speed impact resistance were investigated. Next, the relationship between fiber/matrix interfacial adhesion and mechanical properties of GF/PA6 composites was investigated by combining x‐ray photoelectron spectroscopy, scanning electron microscopy, and x‐ray computed tomography test results. The results showed that the GF‐reinforced PA6 matrix composite with co‐modified GF by PEI and KH550 (PEI‐KH550‐GF/PA6) had the best mechanical properties, with flexural, shear, and pendulum impact strengths of 660.7 MPa, 53.1 MPa, and 261.6 kJ/m2, respectively. Furthermore, the low‐velocity impact resistance was measured in terms of stress peak, absorbed energy, residual stress, and damage extension, and the results showed that the low‐speed impact resistance of PEI‐KH550‐GF/PA6 composites was also substantially improved that the Fmax increased from 7402.1 to 10414.0 N. Due to the poor surface activity of GF, in this experiment, GF was co‐modified with PEI and KH550 to achieve better fiber/matrix interfacial adhesion and successfully improve the mechanical properties of the composites; Different modification methods are used to improve the interfacial adhesion of the fiber/matrix interface. The relationship between the interface and impact strength of composites has been studied; The relationship between fiber/matrix interfacial adhesion and internal cracking in composites was investigated using X‐CT and SEM and other test results. [ABSTRACT FROM AUTHOR]

Converting carbon dioxide into formic acid with formate dehydrogenase (FDH) as a catalyst is a gentle and eco‐friendly process that not only conserves energy and reduces emissions but transforms waste into valuable resource. Enzyme immobilization is a common strategy for improving the stability and recyclability of enzyme, however, the procedures are usually complicated that include surface modification and binding reactions in order to form reliable linkages. Co‐deposition of polydopamine (PDA) with polyethyleneimine (PEI) is a popular surface modification approach in versatile fields, but their co‐deposition with enzymes is rarely reported. Herein, one‐pot immobilization of FDH on SiO2 nanoparticles based on catechol chemistry was attempted for the first time with or without PEI, and the resultant immobilized enzymes, FDH/PDA/PEI‐SiO2 and FDH/PDA‐SiO2, were characterized, and the effects of the composition and deposition conditions on the catalytic performance were investigated. FDH/PDA‐SiO2 exhibited a higher apparent specific activity than FDH/PDA/PEI‐SiO2, which was separately 0.167 and 0.136 mM/h/mg. The activity recovery rate was 464% and 378% of that of free enzyme. After 5 cycles, their relative activity was 82.3% and 87.4%. This research is significant in presenting a simple and high‐efficient one‐pot immobilization method that can be extended to other kinds of enzymes. [ABSTRACT FROM AUTHOR]

As well known in bioactives delivery and cancer/inflammation theranostics, polycations have recently extended their biomedical potentials in reducing visceral fat, embolizing body fluid, modulating blood coagulation, and ameliorating hyperammonemia. However, positive charges that dominate various action mechanisms, often raise risks in biosafety concerns. Also, the lack of intrinsic imaging properties of polycations makes it challenging to uncover their pharmacokinetic profiles in living objects. Herein, dopamine conjugation is demonstrated controllable and highly efficient in boosting the fluorescence or even white color emission of various polycations including hyperbranched poly(amido amine) (HPAA), polyethyleneimine and poly‐L‐lysine. By shielding partial surface positive charges, increasing hydrophobicity, and inducing aqueous self‐assembly, dopamine conjugation can significantly enhance the biocompatibility and decrease the toxicity and immunogenicity of polycations. Furthermore, the catechol‐metal binding interaction facilitates the accessibility of polycation‐based positron emission tomography (PET) probes. Different tissue uptake and biodistributions of gallium‐68‐radiolabeled HPAA before and after dopamine conjugation indicate that PET imaging can be a useful supplement to evaluate the dynamic toxicities of polycations. [ABSTRACT FROM AUTHOR]

Excessive copper (Cu2+) causes adverse effects on human health and the ecological environment. Traditional methods for detecting Cu2+ have drawbacks such as high detection costs, complex operating conditions, and being time consuming. Therefore, there is an urgent need to develop simple detection methods to better meet specific health and environment quality needs. In this work, a paper-based fluorescence sensor was prepared (herein referred to as the as-prepared method) by immersing filter paper in aqueous polyethyleneimine (PEI) solution, and its potential use in Cu2+ detection was investigated. The results showed that the as-prepared paper samples, with fluorescence properties obtained by aggregation-induced luminescence of PEI, have selective recognition of Cu2+ based on the internal filtration effect, and the lowest detection limit is 0.03 μM. In addition, the relative error of this method is in the range of 1.80~2.23%, which is relatively comparable to the national standard method (0.63~630 μM), demonstrating high accuracy. Therefore, paper-based sensors with a simple preparation method have potential applications in the detection of Cu2+ in water. [ABSTRACT FROM AUTHOR]

Antifungal drug resistance in filamentous fungi, particularly Aspergillus species, is increasing worldwide. Therefore, new antifungal drugs or combinations of drugs are urgently required to overcome this public health situation. In the present study, we examined the antifungal activity of vancomycin-functionalized AuNPs. These functionalized AuNPs were characterized, and their antifungal activity and associated killing mechanism were investigated using conventional methodologies against the conidia of A. fumigatus and A. flavus. The differential antifungal activity of vancomycin-functionalized Au-NPs against the conidia of Aspergillus species is dependent on structural differences in the conidial cell wall. The results demonstrated potent fungicidal activity against A. fumigatus, with a MIC value of 4.68 µg/mL, 93% germination inhibition, and 38.4% killing rate within 8 h of exposure. However, the activity against A. flavus was fungistatic; a MIC value of 18.7 µg/mL and 35% conidial germination inhibition, followed by 28.4% killing rate, were noted under similar conditions. Furthermore, endogenous reactive oxygen species (ROS) accumulation was 37.4 and 23.1% in conidial populations of A. fumigatus and A. flavus, respectively. Raman spectroscopy analysis confirmed the possible (but not confirmed) binding of functionalized AuNPs with the chitin and galactomannan components of the cell wall. A potential strategy that involves the exploration of antibacterial drugs using AuNPs as efficient drug carriers may also be appropriate for countering emerging drug resistance in filamentous fungi. [ABSTRACT FROM AUTHOR]

External plasticization is one of the effective ways to toughen epoxy resins. In this study, an inorganic filler (EMD) was prepared by chemical modification of diatomite and was used to fill epoxy resin matrix. The effects of different amounts (5%, 10%, 15%, and 20%) of raw diatomite (RD) and modified‐diatomite (EMD) on the mechanical and thermal properties of epoxy resin composites were studied. The mechanical results showed that the impact strength, tensile strength, and bending strength of EMD/EP were higher than those of RD/EP. The impact strength of EMD‐15/EP reached 5.39 KJ/m2, which was 36.8% higher than that of RD‐15/EP. Thermogravimetric analysis showed that the thermal stability of EMD/EP was better than that of RD/EP. The results of DMA show that the glass transition temperature of EMD/EP was lower than that of RD/EP. Non‐isothermal differential scanning calorimetry study showed that the apparent activation energy of EMD‐15/EP was much lower than that of RD‐15/EP, which proved that EMD could promote the curing of epoxy resin. The Malek method was used to determine that both the RD‐15/EP and EMD‐15/EP curing systems were autocatalytic (Šesták–Berggren) models. [ABSTRACT FROM AUTHOR]

Appropriate mechanical properties is one of the prerequisites for the applications of hydrogels, where cross‐linker is a crucial component in manipulating such mechanical property. Herein, acryloyl‐functionalized polyethyleneimine (APEI) was innovatively used as novel functional cross‐links to optimize the mechanical properties of polyacrylamide (PAM) hydrogels. APEI cross‐links were synthesized by simply adding acryloyl chloride into polyethyleneimine in aqueous solution. The chemical structures of APEI were confirmed by Fourier transform infrared and nuclear magnetic resonance spectra. APEI possessed massive highly acryloyl functional groups that can serve as multifunctional cross‐linking centers for the polymerization of monomers via covalent bonding interactions. These covalent bonds are favorable for constructing a firm 3D cross‐linked networks for hydrogels to withstand deformations, endowing hydrogels with the improved mechanical properties. The tensile strength with an elongation at break for the hydrogels can reach 234 kPa and 18.4‐fold, respectively. In addition, even the hydrogels can bear cyclic mechanical loads and deformations for 50 cycles at 5‐fold stain, indicating a good fatigue resistance. The deformability of APEI cross‐links clusters under stretching was responsible for the stretchability of PAM/APEI hydrogels. This work provides a simple strategy to enhance the mechanical properties of hydrogels via the development of novel APEI chemical cross‐linker. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g‐C3N4) has received much attention as a metal‐free photocatalyst for dye degradation and sterilization. However, the low photocatalytic bactericidal activity and the difficulty in recycling have limited its applications. Here, oxidatively modified g‐C3N4 grafted with polyethyleneimine (PEI) nanofiber membranes (PVA/PEI‐OCN) was reported to enhance the photocatalytic activity. The modification by PEI grafting could reduce the recombination rate of photogenerated carriers and lead to more electrons for the photocatalytic reaction. In addition, electron spin resonance (ESR) results showed that the generation of reactive oxygen species (˙OH, ˙O2− and 1O2) were significantly enhanced in photocatalysis, leading to the significant enhancement of photocatalytic bactericidal activity and dye degradation. Furthermore, the PVA/PEI‐OCN nanofiber membranes prepared by electrospinning had smooth surfaces and uniform fiber formation, with an average diameter of 380 ± 60 nm. The tensile strength was about 73.5% higher than that of PVA nanofiber membranes. The inhibition diameter of PVA/PEI‐OCN‐4 against Escherichisa coli (E. coil) could reach 20 ± 0.2 mm, and the maximum degradation efficiency of methylene blue solution (10 mg/L) could reach 92.8% within 120 min. This work provided an effective paradigm for the rational design of metal‐free photocatalytic materials for elimination of bacterial and dye contamination. [ABSTRACT FROM AUTHOR]

The development of targeted drug delivery systems has been a pivotal area in nanomedicine, addressing challenges like low drug loading capacity, uncontrolled release, and systemic toxicity. This study aims to develop and evaluate dual-functionalized mesoporous silica nanoparticles (MSN) for targeted delivery of celecoxib, enhancing drug loading, achieving controlled release, and reducing systemic toxicity through amine grafting and imidazolyl polyethyleneimine (PEI) gatekeepers. MSN were synthesized using the sol–gel method and functionalized with (3-aminopropyl) triethoxysilane (APTES) to create amine-grafted MSN (MSN-NH2). Celecoxib was loaded into MSN-NH2, followed by conjugation of imidazole-functionalized PEI (IP) gatekeepers synthesized via carbodiimide coupling. Characterization was conducted using Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR). Drug loading capacity, entrapment efficiency, and in vitro drug release at pH 5.5 and 7.4 were evaluated. Cytotoxicity was assessed using the MTT assay on RAW 264.7 macrophages. The synthesized IP was confirmed by FTIR and 1H-NMR. Amine-grafted MSN demonstrated a celecoxib loading capacity of 12.91 ± 2.02%, 2.1 times higher than non-functionalized MSN. In vitro release studies showed pH-responsive behavior with significantly higher celecoxib release from MSN-NH2-celecoxib-IP at pH 5.5 compared to pH 7.4, achieving a 33% increase in release rate within 2 h. Cytotoxicity tests indicated significantly higher cell viability for IP-treated cells compared to PEI-treated cells, confirming reduced toxicity. The dual-functionalization of MSN with amine grafting and imidazolyl PEI gatekeepers enhances celecoxib loading and provides controlled pH-responsive drug release while reducing systemic toxicity. These findings highlight the potential of this advanced drug delivery system for targeted anti-inflammatory and anticancer therapies. [ABSTRACT FROM AUTHOR]

A mussel-inspired multiwalled carbon nanotube (MWCNT) nanocomposite (MWCNTs@CCh-PEI) was prepared by the co-deposition of catechol (CCh)/polyethyleneimine (PEI) and modification of MWCNTs for the efficient removal of methyl orange (MO). The effects of MO solution pH, contact time, initial MO concentration, and temperature on the adsorption capacity of MWCNTs@CCh-PEI were investigated. The results indicate that the adsorption capacity of MWCNTs@CCh-PEI was two times higher than that of pristine MWCNTs under the same conditions. The adsorption kinetics followed the pseudo-second-order model, suggesting that the adsorption process was chemisorption. The adsorption isotherm shows that the experimental data were fitted well with the Langmuir isotherm model, with a correlation coefficient of 0.9873, indicating that the adsorption process was monolayer adsorption. The theoretical maximum adsorption capacity was determined to be 400.00 mg·g−1. The adsorption thermodynamic data show that the adsorption process was exothermic and spontaneous. More importantly, the adsorption capacity of MWCNTs@CCh-PEI showed no significant decrease after eight reuse cycles. These results demonstrate that MWCNTs@CCh-PEI is expected to be an economical and efficient adsorbent for MO removal. [ABSTRACT FROM AUTHOR]

Chrysoidine, an industrial dye, is a banned chemical for use as a food additive. Studies have shown that excessive ingestion, inhalation and dermal contact with the substance can cause acute and chronic toxicological damage. Surface enhanced Raman spectroscopy (SERS) is a spectroscopic detection technique with high selectivity and sensitivity. In this study, a mixture of silver nanoparticles (AgNPs) and polyethyleneimine (PEI) was used as the SERS substrate at room temperature for the rapid and sensitive detection of Chrysoidine in mirinda soft drink, and PEI could attract Chrysoidine to the hot spot region of the AgNPs and enhance its Raman signal. The characteristic peak of the SERS spectrum of Chrysoidine showed obvious SERS enhancement at 1180 cm− 1, and there was a good linear relationship between the SERS intensity and the concentration of Chrysoidine. The limits of detection (LOD) in both water and mirinda soft drink were determined to be 1.32 µg/L and 5.11 µg/L, respectively. In addition, the average recoveries ranged from 95.65 to 102.08% with the RSDs of 3.41-5.02%. The method can be successfully used for the rapid and sensitive detection of Chrysoidine in mirinda soft drink, which provides a new idea for the detection of Chrysoidine in other different samples. [ABSTRACT FROM AUTHOR]

Objective：To investigate the construction, characterization, and role of nanomicelles composed of fluorinated polyethyleneimine (PEI) derivatives in gene delivery across the blood-brain barrier (BBB). Methods：PEI-heptafluorobutyric anhydride (HFAA) was synthesized through a chemical reaction between PEI and HFAA, followed by amide reaction with sinapic acid (SA) to obtain PEI-HFAA-SA (referred as SPF). Finally, PEI-HFAA-SA@PS80 (referred as SPFT) was obtained by encapsulating polysorbitol 80 (PS80) within SPF. The molecular bonds and elemental composition of SPFT were analyzed using Fourier transformation infrared absorption spectroscopy, fluorine nuclear magnetic resonance (NMR), and hydrogen NMR spectroscopy. The hydrodynamic particle size, plasmid adsorption and protection capacity, stability and morphology of the carrier-plasmid complex were further characterized by dynamic light scattering experiments, agarose coagulation experiments and scanning electron microscopy observations, respectively. The gene transfection efficiency and cytotoxicity of SPFT were investigated in mouse glioma cell line Neuro 2a. SPFT carrying green fluoresant protein expression plasmid was injected into C57BL/6J mice by tail vein to observe its distribution in brain tissues and the effect of gene transfection within the BBB. Results：SA and HFAA were modified to synthesize SFPT, which was then wrapped in PS80. SPFT had a hydrodynamic particle size of 100 to 200 nm while exhibiting significant loading capacity for plasmids along with effective protection against degradation. In vitro experiments revealed that SPFT possessed excellent transfection ability and biocompatibility. In vivo experiments showed that SPFT accumulated in the brain successfully and crossed the BBB to deliver the gene effectively after tail vein injection into mice. Conclusion：SPFT exhibits a good biocompatibility and demonstrates an efficient gene delivery across the BBB, presenting a novel approach for drug administration in neurological disorders. [ABSTRACT FROM AUTHOR]

An editorial focuses on the synthesis, properties, and applications of gel materials, particularly hydrogels and aerogels, in adsorption and removal technologies. It highlights advancements in the development of functional hydrogels for wastewater treatment, including methods to enhance their adsorption capabilities and mechanical properties. It also discusses the use of aerogels in gas purification, emphasizing their unique structural advantages.

In this work, Preyssler‐type POM (NH4)14[NaP5W30O110].44H2O (NH4P5W30), has been synthesised and its electrochemical behaviour in solution was examined at the surface of glassy carbon (GC) and gold electrodes. Furthermore, multilayer assemblies of NH4P5W30 POM were constructed onto the surfaces of GCE, gold electrode, and gold quartz electrode via the electrostatic Layer‐by‐Layer (LBL) technique employing polyethyleneimine as the cationic layer and POM as an anionic layer. Cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and electrochemical quartz crystal microbalance measurements (EQCM) were used to monitor the LBL assembly as the NH4P5W30 POM layer was being built. These techniques revealed significant differences in film growth. The multilayer film exhibited well‐defined redox couples associated with POM's tungsten‐oxo framework and showed surface‐confined behaviour up to 100 mVs−1 on both the GC and gold electrodes. The pH dependency and stability of the film were investigated. EIS demonstrated that when the POM layer was the outer layer, the layers were less conductive, and resistance increased as the number of layers increased. In addition, the charge transfer resistance values (Rct) for the layers were calculated. The solvation of ions into the film associated with POM redox activity was studied employing an in‐situ EQCM. [ABSTRACT FROM AUTHOR]

[Display omitted] • Coarse-grained models of oil-water systems with amphiphilic macromolecule (CHPEI) are developed by dissipative particle dynamics simulation. • CHPEI exhibits various adsorption configurations at phase interface, including lamellar, seaweed-like, and even jellyfish-like structures. • CHPEI maintains demulsification efficiency exceeding 96.7 % under high acid-alkali-salt environments or even after being recycled four times. • Integrating mesoscopic DPD simulations with macroscopic experiments validates the design and effectiveness of advanced demulsifiers. Hypothesis: An innovative strategy for designing high-performance demulsifiers is proposed. It hypothesizes that integrating mesoscopic molecular simulations with macroscopic physicochemical experiments can enhance the understanding and effectiveness of demulsifiers. Specifically, it is suggested that amphiphilic hyperbranched polyethyleneimine (CHPEI) could act as an efficient demulsifier in oil–water systems, with its performance influenced by its adsorption behaviors at the oil–water interface and its ability to disrupt asphaltene-resin aggregates. Experiments: Several coarse-grained models of oil–water systems, with CHPEI, are constructed using dissipative particle dynamics (DPD) simulation. Following the insights gained from the simulations, a series of CHPEI-based demulsifiers are designed and synthesized. Demulsification experiments are conducted on both simulated and crude oil emulsions, with the process monitored using laser scanning confocal microscopy. Additionally, adsorption kinetics and small angle X-ray scattering are employed to reveal the inherent structural characteristics of CHPEI demulsifiers. Findings: CHPEI demonstrates over 96.7 % demulsification efficiency in high acid-alkali-salt systems and maintains its performance even after multiple reuse cycles. The simulations and macroscopic experiments collectively elucidate that the effectiveness of a demulsifier is largely dependent on its molecular weight and the balance of hydrophilic and hydrophobic groups. These factors are crucial in providing sufficient interfacial active functional groups while avoiding adsorption sites for other surfactants. Collaborative efforts between DPD simulation and macroscopic measurements deepen the understanding of how demulsifiers can improve oil–water separation efficiency in emulsion treatment. [ABSTRACT FROM AUTHOR]

Polymer-based zeolite imidazolate framework composite membrane (TAPP-ZIF-60). [Display omitted] • Antibacterial TAPP-ZIF-6 h membrane was prepared using temperature regulation and PEI bridging strategies. • The introduction of PEI and MOF enhance the antimicrobial ability of the membrane. • PEI reduces the size of ZIF-8 crystals by inhibiting the Ostwald ripening effect. • CDA is performed to deeply analyze the interaction between ZIF-8 and uranyl ion. • Coordination-driven and covalent-driven PEI-bridging assembly was employed. Extraction uranium (VI) (U(VI)) from wastewater and seawater is highly important for environmental protection and life safety, but it remains a great challenge. In this work, the growth of the zeolitic imidazolate framework-8 (ZIF-8) nanoparticles on the tannic acid (TA)-3-aminopropyltriethoxysilane (APTES) modified PVDF (TAP) membrane was designed to obtain an excellent U(VI) adsorbent. The zeolite imidazolate framework composite membrane (TAPP-ZIF-60) was prepared through polyethyleneimine (PEI) bridging strategy and temperature regulation strategy in solvothermal method. The coordination bond between PEI and ZIF-8 and the covalent bond between PEI and TAP are essential in forming stable composite membrane. TAPP-ZIF with different properties was synthesized through a temperature regulation process and the TAPP-ZIF prepared at 60 °C has the uniform morphology and good performance. The adsorption capacity of TAPP-ZIF-60 is 153.68 mg/g (C 0 = 95.01 mg/L and pH = 8.0) and water permeability is 5459 L m−2 h−1 bar−1. After ten adsorption–desorption cycles, it is proved that TAPP-ZIF-60 has good repeatability and stability. In addition, the TAPP-ZIF-60 composites membrane has a good inhibitory effect on Staphylococcus aureus and Escherichia coli. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) analysis reveal that the coordination between TAPP-ZIF-60 and uranyl ions is the primary factor contributing to the high adsorption capacity. [ABSTRACT FROM AUTHOR]

Although there are many studies on CO2 adsorption via PEI‐modified carbon particles, metal–organic frameworks, zeolitic imidazolate frameworks, and silica‐based porous structures, only a limited number of studies on solely cross‐linked PEI‐based structures. Here, the CO2 adsorption capacities of PEI‐based microgels and cryogels were investigated. The effects of various parameters influencing the CO2 adsorption capacity of PEI‐based structures, for example, crosslinker types, PEI types (branched [bPEI] or linear [lPEI]), adsorbent types (microgel or cryogel), chemical‐modification including their complexes were examined. NaOH‐treated glycerol diglycidyl ether (GDE) crosslinked lPEI microgels exhibited higher CO2 adsorption capacity among other microgels with 0.094 ± 0.006 mmol CO2/g at 900 mm Hg, 25°C with 2‐ and 7.5‐fold increase upon pentaethylenehexamine (PEHA) modification and Ba(II) metal ion complexing, respectively. The CO2 adsorption capacity of bPEI and lPEI‐based cryogels were compared and found that lPEI‐GDE cryogels had higher adsorption capacity than bPEI‐GDE cryogels with 0.188 ± 0.01 mmol CO2/g at 900 mm Hg and 25°C. The reuse studies revealed that NaOH‐treated GDE crosslinked bPEI and lPEI microgels and cryogels showed promising potential, for example, after 10‐times repeated use >50% CO2 adsorption capacity was retained. The results affirmed that PEI‐based microgels and cryogels are encouraging materials for CO2 capture and reuse applications. [ABSTRACT FROM AUTHOR]

Tumor vaccine therapy offers significant advantages over conventional treatments, including reduced toxic side effects. However, it currently functions primarily as an adjuvant treatment modality in clinical oncology due to limitations in tumor antigen selection and delivery methods. Tumor vaccines often fail to elicit a sufficiently robust immune response against progressive tumors, thereby limiting their clinical efficacy. In this study, we developed a nanoparticle-based tumor vaccine, OVA@HA-PEI, utilizing ovalbumin (OVA) as the presenting antigen and hyaluronic acid (HA) and polyethyleneimine (PEI) as adjuvants and carriers. This formulation significantly enhanced the proliferation of immune cells and cytokines, such as CD3, CD8, interferon- γ , and tumor necrosis factor- α , in vivo, effectively activating an immune response against B16–F10 tumors. In vivo fluorescence flow cytometry (IVFC) has already become an effective method for monitoring circulating tumor cells (CTCs) due to its direct, noninvasive, and long-term detection capabilities. Our study utilized a laboratory-constructed IVFC system to monitor the immune processes induced by the OVA@HA-PEI tumor vaccine and an anti-programmed death-1 (PD-1) antibody. The results demonstrated that the combined treatment of OVA@HA-PEI and anti-PD-1 antibody significantly improved the survival time of mice compared to anti-PD-1 antibody treatment alone. Additionally, this combination therapy substantially reduced the number of CTCs in vivo, increased the clearance rate of CTCs by the immune system, and slowed tumor progression. These findings greatly enhance the clinical application prospects of IVFC and tumor vaccines. [ABSTRACT FROM AUTHOR]

Despite their advantages of light weight, complete coating and good formability, the poor high-temperature stability of organic materials limits their use as insulation coatings for soft magnetic powders. Therefore, a polyethyleneimine (PEI)/silicone resin (SR) double organic insulation layer was exploited to release internal stress and maintain insulation stability during the high-temperature annealing process, which achieved low core losses (Pcv) and high effective permeability (μe). Cross-sectional scanning transition images indicate that the PEI/SR layer undergoes the following evolution during annealing at 500–900°C: coating → densification → crack → rupture, implying thermal stability up to 700°C. Because of the integrity of double inorganic shells and the weak pin on magnetic domain movement, FeSiAl@PEI/SR cores annealed at 800°C deliver remarkable AC soft magnetic performance at 50 and 100 kHz, that is, low Pcv of 61.6 mW/cm3 (50 mT, 100 kHz), 121.2 mW/cm3 (100 mT, 50 kHz) and 307.3 mW/cm3 (100 mT, 100 kHz), high μe of 55.6 up to 1 MHz and 140°C, and DC bias of 51.5% at 100 Oe. Eddy current loss reaches the minimum value at 700°C and deteriorates at 800°C, and hysteresis loss continues to decrease with increasing annealing temperature, confirming the evolution of the insulation layer. Moreover, cores annealed at 700°C deliver μe of 57.6 at 1 MHz and Pcv of 278 mW/cm3 (20 mT, 1 MHz), exhibiting great potential for 1 MHz frequency power applications. [ABSTRACT FROM AUTHOR]

Porous silica-based adsorbents for hexavalent chromium (Cr(VI)) ion removal were prepared by the combined use of functionalization with (3-glycidyloxypropyl)trimethoxysilane and the grafting of branched and linear polyethyleneimine (BPEI and LPEI). LPEI was prepared from polyethyloxazolin by hydrolysis with HCl. The preparation of LPEI was identified by NMR measurements and the grafting of BPEI and LPEI on the silica beads was confirmed by an XPS analysis. The Cr(VI) ion adsorption of the obtained BPEI-grafted silica beads (BPEI–silica beads) was investigated as a function of the pH value, the content of amino groups, the temperature, the Cr(VI) ion concentration, and the molecular mass of the grafted BPEI chains. The Cr(VI) ion adsorption at pH 3.0 increased with an increase in the content of amino groups, and the maximum adsorption capacity of 1.06 mmol/g was obtained when the content of amino groups was at 2.17 mmol/g. This value corresponds to 589 mg/g−1.8KPEI, and the adsorption ratio of about 0.5 is a noteworthy result. The data fit to the pseudo-second-order kinetic model, and the suitability of this fitting was supported by the results that the adsorption capacity and initial rate of adsorption increased with the temperature. In addition, the equilibrium data followed the Langmuir isotherm model. These results clearly demonstrate that the Cr(VI) adsorption occurred chemically, or through the electrostatic interaction of protonated amino groups on the grafted BPEI chains with hydrochromate (HCrO4−) ions. A higher adsorption capacity was obtained for the silica beads grafted with shorter BPEI chains, and the adsorption capacity of BPEI–silica beads is a little higher than that of linear PEI-grafted silica beads, suggesting that the Cr(VI) ion adsorption is affected by the chain isomerism of PEI (linear and branched) as well as the molecular mass of the grafted PEI chains, in addition to the content of amino groups. The experimental and analytical results derived from this study emphasize that the BPEI–silica beads can be used as an adsorbent for the removal of Cr(VI) ions from an aqueous medium.

Abstract Background PD-1/PD-L1 blockade has become a powerful method to treat malignant tumors. However, a large proportion of patients still do not benefit from this treatment, due to low tumor immunogenicity and low tumor penetration of the agents. Recently, neutrophil elastase has been shown to induce robust tumor immunogenicity, while the insufficient enzyme activity at the tumor site restricted its anti-tumor application. Here, we designed polyethyleneimine-modified neutrophil elastase (PEI-elastase) loaded with PD-L1small interfering RNA (PD-L1 siRNA) for improving enzymatic activity and delivering siRNA to tumor, which was expected to solve the above-mentioned problems. Results We first demonstrated that PEI-elastase possessed high enzymatic activity, which was also identified as an excellent gene-delivery material. Then, we synthesized anti-tumor lipopolymer (P-E/S Lip) by encapsulating PEI-elastase and PD-L1siRNA with pH-responsive anionic liposomes. The P-E/S Lip could be rapidly cleaved in tumor acidic environment, leading to exposure of the PEI-elastase/PD-L1 siRNA. Consequently, PEI-elastase induced powerful tumor immunogenicity upon direct tumor killing with minimal toxicity to normal cells. In parallel, PEI-elastase delivered PD-L1siRNA into the tumor and reduced PD-L1 expression. Orthotopic tumor administration of P-E/S Lip not only attenuated primary tumor growth, but also produced systemic anti-tumor immune response to inhibit growth of distant tumors and metastasis. Moreover, intravenous administration of P-E/S Lip into mice bearing subcutaneous tumors leaded to an effective inhibition of established B16-F10 tumor and 4T1 tumor, with histological analyses indicating an absence of detectable toxicity. Conclusions In our study, a protease-based nanoplatform was used to cooperatively provoke robust tumor immunogenicity and down-regulate PD-L1 expression, which exhibited great potential as a combination therapy for precisely treating solid tumors. Graphical Abstract

This study introduces an innovative approach to enhance the antibacterial properties of lithium disilicate glass ceramics, widely used in dental restorations. We explored the efficacy of tannic acid (TA) and polyethyleneimine (PEI) as coating agents, capitalizing on a robust defense against microbial colonization and biofilm formation. We employed various analytical techniques, including differential thermal analysis (DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), to characterize the physical, chemical, and antibacterial properties of the TA/PEI coated glass-ceramics. Results indicated a notable improvement in the mechanical properties, such as Weibull modulus, elastic modulus, and fracture toughness of the coated samples. Moreover, the TA/PEI coatings displayed superior thermal stability and effective leaching behavior in different pH, pertinent to dental applications. Significantly, the TA/PEI coatings exhibited high antibacterial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria, making them promising candidates for enhancing the bioactivity of dental restorative materials. This study lays the foundation for developing advanced antibacterial coatings for dental applications, aiming to improve patient outcomes in dental care.

Bacterial diseases are one of the most common issues that result in crop loss worldwide, and the increasing usage of chemical pesticides has caused the occurrence of resistance in pathogenic bacteria and environmental pollution problems. Nanomaterial mediated gene silencing is starting to display powerful efficiency and environmental friendliness for improving plant disease resistance. However, the internalization of nanomaterials and the physiological mechanisms behind nano-improved plant disease resistance are still rarely understood. We engineered the polyethyleneimine (PEI) functionalized gold nanoparticles (PEI-AuNPs) with fluorescent properties and ROS scavenging activity to act as siRNA delivery platforms. Besides the loading, protection, and delivery of nucleic acid molecules in plant mature leaf cells by PEI-AuNPs, its fluorescent property further enables the traceability of the distribution of the loaded nucleic acid molecules in cells. Additionally, the PEI-AuNPs-based RNAi delivery system successfully mediated the silencing of defense-regulated gene AtWRKY1. Compared to control plants, the silenced plants performed better resistance to Pseudomonas syringae, showing a reduced bacterial number, decreased ROS content, increased antioxidant enzyme activities, and improved chlorophyll fluorescence performance. Our results showed the advantages of AuNP-based RNAi technology in improving plant disease resistance, as well as the potential of plant nanobiotechnology to protect agricultural production. Highlights: Polyethyleneimine functionalized gold nanoparticles (PEI-AuNPs) with fluorescent properties and reactive oxygen species (ROS) scavenging ability are synthesized rationally; PEI-AuNPs with fluorescent properties act as the indicator to evaluate the nuclear acid internalization efficiency; PEI-AuNPs platform successfully mediate AtWRKY1 gene silencing and Pst DC3000 resistance by scavenging ROS, increasing antioxidant enzyme activity, and improving photosynthesis. [ABSTRACT FROM AUTHOR]

Background: PD-1/PD-L1 blockade has become a powerful method to treat malignant tumors. However, a large proportion of patients still do not benefit from this treatment, due to low tumor immunogenicity and low tumor penetration of the agents. Recently, neutrophil elastase has been shown to induce robust tumor immunogenicity, while the insufficient enzyme activity at the tumor site restricted its anti-tumor application. Here, we designed polyethyleneimine-modified neutrophil elastase (PEI-elastase) loaded with PD-L1small interfering RNA (PD-L1 siRNA) for improving enzymatic activity and delivering siRNA to tumor, which was expected to solve the above-mentioned problems. Results: We first demonstrated that PEI-elastase possessed high enzymatic activity, which was also identified as an excellent gene-delivery material. Then, we synthesized anti-tumor lipopolymer (P-E/S Lip) by encapsulating PEI-elastase and PD-L1siRNA with pH-responsive anionic liposomes. The P-E/S Lip could be rapidly cleaved in tumor acidic environment, leading to exposure of the PEI-elastase/PD-L1 siRNA. Consequently, PEI-elastase induced powerful tumor immunogenicity upon direct tumor killing with minimal toxicity to normal cells. In parallel, PEI-elastase delivered PD-L1siRNA into the tumor and reduced PD-L1 expression. Orthotopic tumor administration of P-E/S Lip not only attenuated primary tumor growth, but also produced systemic anti-tumor immune response to inhibit growth of distant tumors and metastasis. Moreover, intravenous administration of P-E/S Lip into mice bearing subcutaneous tumors leaded to an effective inhibition of established B16-F10 tumor and 4T1 tumor, with histological analyses indicating an absence of detectable toxicity. Conclusions: In our study, a protease-based nanoplatform was used to cooperatively provoke robust tumor immunogenicity and down-regulate PD-L1 expression, which exhibited great potential as a combination therapy for precisely treating solid tumors. [ABSTRACT FROM AUTHOR]

We report here a method to make a branched and partially ethoxylated polyethyleneimine derivative directly from ethanolamine. The polymerization reaction is catalysed by a pincer complex of Earth-abundant metal, manganese, and produces water as the only byproduct. Industrial processes to produce polyethyleneimines involve the transformation of ethanolamine to a highly toxic chemical, aziridine, by an energy-intensive/waste-generating process followed by the ring-opening polymerization of aziridine. The reported method bypasses the need to produce a highly toxic intermediate and presents advantages over the current state-of-the-art. We propose that the polymerization process follows a hydrogen borrowing pathway that involves (a) dehydrogenation of ethanolamine to form 2-aminoacetaldehyde, (b) dehydrative coupling of 2-aminoacetaldehyde with ethanolamine to form an imine derivative, and (c) subsequent hydrogenation of imine derivative to form alkylated amines. The industrial process for the synthesis of branched polyethylenimine (PEI) and polyethylenimine ethoxylated (PEIE) uses highly toxic and mutagenic chemicals. Here the authors report a method to make a branched and partially ethoxylated polyethyleneimine derivative directly from ethanolamine using a pincer complex of Earth-abundant manganese, and producing water as the only byproduct. [ABSTRACT FROM AUTHOR]