Macromol

The construction sector is responsible for substantial energy consumption, greenhouse gas emissions, and resource depletion, driving the search for sustainable alternatives to conventional petroleum-based insulation materials. Lignocellulosic biomass, comprising cellulose, hemicellulose, and lignin, offers a renewable resource for the development of bio-based foams with potential application in construction systems. This review provides a comprehensive analysis of bio-based foams tailored to building applications, positioning recent scientific advances against the technical properties of commercial synthetic insulation foams. Key performance parameters, including density, thermal conductivity, compressive strength, dimensional stability, water vapour diffusion resistance, and fire behaviour, are critically examined. Developments in lignocellulosic-based foams are discussed, highlighting processing strategies such as crosslinking, chemical modification, and hybrid reinforcement to enhance mechanical, thermal, and fire performance. The reported results demonstrate that lignin-based polyurethane and phenolic foams can achieve competitive compressive strength and thermal insulation, while cellulose-based aerogels and foams exhibit ultra-low density and promising conductivity values. However, challenges related to moisture sensitivity, fire classification, process scalability, standardisation, and market integration remain significant. Overall, lignocellulosic foams represent a promising pathway toward decarbonised, circular construction systems, provided that technical optimisation and regulatory alignment are successfully achieved. Full article

In this work, an in situ UV-assisted photoreduction was used to functionalize silk fibroin films with silver nanoparticles in order to develop antibacterial devices for wound healing applications. The process showed high efficiency (~80%) in terms of reacted silver precursor. The effects of the silver treatment on fibroin macromolecule were evaluated in function of the process parameters in terms of chemical structure, thermal and mechanical properties, swelling behavior, resistance to degradation and antibacterial activity. Silver functionalization significantly improved the mechanical properties of the films, with Young’s modulus increasing from 0.23 ± 0.04 MPa (methanol-treated samples) to 7.26 ± 0.46 MPa (silver-functionalized samples). In parallel, a marked reduction in swelling degree was observed (from ~360–420% to ~60%), indicating enhanced structural stability. The treated films also exhibited improved resistance to degradation over 7 days under physiological conditions. From a functional perspective, the materials showed strong antibacterial activity, with up to 97–98% reduction in bacterial proliferation for Pseudomonas aeruginosa and Escherichia coli, and up to 93% for methicillin-resistant Staphylococcus aureus. Overall, the results demonstrate that silver functionalization process improves the structural stability of silk fibroin while conferring sustained antibacterial activity, thus supporting their potential application as antimicrobial dressings for the treatment of superficial and low-exudate wounds. Full article

This review analyzes the advances over a five-year period in the development of polymeric sorbents for the purification of aqueous media from key classes of pollutants: hydrocarbons (crude oil, diesel fuel), organic dyes, pharmaceuticals (antibiotics), pesticides, herbicides, volatile organic compounds, and polycyclic aromatic hydrocarbons. Attention is paid to the analysis of structure-property-performance relationships, with an emphasis on comparing materials derived from renewable natural feedstocks (such as cellulose, chitosan, terpenes, vegetable oils, and aloe vera) with synthetic polymers. The analysis reveals that biopolymer-based sorbents exhibit comparable or superior sorption capacities combined with environmental safety, biodegradability, and low cost. The key sorption mechanisms include physical adsorption, hydrophobic interactions, and electrostatic interactions. Despite persisting challenges related to scalability, stability in real-world environments, and the need for efficient regeneration protocols, a convergent approach that combines the advantages of modified natural polymers and functional synthetic components appears to be the most promising strategy for developing cost-effective and sustainable technologies for the restoration of water quality. Full article

Fibroin-based films represent a promising platform for sustainable and bio-derived materials. Existing literature has mainly focused on isolated molecules, plasticizers, or chemical cross-linkers, and the function of complex, multi-component natural extracts as structure-modulating agents in fibroin films remains poorly understood. In this study, edible films containing mulberry leaf extract (MLE; 2–8 wt%) and fibroin (8 wt%) were prepared by solution casting, and their structures were investigated using spectroscopic, morphological, thermal, mechanical, and barrier property analyses. The results reveal that MLE induces concentration-dependent changes in film performance through multicomponent, non-covalent interactions with the fibroin. An approximately 187% increase in tensile strength was achieved at high MLE concentration, confirming effective physical reinforcement. The water vapor transmission rate decreased markedly from 0.888 to 0.170 g·h⁻¹·m⁻², indicating an enhanced moisture barrier, whereas oxygen permeability increased at higher extract loadings, suggesting localized chain rearrangements. High optical transparency in the visible region was maintained (79.95–83.77%), while UV response was selectively altered with extract concentration. Overall, the 8MLE formulation exhibited the most balanced performance. This study demonstrates that plant-derived extracts can serve as effective natural modifiers for tailoring fibroin film properties without inducing crystallization, offering a sustainable strategy for designing bio-based and edible protein film systems. Full article

This study focuses on the development and characterization of advanced composite materials based on poly(ε-caprolactone) (PCL) and poly(vinylidene fluoride) (PVDF), with or without silver nanoparticles (AgNPs), planned for peripheral nerve or bone regeneration. The complementary properties of PCL (biocompatibility and biodegradability) and PVDF (mechanical stability and piezoelectric functionality) were exploited by blending the polymers in different ratios, resulting in binary (PCL/PVDF) and ternary (PCL/PVDF/AgNPs) composites. Green-synthesized AgNPs were integrated to enhance antimicrobial activity and to support tissue repair through improved signal transmission. Functional thin films and electrospun fibres were obtained and subjected to advanced characterization techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermal analysis. The results demonstrated appropriate morphology, chemical composition, structural stability, and favourable interactions with simulated physiological media. Preliminary biocompatibility assays confirmed good cell viability, supporting the biomedical applicability of the designed scaffolds. Overall, the obtained results highlight the potential of AgNPs-functionalized PCL/PVDF binary and ternary composites as promising candidates for flexible, durable, and bioactive implants in peripheral nerve or bone regeneration. Full article

This study developed poly(lactic acid) (PLA) biocomposites reinforced with pine wood flour (10, 20, and 30 wt%) to achieve the interphase through chemical modification. Specifically, the wood flour was treated with poly(propylene glycol) toluene 2,4-diisocyanate terminated (PEGTDI), while 1 wt% poly(lactic acid)-g-maleic anhydride (PLA-g-MA) was integrated as a reactive compatibilizer during extrusion and thermocompression. Fourier-transform infrared spectroscopy (FTIR) analysis corroborated the occurrence of urethane formation and ester/anhydride linkages, as substantiated by the presence of characteristic bands indicative of surface carbamation at 1645 and 1726 cm⁻¹. Thermal analysis revealed that both the pine wood flour and coupling agents promoted PLA crystallization; however, thermogravimetric analysis (TGA) indicated a decrease in thermal stability for functionalized composites, suggesting a trade-off between enhanced interfacial interaction and heat resistance. Mechanical testing demonstrated a significant reinforcement effect, with the Young’s modulus increasing by up to 22% in untreated composites. The coupling agents effectively optimized stress transfer at low fiber loadings (10 wt%), while flexural modulus improvements were predominant at higher loadings (20–30 wt%) regardless of treatment. These findings underscore the criticality of surface modification and compatibilizer selection for tailoring the structural and thermo-mechanical properties of PLA-based biocomposites, thereby providing a pathway for optimized performance in structural applications. Full article

Bio-based, biodegradable, and renewable polymers offer a promising alternative to traditional synthetic polymers derived from petroleum or other non-renewable resources. However, their use is limited by suboptimal properties and high costs. Incorporating sustainable reinforcements into the polymer matrix significantly improves biopolymer performance while preserving key properties, sustainability, and cost-effectiveness. Bio-based polymeric composites have emerged as a crucial category of biopolymers, playing a key role in advancing a sustainable, circular economy. This review provides an updated overview of bio-based polymer composites and nanocomposites, focusing on reinforcement strategies using natural nanofillers and engineered nanoparticles. We summarize key synthesis and processing methods, discuss structure–property relationships, and highlight recent advances in applications such as food packaging, biomedical devices, energy systems, environmental remediation, 3D printing, and supercapacitors. Polymer nanocomposites are versatile, with their performance depending on the type, size, and interactions between the fillers and the polymer matrix. Progress in metallic, ceramic, carbon-based, natural, and hybrid fillers has improved their properties. Using bio-based polymers and renewable fillers supports sustainability. Natural nanofillers derived from renewable sources and industrial byproducts offer a sustainable approach to developing high-performance, biodegradable nanocomposites. Smart nanocomposites can react to external stimuli by integrating specialized fillers that enhance their mechanical and mobility properties. Shape memory nanocomposites can be remotely activated—using heat, electricity, magnets, or light—enabling advanced applications. Finally, we address major challenges and outline future directions for scalable, circular-material solutions, drawing on perspectives from the circular economy and life cycle assessment (LCA). Full article

Bacterial cellulose (BC) has emerged as a structurally robust, biologically compatible, and highly adaptable biomaterial with significant potential for next-generation wound-care technologies. Its nanofibrillar, extracellular-matrix-like architecture provides exceptional moisture retention, mechanical stability, and conformability, enabling BC to function as an active scaffold rather than a traditional dressing. Advances in chemical modification, composite engineering, and bioactive functionalization, including antimicrobial metals, chitosan, biosurfactants, enzymes, and growth factors, have expanded BC’s therapeutic capabilities. Emerging smart BC dressings integrate biosensors, stimuli-responsive drug release, and 3D-printed architectures tailored to patient-specific wound geometries. Parallel developments in artificial intelligence (AI) are transforming BC production by optimizing bioprocessing, guiding genetic engineering, reducing culture media costs, and enabling real-time quality control, thereby improving scalability and industrial feasibility. These combined innovations position BC as a multifunctional, immunologically instructive, and digitally integrated platform for advanced regenerative wound care. This review reframes BC within the contemporary pathophysiology of chronic wounds, emphasizing its roles in immunomodulation, macrophage polarization, angiogenesis, mechanotransduction, and the disruption of mixed bacterial–fungal biofilms that characterize diabetic foot ulcers and other non-healing wounds. BC hydrogels typically contain >90–99% water and exhibit tensile strengths exceeding 200 MPa, enabling robust mechanical performance in wound environments. Advances in BC composites have demonstrated antimicrobial reductions of 3–5 log units against common chronic-wound pathogens. Full article

The production and use of plastics have direct consequences on the environment, such as the greenhouse gas emissions (GHGs) they cause. Therefore, it is necessary to develop materials from renewable sources with a lower environmental impact to replace plastic. In this work, films with bioactive properties have been developed from cellulose nanofibers (CNFs) and natural phenolic compounds for food packaging applications. First, the optimization of the incorporation of three different natural phenolic compounds (tannic acid, p-coumaric acid, and acetosyringone) into nanocellulose was studied using a Box–Behnken design, with the phenols adsorbed by the nanocellulose as the output variable. Once the incorporation was optimized, films containing nanocellulose and phenolic compounds were produced and characterized. Tannic acid showed the best results with regard to the optical properties of the resulting films and achieved a complete blocking of UV-B radiation, as well as adding to nanocellulose antioxidant (4.32 mM TE/g film) and antibacterial capacity (log R of 6.6 ± 0.2 and 3.8 ± 0.1 for Staphylococcus aureus and Escherichia coli, respectively), making these films a promising material for use in contact with food as a packaging material, although more in-depth studies and measures are needed to make these films viable for use in food packaging. Full article

This study investigated the structural and anti-inflammatory properties of Zophobas morio lipids (ZMLs). The fatty acid (FAs) composition showed a higher proportion of unsaturated FAs, mainly consisting of oleic (30.30%) and linoleic acids (20.05%), than saturated FAs, including palmitic (24.80%) and stearic acids (12.96%). In addition, FT-IR and ¹H-NMR analyses confirmed that ZML possessed a typical triglyceride structure, with long-chain alkyl groups. Thermogravimetric analysis (TGA) indicated that ZML exhibited high thermal stability, with a degradation peak at 369 °C. Differential scanning calorimetry (DSC) displayed a thermal transition at −8 °C, corresponding to the crystallization of unsaturated FAs in ZML. ZML significantly inhibits lipopolysaccharide (LPS)-induced pro-inflammatory M1 macrophage polarization by suppressing nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thereby attenuating the expression of inflammatory mediators. Additionally, ZML alleviated inflammatory oxidative stress by activating the nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant pathway. Notably, ZML not only induced M2 macrophage polarization in quiescent macrophages but also reprogrammed M1 macrophages toward the anti-inflammatory M2 phenotype. These findings suggest that ZML is a natural nutritional lipid source and a potential therapeutic agent for modulating inflammatory response. Full article

This study aimed to prepare and characterize nanoemulsions containing eugenol and 1,8-cineole using the emulsification method and to investigate their anesthetic effects on guppy fish. The optimized formulation comprised a 5–10% mixture of eugenol and 1,8-cineole in a 1:2 ratio, stabilized with 15–20% Tween 80. The selected formulations displayed mean particle sizes below 15 nm, a low polydispersity index (PDI) (<0.5), and a zeta potential that was more negative than −40 millivolts (mV), indicating stable emulsions. Their pH ranged from 6.50 to 6.63, indicating slight acidity. The formulations exhibited non-Newtonian rheology, as well as thinning under shear stress. Three formulations (F2, F6, and F12) remained stable after both accelerated and long-term stability testing. All nanoemulsions were able to induce guppy fish to the third stage of anesthesia. The nanoemulsions with concentrations of 50 mg/L and 100 mg/L eugenol effectively induced sedation and anesthesia in both sexes and reduced the induction and recovery times compared with the ethanol solution. In conclusion, this study highlights nanoemulsions as a promising drug delivery system for alternative anesthetics in aquaculture. Full article

Among the most structurally diverse biomacromolecules, polysaccharides have attracted increased attention as nanocarriers for precision medicine due to their inherent biocompatibility and versatility in functionalization. Molecular features, such as monomer composition, glycosidic linkages, charge density, and chemical modification, essentially determine the nanoscale assembly process of these biopolymers, as well as their biological compatibility. This review highlights the role of these properties in the assembly process of polysaccharide-based nanocarriers leading to a variety of self-assembled nanostructures, such as polyelectrolyte complexes, protein–polysaccharide complexes, amphiphilic micelles, vesicles, hybrid systems, and nanogels, which are extensively discussed throughout the review. This review also focuses on the structure–property–function relationships of nanocarriers as applied to the rapidly developing area of precision medicine, emphasizing the problems of sustainability and reproducibility. By combining the principles of molecular engineering, supramolecular assembly, and measurable properties, this work aims to present a unified view of the molecular engineering of polysaccharide-based nanocarriers for enhanced translation potential, as well as to outline a coherent framework for the rational development of next-generation polysaccharide-based nanocarriers with improved clinical relevance. Full article

This work focused on the investigation of sulfonated lignin as a novel and sustainable reinforcing filler for polyamide 6 (PA6) composites. Different formulations were thus prepared by melt compounding, varying the lignin content (5, 10, and 20 wt%). The interaction between lignin and PA6 was systematically studied through rheological, structural, morphological, thermo-mechanical, and flammability tests. Rheological measurements showed an increase in the complex viscosity and viscoelastic moduli with increasing lignin content, suggesting restricted polymer chain mobility and the formation of strong physical interactions between the molten PA6 and the lignin particles. Microstructural observations through FESEM highlighted a good dispersion of lignin particles and efficient filler–matrix interfacial adhesion. Moreover, the addition of lignin significantly increased the tensile stiffness of the composites (up to 3.4 GPa), and a lignin content of 10 wt% enhanced the tensile strength up to 58.4 MPa (i.e., +45% compared to neat PA6) without compromising the ductility. Finally, UL-94 tests revealed an improvement in flame retardancy at higher lignin contents due to the intrinsic char-forming ability of this filler. These results demonstrated that lignin could be an effective multifunctional bio-based filler that can improve the thermo-mechanical performance of PA6 without the need for compatibilizing agents. Full article

This study investigates the efficacy of co-assembled, physically cross-linked nanocarriers comprising tannic acid (TA) and a P(DMAEMA-co-OEGMA) random/statistical double-hydrophilic copolymer for ovalbumin (OVA) encapsulation. TA-based nanocarriers, prepared at varying TA molar ratios (10% w/v and 20% w/v), exhibited nanoaggregates of different sizes, as revealed by dynamic light scattering, with Nanocarrier 1 system showing populations of 11 and 109 nm, while Nanocarrier 2 formed a single population of 75 nm in size. Notably, both colloidal systems demonstrated stability under thermal treatment and resilience to changes in salt concentrations higher than 0.15 M, but disassembly phenomena in basic media. Utilizing these nanocarriers for OVA loading via electrostatic interactions revealed strong positive charges (~30 mV) for all protein-loaded nanocarrier cases. In particular, they demonstrated sizes within the desired range (R_h = 96–118 nm) and considerable stability over 20 days and in the presence of serum proteins. Overall, this study underscores the importance of physical cross-linking as a viable strategy for the formation of tunable nanometric hydrocolloids for effective protein encapsulation, with significant implications for drug delivery systems. Full article

Comparative studies report inconsistent peptide yields, bioactivities, and sensory outcomes for Alcalase across substrates, creating uncertainty about when it should be favored over other proteases. This study mapped research on hydrolysis of food proteins with Alcalase to quantify scientific output, organize thematic trends, and identify gaps relevant to peptide-based functional foods. A bibliometric analysis of Web of Science records (2004–2024) was performed in R (bibliometrix), using co-occurrence networks, temporal overlays, and conceptual mapping. The dataset comprised 203 documents from 78 sources, exhibiting a 10.3% annual growth rate and a 36.9% international co-authorship rate. Themes clustered around antioxidant and angiotensin-converting enzyme (ACE) inhibitory peptides, particularly in dairy and marine matrices, are supported by workflows combining Alcalase hydrolysis with size-guided ultrafiltration, RP-HPLC (Reverse Phase High-Performance Liquid Chromatography), and, more recently, in silico analyses and encapsulation studies. Recurrent limitations were identified: heterogeneous hydrolysates and uneven reporting that hinder sequence–activity correlations, gastrointestinal degradation and bitterness affecting applicability, and scale-up and purification choices influencing feasibility. The mapping clarified where Alcalase enables bioactive peptide generation and highlighted practical priorities, including protocol standardization and enzyme benchmarking, the integration of peptidomics and machine learning with targeted assays, and formulation-focused validation (encapsulation, stability, and delivery) to bridge in vitro activity to real-world use. These directions support the production of reproducible, application-ready peptide ingredients. Full article

Waste lignin from the hydrolysis of lignocellulosic materials is an abundant but underused by-product of the pulp and biorefinery industries. Phenolic compounds derived from lignin, rich in aromatic structures, show strong antioxidant potential and can be applied in polymer stabilization, food, and medical fields. This study evaluated the radical-scavenging activity of phenolic fractions obtained from alkaline-treated waste lignin against DPPH● and ABTS•⁺, using Trolox as a reference. Both spectrophotometric and electrochemical techniques were employed, providing deeper insight into the underlying mechanisms. Depending on the assay, the phenolic extracts demonstrated substantial radical-scavenging capacity, in some cases matching or surpassing that of Trolox. This behavior was linked to electron/proton transfer pathways, radical reactivity, and solubility effects. The combined use of multiple antioxidant tests offered a comprehensive characterization of the bioactivity of lignin-derived phenolics and supports their potential as sustainable sources of antioxidant compounds within a circular economy framework. Furthermore, the study examined how toluene-extracted phenolics affect the thermo-oxidative stability of model polyurethane films. Incorporating small amounts (1%, 3%, 5%) into the polymer matrix showed that a 1% loading provides the most effective stabilization. At higher concentrations, however, additional oxidative processes seem to be activated, as indicated by FTIR measurements and thermogravimetric analysis. Full article

Quinoa (Chenopodium quinoa) is a promising source of plant proteins with the potential to produce bioactive peptides through enzymatic hydrolysis. This study aimed to extract quinoa protein and produce bioactive peptides using two microbial proteases: Alcalase (from Bacillus licheniformis) and Flavourzyme (from Aspergillus oryzae). The protein was extracted through alkaline solubilization and isoelectric precipitation, achieving a 72% yield. Hydrolysis was conducted for 4 h, and enzymatic activity was measured using the TNBS method to determine the degree of hydrolysis, while SDS-PAGE was used to analyze protein breakdown. The reaction was performed at controlled pH and temperature (Alcalase: 9.5 and 55 °C; Flavourzyme: 7 and 37 °C). Both enzymes achieved maximum hydrolysis at 60 min. Consequently, the separation and inhibitory capacity of angiotensin-converting enzyme (ACE-I) were tested at the first four time points (0, 20, 40, and 60 min). A wider variety and higher concentration of peptides smaller than 2 kDa were found in hydrolysates treated with Flavourzyme, which is associated with antihypertensive activity. The ACE-I assay showed greater activity at the end of hydrolysis. Inhibition percentages of 87.5 ± 2.11 were observed in hydrolysates with Flavourzyme, and 94.1 ± 1.11 in those with Alcalase. These findings indicate that quinoa protein, hydrolyzed with microbial proteases, is a feasible source of peptides with potential antihypertensive effects for use in functional foods and nutraceuticals. Full article

In response to the environmental and health concerns associated with high-sodium brine disposal and the sodium content in table olives, this study proposes a novel, sustainable preservation method that completely replaces traditional brine with chitosan solutions. Three food-grade chitosan solutions were formulated using acetic acid, vinegar, and vinegar neutralized with baking soda as alternative liquid media for preserving Kalamata olives. Over a five-month storage period with a one-year endpoint, these solutions were evaluated against a conventional 8% NaCl brine control. The chitosan-based systems demonstrated effective microbial control, maintaining significantly lower total viable counts for most of the storage period, while yeast and mold populations were comparable to or slightly higher than the control over extended storage. Notably, they reduced the medium’s salinity by 75–85%, directly addressing the issue of high sodium content. The chitosan solutions also provided superior pH stability and color maintenance in the olives. A key finding was the distinct nature of the interaction between the olives and the chitosan medium compared to brine: while antioxidant activity within the olive flesh declined, the chitosan solutions themselves exhibited high and stable intrinsic antioxidant capacity (>78%), acting as an active antioxidant reservoir—a dynamic not observed with traditional brine. This research successfully validates chitosan solution as a viable, low-sodium, brine-free preservation medium, offering a novel strategy for sustainable olive processing that valorizes seafood waste and aligns with circular economy principles. Full article

Ionic liquids (ILs) and deep eutectic solvents (DESs) have emerged as effective solvents for poorly soluble materials such as natural polysaccharides, including chitin. This review describes recently developed efficient chitin derivatization methods that harness the solubilizing power of ILs and DESs. It covers chitin acylation approaches, including acylation and mixed ester formation, as well as chitin etherification protocols. For example, the ILs 1-allyl-3-methylimidazolium bromide (AMIMBr) and 1-allyl-2,3-dimethylimidazolium bromide serve as effective media for chitin acylation and etherification, respectively, yielding single esters and benzyl derivatives with high degrees of substitution (DS). The use of DESs comprising AMIM chloride (AMIMCl) as a hydrogen bond acceptor and several hydrogen bond donors for chitin acylation are presented. In an optimized system, acylation using acyl chlorides proceeded smoothly without additives, such as a base/catalyst, in a DES comprising AMIMCl and 1,1,3,3-tetramethylguanidine, affording high-DS ester derivatives. The method was extended to the synthesis of mixed chitin esters bearing both long and bulky acyl substituents at appropriate substitution ratios, which exhibit thermoplasticity. Full article