Macromol

Edible mushrooms are an underexplored source of industrial proteases, whose synthesis is highly dependent on the cultivation substrate. This study investigated the effect of nine culture media on the proteolytic profiles of Auricularia sp., Lentinus sp., Macrocybe sp., and Grifola frondosa. Fungi were cultivated on diverse media (e.g., Czapek, Malt, Soy Flour). We analyzed total protein, specific activities (total, cysteine, serine proteases) using a biochemical assay, and protein secondary structure via FTIR, with metabolic patterns identified by PCA. A dissociation was found between total protein yield (highest in MFI/Casein media) and specific activity (highest in maltose media), suggesting catabolite repression. Distinct metabolic strategies emerged: Grifola frondosa specialized in serine protease production in the minimal Czapek medium (catabolic derepression), while Macrocybe sp. maximized cysteine protease production on soy flour (substrate induction). FTIR confirmed this, revealing a β-sheet-dominant (75.5%) structure for Grifola extract versus a random-coil-dominant (60.8%) structure for Macrocybe. This study provides a framework for mechanism-based bioprocess design, enabling the tailored production of serine proteases from G. frondosa (Czapek medium) or cysteine proteases from Macrocybe sp. (soy medium) for customized biotechnological applications. Full article

Optical frames are used worldwide to correct visual impairments, protect from UV damage, or simply for fashion purposes. Optical frames are often made of poorly biodegradable and fossil-based materials, with designs not targeted to everyone’s tastes and requirements. Additive manufacturing processes allow personalisation of optical frames and the use of new sustainable biomaterials to replace fossil-based ones. This comprehensive review combines an extensive survey of the scientific literature, market trends, and information from other relevant sources, analysing the biomaterials currently used in additive manufacturing and identifying biomaterials (biopolymers, natural fibres, and natural additives) with the potential to be developed into biocomposites for printing optical frames. Requirements for optical devices were carefully considered, such as standards, regulations, and demands for manufacturing materials. By comparing with fossil-based analogues and by discussing the chemical, physical, and mechanical properties of each biomaterial, it was found that combining various materials in biocomposites is promising for achieving the desirable properties for printing optical frames. The advantages of the various techniques of this cutting-edge technology were also analysed and discussed for optical industry applications. This study aims to answer the central research question: which biopolymers and biocomposite constituents (natural fibres, plasticisers, and additives) have the ideal mechanical, thermal, physical, and chemical properties for combining into a biomaterial suitable for producing sustainable, customisable, and inclusive optical frames on demand, using additive manufacturing techniques. Full article

Poly(L-lactide-co-ε-caprolactones) (PLCL) are promising biodegradable polymers with tunable properties for various biomedical applications. Along with the composition, the microstructure of PLCL chain is an important factor affecting its properties, crystallinity, and degradation profile. In this study, to find effective ways for tailoring the microstructure of PLCL chain, kinetic patterns of L-lactide/ε-caprolactone (75:25) ring-opening copolymerization in the presence of two different catalysts were evaluated. The kinetic studies, accompanied by the assessment of the evolution of PLCL microstructure over the reaction course, provided the optimal regimes for synthesis of PLCL with a fixed composition (LA:CL = 75:25) and different chain microstructure. This was achieved by employing two types of catalysts (tin(II) 2-ethylhexanoate and zirconium(IV) acetylacetonate) and delayed co-monomer addition approach. The control of average LA block length (l_LA) was achieved in a wide range from 4 to 14 monomeric units. Differential scanning calorimetry and wide-angle X-ray scattering revealed a pronounced effect of l_LA on glass transition temperature, melting temperature, and crystallinity. Full article

Microbial biosurfactants (mBSs) are bioactive molecules with diverse applications, notably as antimicrobial agents against antibiotic-resistant pathogens. Produced by bacteria and yeasts, mBSs are classified as glycolipids, lipopeptides, polymeric, and particulate types. The global rise in multidrug-resistant organisms, such as Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, Pseudomonas aeruginosa, and Acinetobacter baumannii, underscores the urgent need for new antimicrobial strategies. mBSs disrupt microbial growth by interacting with the lipid components of pathogens, offering promising alternatives to conventional antibiotics. This review highlights the sources, chemical structures, and properties of mBSs, their antimicrobial activities, synergistic effects with antibiotics, and structure–activity relationships. Special emphasis is placed on surfactant modification, where targeted changes—such as valine substitution in surfactin—significantly lower critical micelle concentrations (CMC) and enhance antimicrobial potency. Such rational engineering demonstrates how biosurfactants can be tailored for improved biomedical performance while minimizing cytotoxicity. In parallel, artificial intelligence (AI) algorithms, including artificial neural networks and genetic algorithms, optimize yields, predict substrate suitability from agricultural residues, and guide microbial strain engineering. AI models can predict interfacial behavior and synchronize fermentation with purification. Advancing the understanding of mBS interactions with microbial membranes, combined with modification strategies and AI-guided optimization, is essential for developing targeted therapies against resistant infections. Future research should integrate these approaches to engineer novel derivatives, reduce costs, and validate clinical potential through comprehensive in vivo studies. Full article

Fibrous polycaprolactone-based composite materials with the addition of hardystonite (1, 3, and 5 wt.%) were developed using the electrospinning method. The obtained PCL and PCL-HT nonwovens were evaluated in terms of their physiochemical properties (SEM, EDS, BET, and zeta potential). Furthermore, the antioxidant potential [measured by thiobarbituric acid reactive substance (TBARS) levels], blood plasma coagulation parameters, and cyto- and genotoxicity towards PBM and Hs68 cells were assessed to determine the biochemical activity of the composites. The conducted experiments confirmed that hardystonite was successfully incorporated into the PCL matrix. No substantial changes in the fibres’ surface morphology and the structure of the composites were observed. Similarly, the specific surface area, total pore volume, and average pore size did not change significantly. The addition of hardystonite to the polymer solution resulted in a shift in zeta potential toward less negative values. With regard to plasma coagulation parameters, no significant changes were observed in the aPTT, PT, or TT, likely due to the counterbalancing effect of Zn²⁺ and Ca²⁺ ions. Furthermore, the PCL-HT composites exhibited a lowered TBARS level, suggesting antioxidant properties, which could be attributed to the presence of zinc in hardystonite. The PCL and PCL-HT composites demonstrated no cytotoxic or genotoxic effects on the tested blood or skin cell types, suggesting their safety. Full article

Agave lechuguilla fibers exhibit high tensile strength, low density and durability, but their use in natural rubber composites is underexplored. This study investigates alkaline-treated fibers (149–180 µm) as reinforcements for natural latex. Fibers were pretreated with a methanol–acetone mixture, followed by immersion in 10% NaOH at 70 °C for 1 h, removing lignin and hemicellulose as confirmed by FTIR and SEM. Thermogravimetric analysis showed three weight-loss stages: moisture/volatiles (9.4%), hemicellulose (peak at 341 °C), and cellulose/lignin (peak at 482 °C), with <3% residue above 500 °C. Treated composites exhibited enhanced tensile strength (4.68 ± 1.2 MPa vs. 1.3 ± 0.8 MPa for untreated) and elongation at break (530 ± 51% vs. 452 ± 32%). Hardness increased from 21.8 (neat latex) to 30.3, and compression resistance was improved. Optical microscopy revealed strong fiber–matrix adhesion with uniform dispersion. Alkaline treatment enhances interfacial bonding and mechanical performance, making A. lechuguilla fibers a sustainable reinforcement for eco-friendly composites in automotive, construction, and packaging sectors. Full article

Kefiran, the extracellular polysaccharide produced by Generally Recognized as Safe (GRAS) bacteria found in kefir grains, is a promising biopolymer with multiple applications in agri-food and biomedical fields. Besides its characteristics and potential applications, the factors that affect its production remain a prime subject of interest. Lactic acid bacteria synthesize polysaccharides to protect their cells from adverse conditions. Therefore, low-temperature storage (4 °C) of kefir grains inoculated into Ultra-High-Temperature (UHT) milk at two different concentrations (5% and 30%) was studied as a factor for increasing kefiran production in the medium. The cryoprotectant disaccharide trehalose, which comprises a carbon and energy source for many microorganisms, was also evaluated for its effectiveness in enhancing kefiran production. The pH, the increase in kefir grain mass, the amount of kefiran produced, and the rheological properties of the acidified milk were determined during two distinct storage periods, depending on kefir grain concentration. For comparison, kefir grains were also fermented at 25 °C and 30 °C. Low-temperature storage at a kefir grain concentration of 30% resulted in an increase in the amount of polysaccharide produced beyond that obtained through fermentation. Fermentation of a 5% grain inoculum at 30 °C resulted in the lowest kefiran production. In the presence of trehalose, prolonged low-temperature storage favored an increase in the biosynthesis of kefiran, especially at a 30% kefir grain inoculum. Trehalose, however, was not a significant factor in the fermentation experiments. Proper selection of low-temperature storage time is required to avoid a reduction in kefiran concentration due to the metabolic activity of the microorganisms in kefir grains. The acidified milk (low-temperature storage) and kefir (fermentation) samples both exhibited increased elasticity and apparent viscosity with increasing kefir grain concentration. However, the rheological behavior of acidified milk was greatly affected by protein degradation during low-temperature storage. As shown by the findings of the present study, low-temperature storage (4 °C) of a 30% kefir grain inoculum in the presence of trehalose (3% w/w) until a final pH of 4.2 proves to favor kefiran production in the medium the most. Full article

Protein-based films are attractive candidates for biodegradable packaging, yet their performance is often compromised by phase separation when combining components with contrasting hydrophilicity. In this study, gelatin/zein films were used as a model system to elucidate how phase separation governs multifunctional properties. FTIR, XRD, TGA, and SEM analyses confirmed heterogeneous domains arising from immiscibility, which strongly influenced mechanical, heat-sealing, barrier, and optical behaviors. Zein incorporation improved tensile strength, water resistance, and UV-blocking capacity, while it simultaneously compromised heat-sealing strength, transparency, and gas barrier uniformity. To rationalize these trade-offs, a Multi-Criteria Decision-Making (MCDM) framework integrating the Analytic Hierarchy Process (AHP) and Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS) was applied, revealing that gelatin/zein blends performed worse overall than pure films. These findings demonstrate that phase separation can improve individual attributes without generating synergistic effects, emphasizing the importance of compatibility control and holistic evaluation in the rational design of biodegradable packaging materials. Full article

The stability of physical and mechanical properties of highly filled swelling rubbers in polar and nonpolar liquids (oil, mineralized water) was studied. Nitrile butadiene rubber of BNKS-28 AMN grade served as the elastomer matrix, with sodium salt of carboxymethylcellulose (NaCMC) as the swelling filler. Oxal T-92, a mixture of dioxane alcohols (10–50 phr, step 10 phr), was used as a plasticizer due to its good thermodynamic miscibility with rubber (confirmed by Scatchard–Hildebrand calculations). Adding Oxal T-92 to NaCMC-filled compounds markedly reduced Mooney viscosity, improving processing through increased macromolecule mobility, without significantly affecting vulcanization kinetics—indicating chemical inertness toward crosslinking centers. Increasing Oxal T-92 from 10 to 50 phr reduced tensile strength from 4.1 MPa to 2.9 MPa. Swelling in aqueous solutions of varying mineralization was evaluated via volume and mass change. The optimal plasticizer content for high swelling with acceptable strength is 20–30 phr. After 3 days in oil and formation water, NaCMC-filled rubbers retained stable physical and mechanical properties. Full article

Poly(hydroxyalkanoates) (PHAs) have garnered significant attention due to their biodegradable and biocompatible properties, making them promising alternatives to conventional petroleum-based plastics. As microbial-derived polyesters, PHAs offer a sustainable solution to plastic waste accumulation and microplastics because they can be produced from renewable resources, including food-related waste. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a copolymer in the PHA family, exhibits improved mechanical flexibility and thermal properties compared to poly(3-hydroxybutyrate), thereby broadening its potential applications. In this work, eight samples of PHBV, including those made from food waste and municipal waste streams, were studied by solid-state NMR. Information obtained includes the copolymer composition, chemical shifts due to crystalline lattices, crystallinity, and polymer chain mobility. The composition matches the results from the fatty acid feed and solution NMR analysis. The samples appear to be about 62–70% crystalline. No significant differences in mobility are observed from NMR relaxation data. These results indicate that PHBV materials generated from different food-related waste sources, despite their compositional differences, possess similar crystallinity and molecular mobility, suggesting their suitability as biobased semi-crystalline plastics. Full article

Fused Filament Fabrication (FFF) is an additive manufacturing technique that constructs parts by extruding material layer by layer. It offers advantages such as rapid prototyping, cost-effectiveness, and the ability to produce complex geometries. This study investigates the mechanical behavior of a composite filament composed of silicon carbide (SiC) ceramic particulates embedded in a polylactic acid (PLA) matrix, fabricated via FFF. Pure PLA specimens were also printed and tested to serve as a baseline. A Design of Experiments (DOE) methodology was employed to evaluate the influence of key printing parameters on mechanical properties, including Young’s modulus, yield strength, and ultimate strength. Microstructural analysis was performed on printed specimens using scanning electron microscopy (SEM). For compression testing, the parameters studied were infill percentage, number of shells, and print orientation. For tensile testing, the parameters included layer height, number of shells, and infill angle. Results indicated that infill percentage had the most significant impact on compressive properties, while layer height was the dominant factor in tensile performance. These findings provide insights into optimizing FFF process parameters for ceramic-particulate-reinforced polymer composites. Full article

The selenized glutelin (Se-G) from Se-enriched chickpea sprouts has demonstrated high antioxidant potential. In this study, the response surface methodology was employed to optimize Se-G content (1–4%) and grape or rosehip oils (10–40%) for the preparation of W/O emulsions with strong antioxidant activity. In the optimal emulsions (Se-GG with grape oil and Se-GR with rosehip oil), antioxidant, photoprotective, and antiaging properties were evaluated. Non-Se glutelin was used in the control emulsions. The optimal conditions determined (4.0% Se-G/10.0% rosehip oil and 3.39% Se-G/12.50% grape oil) allowed for the preparation of emulsions with higher antioxidant capacity. The Se-GR with rosehip oil had greater antioxidant capacity than the Se-GG with grape oil. The optimal emulsions with Se, compared to their Se-free controls, had significantly higher antioxidant activity. The zeta potential value increased with the presence of Se. A positive effect on the inhibition of ROS production and lipid peroxidation was observed, as well as the inhibition of collagenase, elastase, and hyaluronidase activity, mainly due to the presence of selenium. Se-G represents a powerful tool for preventing damage to the skin caused by UV exposure. Full article

Pectin is widely used in different areas like biomedical, pharmaceutical, food, and environmental industries thanks to its gelling properties. Pectin hydrogels are of great interest because of their wide biomedical applications in drug delivery, tissue engineering, wound healing, the food industry, agriculture, and cosmetic products because of their biocompatibility, biodegradability, and non-toxic nature. This review provides an understanding of pectin-based hydrogels and their applications in various industrial areas. In addition, an overview of emerging technologies and recent applications of pectin hydrogels is provided, including the controlled and targeted release of bioactive compounds or drugs. They are used as a scaffold for cell growth, as a wound dressing to promote healing, as a fat replacer in food, and as a texturizer in skin-care products. It also serves as a coating for seeds to improve their germination and growth. This paper also identifies knowledge gaps and future research direction for optimizing pectin hydrogels. Full article

Biocompatible electroactive hydrogels with bidirectional pH-responsive bending are important for the creation of biomedical actuators. This study developed chitosan/carboxymethylcellulose (CS/CMC) semi-interpenetrating networks (SIPNs) with different volume ratios, which were crosslinked with glutaraldehyde. The swelling and bending behaviors of SPINs were systematically characterized as a function of the pH of the solution and the magnitude of the applied electric field. The hydrogels exhibited pH-dependent bidirectional actuation, with the maximum swelling of 4.67–6.00 at pH ≈ 3.9 and minimum swelling of 1.58–2.53 at pH ≈ 5.7. The SPINs with CS/CMC = 1:1 composition achieved the highest bending angle of 77° at pH ≈ 5.7, while cathodic bending up to an angle of −13.7° was observed in basic conditions. The electromechanical response was significantly enhanced by decreasing the electrode distance and increasing the applied voltage. The observed correlation between the composition, swelling behavior, and bending performance was explained in terms of the electrostatic interactions between NH₃⁺ and COO⁻ groups present in the CS/CMC mixtures. These findings provided novel insight into the ongoing efforts for the development of non-toxic electroactive hydrogels with tailored electromechanical bending behavior necessary for use as artificial muscles and biomedical actuators. Full article

Ribonucleic acid (RNA) polymerases are macromolecular machines that catalyze the synthesis of RNA macromolecules, the sequences of which are coded for by the sequences of regions of deoxyribonucleic acid (DNA) macromolecules in the nucleus of eukaryotic cells, or nuclei in the case of many mature striated muscle cells, or myocytes, which are in many cases polynucleated. Herein, we review the evidence that transcription, the activity of RNA polymerases that is an essential step in gene expression, and processes related to maturation of eukaryotic RNA can be influenced by the macromolecule actin and its macromolecular complex of filamentous actin and its association with actin-binding proteins in the nucleus. We furthermore hypothesize that the macromolecular complexes of troponin (Tn) and tropomyosin (Tm), which bind actin filaments in the cytoplasm of striated muscle myocytes to form thin filaments and which are also found in the nuclei of striated muscle myocytes and some cancerous cells, could modulate that influence of nuclear actin on transcription when present in a nucleus. Interestingly, troponin and tropomyosin could confer Ca²⁺ dependence to transcriptional modulation by nuclear actin, a mechanism that would complement Ca²⁺-dependent modulation of post-translational modifications that influence gene expression. Full article

Owing to their tunable and biocompatible characteristics, collagen- and gelatin-based hydrogels have gained attention in numerous applications, including biomedical, food, pharmaceutical, and environmental. The gelation mechanisms and resulting network structures of collagen and gelatin differ significantly depending on the presence of intra- and intermolecular crosslinks. These differences enable the tailoring of mechanical properties to achieve desired characteristics in the final product. Mechanical gel strength and elasticity determine how effectively hydrogels can mimic natural tissues and respond to deformations. Probing the rheological properties of these gels enables a deeper understanding of their structure, physical attributes, stability, and release profiles. This review provides an in-depth evaluation of the factors affecting the mechanical strength of collagen- and gelatin-based hydrogels, highlighting the influence of co-molecules and the application of physical, chemical, and mechanical treatments. Herewith, it brings insights into how to manipulate the mechanical properties of these gels to improve their end-use functionality. Full article

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

Single-use plastic cups and packaging materials pose severe environmental challenges due to their persistent nature and harmful impact on ecosystems and wildlife. Simultaneously, the indiscriminate disposal and burning of agricultural and food processing biomass contribute significantly to pollution. Among this biomass, waste generated from corn and fruit processing is produced in substantial quantities and is rich in natural fibres, making it a potential source for developing biodegradable products. This study focuses on the development of biodegradable cups using corn cob powder, mango peel powder, and pineapple peel powder through hot-press compression and moulding technology. The formulation was optimized using response surface methodology, with independent variables, i.e., corn cob (20–40 g), mango peel (30–50 g), and pineapple peel (20–30 g). The responses evaluated including hardness, colour (L* value), and water-holding capacity. The model was fitted using a second-order polynomial equation. Optimum results were achieved with 34 g of corn cob, 40 g of mango peel, and 26 g of pineapple peel powder, yielding a maximum hardness of 2.41 kg, an L* value of 47.03, and a water-holding capacity of 18.25 min. The optimized samples further underwent characterization of physical properties, functional groups, lattice structure, surface morphology, and biodegradability. Colour parameters were recorded as L* = 47.03 ± 0.021, a* = 10.47 ± 0.041, and b* = 24.77 ± 0.032. Textural study revealed a hardness of 2.411 ± 0.063 and a fracturability of 2.635 ± 0.033. The developed biodegradable cup had a semicrystalline nature with a crystallinity index of 44.4%. Soil burial tests confirmed that the developed cups degraded completely within 30 days. These findings highlight the potential of corn and fruit processing waste for developing eco-friendly, biodegradable cups as sustainable alternatives to single-use plastics. Full article

Human adenovirus infections are typically self-limiting but can become life-threatening in pediatric populations and immunocompromised individuals. Despite this clinical importance, efforts to develop antiviral drugs against adenoviruses remain limited. A promising strategy is to target the adenovirus protease (AVP), an enzyme essential for viral maturation and infectivity. Yet, research on AVP has lagged far behind that on other viral proteases. In this work, we aimed to reposition AVP as a viable target for antiviral therapy. We first discuss why AVP research has fallen behind and emphasize the need to redirect attention toward this protease. Building on advances in SARS-CoV-2 drug discovery, we evaluated the potential of repurposing inhibitors of the main protease (M^pro) and papain-like protease (PL^pro) as modulators of AVP. Additionally, we examined the untapped potential of phytochemicals as novel scaffolds. These analyses were supported by original molecular docking studies. Our results revealed that previously reported SARS-CoV-2 inhibitors, such as the M^pro inhibitor ensitrelvir and the PL^pro inhibitor (compound) 19, engage the catalytic site of AVP and may serve as starting scaffolds for inhibitor design. Screening of phytochemicals further identified promising candidates, including apigenin, camptothecin, kaempferol, and piperine. Together, these findings highlight AVP’s druggability and suggest that both repurposed antivirals and natural products provide complementary avenues for inhibitor development. Finally, we provide some recommendations to facilitate efforts in the discovery of novel AVP inhibitors. Full article