Search Results (325)

Triclosan (TCS) is an antimicrobial agent belonging to the bisphenol class, and is widely used in healthcare applications and in personal care products (PCPs). As an emerging pollutant frequently detected in aquatic environments, its toxicity to aquatic organisms and the male reproductive system highlights the need for effective removal methods such as adsorption. In this study, bio-based activated carbon was prepared from chestnut shell as waste biomass (CnSAC), modified by polyethylenimine (PEI) (CnSAC/PEI), manganese oxide MnO₂ (CnSAC/Mn) or a combination of these (CnSAC/Mn-PEI). The prepared adsorbents were evaluated for their efficiency in TCS removal. The composite material CnSAC₅₀₀PEI exhibited improved adsorption efficiency for TCS (99.5%) at pH 3, whereas MnO₂ modification alone did not provide a significant improvement over the pristine activated carbon. The pH_pzc analysis determined the surface charge of the adsorbent, while SEM, FTIR, EDS, and XRD characterization confirmed that the modification formed a thin, homogeneous PEI layer. This layer introduced N–H and C–N functional groups without affecting the porous structure of the activated carbon. The adsorption kinetics showed excellent agreement between both the PSO and PFO models, a combination of physical adsorption mechanisms and surface interactions. Isotherm analysis revealed a Freundlich behavior, indicating adsorption on a heterogeneous surface and a maximum capacity of 250.33 mg/g at 303 K for the CnSAC₅₀₀PEI material. Full article

Background/Objectives: Tissue bio-adhesives have gained significant attention as efficient alternatives to conventional wound closures, which are often hindered by insufficient adhesion and poor biocompatibility. Methods: Inspired by nature’s robust wet-adhesion strategies that use dynamic covalent interactions, we have reported a facilely fabricated hydrogel bio-adhesive based on lactobionic acid-conjugated polyethylenimine (LA-PEI) and oxidized dextran (ODex) via Schiff base linkages. Results: The prepared hydrogels exhibited three-dimensional interconnected porous networks, regulated swelling ratios, typical viscoelasticity, shear-thinning behavior, and self-healing ability. Notably, the swelling ratios of the hydrogels depended on composition, and OLP11 displayed the highest swelling ratio of over 1500%. The hydrogel bio-adhesives exhibited strong adhesion to various surfaces, including glass, metal, plastic, rubber, and wood, as well as to different chicken organs, including the heart, liver, spleen, and stomach. Furthermore, the hydrogels exhibited excellent ABTS radical-scavenging activity, effective intracellular reactive oxygen species (ROS) scavenging, and good hemocompatibility, with hemolysis ratios of all hydrogels close to 0%, below the threshold of 5%. After culturing with NIH 3T3 fibroblasts, the hydrogels demonstrated good cytocompatibility and promoted cell proliferation, with cell viabilities on day 3 reaching over 90%. Conclusions: This design yields multifunctional hydrogel bio-adhesives, showing strong promise for wound care and tissue repair applications. Full article

Tissue adhesives are gaining increasing attention as efficient alternatives to conventional wound closure methods, yet their clinical translation is often hindered by insufficient wet adhesion and inadequate biocompatibility. Drawing inspiration from nature’s robust wet-adhesion strategies, particularly dynamic covalent interactions and reversible crosslinking, we report a family of bioinspired composite hydrogels fabricated from 4-carboxyphenylboronic acid-grafted polyethylenimine (4-CPBA-PEI) and polyvinyl alcohol (PVA) that serve as versatile bioadhesives. The polyethylenimine with different molecular weights (18,000, 70,000, and 100,000 Da) was used to prepare the 4-CPBA-PEI derivatives via EDC/NHS-mediated amidation. The resulting hydrogels exhibited three-dimensional interconnected porous networks with tunable pore dimensions and equilibrium swelling ratios (ranging from 400% to 700%), closely correlated with the PEI molecular weight. Rheological measurements confirmed typical viscoelasticity, shear-thinning behavior, and outstanding self-healing performance, which are mainly attributed to hydrogen bonds and dynamic borate ester bonds in the network. The hydrogels firmly adhered to the surfaces of diverse matrices, such as glass, rubber, metal, plastic, wood, human skin, and wet mouse organs. Additionally, the obtained hydrogels exhibited high 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activity (>85%), excellent hemocompatibility (hemolysis rate < 0.5%), and potent intracellular reactive oxygen species (ROS) scavenging activity. Cytocompatibility studies using NIH 3T3 fibroblasts demonstrated low cytotoxicity and favorable cytocompatibility. This biomimetic design yields multifunctional hydrogels that integrate tunable physical properties, wet-surface attachment, self-healing, antioxidant activity, and good biocompatibility, suggesting their potential as wound dressing candidates. Full article

Background/Objectives: Intracellular delivery of RNA molecules is challenging. To solve this problem, many carrier systems are available, which are based on liposomes or polymers. Cyclodextrins are widely used excipients to increase the solubility of small molecules, but their polymer derivatives are able to deliver macromolecules. In the present study, we aimed to investigate and compare the siRNA and mRNA carrying capacity of a cationic quaternary ammonium β-cyclodextrin polymer (QABCDPS) and polyethylenimine (PEI). Methods: Cytotoxicity of the polymers was tested by the MTT method. Polyplexes were formulated with different nitrogen/phosphate ratios (NP), and their physicochemical properties were examined using dynamic light scattering and zeta potential measurements. Cellular internalization and intracellular effects of the polyplexes were investigated by confocal microscopy and flow cytometry. Results: QABCDPS exhibited lower toxicity compared to PEI, effectively binding both siRNA and mRNA and delivering them into vesicles in the cytoplasm, but showing different internalization patterns. Polyplexes formed with PEI showed stronger biological effect than those with QABCDPS, which can be attributed to the strength of interactions facilitated by the polymers. Conclusions: In summary, QABCDPS is a low-toxicity carrier that shows some promise for mRNA delivery but is ineffective for siRNA silencing under the tested conditions and requires further structural optimization. Full article

High-efficiency energy storage technologies have become particularly crucial with the ever-increasing demand for energy in recent years. Research on polymer nanocomposite dielectric materials has emerged as a prominent focus. Particularly, there is an urgent demand for the development of advanced dielectric film materials that exhibit superior energy storage performance over a wide temperature range. To this end, this study aims to investigate the effect of the molecular weight of reduced polyaniline (R-PANI) on the dielectric properties of all-organic composite films based on high-temperature-resistant polyetherimide (PEI). All-organic R-PANI/PEI composite films were fabricated by blending PEI matrix with R-PANI of varying molecular weights. Through combined density functional theory (DFT) calculations and experimental measurements, the blocking mechanism of R-PANI on charge carrier migration within the composite films was elucidated, showing a significant enhancement in the discharge energy density of PEI polymers while maintaining high charge–discharge efficiency. With charge–discharge efficiency maintained above 95%, R-PANI3/PEI achieved a discharge energy density of 2.36 J cm⁻³ at room temperature, nearly double that of pristine PEI (1.2 J cm⁻³). At 150 °C, the 1.0 wt% R-PANI3/PEI composite film retained a discharge energy density of 2.27 J cm⁻³ with a charge–discharge efficiency of 89.2%, outperforming pure PEI (1.1 J cm⁻³, 85.1%). These findings provide a new strategy for the design of all-organic composite dielectric films and demonstrate the potential of R-PANI in the application of high-performance capacitors and electrical energy storage. Full article

Polyester/cotton blended fabrics—valued for comfort and durability—face significant fire hazards due to a synergistic “scaffold effect” during combustion. Conventional treatments with high temperature or some acidic phosphorus flame retardants during preparation often compromise the mechanical strength. Inspired by mussel adhesion chemistry, a mechanically enhanced polyester/cotton fabric was developed by using a novel bio-inspired phosphorus/nitrogen (P/N) synergistic coating. A uniform polydopamine-polyethylenimine (PDA-PEI) layer is rapidly deposited via co-deposition, suppressing dopamine self-polymerization. Subsequent covalent bonding with 2,2-dimethyl-1,3-propanediyl bis (phosphoryl chloride) (DPPC) establishes a robust P/N network. The fabricated PDA-PEI/DPPC coating reduces peak heat release rate (pHRR) and total heat release (THR) by 57.7% and 32.6%, respectively, in cone calorimetry, achieving self-extinguishment and a high limiting oxygen index (LOI) of 24.6%. Remarkably, the coating simultaneously increases the weft-direction breaking strength by 55% and elongation at break by 27.2%; these changes overcome the typical mechanical degradation associated with acidic phosphorus flame retardants. A comprehensive analysis reveals a synergistic mechanism: phosphoric acids catalyze cellulose dehydration and char layer formation in the condensed phase (90% stable C–C bonds), while radical scavengers (PO·, HPO·, and PDA) and non-flammable gases suppressed gas-phase combustion. This work presents a facile and effective strategy for fabricating high-performance and mechanically robust flame retardant polyester/cotton textiles, demonstrating the significant potential for improving fire safety in practical applications. Full article

Background/Objectives: Peri-implantitis is a chronic inflammatory condition affecting tissues surrounding dental implants and is characterized by progressive marginal bone loss that can ultimately lead to implant failure. Reduced vascularization and impaired immune clearance in peri-implant tissues contribute to persistent inflammation and limited therapeutic efficacy. MicroRNAs (miRNAs), particularly miR-21, have emerged as key regulators of inflammatory responses and bone remodeling. The objective of this study was to develop a bioactive dental implant coating capable of locally delivering miR-21 to modulate inflammation and promote peri-implant tissue regeneration, thereby preventing peri-implantitis. Methods: Cationic nanoparticles were synthesized using lecithin and low-molecular-weight polyethylenimine (PEI) as a non-viral delivery system for miR-21. Lecithin was employed to enhance biocompatibility, while PEI functionalization provided a positive surface charge to improve miRNA complexation and cellular uptake. The resulting lecithin–PEI nanoparticles (LEC–PEI NPs) were incorporated into a chitosan-based coating and applied to titanium implant surfaces to obtain a sustained miR-21–releasing system (miR21-implant). Transfection efficiency and biological activity were evaluated in human periodontal ligament fibroblasts (hPDLFs) and compared with a commercial transfection reagent (Lipofectamine). Release kinetics and long-term activity of miR-21 from the coating were also assessed. Results: MiR-21-loaded LEC–PEI nanoparticles demonstrated significantly higher transfection efficiency than Lipofectamine and retained marked biological activity in hPDLFs relevant to peri-implantitis prevention. The chitosan-based nanoparticle coating enabled controlled and sustained miR-21 release over time, supporting prolonged modulation of inflammatory and osteogenic signaling pathways involved in peri-implant tissue homeostasis. Conclusions: The miR21-implant system, based on lecithin–PEI nanoparticles incorporated into a chitosan coating, represents a promising therapeutic strategy for peri-implantitis prevention. By enabling sustained local delivery of miR-21, this approach has the potential to preserve peri-implant bone architecture, modulate chronic inflammation, and enhance the osseointegration of titanium dental implants. Full article

The reliance on unstable hydrogen peroxide (H₂O₂) adversely affects the robustness and simplicity of chemiluminescence (CL)-based immunoassays. We report a novel external H₂O₂-free Fenton CL system integrated into a highly sensitive non-enzymatic immunoassay for the detection of SARS-CoV-2 nucleoprotein, utilizing cuprous–polyethylenimine–lipoic acid nanoflowers (Cu(I)-PEI-LA-Ab NF) as a non-enzymatic tag. The signaling polymer (PEI-LA) was synthesized via EDC/NHS coupling, which conjugated approximately 550 LA units to the PEI backbone. This polymer formed antibody-conjugated NF with various metal ions, and the Cu(I)-based variant was selected for its intense and sustained CL with luminol. The mechanism relies on an in situ Fenton reaction, in which dissolved oxygen is reduced by Cu(I) to H₂O₂, which reacts with oxidized Cu(II), producing hydroxyl radicals that oxidize luminol. Direct calibration of the SARS-CoV-2 nucleoprotein fixed on microplate wells demonstrated excellent linearity in the range of 0.01–3.13 ng/mL (LOD = 3 pg/mL). In a final competitive immunoassay format for samples spiked with the antigen, a decreasing CL signal that correlated with increasing antigen concentration was obtained in the range of 0.1–20.0 ng/mL, achieving excellent recoveries that were favorable compared with those of the sandwich ELISA kit, establishing this H₂O₂-independent platform as a powerful and robust tool for clinical diagnostics. Full article

Background/Objectives: Mesenchymal stem cells (MSCs) are recognized for their therapeutic potential due to their ability to secrete bioactive molecules. Among these secreted factors, bone morphogenetic protein-2 (BMP-2) is known as a secreted factor that plays a crucial role in bone healing and regeneration. However, MSCs naturally secrete only small amounts of BMP-2. To improve the bone healing capacity of MSCs, it is essential to enhance the secretion of BMP-2 in MSCs. One approach that can be used to achieve this goal is by genetically engineering MSCs. Incorporating signal peptides (SPs) into the inserted gene sequence can significantly improve protein secretion efficiency. In this proof-of-concept study, we explored the role of SPs in optimizing BMP-2 secretion in umbilical cord-derived MSCs; Methods: Three human-derived SPs, namely glial-derived neurotrophic factor (GDNF), chemotactic antibacterial glycoprotein 7 (CAP7), and platelet-derived growth factor subunit B (PDGFB), were selected. Transfection of MSCs was performed using polyethylenimine, Lipofectamine 2000^®, and Lipofectamine 3000^®. Transfection efficiency confirmed based on Green Fluorescence Protein expression. BMP-2 secretion levels were quantified using an ELISA assay; Results: Lipofectamine 3000^® achieved the highest transfection efficiency, reaching approximately 10%. BMP-2 secretion levels varied significantly depending on the SPs used, with PDGFB yielding the highest BMP-2 concentration (279.21 ± 6.91 pg/mL), followed by GDNF (265.65 ± 11.49 pg/mL) and CAP7 (233.72 ± 32.33 pg/mL); Conclusions: These findings demonstrate that SP selection critically influences BMP-2 secretion efficiency in genetically engineered MSCs and underscore its potential to enhance the therapeutic applicability of MSC-based strategies for bone healing. Full article

A comparative sorption dependence was carried out between the Dowex HCR-S/S″ industrial ion-exchange sorbent and the synthesized ion-exchange sorbent based on dibenzylamine, epichlorohydrin and polyethylenimine in relation to copper and silver ions. The sorption of copper and silver was studied by ionometry and the dependences of the sorption of copper and silver ions in the static mode were established depending on the concentration of metal ions and the duration of ionite contact with solutions of copper and silver nitrates. It was found that the maximum sorption capacity of the synthesized ion exchanger is 672.4 mg/g for copper ions and 721.0 mg/g for silver ions, and 626.3 mg/g and 679.7 mg/g for industrial Dowex HCR-S/S″ ionite, respectively. It is shown that the sorption of copper and silver is described by various kinetic models: for copper, the best correspondence is demonstrated by a pseudo second order kinetic model, whereas for silver, the Elovich kinetic model the different nature of the interaction of ions with active centers. It has been revealed that the synthesized ion exchanger is superior to an industrial sorbent in terms of sorption rate and degree of extraction of valuable metals, especially in concentrated solutions, which indicates the prospects of its use in the processes of selective extraction of copper and silver. Full article

This study investigates the valorization of two agri-food residues, specifically olive pomace (alperujo, A) and banana peel (B), into efficient N-doped carbon-based catalysts for polluted wastewater treatment. The residues were converted into hydrochar (HA and HB), which were subsequently N-doped using polyethylenimine (PEI) in combination with cross-linkers (glutaraldehyde (GTA) or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)) to optimize their catalytic properties. The enhanced hydrochars were utilized as catalysts for the removal of organic pollutants from water by activation of peroxymonosulfate (PMS). Characterization techniques, including CHNS, FTIR, XPS, SEM and electrochemical analysis, were employed to understand the physicochemical properties of the materials. The catalytic activity was evaluated using Reactive Black 5 (RB5) as a model pollutant, with the N-doped alperujo-derived hydrochar cross-linked with EDC (N-HA-EDC) showing the best performance, achieving 80% removal in 60 min and an adsorption capacity of 97 mg/g. The versatility of this functionalization approach was assessed through tests with three pharmaceuticals, corroborating the adaptability and efficacy of the catalyst and demonstrating its potential for wastewater treatment applications. This study provides insights into the development of sustainable, cost-effective carbocatalysts, aligning with circular economy and zero waste principles. Full article

Tetrakis (Hydroxymethyl) Phosphonium chloride (THPC) in aqueous solution reacts with amines to form aminomethylenephosphines. The reaction was studied with piperidine, and THPC was used with PEI. The reaction with PEI leads to new polymers with phosphine groups (PEI-P) and phosphine oxide (PEI-PO) after oxidation by hydrogen peroxide. These polymers coordinate cations of transition metals, lanthanides and actinides. Full article

Due to the large emissions of greenhouse gases from the burning of fossil fuels and people’s demand for green materials and energy, the development of environmentally friendly triboelectric nanogenerators (TENGs) is becoming increasingly significant. Silk fibroin (SF) is considered an ideal biopolymer candidate for fabricating green TENGs due to its biodegradability and renewability. However, its intrinsic brittleness and relatively weak triboelectric performance severely limit its practical applications. In this study, SF was physically blended with poly(ethylenimine) (PEI), a polymer rich in amino groups, to fabricate SF/PEI composite films. The resulting films were employed as tribopositive layers and paired with a poly(tetrafluoroethylene) (PTFE) tribonegative layer to assemble high-performance TENGs. Experimental results revealed that the incorporation of PEI markedly enhanced the flexibility and electron-donating capability of composite films. By optimizing the material composition, the SF/PEI-based TENG achieved an open-circuit voltage as high as 275 V and a short-circuit current of 850 nA, with a maximum output power density of 13.68 μW/cm². Application tests demonstrated that the device could serve as an efficient self-powered energy source, capable of lighting up 66 LEDs effortlessly through simple hand tapping and driving small electronic components such as timers. In addition, the device can function as a highly sensitive self-powered sensor, capable of generating rapid and distinguishable electrical responses to various human motions. This work not only provides an effective strategy to overcome the intrinsic limitations of SF-based materials but also opens up new avenues for the development of high-performance and environmentally friendly technologies for energy harvesting and sensing. Full article

L-asparaginase (L-ASNase) is a vital enzymatic drug widely used for treating acute lymphoblastic leukemia (ALL) and certain lymphomas. However, its clinical application is often limited by a short plasma half-life, pronounced immunogenicity, and systemic toxicities. To address these challenges, we recently developed conjugates of L-ASNase with cationic polymers, enhancing its cytostatic activity by increasing enzyme binding with cancer cells. The present study focuses on the development of liposomal formulations of E. coli L-asparaginase (EcA) and its conjugates with cationic polymers: the natural oligoamine spermine (spm) and a synthetic polyethylenimine–polyethyleneglycol (PEI-PEG) copolymer. This approach aims to improve enzyme encapsulation efficiency and stability within liposomes. Various formulations—including EcA conjugates with polycations incorporated into 100 nm and 400 nm phosphatidylcholine/cardiolipin (PC/CL, 80/20) anionic liposomes—were synthesized as a delivery system of high enzyme load. Fourier Transform Infrared (FTIR) spectroscopy confirmed successful enzyme association with liposomal carriers by identifying characteristic changes in the vibrational bands corresponding to both protein and lipid components. In vitro release studies demonstrated that encapsulating EcA formulations in liposomes more than doubled their half-release time (T_1/2), depending on the formulation. Cytotoxicity assays against Raji lymphoma cells revealed that liposomal formulations, particularly 100 nm EcA-spm liposomes, exhibited markedly superior anti-proliferative activity, reducing cell viability to 4.5%, compared to 35% for free EcA. Confocal Laser Scanning Microscopy (CLSM) provided clear visual and quantitative evidence that enhanced cellular internalization of the enzyme correlates directly with its cytostatic efficacy. Notably, formulations showing higher intracellular uptake produced greater cytotoxic effects, emphasizing that hydrolysis of asparagine inside cancer cells, rather than extracellularly, is critical for therapeutic success. Among all tested formulations, the EcA-spermine liposomal conjugate demonstrated the highest fluorescence intensity within cells providing enhanced cytotoxicity. These results strongly indicate that encapsulating cationically modified L-ASNase in liposomes is a highly promising strategy to improve targeted cellular delivery and prolonged enzymatic activity. This strategy holds significant potential for developing more effective and safer antileukemic therapies. Full article

Waste materials have emerged as attractive low-cost feedstocks for adsorbent development in environmental remediation and materials engineering. Organic wastes are particularly rich in cellulose, hemicellulose, lignin, and pectin, which provide reactive oxygenated groups such as hydroxyls and carboxyls. While inorganic wastes offer stability, lower water retention makes them promising candidates. This study explores the functionalization of waste-derived organic and inorganic matrices using two amine-based agents: 3-aminopropyltrimethoxysilane (APTMS) and polyethylenimine (PEI). The materials were categorized as organic (orange peel, corn cob) or inorganic (silica gel, eggshell) and subjected to a pretreatment process involving drying, grinding, and sieving; inorganic substrates additionally underwent acid activation with citric acid. Surface modification was carried out in ethanolic (APTMS) or aqueous (PEI) media. To assess their suitability and processability as particulate sorbents, drying kinetics, physicochemical properties (FTIR, ζ-potential, pH, conductivity, Boehm titration), and flow characteristics (Carr and Hausner indices) were evaluated. The findings enable a comparative analysis of the functionalization efficiency and elucidate the relationship between substrate type (organic vs. inorganic) and its performance as a modified adsorbent. This approach advances the development of novel sorbent matrices for greenhouse gas mitigation while reinforcing circular economy principles through the valorization of low-cost, readily available waste materials. Full article