Search Results (302)

Hydrophobic nanofiber membranes derived from the biopolymer alginate were fabricated by electrospinning followed by metal ion crosslinking, and their potential as oil-water separation membranes was primarily investigated. Sodium alginate (SA) was co-electrospun with polyethylene glycol and subsequently crosslinked using calcium chloride and group IV metal ions (zirconium or titanium). Metal ion crosslinking changed the surface wettability of the nanofiber membranes, as confirmed by water contact angle measurements. Both zirconium- and titanium-crosslinked SA nanofiber membranes exhibited effective gravity-driven oil–water separation with complete water blocking. Although hydrophobic modification reduced direct water affinity, the resulting membranes retained residual adsorption capability toward methylene blue, indicating the presence of accessible internal polar sites. The adsorption behavior varied depending on the crosslinking ion. In addition, titanium-crosslinked membranes showed an auxiliary UV-assisted dye removal contribution under irradiation, arising from photoactive Ti species. These findings demonstrate that metal ion crosslinking provides a practical route for tuning the functional properties of alginate nanofiber membranes, with oil-water separation as the primary application and dye adsorption/photocatalysis as secondary functionalities. Full article

Bone regeneration remains a clinical challenge, particularly in critical-size defects, motivating the investigation of biomaterials and adjuvant therapies that may support tissue repair. This experimental study evaluated bone healing in critical-size calvarial defects created in rats, using different combinations of regenerative strategies, including heterologous fibrin biopolymer gel, bovine cortical bone biological membrane, and photobiomodulation. Standardized 5.0 mm calvarial defects were surgically created in sixty Wistar rats, which were randomly allocated into six experimental groups according to the filling material and the application or absence of photobiomodulation. The treatments included clot alone, fibrin biopolymer gel, biological membrane, photobiomodulation, or their respective combinations. Animals were euthanized at 14 or 42 days, and bone repair was evaluated by histomorphometric analysis. At 14 days, differences in the extent of newly formed bone were observed among the experimental groups, with higher bone formation values detected in groups receiving combined treatments and lower values in groups treated with fewer regenerative components. At 42 days, all groups showed progression of bone repair, with greater bone formation observed in groups in which a biological membrane was used, regardless of photobiomodulation. Overall, the findings indicate that the association of different regenerative approaches was related to variations in bone repair patterns over time, suggesting that photobiomodulation, when applied in combination with biomaterials, may be associated with differences in early bone healing, without implying a direct causal effect. Full article

Polymeric membranes based on chitosan (Cs) were extracted from shrimp shells and evaluated. These membranes were modified using polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and glycerol (Gly) and crosslinked with glutaraldehyde (GA) to examine their suitability for water filtration processes. The Cs exhibited high purity, a total nitrogen content of 6.49%, and an average molecular weight of 456 kDa, all of which are suitable for membrane formation. Four membranes (Cs-GA, B2: Cs-PEG, B5: Cs-PEG-PVP, and B7: Cs-Gly) were characterized by means of FTIR, SEM, AFM, thickness, contact angle, tensile testing, TGA, DSC, and filtration with distilled water at 4.83 bar. B2 and B5 showed thicknesses of 207 and 190 μm and contact angles of 56.7° and 58.9°, lower than that of Cs-GA (89.4°). In filtration, B2 achieved a flux of 2222.70 LMH, a permeance of 460.19 LMH·bar⁻¹, and a hydraulic resistance of 8.79 × 10¹¹ m⁻¹, while Cs-GA, B5, and B7 exhibited fluxes of 24.10, 40.43, and 24.77 LMH, respectively, permeances of 9.75, 8.37, and 5.13 LMH·bar⁻¹, and hydraulic resistances of 4.15 × 10¹³, 4.83 × 10¹³, and 7.89 × 10¹³ m⁻¹, in the same order. Overall, membranes B2 and B5 are recognized as the most promising for water filtration under pressured operating conditions. Full article

Microbial fuel cells (MFCs) offer a sustainable solution for energy generation and wastewater treatment, yet their scalability is hindered by reliance on expensive and non-renewable synthetic membranes. This study addresses the critical need for eco-friendly alternatives by conducting a bibliometric analysis of biopolymers used in MFC membrane development. Using data from Scopus and Web of Science (2012–2025), we applied quantitative and network-based methods to evaluate publication trends, collaboration patterns, and thematic evolution. The analysis identified chitosan, alginate, and cellulose as the most studied biopolymers due to their favorable proton conductivity, biodegradability, and potential for waste-derived production. Key findings include a surge in research output post-2018, strong interdisciplinary collaboration across materials science and microbiology, and emerging interest in nanomaterial integration and 3D printing for membrane enhancement. Despite promising advances, challenges persist with regard to the mechanical stability and standardization of fabrication methods. This study provides a strategic overview of the field, highlighting scientific progress and guiding future research toward scalable, high-performance biopolymer membranes for MFCs applications. Full article

Sustainable membranes for efficient separation processes are increasingly necessary to counteract the significant environmental and human health impacts of manufacturing conventional membranes, which rely on synthetic polymers, toxic solvents, and harmful additives. A greener approach currently involves the use of bio-based polymers, blending synthetic polymers with biopolymers, utilizing nanocomposites, and greener solvents. Biopolymers are emerging as an environmentally friendly alternative for developing polymeric membranes due to their biological, biodegradable, recyclable, and biocompatible properties. However, the development of sustainable biopolymer-based membranes poses greater challenges to achieving a truly low environmental impact across all aspects of raw material production, manufacturing methods, operational systems, and waste disposal. Another challenge for its market competitiveness is achieving high functional and operational performance, wider applications, low commercial costs, and strong scale-up potential. This critical review assesses the current state of sustainability in membrane manufacturing based on recent literature. It also evaluates the role of biopolymers in sustainable membranes and discusses research opportunities in biopolymer production for membrane manufacturing, highlighting biotechnological tools, the circular economy and waste valorization. Full article

Triarylmethyl radicals (TAMs) have recently emerged as highly effective polarizing agents in dynamic nuclear polarization (DNP) under viscous conditions, enabling substantial hyperpolarization via the solid-effect (SE) DNP mechanism even at room temperature. A comparable, though less pronounced, enhancement was observed for BDPA radicals embedded in phosphocholine-based lipid bilayers. Given the increasing interest in elucidating the structure and dynamics of biopolymers and their high-molecular-weight assemblies—such as cell membranes—this study focuses on the design, synthesis, and characterization of paramagnetic agents tailored for DNP-based structural biology. To this end, we synthesized a series of TAM derivatives functionalized with lipophilic substituents and characterized their magnetic resonance properties, including isotropic hyperfine interaction (HFI) constants on carbon nuclei and electron spin relaxation times (T₁ and T_m) at low temperatures (80 K). Echo-detected EPR spectra and electron spin echo envelope modulations (ESEEM) were recorded for novel TAM incorporated into liposomes composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). These low-temperature measurements revealed that the radicals are localized either at the liposome surface or within the lipid bilayer, ensuring optimal accessibility to water molecules. Crucially, the presence of a single cholesterol moiety provides strong noncovalent anchoring within the hydrophobic core of the bilayer. Guided by these findings, we identify an amphiphilic TAM bearing a single cholesterol group and polar carboxyl functionalities as a highly promising candidate for DNP applications in membrane biology, combining efficient polarization transfer, bilayer integration, and aqueous accessibility. Full article

This article provides a comparative analysis of sustainable polymer membranes based on biopolymers and Nafion in the context of proton exchange membrane (PEM) for water electrolyzers. Nafion, a perfluorinated polymer, has been a standard choice for PEM applications due to its excellent proton conductivity and chemical stability. However, the sustainability challenges associated with its production, lifecycle and cost necessitate the exploration of alternative materials that may offer comparable performance while being environmentally friendly. The most promising alternative polymer for PEM electrolyzers appears to be cellulose with good thermal stability at 200 °C and a water absorption of 35%, which is slightly higher compared to Nafion membranes with a water absorption value of around 30%. Sustainable PEMs also have much lower hydrogen permeability, e.g., chitosan has been determined to have a permeability of 7 barrers, while Nafion is characterized by a value of more than 100 barrers. The biggest drawbacks of sustainable membranes are proton conductivity and durability, where Nafion membranes are still superior. This review also focuses on mechanical properties, chemical resistance, preparation methods and cost-effectiveness. Sustainable polymers show promising properties for supporting efficient hydrogen production, especially in dynamic operating environments facilitated by renewable energy sources. Full article

Treatment of polymeric solid waste, such as used membranes, is vital for environmental sustainability. Cellulose-based membranes are widely utilized in the water industry due to their resistance to biodegradation. These non-biodegradable membranes can persist in landfills and aquatic environments for extended periods. Our study assessed the biodegradation potential of Trametes versicolor on a newly fabricated cellulose acetate (CA) membrane and a commercially produced membrane under various conditions, including oxidative stress. Additionally, we employed T. versicolor encapsulated in a small bioreactor platform (SBP) for media inoculation and biomass augmentation. Treatment of the commercially produced CA membrane within a timeframe of 30 days was unsuccessful. This was primarily attributed to the structural stability of the membrane over time and the limited ability of the culture to attach to the membrane surface. These results underscore the necessity of exploring alternative biopolymer cellulose-based materials for ultrafiltration (UF) and microfiltration (MF) membrane applications. The custom-made UF membrane, treated by ozonation as a pretreatment, emerged as an effective approach for enhancing biodegradation. Combining these factors, we expect to achieve over 27.75 ± 1.5% weight loss in membrane solids by 30 days of treatment. This study represents the first inquiry into the biodegradation capabilities of T. versicolor on CA-based membranes. Full article

The incorporation of bioactive natural compounds into biomedical applications offers a promising route to enhance therapeutic efficacy while supporting sustainability. In this study, we investigated the synergistic potential of Sericin, a silk-derived biopolymer, and Chelidonium majus L. (C. majus), a medicinal plant with a diverse phenolic profile, in relation to biological activities relevant for wound care and infection control. A combined experimental strategy was applied, integrating detailed chemical characterization of C. majus extracts with antimicrobial and cytocompatibility assays across different Sericin–plant extract ratios (1:1, 1:2, 2:2, and 2:1). Phytochemical analysis identified and quantified 57 phenolic compounds, including high levels of flavonoids (quercetin, kaempferol, isorhamnetin) and phenolic acids (caffeic and ferulic acid). Salicylic acid (123.6 µg/g), feruloyltyramine (111.8 µg/g), and pinocembrin (98.4 µg/g) were particularly abundant, compounds previously reported to disrupt microbial membranes and impair bacterial viability. These metabolites correlated with the strong antimicrobial activity of C. majus against Gram-positive strains (MIC = 5–10 mg/mL). In combination with Sericin, antimicrobial performance was ratio-dependent, with higher proportions of C. majus (2:1) retaining partial inhibitory effects. Cytocompatibility assays with HFF1 fibroblasts demonstrated low antiproliferative activity across most formulations (GI₅₀ > 400 µg/mL), supporting their potential safety in topical applications. Collectively, the results indicate a concentration-dependent interaction between C. majus phenolics and the Sericin protein matrix, reinforcing their suitability as candidates for natural-based wound healing materials. Importantly, the valorization of Sericin, an underutilized byproduct of the silk industry, together with a widely accessible medicinal plant, underscores the ecological and economic sustainability of this approach. Overall, this work supports the exploration of the development of biomaterials with potential for advancing tissue repair and wound management. Full article

Lignin is one of the most abundant natural biopolymers and plays a crucial role in the development of safe and sustainable alternatives for healthcare products. In this study, we employed molecular dynamics simulations and free energy calculations to investigate lignin derivatives’ interactions with skin-like membranes. Specifically, we designed a small lignin derivative composed of syringyl and guaiacyl subunits. Our results reveal that molecular size, concentration, and thermal conditions critically influence the insertion, interaction dynamics, and localization behavior of lignin derivatives. Notably, variations in these parameters induce distinct behaviors, including rapid membrane insertion, hydrogen bonding, clustering, and surface adhesion. The findings provide insights into the molecular mechanisms governing lignin derivatives’ interactions with skin-like membranes, with implications for developing bio-based skincare formulations and transdermal delivery systems. Our results highlight the importance of molecular size and concentration in optimizing lignin-derived compounds for dermatological and therapeutic applications. Full article

Chitosan, a naturally abundant and biodegradable biopolymer derived from chitin found in crustacean shells, has emerged as a promising material for addressing environmental challenges. Its reactive amino and hydroxyl groups enable diverse interaction mechanisms. This makes it effective for removing heavy metals, dyes, pharmaceuticals, and other contaminants from water. However, the limitations of native chitosan, such as poor solubility and mechanical strength, necessitate strategic modifications. This review comprehensively examines recent advances in chitosan derivatives and composites. It focuses on modern modification strategies, such as chemical, physical, and composite formation, that enhance stability, selectivity, and efficiency. It explores the design principles of high-performance composites. It also details the multifaceted mechanisms of pollutant removal, including adsorption, catalysis, membrane filtration, and flocculation. Critical practical challenges are critically assessed. These include scalability, regeneration, lifecycle sustainability, and real-world implementation. Furthermore, emerging trends are highlighted. These integrate circular economy principles, seafood waste valorization, and digital optimization through the use of artificial intelligence. By consolidating current knowledge, this review aims to bridge the gap between laboratory innovations and large-scale environmental applications. It guides the development of intelligent, scalable, and ecologically responsible solutions based on this remarkable biopolymer. Full article

Chitosan biopolymer membranes reinforced with channel-selective ZIF-8 nanofillers were developed and thoroughly characterized as separators for bioelectrochemical systems. This study explores the synergistic effect of incorporating ZIF-8 into a chitosan matrix to enhance membrane performance. Key properties including water retention, chemical and thermal stability, surface resistance, antifouling capacity, and ionic conductivity were evaluated and benchmarked against commercial Nafion-117 and nanofiltration (NF) membranes. The ZIF-8/chitosan composite membranes (ZIF-8/CS) demonstrated excellent water retention and structural stability under harsh conditions, along with significantly reduced surface resistance and effective rejection of organic contaminants and salts (NaCl, Na₂SO₄). Notably, the composite ZIF-8/CS membranes achieved an ionic conductivity of 0.099 S/cm, approaching the value of Nafion-117 (0.13 S/cm) and substantially surpassing that of the NF membrane (0.013 S/cm). These results indicate that ZIF-8-reinforced chitosan membranes present a promising, sustainable, and cost-effective alternative to traditional separators in bioelectrochemical applications. Full article

Bacterial cellulose (BC) is a high-purity biopolymer with excellent physicochemical and mechanical properties, including high crystallinity, water absorption, biocompatibility, and structural tunability. However, its large-scale production is hindered by high substrate costs and limited sustainability. In this study, spent black tea waste was utilized as a low-cost and eco-friendly carbon source for BC synthesis by Komagataeibacter xylinus ATCC 53524 under varying initial pH conditions (4–9). Six different BC membranes were produced and systematically characterized in terms of mechanical strength, water absorption capacity, electrical conductivity, antimicrobial performance, and polyvinyl alcohol (PVA) attachment efficiency. Morphological and chemical analyses were conducted using SEM and FTIR techniques to investigate pH-induced structural variations. The results revealed that the BC6 sample (pH 6) exhibited the highest tensile strength (2.4 MPa), elongation (13%), PVA incorporation (12%), and electrical conductivity, confirming the positive impact of near-neutral conditions on nanofiber assembly and functional integration. In contrast, the BC4 sample (pH 4) demonstrated strong antimicrobial activity (log reduction = 3.5) against E. coli, suggesting that acidic pH conditions enhance bioactivity. SEM images confirmed the most cohesive and uniform fiber morphology at pH 6, while FTIR spectra indicated the preservation of characteristic cellulose functional groups across all samples. Overall, this study presents a sustainable and efficient strategy for BC production using food waste and demonstrates that synthesis pH is a key parameter in tuning its functional performance. The optimized BC membranes show potential for biomedical, flexible electronic, and antibacterial material applications, particularly in wearable electrode technologies. Full article

Chitosan is a natural polymer derived from chitin through the deacetylation process. It has emerged as a key ingredient in sustainable wastewater treatment, due to its biodegradability, non-toxicity, and low cost. This biopolymer possesses abundant functional groups, such as -NH₂ and -OH, that efficiently interact with pollutants. This review offers a comprehensive evaluation of pollutant separation techniques involving chitosan-based materials, including adsorption, membrane filtration, flocculation, and photocatalysis. It further examines the underlying adsorption mechanisms, emphasizing how pollutants interact with chitosan and its derivatives at the molecular level. Special focus is given to various modifications of chitosan, alongside a comparative assessment of different chitosan-based adsorbents (hydrogels, nanoparticles, nanocomposites, microspheres, nanofibers, etc.), highlighting their performance in removing heavy metals, dyes, and emerging organic pollutants. The reviewed performance of these polymeric materials from 2015–2025 not only gives an insight about the recent advancement but also points the need for the design of high-performing chitosan-based adsorbents with applications in real water matrices. Full article

The growing threat of antimicrobial resistance drives the need for innovative and multifunctional therapeutic systems. In this study, a controlled-release system based on a bioactive film composed of gelatin, bacterial cellulose (BC), sericin, citric acid, PEG 400, and nisin was developed for topical applications in infected wound treatment. BC membranes were produced using Komagataeibacter xylinus and enzymatically treated to optimize dispersion within the polymer matrix. The resulting system exhibited a semi-rigid, homogeneous morphology with appropriate visual characteristics for dermatological use. Microbiological assays demonstrated significant antimicrobial activity against Gram-positive (Staphylococcus aureus) and resistant Gram-negative strains (Escherichia coli and Enterobacter cloacae), attributed to the synergistic action of nisin and citric acid, which enhanced bacterial outer membrane permeability. The antioxidant capacity was confirmed through DPPH radical scavenging assays, indicating a progressive release of bioactive compounds over time. Scanning electron microscopy (SEM) analyses revealed good integration of biopolymers within the matrix. These results suggest that the strategic combination of natural biopolymers and antimicrobial agents produced a functional system with improved mechanical properties, a broadened antimicrobial spectrum, and promising potential as a bioactive wound dressing for the treatment of infected skin lesions. Full article