Search Results (604)

Inhalable ribonucleic acid (RNA) nanomedicines are emerging as versatile therapeutics for respiratory diseases and pulmonary metastases, enabling localized delivery of messenger RNA (mRNA), small interfering RNA (siRNA), antisense oligonucleotides, microRNA (miRNA) mimics, self-amplifying RNA, and genome-editing systems. This review synthesizes the available evidence and argues that the field has moved beyond asking whether RNA can reach the lungs. The more consequential translational question is whether RNA cargo, nanocarrier, excipients, manufacturing process, inhalation device, and pulmonary target cell can be integrated into a reproducible therapeutic product. Current research demonstrates progress in disease-corrective mRNA expression, silencing of inflammatory and fibrotic pathways, mucosal vaccination, antiviral therapy, and localized cancer treatment, alongside advances in ionizable lipid nanoparticles, lipid–polymer hybrids, chitosan and polyethyleneimine (PEI) polyplexes, dendrimers, peptide carriers, biomimetic systems, and dry-powder formulations. Translational maturity, however, remains uneven. Many studies demonstrate carrier feasibility, reporter expression, or preclinical activity, whereas fewer establish device-compatible aerosolization, preservation of RNA integrity during processing, traversal of pulmonary barriers, target-cell engagement, repeat-dose tolerability, and clinically meaningful benefit. Development should therefore be target-defined, analytically gated, device-specific, and outcome-centered. Inhalable RNA nanomedicines are best understood as integrated pulmonary products whose success depends on preserving RNA function throughout manufacturing, aerosolization, post-deposition barrier navigation, intracellular delivery, and disease-relevant pharmacodynamic activity. Full article

Per- and polyfluoroalkyl substances (PFAS) such as perfluorooctanoic acid (PFOA) persist in aquatic environments due to their extremely strong C–F bonds and high environmental stability/poor biodegradability, creating an urgent demand for high-performance and scalable adsorption treatment technologies. This study reports the synthesis, characterization, and fixed-bed column adsorption performance of a dual-polymer-modified activated carbon adsorbent engineered for enhanced PFAS capture. Activated carbon (AC) was sequentially functionalized with polyethyleneimine (PEI) and poly(chlorotrifluoroethylene–co-vinylidene fluoride) (Kel–F) to form the fluorine-rich, amine-grafted composites AC–PEI–KelF and AC–PEI–KelF–PEI. Surface-area studies of the modified AC adsorbents showed a reduction in surface area of about a factor of two, possibly due to pore blockage by the polymers. Continuous-flow column breakthrough studies demonstrated dramatic improvements in perfluorooctanoic acid (PFOA) removal efficiency, with 50% maximum breakthrough time increasing from 80 min for AC to 540 min for AC–PEI–KelF and 1500 min for the AC–PEI–KelF–PEI formulation. Thomas model adsorption capacities for AC, AC–PEI–KelF and AC–PEI–KelF–PEI were, respectively, 65, 490, and 1130 mg/g. The adsorption mechanism, using selective mobile phases, was shown to be due to a combination of electrostatic and hydrophobic/fluorophilic interactions. Kinetic analysis showed that adsorption exhibited pseudo-second-order behavior, with multi-stage intraparticle diffusion. The optimized composite also exhibited strong regeneration stability, retaining 79% performance after six adsorption–desorption cycles, and displayed high selectivity for PFOA, even in the presence of structurally related competitors such as octanoic acid. The adsorption of perfluoropentanoic acid and undecafluoro-2-methyl-3-oxahexanoic acid (GenX) was also significant, and some interaction with trifluoroacetic acid was noted. Full article

Background: Triple-negative breast cancer (TNBC), devoid of actionable targets for endocrine or HER2-directed therapy, is highly aggressive with elevated risks of recurrence and metastasis; surgical resection remains the mainstay of treatment, and postoperative chemotherapy serves as a key adjuvant modality for controlling residual disease. Doxorubicin (DOX), although widely used, shows limited tumor selectivity, considerable systemic toxicity, and poor control over drug release at the tumor site. To address these issues, we developed near-infrared (NIR)-responsive gold-decorated phase-change nanodroplets (AuNPs-DOX-NDs) that combine photothermal conversion, liquid-to-gas phase transition, and controlled DOX release in a single platform. Methods: The nanodroplets consisted of a perfluorohexane (PFH) core, a DOX-loaded lipid shell, and polyethyleneimine-modified gold nanoparticles (PEI-AuNPs) conjugated to the surface as the NIR photothermal component. Physicochemical characterization was performed to evaluate morphology, colloidal dispersity, and storage stability. Under 808 nm laser irradiation, the photothermal behavior, PFH vaporization, and DOX release properties of AuNPs-DOX-NDs were investigated. In vitro studies using 4T1 TNBC cells were conducted to assess intracellular DOX accumulation, cell proliferation, migration, and apoptosis. Results: Physicochemical characterization showed that the nanodroplets had a uniform nanoscale morphology, good colloidal dispersity, and acceptable storage stability. Under 808 nm laser irradiation, AuNPs-DOX-NDs exhibited concentration-dependent photothermal heating, which induced PFH vaporization and accelerated DOX release, indicating a clear stimulus-responsive release behavior. In vitro studies using 4T1 TNBC cells showed enhanced intracellular DOX accumulation after treatment with AuNPs-DOX-NDs. Upon laser irradiation, the nanodroplets further inhibited cell proliferation and migration and promoted apoptosis, suggesting an enhanced combined photothermal–chemotherapeutic effect in 4T1 TNBC cells. Conclusions: These results indicate that AuNPs-DOX-NDs may serve as a useful NIR-responsive platform for externally controlled drug release and enhanced combined photothermal-chemotherapy, and deserve further evaluation in vivo. Full article

Rapid detection of heavy metals is vital for monitoring surface water contamination and preventing environmental and health risks. Traditional detection methods for metals such as lead and copper often require sophisticated, costly instrumentation, limiting their use in routine analyses. To address this challenge, we developed a cost-effective fluorescence-based approach using semiconductor quantum dots (QDs) as nanosensors for metal ion detection. The QDs were synthesized directly in aqueous medium through a reflux-assisted process employing cadmium precursors, selenium, thioglycolic acid (TGA), and branched polyethyleneimine (PEI, Mw ~25,000) as stabilizing agents. Structural analysis revealed nanoparticles with diameters below 5 nm, spherical morphology, and a zinc blende (face-centered cubic) crystalline structure. Optical characterization by UV–Vis, photoluminescence (PL), and FTIR spectroscopy confirmed effective surface functionalization and strong quantum confinement. PEI-capped QDs exhibited enhanced colloidal stability and showed pronounced fluorescence quenching in the presence of Pb²⁺ ions, indicating high sensitivity and selectivity toward lead. Both TGA- and PEI-capped QDs also demonstrated moderate responses to Co²⁺ but negligible interaction with Sn²⁺, confirming ion-specific detection. Overall, this study demonstrates that surface-engineered QDs constitute a simple, accessible platform for selective detection of toxic metals, with promising applications in environmental monitoring and water quality assessment. Full article

Achieving efficient demulsification of water-in-heavy oil (W/HO) emulsions remains a critical issue that urgently needs to be addressed in the heavy oil industry. Despite being a new generation of green demulsification materials, magnetic carbon nanoparticles still suffer from low demulsification efficiency when applied to water-in-heavy oil emulsions. Herein, polyethyleneimine-modified magnetic carbon nanoparticles (P-MCNs) were successfully prepared via a surface functionalization strategy. The demulsification performance of P-MCN in water-in-heavy oil (W/HO) emulsions was evaluated via the standard bottle test. The results demonstrated that P-MCN (500 ppm) achieved effective water removal within 60 min at 50 °C. Microscopic visualization characterization revealed that the efficient water removal from W/HO emulsions by P-MCN is attributed to its high interfacial activity. Specifically, P-MCN can rapidly migrate to the heavy oil–water interface and effectively disrupt the interfacial film through electrostatic interactions and hydrogen bonding, thereby achieving efficient demulsification of W/HO emulsions. This study provides a solid theoretical foundation for the further development of magnetic carbon nanoparticles with higher demulsification efficiency for applications in the petroleum industry. Full article

The performance of CdS-based photocatalysts can be enhanced by incorporating graphene co-catalysts in close contact with the photoactive phase. However, assembling these distinct components remains a bottleneck, as their differing chemical natures often limit effective interfacial interaction when they are synthesized separately. In this work, we present an adaptable PEI-mediated interfacial assembly strategy for promoting the nucleation and growth of nanocrystalline CdS phases on different graphene-based supports within a common, yet support-adapted, approach. Specifically, by functionalizing the surface of various graphene materials with hyperbranched polyethyleneimine (PEI) as a multifunctional interlayer mediator, we achieve controlled CdS formation. This strategy provides a common chemical framework for producing CdS nanocrystals closely associated with the carbon surface, regardless of the substrate. Diverse materials, including low-defect graphene sheets (G-Sheets), graphene nanoplatelets (GNPs), and graphene oxide (GO), were integrated using tailored architectures: noncovalent PDI-anchoring for GNP and G-Sheets and direct covalent functionalization for GO. In the latter case, PEI acts simultaneously as a mild reducing agent, yielding a covalently grafted reduced graphene oxide hybrid (rGO-PEI). XRD patterns confirm comparable CdS crystallinity across all hybrids, while photocatalytic hydrogen evolution measurements reveal a strong dependence on the nature of the graphene support. rGO-PEI@CdS exhibits the highest hydrogen evolution rate (0.44 mmol g⁻¹ h⁻¹) without any noble-metal cocatalyst, highlighting the role of surface defects and oxygen functionalities in interfacial charge transfer. Thermal treatment of rGO-PEI@CdS enhances activity (average 1.20 mmol g⁻¹ h⁻¹) but leads to partial deactivation over time. Overall, this study provides an adaptable PEI-mediated framework for integrating diverse graphene-type materials as co-catalysts within CdS-based photocatalytic materials and investigates structure–function relationships in graphene@CdS systems. Full article

Messenger RNA (mRNA) therapeutics are redefining treatment approaches in vaccines, cancer immunotherapy, protein replacement, and gene editing. Lipid nanoparticles have enabled early clinical successes, but they can be limited by liver-dominant biodistribution, long-term storage stability, and systemic tolerability. Polymeric delivery systems offer a versatile alternative, with tunable physicochemical properties enabling precise control over mRNA complexation, protection, release, and targeting. This review examines recent progress across polyethyleneimine derivatives, poly(β-amino ester)s, poly(amino acid)s, polyesters, dendrimers, charge-altering releasable transporters, and lipid-polymer hybrids. We highlight strategies such as structural modification, stimuli-responsive designs, and high-throughput polymer screening that enhance stability, reduce cytotoxicity, and enable organ- or cell-specific delivery. Addressing challenges in immunogenicity, biodistribution, and manufacturing scalability will be pivotal to translating these innovations into safe and effective mRNA therapeutics. Full article

Solid amine adsorbents can capture CO₂ at indoor-relevant concentrations (~1000 ppm), but many high-capacity adsorbents rely on granular or powdery supports that are difficult to integrate directly into air purification systems. Here, we applied three amination strategies to commercial fibrous substrates: bridge-grafting on viscose (TEPA-AMVF), direct grafting on polyacrylonitrile (TEPA-PAN), and physical impregnation on pore-engineered activated carbon fibre felt (PEI-ACF). These adsorbents were systematically screened under simulated indoor conditions (1000 ppm CO₂, 27 °C, 50% RH). A significant capacity difference was observed: TEPA-AMVF (24.8 mg g⁻¹) < TEPA-PAN (35.8 mg g⁻¹) ≪ PEI-ACF (97.0 mg g⁻¹). The superior performance of PEI-ACF was attributed to KOH activation, which produced a mesopore-rich structure (average pore diameter 26.1 nm at an optimal KOH/carbon ratio of 1.25) and enabled high nominal amine utilisation (0.19 mmol CO₂ mmol N⁻¹). PEI-ACF maintained high breakthrough-derived CO₂ uptake across realistic indoor conditions (64.2–118.6 mg g⁻¹ over 0%–100% RH; 71.6–124.5 mg g⁻¹ over 400–5000 ppm CO₂), exhibited rapid kinetics (pseudo-first-order rate constant k = 1.77 h⁻¹; 81.7% of equilibrium uptake within 1 h), and showed stable but partial regeneration over four adsorption–desorption cycles at 60–70 °C under N₂. Compared with granular or resin-based amine sorbents, the self-supporting PEI-ACF felt is expected to offer practical advantages for filter-integrated CO₂ removal, including mechanical integrity under airflow, reduced risk of particle leakage, and compatibility with HVAC filter slots. Remaining challenges include direct pressure-drop validation, operation in O₂-containing indoor air, long-term cycling, and management of CO₂ released during regeneration. Full article

Thin-film composite (TFC) polyamide (PA) nanofiltration membranes are the state of the art for water purification and reclamation, although a selectivity–permeability trade-off often restricts their development. To mitigate this problem, in this work, a novel three-layer structured nanofiltration (NF) membrane was fabricated consisting of a negatively charged poly (sodium 4-styrenesulfonate) (PSS) interlayer, a high-performance polyethyleneimine (PEI)-based PA separation layer and a PEI-grafted top layer. The PSS interlayer aimed to regulate interfacial polymerization (IP) of PEI with trimesoyl chloride (TMC) and enhance water transport, while PEI-grafting ensured high salt rejections. The relevant characterizations indicated that PEI-grafting endowed the resulting membrane (I-TFC-g) with a positive surface charge and increased the crosslinking degree to achieve much higher rejections for Mg⁺² ions through the synergistic effect of Donnan and size-exclusion mechanisms, while the incorporation of the PSS interlayer resulted in an increased pure-water permeability (PWP) value of 7 L m⁻² h⁻¹ bar⁻¹ (a value 2.8 times higher compared to the membrane TFC-g without a PSS interlayer). In specific, the I-TFC-g membrane displayed the highest salt rejections of 91% for MgCl₂, 92% for MgSO₄, 73% for Na₂SO₄ and 58% for NaCl and a good long-term stability. Overall, this work presents a simple strategy to improve NF performance by simultaneous enhancement of water permeability and salt selectivity. Full article

Alginate-based hydrogels are well-known materials for drug delivery. However, their sensitivity towards chelators and burst release remain concerns. Polyelectrolyte coatings have been proposed to control drug release from hydrogels, but it remains unclear how the types of coating influence the release kinetics of drugs with varying ionic properties. Hence, we explored combinations of natural (chitosan, alginate) and synthetic (polyethyleneimine [PEI], polyacrylic acid [PAA]) polyelectrolytes to modulate the release kinetics of alginate-based hydrogel beads. Rhodamine B (RhB, cationic) and trypan blue (TB, anionic) were used as model drugs. PAA resulted in a less porous coating, and PEI effectively reduced swelling. While uncoated beads showed burst release, polyelectrolyte coatings slowed release to varying degrees. Chitosan+alginate and chitosan+PAA coatings showed limited impact on RhB release. In contrast, PEI+alginate and PEI+PAA coatings significantly reduced RhB release from 86% (uncoated) to 61% and 6% after 4 days, respectively. Alginate–TB displayed inherently slower release across all systems, with polymer coatings further reducing cumulative release from 49% (uncoated) to 7% in PEI+PAA-coated beads. Overall, polyelectrolyte coatings had a greater influence on the anionic payload, and PEI+PAA-coated beads emerged as promising carriers for controlled release of both cationic and anionic drugs. Full article

This work presents an energy-efficient and simple method for producing luminescent, antibacterial sulfur quantum dots (SQDs). For the first time, polyethyleneimine (PEI)-coated SQDs were synthesized via a mechanochemical technique, utilizing either elemental sulfur or sodium thiosulfate as the sulfur source. The roles of hydrogen peroxide (H₂O₂) as an etching agent and of sodium hydroxide (NaOH) in the PEI-mediated SQD formation were investigated. The as-synthesized SQDs were characterized by UV-visible, Raman, infrared (IR), and photoluminescence (PL) spectroscopy, as well as by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Both TEM and AFM analyses revealed similarly small SQD sizes (average diameter ~3 nm), independent of the sulfur source used. The influence of synthesis conditions on the optical properties, including the photoluminescence quantum yield (QY), was evaluated. SQDs derived from elemental sulfur, PEI, and NaOH exhibited the best water solubility and the strongest photoemission in the 400–550 nm range. Antibacterial activity was assessed against representative Gram-positive and Gram-negative strains, and minimum inhibitory concentration (MIC) values were determined. The PEI-coated SQDs demonstrated antibacterial activity against the Gram-positive bacteria Bacillus subtilis, Staphylococcus aureus, and Staphylococcus epidermidis, which is attributed primarily to the sulfur component. Full article

This study optimized corncob-derived magnetic biochar (MBC) with tailored iron content for laccase immobilization to boost nonylphenol (NP) degradation in water. Low-iron MBC (LMBC) and high-iron MBC (HMBC) from corncob were prepared via impregnation–pyrolysis at 700 °C, followed by modification with polyethyleneimine (PEI) and covalent immobilization of laccase using glutaraldehyde. Compared to HMBC, LMBC exhibited more mesopores, superior laccase activity recovery (60.5%) and Fe²⁺ release that was only 1/78 of HMBC’s. Furthermore, PEI modification and subsequent laccase immobilization on LMBC significantly reduced iron leaching (p < 0.05). X-ray diffraction and vibrating sample magnetometry analyses indicated that LMBC consists of crystalline Fe₃O₄, α-Fe, graphite, and carbon, with a saturation magnetization of 45.8 emu g⁻¹. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy confirmed the microporous and mesoporous structure of LMBC, the successful PEI modification, and the effective immobilization of laccase on LMBC (L-LMBC). L-LMBC exhibited enhanced stability under acidic conditions (pH 3–7) and elevated temperatures (20–70 °C). After six repeated cycles, the NP removal efficiency by L-LMBC remained at 84.8%. Moreover, L-LMBC demonstrated effective NP removal in real environmental water samples. This study provides fundamental insights and demonstrates the potential application of MBC-immobilized laccase for degrading persistent pollutants in aqueous systems. Full article

A ternary gel composed of polyvinyl alcohol (PVA), polyethyleneimine (PEI), and polyaluminum chloride (PAC) was prepared to address the limited controllability of gelation and the insufficient high-temperature resistance to re-ignition observed in existing mine fire prevention and extinguishing gels. Based on an orthogonal experimental design, the optimal formulation was identified as 14% PVA, 7% PEI, and 5.5% PAC (by mass), achieving a gelation time of 8.2 min. Microscopic characterization revealed that the gel forms a dense, interconnected three-dimensional network structure capable of effectively encapsulating the coal particles. Fourier transform infrared spectroscopy (FTIR) analysis showed that gel treatment resulted in a 29.8% reduction in the peak area of free hydroxyl groups. Thermogravimetric–differential scanning calorimetry (TG-DSC) analysis indicated that the gel increased the ignition temperature by 33.27 °C and shifted the maximum exothermic peak temperature by 13.28 °C. Fire suppression experiments demonstrate that the gel could continuously lower the temperature of high-temperature coal without re-ignition, demonstrating significantly superior performance compared to traditional sodium silicate gel. This gel achieves highly efficient fire prevention and suppression through the cooperative effects of water retention, oxygen barriers, and chemical passivation, providing a new material for the prevention and control of spontaneous coal combustion in deep mines. Full article

This study reports the effect of polyethyleneimine’s molecular weight (PEI, Mn: 1200, 10,000, and 60,000 g/mol, denoted as PEI_1.2, PEI₁₀, and PEI₆₀) on the physical, chemical, and biological characteristics of carbon dots (Cdots) derived from chitosan (Chi) and PEI (Chi-PEI Cdots). The size of Chi Cdots was 41.5 ± 6.1 nm, which increased to 50.9 ± 5.9, 71.4 ± 4.2, and 93.3 ± 7.4 nm with the preparation of Chi-PEI_1.2, Chi-PEI₁₀ and Chi-PEI₆₀ Cdots. The fluorescence properties and quantum yield% values of the Cdots prepared from Chi, PEI_1.2, PEI₁₀, and PEI₆₀ and their corresponding biopolymeric Chi-PEI Cdots were compared. A higher quantum yield of 26 ± 1.6% was observed for Chi-PEI_1.2. This decreased with the increasing molecular weight of PEI and was calculated to be 15 ± 1.9% for Chi-PEI₆₀. All the prepared bare Chi, bare PEI and corresponding bipolymeric Chi-PEI Cdots were observed to be nonhemolytic up to a 1 mg/mL concentration. Lower cytotoxic properties were observed for Chi-PEI Cdots on L929 fibroblast cells compared to their corresponding bare forms. Higher cell viability was observed for Chi-PEI_1.2 Cdots with 95% viability in the presence of a 1000 µg/mL concentration. The antibacterial activity of the prepared Cdots against pathogens such as E. coli, K. pneumoniae, S. aureus, B. subtilis, and C. albicans was investigated and compared. Lower MIC and MBC values were determined for Chi-PEI₁₀ against C. albicans with values of 12.5 and 50 mg/mL, respectively. Although the antibacterial properties of Chi-PEI Cdots were less strong than those of bare Cdots derived from individual Chi and PEI molecules, their light-induced antibacterial activities were found to be better. Full article

Human adipose biology is strongly influenced by three-dimensional (3D) architecture, cell–cell interactions, and local oxygen availability maintained over a long-term culture period, features that are not reproduced in traditional two-dimensional (2D) culture systems. To address this gap, we established a long-term human adipose-derived stem cell (hASC) spheroid model using elastin-like polypeptide–polyethyleneimine (ELP-PEI) coating. The ELP-PEI coating facilitated stable spheroid formation and sustained adipogenic differentiation over 56 days. As spheroids enlarged and matured, they exhibited hallmark features of adipocytes, including lipid accumulation, morphological compaction, and transition out of the proliferative state. Glucose uptake increased during maturation and declined as spheroids became larger. This reduction coincided with a marked rise in hypoxia-inducible factor-1α (HIF-1α) expression, indicating the emergence of a hypoxic microenvironment within larger spheroids. Notably, inhibiting HIF-1α restored insulin-stimulated glucose uptake, demonstrating that hypoxia was the primary driver of impaired insulin responsiveness in late-stage spheroids. These findings position ELP-PEI-supported hASC spheroids as a practical and physiologically relevant platform for studying human adipocyte biology, particularly the development and reversibility of hypoxia-associated metabolic dysfunction. This model offers new opportunities for mechanistic studies and for evaluating therapeutic strategies targeting insulin resistance and adipose tissue pathology. Full article