Search Results (1,856)

Background: Iodine-based antimicrobial systems remain highly attractive due to their broad-spectrum activity; however, the clinical application of free iodine is limited by its instability and cytotoxicity. This study aimed to develop polyethylene glycol (PEG)-based hydrophilic ointment formulations containing a dextrin/polyvinyl alcohol/iodine complex (D/PVA/I) and to evaluate their physicochemical properties, antimicrobial activity, and cytotoxicity. Methods: Hydrophilic ointment formulations containing 2.5%, 5.0%, and 10.0% D/PVA/I were prepared using a PEG-based matrix composed of PEG 4000, PEG 400, and glycerol. Physicochemical characterization included organoleptic evaluation, pH measurement, rheological analysis, and UV–visible (Ultraviolet–visible) spectroscopy. Antimicrobial activity was assessed using agar diffusion and minimum bactericidal concentration (MBC) assays against Staphylococcus aureus, Escherichia coli, Enterococcus hirae, and Pseudomonas aeruginosa. Cytotoxicity was evaluated in Madin–Darby Canine Kidney (MDCK) cells using the MTT assay. Results: All formulations exhibited homogeneous semisolid structure and physiologically acceptable pH values (4.94–5.45). Rheological analysis demonstrated non-Newtonian pseudoplastic (shear-thinning) behavior. The flow behavior index (n) ranged from 0.03 to 0.33 according to the Ostwald–de Waele model, confirming shear-thinning characteristics, while viscosity increased with increasing D/PVA/I concentration. UV–visible spectroscopy confirmed the presence of triiodide ions (I₃⁻), characterized by absorption maxima at approximately 287 and 350 nm, indicating preservation of active iodine species within the PEG matrix, while placebo (blank) formulation analysis confirmed the absence of corresponding absorption bands, demonstrating that the PEG-based matrix does not contribute to the characteristic spectral features. The formulations demonstrated broad-spectrum antimicrobial activity, with MBC values ranging from 0.01 to 0.02 µg/mL. Cytotoxicity studies revealed moderate toxicity of the D/PVA/I complex (CC₅₀ = 0.82%) (50% cytotoxic concentration (CC₅₀) and significantly lower toxicity of the PEG-based ointment base (CC₅₀ = 18.38%). Conclusions: The developed PEG-based hydrophilic ointment formulations containing the D/PVA/I complex demonstrated favorable physicochemical characteristics, stability of iodine species, pronounced antimicrobial activity, and acceptable cytotoxicity profiles. These findings highlight the potential for the developed systems to be promising topical antimicrobial formulations. Full article

Polymer coatings are integral to nearly every modern cardiovascular and endovascular device, including drug-eluting stents (DESs) and drug-coated balloons (DCBs), bioabsorbable vascular scaffolds (BVSs), occluders, grafts, and catheter and guidewire hydrophilic surfaces. Persistent complications, including late stent thrombosis, delayed endothelialization, hypersensitivity, and restenosis, show that coatings actively shape biological responses rather than acting as inert drug carriers. Their surface chemistry, drug release kinetics, and degradation behavior are upstream determinants of blood– and tissue–material responses that govern healing and failure. This review frames coating selection as a structure–property–biological response problem. It surveys the major classes of synthetic polymer coatings and the defining surface and bulk properties. This review also examines how composition and architecture control drug release, and traces the interfacial cascade of protein adsorption, coagulation and complement activation, platelet and leukocyte responses, and neutrophil extracellular trap (NET) formation. These mechanisms are linked to contemporary design strategies that improve hemocompatibility, limit thrombosis, promote endothelial recovery, and tune degradation, and to the standardization and translation gaps that remain. The central message is that polymer coatings are not biologically equivalent. Their surface chemistries and degradation profiles determine the thrombo-inflammatory outcomes. Therefore, coating design should be guided by intended biological response, not drug release alone. Full article

With the rapid advancement of portable wearable electronics, flexible supercapacitors have ushered in new development opportunities. In recent years, MXene and its composites have demonstrated potential as advanced supercapacitor electrode materials due to their outstanding theoretical capacitance, specific surface area, conductivity, hydrophilicity, and mechanical flexibility. This review traces the development of MXene and summarizes common synthesis strategies, with a focus on the effects of different preparation methods on its structure and properties. Departing from previously reported work, this review draws from the practical requirements of flexible supercapacitors to conduct an in-depth analysis of the key factors influencing the charge storage, rate capability, cycling life, and mechanical flexibility of the devices. It summarizes common design strategies for MXene composites currently used to enhance device performance. Additionally, this study analyzes key challenges facing MXene-based electrode materials, including issues such as self-stacking of layers, insufficient oxidation stability, limited energy density, and structural degradation under complex deformation conditions. Mitigation strategies are summarized, including optimizing synthesis methods and constructing composite systems integrating carbon materials, conducting polymers, and transition metal compounds. Finally, future research directions for MXene in flexible energy storage are explored, emphasizing the need to achieve a balance between performance and manufacturability through synergistic regulation at structural design, interfacial engineering, and device levels. This review aims to provide theoretical guidance for the development of practical MXene-based wearable energy storage devices. Full article

The amniotic membrane is widely recognized in regenerative medicine due to its rich content of extracellular matrix proteins and growth factors that confer anti-inflammatory and pro-regenerative properties. However, its rapid degradation restricts its standalone clinical use. To overcome these limitations, we developed biofilms by incorporating decellularized human amniotic membrane matrix (dHAM) into polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) matrices using spin-coating. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were used to evaluate film biocompatibility through cell viability, proliferation, and wound healing migration assays. Surface characterization was performed using contact angle measurements, Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, and scanning electron microscopy. Soluble dHAM extracts (4–6 mg/mL) significantly enhanced BM-MSC proliferation at 48 h compared to controls (p ≤ 0.01 and p ≤ 0.0001). Both PCL-dHAM and PVP-dHAM biofilms exhibited high cell viability (>90%) and improved initial adhesion. Notably, dHAM incorporation significantly increased wound closure rates at 24 h, reaching 98.47% for PCL-dHAM and 93.13% for PVP-dHAM, compared to 76.56% and 64.20% for pure polymers (p = 0.0001). All scaffolds maintained hydrophilic surfaces (<90°), favorable for cell interaction. The integration of dHAM into PCL and PVP by spin-coating produces biofilms biocompatible with enhanced regenerative potential, representing promising candidates for wound healing applications. In conclusion, these coatings support BM-MSC adhesion, proliferation, and migration, while significantly accelerating wound closure, underscoring their value as advanced bioactive coatings for regenerative medicine. Full article

Background: Polymeric drug-eluting films are promising platforms for local antibacterial delivery, but their release profiles depend strongly on the permeability and morphology of the barrier layer. Here, the previously proposed concept of additively manufactured PLACE (Printed Layered Adjustable Cargo Encapsulation) coatings was extended from "single orifice"-defined release toward porosity-assisted barrier control. Two conventional water-soluble porogens, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP), were compared with poly(2-ethyl-2-oxazoline) (PEOx), a hydrophilic polymer proposed as an alternative to PEG in biomedical formulations, but whose use as a leachable porogen has received little attention. Methods: Each porogen was introduced into the upper PLGA barrier of multilayer PLACE films. The resulting films were characterized for film formation, post-hydration morphology by SEM, release of methylene blue and vancomycin, and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Results/Conclusions: PEG was poorly compatible with PLGA and mainly produced surface-localized defects rather than a barrier with controlled permeability suitable for prolonged delivery. PVP K17 provided sustained release at 10 wt.%, whereas 20 wt.% PVP caused burst-dominated release and stronger morphological disruption. PEOx formed developed porosity at lower loading and produced release regimes ranging from several days to approximately two weeks. Vancomycin-loaded films containing 5 wt.% PEOx enabled near-complete release over two weeks while preserving film integrity and showed pronounced early anti-MRSA activity. These results identify porogen selection as a key formulation step and support PEOx as a useful porogen for early high-output antibacterial PLACE coatings. Full article

The sustainable recovery of high-value metals from wastewater has garnered significant attention in light of the circular economy and environmental preservation. Because of its appealing characteristics, membrane separation technology is essential for the sustainable and effective recovery of valuable metals from wastewater, in contrast to conventional methods, which are chemical- or energy-intensive. In this study, a rational design approach was utilized to synthesize a metal–organic framework (MOF) using a deep eutectic solvent (DES) as a mediating medium to control the reaction of framework formation and particle properties. While DESs have been widely used for the physical modification of materials, their role as a chemically modifying medium during MOF synthesis for structural tailoring remains less explored. This synthesized MOF (DM-Zn-PDC@MOF) was further introduced as filler in polysulfone (PSf)-based mixed matrix membranes (MMMs). The performance of DM-Zn-PDC@MOF within the polymer matrix was examined. Several characterization techniques were used to thoroughly analyze the morphological, chemical, and physical characteristics of the MMMs and DM-Zn-PDC@MOF. The addition of the filler material significantly enhanced the membrane characteristics, including pure water flux, hydrophilicity, porosity, surface roughness, pore size, and heavy metal resource recovery in comparison with the pristine membrane. Stable incorporation of the filler within the membrane matrix was indicated by much less filler leaching (<5%) at all concentrations. With DM-Zn-PDC@MOF loading, the pure water flux increasedmore than nine times from 102.8 L/m²h (M-0) to 971.5 L/m²h (M-4). The functionalized membranes showed better flux retention in high-value heavy metal resource recovery using simulated wastewater: 871.8 L/m²h when filtering a Pb(II) ion solution (compared to M-0 with flux 120.6 L/m²h) and 526.8 L/m²h when filtering a Cr(III) ion solution (compared to M-0 with flux 97.1 L/m²h). These values represented approximately 7-fold and 5-fold improvements, respectively. Overall, Pb⁺² > Cr⁺³, but the rejection of Cr(III) ions was also improved, when compared with M-0. The high flux of the membrane makes it easier to process large volumes and concentrate metals in the retentate, turning diluted contaminated streams into a concentrated feedstock for subsequent recovery procedures. Full article

To address the global water crisis, desalination technologies contribute about 1% of the global freshwater supply. Membrane-based desalination technologies offer high performance, operational ease, cost-effectiveness and high scalability compared to conventional thermal desalination modes. Among all membrane-based technologies, reverse osmosis is prevailing globally. However, the high energy demand of the reverse osmosis process and fouling in case of hypersaline feed streams motivate the exploration of alternative technologies, i.e., pervaporation. Pervaporation desalination involves dense hydrophilic polymer membranes to deal with high salt streams at low cost, along with less fouling than a few other membrane processes, i.e., reverse osmosis and membrane distillation. Mass transport through pervaporation desalination membranes is well-explained by solution-diffusion theory involving a tri-stage transfer, i.e., sorption, diffusion and evaporation. Since the last few decades, a green approach in all domains has offered chemical products and processes with the least hazards and minimal waste production. Application of biodegradable materials like poly(lactic acid) in combination with suitable green solvents, e.g., ethyl lactate, methyl lactate, cyrene, dimethyl isosorbide and gamma valerolactone for pervaporation desalination would be a good roadmap to meet the sustainability criterion. Some intrinsic features of poly(lactic acid) that make it a ‘material of choice’ for pervaporation desalination include hydrophilicity imparted by the presence of polar ester groups, high salt rejection, biodegradability with simple mineralization products, i.e., H₂O and CO₂, sustainable production, low toxicity, low carbon footprint, ease of processing and versatility. Poly(lactic acid) undergoes four interrelated degradation mechanisms: hydrolytic degradation, biodegradation, thermal degradation and photodegradation. The concern for poly(lactic acid) based pervaporation desalination is increased hydrolytic cleavage of poly(lactic acid) at high temperatures, which requires some modifications, e.g., nanoenhancement, additions of crosslinkers, surface modifications, addition of other polymers to prepare blends and post-treatments. These modifying strategies result in an increased stability and better performance of poly(lactic acid) films. However, optimization of various parameters relevant to such modifications leaves room for further research. This review offers a critical analysis of the need for biodegradable polymers with special focus on poly(lactic acid) rather than their fossil fuel-based alternatives, the environmental and health effects of all these polymers, cost estimation and possible performance-efficient, green and eco-friendly solutions. Full article

Due to the environmental concerns associated with petroleum-based plastics, industry and academia have directed increasing attention toward marine-derived biodegradable biopolymers, particularly those obtained from seaweed. In line with global efforts to enhance resource efficiency and sustainability by introducing non-fossil raw materials into the circular economy, seaweed valorization has emerged as a promising pathway. Seaweeds are attractive feedstocks due to their biodegradability, non-toxicity, antioxidant activity, and excellent film-forming capacity. This review provides a critical and application-oriented overview of seaweed biomass for food packaging applications by comparatively discussing the relationship between seaweed composition, extraction technologies, material functionality, packaging performance, and regulatory considerations. Emphasis is placed on the role of structural biopolymers and bioactive compounds in the development of passive, active, and intelligent packaging systems. Recent advances in extraction technologies, polymer modification strategies, and incorporation of functional additives are critically discussed in relation to their influence on the physicochemical, mechanical, barrier, antioxidant, and antimicrobial properties of seaweed-based composites. Furthermore, the review highlights key challenges limiting industrial implementation, including high hydrophilicity, high variability between the batches, energy-intensive drying processes, regulatory compliance, migration safety, and long-term material stability. Overall, seaweed-derived materials demonstrate strong potential as sustainable alternatives to conventional packaging systems, particularly in food applications. However, further optimization of processing technologies, material standardization, techno-economic feasibility, and end-of-life management are still required before large-scale commercialization can be achieved. Full article

We report di- and triblock copolymers that combine hydrophilic polyethers—poly(ethylene glycol) monomethyl ether (mPEG) and polyglycidol (PGl)—with a hydrophobic, degradable polyester, poly(β-butyrolactone) (P(β-BL)). A mild hydrolysis method was developed to selectively remove acetal protecting groups from poly(ethoxy ethyl glycidyl ether) (PEEGE) without cleaving the β-butyrolactone polyester backbone, enabling the preparation of PGl-b-P(β-BL) and mPEG-b-PGl-b-P(β-BL) block copolymers. Thermal analysis revealed that the glass transition temperatures (T_g) of the copolymers could be tuned by varying block composition and length. Diblock copolymers containing the PGl segment were amorphous, with T_g values ranging from −2.7 to −19.9 °C. The presence of an mPEG segment in the triblock copolymers resulted in a further decrease in T_g, reaching values between −32.3 and −38.9 °C. Solubility and water affinity studies demonstrated that incorporation of hydrophilic polyether blocks enhances copolymer–solvent interactions, leading to increased wettability of the polymer-coated surface. The water contact angle for films formed from PGl-b-P(β-BL) decreased to 53 °C, while for mPEG-b-PGl-b-P(β-BL) copolymers, it was further reduced to 43 °C compared with the hydrophobic P(β-BL) film. Hydrolytic degradation experiments showed accelerated cleavage of the P(β-BL) segment in copolymers containing hydrophilic blocks compared to the P(β-BL) homopolymer, which is attributed to increased water accessibility and surface hydrophilicity. The most pronounced decrease in molar mass, reaching at least 50% relative to the initial non-degraded sample, was observed for the diblock copolymers, whereas the P(β-BL) sample showed only a marginal weight reduction of a few percent. Overall, this study demonstrates that the combination of hydrophilic mPEG and PGl blocks with P(β-BL) enables the design of block copolymers with tunable thermal properties, solubility, and degradation behavior, offering potential for a wide range of applications. Full article

Advances in polysaccharide-based polymer matrices have expanded the possibilities for developing controlled-release systems for bioactive compounds. This study evaluated the effect of incorporating maltodextrin (0, 1, 3, and 5% w/w) into films composed of thermoplastic starch (5%) and chitosan (2%) was evaluated with the aim of improving their structural, thermal, mechanical, and surface properties. The films were obtained by solvent casting and characterized by XRD, TGA-DSC, FTIR, SEM, contact angle, and mechanical analysis. X-ray diffraction revealed greater organization in sample TPS-CH-M3 compared with TPS-CH-M0 (23,316.7) and TPS-CH-M5 (18,941.4), indicating a balanced semicrystalline structure. Thermal analyses showed an increase in the glass transition temperature from 63.0 °C to 72.6 °C and a shift in the main degradation step from 308 °C to 311 °C, indicating greater thermal stability. The contact angle decreased from 89.5° to 74°, confirming increased hydrophilicity. SEM micrographs revealed a homogeneous surface in TPS-CH-M0 and controlled roughness in TPS-CH-M3. Mechanical tests recorded the highest tensile strength (12.5 MPa) and elongation (18%) for TPS-CH-M3. FTIR spectra revealed physical interactions without the formation of new chemical bands, while colorimetry showed an increase in yellow hue, suggesting potential applications related to photosensitive materials. Overall, the incorporation of 3% maltodextrin optimized the functional properties of the matrices for potential controlled-release applications. Full article

The functionality of ionomeric membranes is influenced by small changes of several parameters. Aqueous network formation by phase separation between the hydrophilic and hydrophobic parts of the polymer is one critical factor for water and ion transport. In particular, the transport of highly charged ions like ${\mathrm{V}}^{3+}$ is not well understood. The unsteady diffusion in Nafion, a sulfonic acid based cation exchange polymer, using ${\mathrm{V}}^{3+}$ profiles obtained with micro X-ray fluorescence ($0.5 \mathsf{\mu }$m spot over a $180 \mathsf{\mu }$m scan) yields a diffusion coefficient of $4\times {10}^{-13} {\mathrm{m}}^2{\mathrm{s}}^{-1}$ at ${\lambda }_{H_{2}O/S{O}_3}=12$ and at ca. $20 °$C. It is confirmed that the concentration profile can be described by an error function formalism. The diffusivity, determined from the entire profile, represents mainly the transport into a vanadium free environment with very low ionic strength as the membrane was conditioned in ultra-pure water. The macroscopic ion transport is influenced by local molecular interactions, interconnection of water pockets and long range ionic interactions. The local interactions of ${\mathrm{V}}^{3+}$ were studied using molecular dynamics (MDs) simulations. The MD simulation studies diffusion at a constant ion concentration and short length scale (ca. 30 nm). It gives insights on the effects of dissolved ${\mathrm{V}}^{3+}$ ions on the local structure. Radial distribution functions reveal that at low hydration, the vanadium ions have an ordering effect on water molecules. The diffusion coefficient of ${\mathrm{V}}^{3+}$ is determined on a molecular level from the mean-square displacement yielding $2.5\times {10}^{-10} {\mathrm{m}}^2{\mathrm{s}}^{-1}$ for ${\mathrm{V}}^{3+}$ ions at a membrane water content of ${\lambda }_{H_{2}O/S{O}_3}$ = 6. The phenomenon in which the diffusivity decreases over longer length scales was documented before for water and ${\mathrm{H}}^{+}$ in Nafion; however, this was by only about one order of magnitude. The experimental microscopic approach described by us is universally applicable, e.g., to environments of higher ionic strength, ions with different charges, and different types of ion-exchange membranes. Longer diffusion times allow us to distinguish between different concentration regimes. Full article

In this study, a functional surface coating composed of Fe-Mn binary oxide (FM) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS, PP) was applied to a PVDF membrane (PP-FM-PVDF) for efficient arsenate (As(V)) removal. PP acts as a dispersant and hydrophilic modifier, ensuring uniform FM distribution and reducing the water contact angle to 50.1°. The PP-FM-PVDF membrane achieves a maximum As(V) adsorption capacity of 30.43 mg/g, outperforming pristine and singly modified membranes. The batch adsorption data fit the Langmuir isotherm (R² = 0.999) and pseudo-second-order kinetic model (R² = 0.99), indicating monolayer chemisorption. The coating increases the specific surface area to 27.33 m²/g and the tensile strength to 6.41 MPa. Dynamic filtration shows that 2.70 L (2149.7 L/m²) of 100 μg/L As(V) solution can be treated before the permeate concentration exceeds the WHO guideline of 10 μg/L. After alkaline regeneration (pH 11), 62.9% of the initial capacity is retained. Complementary surface-sensitive analyses (zeta potential, XPS, and EXAFS) reveal that arsenate adsorption occurs primarily through ligand exchange between arsenate oxyanions and Fe/Mn surface hydroxyl groups on the coating, forming inner-sphere bidentate complexes (Fe–O–As and Mn–O–As), while electrostatic interactions play a secondary, pH-dependent role. This surface engineering strategy—synergistically integrating a conductive hydrophilic polymer with a metal oxide as a functional coating on PVDF—offers a reusable, high-performance platform for arsenate remediation, underscoring the critical role of interface design in environmental membrane applications. Full article

We present an optimized method for producing semiconducting polymer dots using a water–ethanol mixed antisolvent during nanoprecipitation. Compared to conventional Pdots made with pure water as the antisolvent, these newly produced Pdots exhibit simultaneously enhanced fluorescence efficiency and stability of particle size and emission spectra. These findings should be mainly attributed to an improved core–shell Pdots nanostructure formed by a sequential nanoprecipitation process. It offers Pdots a purer, more compact, and hydrophobic inner core, coated with a greater number of hydrophilic polyethylene glycol shells. This viewpoint is further reinforced by Förster energy-transfer efficiency in a fluorescence donor-acceptor Pdots system. The novelly prepared Pdots can better encapsulate small-molecular cargoes and more efficiently bioconjugate to targets. Consequently, it demonstrates improved specific immunofluorescence staining of microtubule structures in living cells. Full article

Biochar, a carbon-rich material derived from biomass pyrolysis, offers a promising pathway for valorising agricultural and industrial residues within a circular economy. This review analyses the evolution of biochar properties, including fixed carbon content, elemental composition, surface functional groups, porosity, pH, hydrophobicity, and thermal stability, as a function of pyrolysis temperature. The novelty of this work lies in the systematic correlation between the thermal history of biochar and its performance as a functional filler in polymer composites. In fact, increasing temperature enhances carbonisation and aromatic ordering, and in turn induces a transition from hydrophilic to hydrophobic behaviour, thereby promoting micro–mesoporous development. These shifts are critical for compatibility with polymer matrices and thus the production of light-weight, cost-effective, and environmentally friendly composite materials through processes such as melt extrusion and injection moulding. This study highlights how biochar can be tuned for compatibility: low-temperature biochar enhances adhesion in polar systems, while high-temperature biochar favours non-polar matrices, improving stiffness, thermal stability, and electrical conductivity. In biodegradable polymer composites, additional effects on crystallisation behaviour and degradation mechanisms emerge, further highlighting the complexity of designing biochar-reinforced systems. Full article

Efficient separation of Cu–Mo sulfide minerals from moraine materials remains a major challenge for low-grade, high-moraine Cu–Mo ores. Fine-grained muscovite induces severe slime coating and gangue entrainment, thereby markedly reducing flotation selectivity. In this work, a biodegradable polymer depressant, polyaspartic acid (PASP), was employed to regulate Cu–Mo sulfide flotation under muscovite interference conditions. Microflotation tests, particle size distribution analysis, zeta potential measurements, SEM-EDS observations, contact angle measurements, and XPS analyses were conducted to clarify the dispersion behavior, slime-coating mechanism, and selective adsorption characteristics of PASP. The results demonstrated that PASP selectively depressed muscovite at relatively low dosages while exerting negligible influence on the floatability of chalcopyrite and molybdenite. Notably, at a dosage of 15 mg/L, PASP reduced muscovite recovery by 43.07% and 31.23% more effectively than sodium silicate and sodium hexametaphosphate, respectively, demonstrating superior selective depression efficiency under moraine interference conditions. Particle size distribution and zeta potential analyses confirmed that PASP effectively weakened heterocoagulation and electrostatic attraction between muscovite and sulfide minerals, thereby suppressing slime coating and improving slurry dispersion stability. SEM-EDS and contact angle analyses further revealed that PASP significantly reduced muscovite deposition on sulfide mineral surfaces while maintaining the hydrophobicity of chalcopyrite and molybdenite. High-resolution XPS analysis further indicated that PASP adsorbed onto muscovite mainly through coordination between carboxylate groups and surface Al–OH sites, forming a stable hydrophilic adsorption layer. Overall, PASP provides a low-dosage, highly selective, and biodegradable depressant strategy for mitigating muscovite-induced slime coating and improving the flotation separation of Cu–Mo sulfide ores under moraine interference conditions. Full article