New cellulose–lignin hydrogels and their application in controlled release of polyphenols

Grape pomace and pecan shell fortified bread: The effect of dietary fiber-phenolic compounds interaction on the in vitro accessibility of phenolic compounds and in vitro glycemic index

Grape pomace (GP) and pecan shell (PS) are two by-products rich in phenolic compounds (PC), and dietary fiber (DF) that may be considered for the development of functional baked foods. In this study, four formulations with different GP:PS ratios (F1(8%:5%), F2(5%:5%), F3(5%:2%), F4(0%:5%), and control bread (CB)) were elaborated and characterized (physiochemical and phytochemical content). Also, their inner structure (SEM), changes in their FTIR functional group's vibrations, and the bioaccessibility of PC and sugars, including an in vitro glycemic index, were analyzed. Results showed that all GP:PS formulations had higher mineral, protein, DF (total, soluble, and insoluble), and PC content than CB. Additionally, PC and non-starch polysaccharides affected gluten and starch absorbance and pores distribution. In vitro digestion model showed a reduction in the glycemic index for all formulations, compared to CB. These findings highlight the possible health benefits of by-products and their interactions in baked goods.

Enhanced photocatalytic regeneration of carboxymethyl cellulose/lignin/ZnO complex hydrogel after methylene blue adsorption

The biodegradable, nontoxic, and renewable carboxymethyl cellulose (CMC) hydrogel has been developed into a green adsorbent. However, the weak chemical interaction limits its adsorption capability and reusability. This work incorporated lignin with complex structure and ZnO nanoparticles with photocatalytic properties into CMC hydrogel beads to improve the removal of methylene blue (MB) through chemical interaction. Scanning electron microscopic images and Fourier-transform infrared spectra confirmed the compatibility between lignin and ZnO nanoparticles as well as the increment of active sites for dye removal. The MB adsorption on CMC hydrogel beads was more significantly affected by the temperate and initial concentration compared to contact time, pH, and adsorbent dosage. The MB adsorption capacity of CMC hydrogel was improved to 276.79 mg/g after incorporating lignin and ZnO nanoparticles. The adsorption followed the pseudo-second-order kinetic model and Langmuir isotherm model, indicating chemical adsorption. After 6 cycles, the adsorption capacity was reduced by about 15 %. The UV irradiation could recover and improve MB adsorption capacity of CMC hydrogel beads containing ZnO nanoparticles due to the introduction of reactive oxygen species.

Setting the morphologic quality limits enabling accurate classification of charred archaeological grape seeds

This study investigates the morphological changes in grape pips resulting from various charring conditions. Employing high-resolution scanning combined with morphometric measurements for morphological analysis, we aimed to understand the effects of charring on grape pips. Our morphometric analysis demonstrated significant alterations in seed shape above 250 °C. The length-width ratio and the occurrence of cracks notably changed, providing a basis for assessing charring conditions. In addition, applying a machine learning classification method, we determined that accurate classification of grape varieties by the morphometric analysis method is feasible for seeds charred at up to 250 °C and 8 h. Integrating the morphometric changes and temperature ranges suitable for classification, we developed a sorting model for archaeological seeds. By projecting length-width ratios onto a curve calculated from controlled conditions, we estimated charring temperatures. Approximately 50% of archaeological seeds deviated from the model, indicating drastic charring conditions. This sorting model facilitates a stringent selection of seeds fit for classification, enhancing the accuracy of our machine learning-based methodology. In conclusion, combining machine learning with morphometric sorting enables the identification of charred grape seeds suitable for identification by the morphometric method. This comprehensive approach provides a valuable tool for future research for the identification of charred grape seeds found in archaeological contexts, enhancing our understanding of ancient viticulture practices and grape cultivation.

Synthesis of poly(ionic liquid-OH) mediated deacetylated chitin and its hydrogels: A study on their applications in controlled release of paracetamol and urea

Due to the biodegradable and biocompatible nature of chitin and chitosan, they are extensively used in the synthesis of hydrogels for various applications. In this work, deacetylation of chitin is carried out with alkaline poly(dimethyldiallylammonium-hydroxide) that gave a higher amount of water-soluble chitin (with 84 % of the degree of deacetylation = chitosan0.84) compared to deacetylation using NaOH. The water-soluble chitosan0.84 is used as intercalating chains for the preparation of acrylic acid and vinylimidazole-based hydrogels. The quaternization of imidazole groups is done with 1,ω-dibromoalkanes, which sets off the crosslinking in the above polymer network. A set of three chitosan0.84 intercalated hydrogels, namely Cs-C4-hydrogel, Cs-C5-hydrogel, and Cs-C10-hydrogel are prepared bearing butyl, pentyl, and decyl chains as respective crosslinkers. The swell ratios of these intercalated hydrogels are compared with those of non-intercalated hydrogels (C4-hydrogel, C5-hydrogel, and C10-hydrogel). Chitosan0.84 intercalated Cs-C10-hydrogel has excellent swelling properties (2330 % swelling ratio) among six synthesized hydrogels. SEM analysis reveals that decyl crosslinker-bearing hydrogels are highly porous. The multi-functionality of Cs-C10-hydrogel and C10-hydrogel is explored towards -the controlled release of paracetamol/urea, and methyleneblue dye absorption. These studies disclose that chitosan0.84 intercalated hydrogels are showing superior-swelling behavior, high paracetamol/urea loading capacities and better dye entrapment than their non-intercalated counterparts.

Synthesis of xylan and lignin based hydrogels and their use as growth media for rice (Oryza sativa)

Different hydrogels were synthesised using lignin and xylan (extracted from rice straw) as the raw material, PVA as matrix template, citric acid, and succinic acid as crosslinkers and were structurally characterised by FT-IR and SEM analysis. Citric acid cross-linked hydrogels caused loose bonding between polymers and resulted in formation of large pores whereas succinic acid cross-linked hydrogels were observed to have less porosity and tight bonding network. The swelling ratio and reswelling capacity of hydrogels revealed that lignin hydrogels outperformed all other hydrogels. All the synthesised hydrogels were tested for their use as soil culture media ingredient for the germination of rice seedlings. All the hydrogels performed well in stress conditions as compared to normal conditions. Xylan/lignin hydrogel and lignin hydrogels performed best under stress conditions. These hydrogels could be used effectively as an ingredient of soil culture media owing to their tendency to absorb and retain water properly.

Lignin derivatives-based hydrogels for biomedical applications

Recently, numerous studies have been conducted on renewable polymers derived from different natural sources, exploring their suitability for diverse biomedical applications. Lignin as one of the main components of lignocellulosic has garnered significant attention as a promising alternative to petroleum-based polymers. This interest is primarily due to its cost-effectiveness, biocompatibility, eco-friendly nature, as well as its antioxidant and antimicrobial properties. These characteristics could be more beneficial when incorporating lignin into the formulation of value-added products. Although lignin has a chemical structure that is suitable for various applications, these characteristics require modifications to guarantee that the resultant materials display the desired biological, chemical, and physical properties when applied in the creation of biodegradable hydrogels, particularly for biomedical purposes. This study delineates the recent modification approaches that have been employed in the creation of lignin-based hydrogels. These strategies encompass both chemical and physical interactions with other polymers. Additionally, this review encompasses an examination of the current applications of lignin hydrogels, spanning their use as scaffolds for tissue engineering, carriers for pharmaceuticals, materials for wound dressings and biosensors, and elements in flexible and wearable electronics. Finally, we delve into the challenges and constraints associated with these materials, discuss the necessary steps required to attain the appropriate properties for the development of innovative lignin-based hydrogels, and derive conclusions based on the presented findings.

Production and characterization of starch-lignin based materials: A review

In their pristine state, starch and lignin are abundant and inexpensive natural polymers frequently considered green alternatives to oil-based and synthetic polymers. Despite their availability and owing to their physicochemical properties; starch and lignin are not often utilized in their pristine forms for high-performance applications. Generally, chemical and physical modifications transform them into starch- and lignin-based materials with broadened properties and functionality. In the last decade, the combination of starch and lignin for producing reinforced materials has gained significant attention. The reinforcing of starch matrices with lignin has received primary focus because of the enhanced water sensitivity, UV protection, and mechanical and thermal resistance that lignin introduces to starch-based materials. This review paper aims to assess starch-lignin materials' production and characterization technologies, highlighting their physicochemical properties, outcomes, challenges, and opportunities. First, this paper describes the current status, sources, and chemical modifications of lignin and starch. Next, the discussion is oriented toward starch-lignin materials and their production approaches, such as blends, composites, plasticized/crosslinked films, and coupled polymers. Special attention is given to the characterization methods of starch-lignin materials, focusing on their advantages, disadvantages, and expected outcomes. Finally, the challenges, opportunities, and future perspectives in developing starch-lignin materials, such as adhesives, coatings, films, and controlled delivery systems, are discussed.

Drying Technique Providing Maximum Benefits on Hydrogelling Ability of Avocado Seed Protein: Spray Drying

The current study focused on creating natural hydrogels consisting of mixtures of avocado seed proteins dried with different techniques and locust bean gum. Proteins were extracted from avocado seed by alkali and isoelectric precipitation methods. Avocado seed proteins were dried by five different drying methods, namely ambient drying, oven drying, vacuum drying, freeze drying, and spray drying. FT-IR spectra were used to analyze the chemical structure of proteins dried using various techniques. Additionally, hydrogel models were constructed in the presence of avocado seed proteins and locust bean gum to clarify the effect of drying techniques on their hydrogelling ability. The impact of drying techniques on the functional behavior of hydrogels was notable. The maximum water holding capacity values were detected in the hydrogel system containing spray-dried proteins (93.79%), followed by freeze-dried (86.83%), vacuum-dried (76.17%), oven-dried (72.29%), and ambient-dried (64.8%) counterparts. The swelling ratio was 34.10, 33.51, 23.05, 18.93, and 14.39% for gels in the presence of freeze-dried, spray-dried, vacuum-dried, oven-dried, and ambient-dried proteins, respectively. Additionally, the desirable values for the amount of protein leaking from the systems prepared using spray-dried (7.99%) and freeze-dried (12.14%) proteins were obtained compared to others (ambient-dried: 24.03%; oven-dried: 17.69%; vacuum-dried: 19.10%). Superior results in terms of textural properties were achieved in hydrogel models containing spray-dried and freeze-dried proteins. In general, hydrogel models exhibited elastic behavior rather than viscous properties; however, the magnitudes of elasticity varied. Furthermore, the success of gels containing hydrogel models containing spray-dried protein and locust bean gum in the bioactive compound delivery system was obvious compared with protein ones alone.

Multifunctional Hydrogels Based on Cellulose and Modified Lignin for Advanced Wounds Management

Considering the complex process of wound healing, it is expected that an optimal wound dressing should be able to overcome the multiple obstacles that can be encountered in the wound healing process. An ideal dressing should be biocompatible, biodegradable and able to maintain moisture, as well as allow the removal of exudate, have antibacterial properties, protect the wound from pathogens and promote wound healing. Starting from this desideratum, we intended to design a multifunctional hydrogel that would present good biocompatibility, the ability to provide a favorable environment for wound healing, antibacterial properties, and also, the capacity to release drugs in a controlled manner. In the preparation of hydrogels, two natural polymers were used, cellulose (C) and chemically modified lignin (LE), which were chemically cross-linked in the presence of epichlorohydrin. The structural and morphological characterization of CLE hydrogels was performed by ATR-FTIR spectroscopy and scanning electron microscopy (SEM), respectively. In addition, the degree of swelling of CLE hydrogels, the incorporation/release kinetics of procaine hydrochloride (PrHy), and their cytotoxicity and antibacterial properties were investigated. The rheological characterization, mechanical properties and mucoadhesion assessment completed the study of CLE hydrogels. The obtained results show that CLE hydrogels have an increased degree of swelling compared to cellulose-based hydrogel, a better capacity to encapsulate PrHy and to control the release of the drug, as well as antibacterial properties and improved mucoadhesion. All these characteristics highlight that the addition of LE to the cellulose matrix has a positive impact on the properties of CLE hydrogels, confirming that these hydrogels can be considered as potential candidates for applications as oral wound dressings.

Sustainable Biomass Lignin-Based Hydrogels: A Review on Properties, Formulation, and Biomedical Applications

Different techniques have been developed to overcome the recalcitrant nature of lignocellulosic biomass and extract lignin biopolymer. Lignin has gained considerable interest owing to its attractive properties. These properties may be more beneficial when including lignin in the preparation of highly desired value-added products, including hydrogels. Lignin biopolymer, as one of the three major components of lignocellulosic biomaterials, has attracted significant interest in the biomedical field due to its biocompatibility, biodegradability, and antioxidant and antimicrobial activities. Its valorization by developing new hydrogels has increased in recent years. Furthermore, lignin-based hydrogels have shown great potential for various biomedical applications, and their copolymerization with other polymers and biopolymers further expands their possibilities. In this regard, lignin-based hydrogels can be synthesized by a variety of methods, including but not limited to interpenetrating polymer networks and polymerization, crosslinking copolymerization, crosslinking grafted lignin and monomers, atom transfer radical polymerization, and reversible addition-fragmentation transfer polymerization. As an example, the crosslinking mechanism of lignin-chitosan-poly(vinyl alcohol) (PVA) hydrogel involves active groups of lignin such as hydroxyl, carboxyl, and sulfonic groups that can form hydrogen bonds (with groups in the chemical structures of chitosan and/or PVA) and ionic bonds (with groups in the chemical structures of chitosan and/or PVA). The aim of this review paper is to provide a comprehensive overview of lignin-based hydrogels and their applications, focusing on the preparation and properties of lignin-based hydrogels and the biomedical applications of these hydrogels. In addition, we explore their potential in wound healing, drug delivery systems, and 3D bioprinting, showcasing the unique properties of lignin-based hydrogels that enable their successful utilization in these areas. Finally, we discuss future trends in the field and draw conclusions based on the findings presented.

Significance of biopolymer-based hydrogels and their applications in agriculture: a review in perspective of synthesis and their degree of swelling for water holding

Hydrogels are three-dimensional polymer networks that are hydrophilic and capable of retaining a large amount of water. Hydrogels also can act as vehicles for the controlled delivery of active compounds. Bio-polymers are polymers that are derived from natural sources. Hydrogels prepared from biopolymers are considered non-toxic, biocompatible, biodegradable, and cost-effective. Therefore, bio-polymeric hydrogels are being extensively synthesized and used all over the world. Hydrogels based on biopolymers finds important applications in the agricultural field where they are used as soil conditioning agents as they can increase the water retention ability of soil and can act as a carrier of nutrients and other agrochemicals. Hydrogels are also used for the controlled delivery of fertilizer to plants. In this review, bio-polymeric hydrogels based on starch, chitosan, guar gum, gelatin, lignin, and alginate polymer have been discussed in terms of their synthesis method, swelling behavior, and possible agricultural application. The urgency to address water scarcity and the need for sustainable water management in agriculture necessitate the exploration and implementation of innovative solutions. By understanding the synthesis techniques and factors influencing the swelling behavior of these hydrogels, we can unlock their full potential in fostering sustainable agriculture and mitigating the challenges posed by an ever-changing environment.

Lignin-based nanomaterials for food and pharmaceutical applications: Recent trends and future outlook

Small particles of size ranging from 1 to 100 nm are referred to as nanoparticles. Nanoparticles have tremendous applications in various sectors, including the areas of food and pharmaceutics. They are being prepared from multiple natural sources widely. Lignin is one such source that deserves special mention due to its ecological compatibility, accessibility, abundance, and low cost. This amorphous heterogeneous phenolic polymer is the second most abundant molecule in nature after cellulose. Apart from being used as a biofuel source, lignin is less explored for its potential at a nano-level. In plants, lignin exhibits cross-linking structures with cellulose and hemicellulose. Numerous advancements have taken place in synthesizing nanolignins for manufacturing lignin-based materials to benefit from the untapped potential of lignin in high-value-added applications. Lignin and lignin-based nanoparticles have numerous applications, but in this review, we are mainly focusing on the applications in the food and pharmaceutical sectors. The exercise we undertake has great relevance as it helps scientists and industries gain valuable insights into lignin's capabilities and exploit its physical and chemical properties to facilitate the development of future lignin-based materials. We have summarized the available lignin resources and their potential in the food and pharmaceutical industries at various levels. This review attempts to understand various methods adopted for the preparation of nanolignin. Furthermore, the unique properties of nano-lignin-based materials and their applications in fields including the packaging industry, emulsions, nutrient delivery, drug delivery hydrogels, tissue engineering, and biomedical applications were well-discussed.

Preparation and Characterization of the Composition of Volatile Compounds, Fatty Acids and Thermal Behavior of Paprika

This study aimed to investigate the thermal behavior and composition of volatile compounds, fatty acids and polyphenols in paprika obtained from peppers of different countries. The thermal analysis revealed various transformations in the paprika composition, namely drying, water loss and decomposition of volatile compounds, fatty acids, amino acids, cellulose, hemicellulose and lignin. The main fatty acids found in all paprika oils were linoleic (20.3-64.8%), palmitic (10.6-16.0%) and oleic acid (10.4-18.1%). A notable amount of omega-3 was found in spicy paprika powder varieties. The volatile compounds were classified into six odor classes (citrus (29%), woody (28%), green (18%), fruity (11%), gasoline (10%) and floral (4%)). The total polyphenol content ranged between 5.11 and 10.9 g GA/kg.

Polyphenols—Ensured Accessibility from Food to the Human Metabolism by Chemical and Biotechnological Treatments

Polyphenols are plant-based compounds famous for their positive impact on both human health and the quality of food products. The benefits of polyphenols are related to reducing cardiovascular diseases, cholesterol management, cancers, and neurological disorders in humans and increasing the shelf life, management of oxidation, and anti-microbial activity in food products. The bioavailability and bio-accessibility of polyphenols are of the highest importance to secure their impact on human and food health. This paper summarizes the current state-of-the-art approaches on how polyphenols can be made more accessible in food products to contribute to human health. For example, by using food processing methods including various technologies, such as chemical and biotechnological treatments. Food matrix design and simulation procedures, in combination with encapsulation of fractionated polyphenols utilizing enzymatic and fermentation methodology, may be the future technologies to tailor specific food products with the ability to ensure polyphenol release and availability in the most suitable parts of the human body (bowl, intestine, etc.). The development of such new procedures for utilizing polyphenols, combining novel methodologies with traditional food processing technologies, has the potential to contribute enormous benefits to the food industry and health sector, not only reducing food waste and food-borne illnesses but also to sustain human health.

Novel succinoglycan dialdehyde/aminoethylcarbamoyl-β-cyclodextrin hydrogels for pH-responsive delivery of hydrophobic drugs

β-Cyclodextrin cross-linked succinoglycan dialdehyde hydrogels was prepared for hydrophobic drug delivery. Succinoglycan dialdehyde (SGDA) was synthesized from sodium periodate oxidation of succinoglycan isolated from Sinorhizobium meliloti Rm1021. Aminoethylcarbamoyl-β-cyclodextrin (ACD) was crosslinked with SGDA to form a succinoglycan dialdehyde/aminoethylcarbamoyl-β-cyclodextrin (SGDA/ACD) hydrogels. The SGDA/ACD hydrogels exhibited a 65.7 % improvement in storage modulus (G') and a 5.7-fold higher compressive strain than the SGDA/poly(ethylene glycol) diamine (PEG) hydrogels as controls. A hardly soluble drug, baicalein was used for the drug loading and release properties of SGDA/ACD hydrogels. Baicalein was released about 98 % within 48 h at pH 7.4, but not completely released even after 48 h at pH 2.0. In addition, at pH 7.4, only about 56 % of the baicalein loaded on the SGDA/PEG hydrogels was released within 48 h, while about 98 % of the baicalein loaded on the SGDA/ACD hydrogels was released within 48 h. It indicates that ACD significantly improved the solubilization efficacy of the baicalein. In vitro testing of cell viability using HEK-293 cells also showed that the SGDA/ACD hydrogels were suitable for the cells. In conclusion, SGDA/ACD hydrogels significantly enhance the utilization of baicalein and provide potential applications in drug delivery systems for hardly soluble drugs.

Designing Lignin-Based Biomaterials as Carriers of Bioactive Molecules

There is a need to develop circular and sustainable economies by utilizing sustainable, green, and renewable resources in high-tech industrial fields especially in the pharmaceutical industry. In the last decade, many derivatives of food and agricultural waste have gained considerable attention due to their abundance, renewability, biocompatibility, environmental amiability, and remarkable biological features. Particularly, lignin, which has been used as a low-grade burning fuel in the past, recently attracted a lot of attention for biomedical applications because of its antioxidant, anti-UV, and antimicrobial properties. Moreover, lignin has abundant phenolic, aliphatic hydroxyl groups, and other chemically reactive sites, making it a desirable biomaterial for drug delivery applications. In this review, we provide an overview of designing different forms of lignin-based biomaterials, including hydrogels, cryogels, electrospun scaffolds, and three-dimensional (3D) printed structures and how they have been used for bioactive compound delivery. We highlight various design criteria and parameters that influence the properties of each type of lignin-based biomaterial and corelate them to various drug delivery applications. In addition, we provide a critical analysis, including the advantages and challenges encountered by each biomaterial fabrication strategy. Finally, we highlight the prospects and future directions associated with the application of lignin-based biomaterials in the pharmaceutical field. We expect that this review will cover the most recent and important developments in this field and serve as a steppingstone for the next generation of pharmaceutical research.

Locust bean gum provides excellent mechanical and release attributes to soy protein-based natural hydrogels

The current study concentrated on designing soy protein (SP)-based natural hydrogels in the presence of locust bean gum (LBG). For this, the gums were recovered from the kernel of the relevant plant and incorporated into SP gel models. Three more hydrogels were fabricated using commercial carbohydrates (gum Arabic (GA), maltodextrin (MD), and pectin (PC)) to decipher exactly the ability of LBG in these models. The chemical and morphological structures of the samples were elaborated by FTIR and SEM analyses. The coexistence of protein and carbohydrates led to an enhancement in functional (water holding capacity (WHC), swelling ratio, protein leachability, volumetric gel index (VGI)) and mechanical (textural and rheological behavior) features of natural gels compared to SP alone (control) but the quality of hydrogels was impressed by the carbohydrate type. Hydrogels designed with LBG came to the fore in terms of these attributes. Additionally, these gel models created awareness for phenolic delivery.

Green and sustainable extraction of lignin by deep eutectic solvent, its antioxidant activity, and applications in the food industry

Lignin, an amorphous biomacromolecule abundantly distributed in the plant kingdom, has gained considerable attention due to its intrinsic bioactivities and renewable nature. Owing to its polyphenolic structure, lignin has a variety of human health activities, including antioxidant, antimicrobial, antidiabetic, antitumor, and other activities. The extraction of lignin from various sources in a green and sustainable manner is critical in the food industry. Deep eutectic solvent (DES) has recently been recognized as a class of safe and environmentally friendly media capable of efficiently extracting lignin. This article comprehensively reviews the recent advances in lignin extraction using DES, discusses the influential factors on the antioxidant activity of lignin, interprets the relationship between antioxidant activity and lignin structure, and overviews the applications of lignin in the food industry. We aim to highlight the advantages of DES in lignin extraction and valorization from the nutrition and food views.

3D Matrices for Enhanced Encapsulation and Controlled Release of Anti-Inflammatory Bioactive Compounds in Wound Healing

Current trends in the development of wound dressings are oriented towards the use of biopolymer-based materials, due to their unique properties such as non-toxicity, hydrophilicity, biocompatibility and biodegradability, properties that have advantageous therapeutic characteristics. In this regard, the present study aims to develop hydrogels based on cellulose and dextran (CD) and to reveal their anti-inflammatory performance. This purpose is achieved by incorporating plant bioactive polyphenols (PFs) in CD hydrogels. The assessments include establishing the structural characteristics using attenuated total reflection Fourier transformed infrared (ATR-FTIR) spectroscopy, the morphology by scanning electron microscopy (SEM), the swelling degree of hydrogels, the PFs incorporation/release kinetics and the hydrogels' cytotoxicity, together with evaluation of the anti-inflammatory properties of PFs-loaded hydrogels. The results show that the presence of dextran has a positive impact on the hydrogel's structure by decreasing the pore size at the same time as increasing the uniformity and interconnectivity of the pores. In addition, there is an increased degree of swelling and of the encapsulation capacity of PFs, with the increase of the dextran content in hydrogels. The kinetics of PFs released by hydrogels was studied according to the Korsmeyer-Peppas model, and it was observed that the transport mechanisms depend on hydrogels' composition and morphology. Furthermore, CD hydrogels have been shown to promote cell proliferation without cytotoxicity, by successfully culturing fibroblasts and endothelial cells on CD hydrogels (over 80% viability). The anti-inflammatory tests performed in the presence of lipopolysaccharides demonstrate the anti-inflammatory properties of the PFs-loaded hydrogels. All these results provide conclusive evidence on the acceleration of wound healing by inhibiting the inflammation process and support the use of these hydrogels encapsulated with PFs in wound healing applications.

Amino-Functionalized Cellulose Nanofiber/Lignosulfonate New Aerogel Adsorbent for the Removal of Dyes and Heavy Metals from Wastewater

Due to the increasingly widespread water pollutants and the high cost of treatment methods, there is a demand for new, inexpensive, renewable, and biodegradable adsorbent materials for the purification of wastewater contaminants. In this study, a new biocomposite aerogel (Amf-CNF/LS) was prepared using a chemically cross-linking method between the amino-functionalized cellulose nanofibers (Amf-CNF) and lignosulfonates (LS). The physical and chemical properties of the prepared aerogel were investigated using several techniques including elemental analysis, scanning electron microscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and N₂ adsorption-desorption analysis. The Amf-CNF/LS aerogel was then applied for the removal of methylene blue (MB), rhodamine B dye (RhB), and the heavy metal cadmium ion (Cd²⁺) from synthetic wastewater solutions. The adsorption parameters controlling the adsorption process including the pH, contact time, adsorbent dosage, and adsorbate concen-tration were optimized. High adsorption kinetics and isotherms were observed, with the adsorption isotherms of the Amf-CNF/LS aerogel fitting the Langmuir model with maximum adsorption capacities of 170.94, 147.28, and 129.87 mg/g for MB, RhB, and Cd²⁺, respectively. These results show that Amf-CNF/LS aerogel is a promising green and inexpensive adsorbent for MB, RhB, and Cd²⁺ removal from wastewater.

Kraft lignin-based carbon xerogel/zinc oxide composite for 4-chlorophenol solar-light photocatalytic degradation: effect of pH, salinity, and simultaneous Cr(VI) reduction

Considering the ever-increasing need for efficient wastewater treatment, this study focused on the development of new kraft lignin-based carbon xerogel/zinc oxide (XCL/ZnO w) photocatalysts. The inclusion of the carbon xerogel is expected to cause an improvement in charge transfer throughout the photoactivation process, consequently enhancing its overall photocatalytic efficiency. Characterization shows that the materials developed are composed of both zinc oxide and carbon xerogel. The addition of the lignin-based carbon xerogel caused a significant morphological modification to the composite materials, resulting in a greater specific surface area. Regarding the photocatalytic efficiency, the optimized composite (XCL/ZnO 1.0) displayed superior efficiency to the pure zinc oxide, especially when calcined at 700 °C, with an increase of 20% in the overall photodegradation capacity for the 4-chlorophenol (4CP) molecule. The XCL/ZnO 1.0 also displayed better performance than its tannin counterpart, previously reported in the literature, obtaining a 60% increase in the apparent reaction rate constant. The XCL/ZnO 1.0 also displayed better performance for the simultaneous hexavalent chrome (Cr (VI)) reduction/4CP oxidation reaction. Salinity and system pH had a significant influence on the efficiency of the 4CP photodegradation, as higher values of salinity and lower pHs caused a decrease in the overall efficiency of the process. At last, chronoamperometry and open-circuit potential tests confirmed the superiority of the XCL/ZnO 1.0 over the pure ZnO, highlighting the beneficial impact of the carbon xerogel on the charge transport dynamics of the composite.

Synthesis of Gallic Acid-Loaded Chitosan-Grafted-2-Acrylamido-2-Methylpropane Sulfonic Acid Hydrogels for Oral Controlled Drug Delivery: In Vitro Biodegradation, Antioxidant, and Antibacterial Effects

In this study, chitosan (CS) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS)-based hydrogels were formulated by the free radical polymerization technique for the controlled release of gallic acid. Fourier transform infrared spectroscopy (FTIR) confirmed the successful preparation and loading of gallic acid within the hydrogel network. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed the increased thermal stability of the hydrogels following the crosslinking and polymerization of chitosan and AMPS. In X-ray diffraction analysis (XRD), the crystallinity of the raw materials decreased, indicating strong crosslinking of the reagents and the formation of a new polymeric network of hydrogels. Scanning electron microscopy (SEM) revealed that the hydrogel had a rough, dense, and porous surface, which is consistent with the highly polymerized composition of the hydrogel. After 48 h, the hydrogels exhibited higher swelling at pH 1.2 (swelling ratio of 19.93%) than at pH 7.4 (swelling ratio of 15.65%). The drug release was analyzed using ultraviolet-visible (UV-Vis) spectrophotometer and demonstrated that after 48 h, gallic acid release was maximum at pH 1.2 (85.27%) compared to pH 7.4 (75.19%). The percent porosity (78.36%) and drug loading increased with the increasing concentration of chitosan and AMPS, while a decrease was observed with the increasing concentration of ethylene glycol dimethyl methacrylate (EGDMA). Crosslinking of the hydrogels increased with concentrations of chitosan and EGDMA but decreased with AMPS. In vitro studies demonstrated that the developed hydrogels were biodegradable (8.6% degradation/week) and had antimicrobial (zone of inhibition of 21 and 16 mm against Gram-positive bacteria Escherichia coli and Staphylococcus aureus as well as 13 mm against Gram-negative bacteria Pseudomonas aeruginosa, respectively) and antioxidant (73% DPPH and 70% ABTS) properties. Therefore, the prepared hydrogels could be used as an effective controlled drug delivery system.

Synthesis of a biobased resin and its screening as an alternative adsorbent for organic and inorganic micropollutant removal

The sol-gel route was used to synthesize a biophenolic resin from a blend of Kraft black liquor and condensed tannin. The biobased resin has an amorphous structure and diversified surface functional groups. The biomaterial thermal stability was improved by Kraft black liquor, which increased the fixed carbon yield by 19.78% in an oxidant medium and 9.07% in an inert medium. Moreover, the presence of fixed carbon and char is positively related to the material flame retardant property. Additionally, impedance measurements were used to understand the physical phenomena occurring at the polymeric matrix's interface and the material's final properties. The biobased resin characterization and the considerable increase in the presence of micropollutants in surface and water bodies suggest the new biomaterial application in the adsorption process. Thus, its adsorption capacity toward several organic and inorganic micropollutants and its effectiveness in complex water matrices were evaluated. Methylene blue was used as a model compound to assess the influence of the resin composition on the adsorption capacity, and the type H isotherm indicates the high affinity of the biobased resin toward the micropollutant. The adsorption occurs in multilayer by intermolecular interaction and electrostatic forces. The amount of Kraft black liquor favored the adsorption, and the adsorption capacity was greater than 1250 mg g-1. When inorganic compounds were evaluated, the carboxyl and phenol groups favor the biomaterial affinity toward metal ions. Cu2+ and Ni2+ were completely removed from the contaminated water, and the adsorption capacity of the other inorganic compounds was: Pb2+ (36.97 mg g-1), Al3+ (22.17 mg g-1), Ba2+ (12.76 mg g-1), Ag1+ (33.85 mg g-1), and Fe2+ (19.44 mg g-1). In contrast, the adsorption capacity of the organic micropollutants was: 2,4-D (3.09 mg g-1), diuron (5.89 mg g-1), atrazine (2.71 mg g-1), diclofenac (2.04 mg g-1), caffeine (5.79 mg g-1), acetaminophen (4.80 mg g-1), methylene Blue (106.66 mg g-1), and methyl orange (30.48 mg g-1). The results pointed that the adsorption efficiency of organic micropollutants increases with the distribution coefficient (logD), indicating the biobased resin affinity toward more lipophilic compounds and ionized species.

Antioxidant, Antimicrobial, and Kinetic Studies of Β-Cyclodextrin Crosslinked with Lignin for Drug Delivery

β-Cyclodextrin was attached to lignin/lignin crosslinked by epichlorohydrin and served as a drug delivery matrix. Ketoconazole and piroxicam were added into the polymeric matrix as antifungal and anti-inflammatory agents, respectively. The percentage of drug retained ranged from 48.4% to 58.4% for ketoconazole and piroxicam, respectively. It was found that their tensile strengths increased with decreasing particle size, ranging between 59% and 71% for lignin crosslinked with β-cyclodextrin base matrix (LCD). Depending on the polymeric matrix, the drug release kinetics fit well in the Korsmeyer-Peppas model, with or without Fickian diffusion. From the materials based on the mixture of epoxidized lignin and β-cyclodextrin, the medicines were released more slowly (the release rate constant presents lower values ranging between 1.117 and 1.783), as compared with those comprising LCD (2.210-4.824). The materials were also demonstrated to have antimicrobial activity. The antioxidant activity of LCD loaded with piroxicam was found to be 23.9% greater than that of the base matrix (LCD). These findings could be useful towards β-cyclodextrin attached to lignin formulation development of drug carriers with antioxidant activity.

Surface ion-imprinted brewer's spent grain with low template loading for selective uranyl ions adsorption from simulated wastewater

Efficient removal of uranyl ions from wastewater requires excellent selectivity of the adsorbents. Herein, we report a new strategy using a high monomer/template molar ratio of 500:1 to prepare surface ion-imprinted brewer's spent grain (IIP-BSG) for selective U(VI) removal using binary functional monomers (2-hydroxyethyl methacrylate and diethyl vinylphosphonate) with high site accessibility and easy template removal. IIP-BSG exhibits a maximum U(VI) adsorption capacity of 165.7 mg/g, a high selectivity toward U(VI) in the presence of an excess amount of Eu(III) (Eu/U molar ratio = 20), a good tolerance of salinity, and a high reusability. In addition, mechanism studies have revealed electrostatic interaction and a coordination of uranyl ions by carboxyl and phosphoryl groups, the predominant contribution of high-energy (specific) sites during selective adsorption, and internal mass transfer as the rate-controlling step of U(VI) adsorption. Furthermore, IIP-BSG shows great potentials to separate U(VI) from lanthanides in simulated nuclear wastewater (pH₀ = 3.5) and selectively concentrate U(VI) from simulated mine water (pH₀ = 7.1). This study proves that the ion-imprinting effect can be achieved using a very low template amount with reduced production cost and secondary pollution, which benefits large-scale promotion of the ion-imprinted materials for selective uranyl ions removal.

One-pot synthesis of brewer's spent grain-supported superabsorbent polymer for highly efficient uranium adsorption from wastewater

High-efficient and fast adsorption of uranium is important to reduce the hazards caused by the uranium contamination of water environment due to the increased human activities. Herein, brewer's spent grain (BSG)-supported superabsorbent polymers (SAP) with different cross-linking densities are prepared as cheap and eco-friendly adsorbents for the first time via one-pot swelling and graft polymerization. A 7 wt% NaOH solution is used to swell BSG before grafting and subsequently neutralize the acrylic acid to control the reaction rate without producing alkaline wastewater. Compared with the traditional methods, swelling improves the grafting density and the utilization of raw materials due to the increased disorder degree of the BSG fibers. This results in the grafting of abundant carboxyl and amide groups onto the BSG backbone, forming a strongly hydrophilic polymer network of the BSG-SAP. Compared with the reference polymers without BSG, BSG-SAP presents higher adsorption capacity and enhanced reusability. The highly cross-linked BSG-SAP (BSG-SAP-H) shows an outstanding adsorption capacity of U(VI) (1465 mg/g at pH₀ = 4.6), a fast adsorption rate (81% of equilibrium adsorption capacity in 15 min), and a high selectivity in the presence of competing ions. Adsorption mechanism studies reveal the involvement of amide groups, a bidentate binding structure between UO₂²⁺ and the carboxyl groups, and a cation exchange between Na⁺ and UO₂²⁺. More importantly, the adsorption capacity of BSG-SAP-H reaches 254.4 mg/g in the fixed-bed column experiment at a low initial concentration (c₀(U) = 30 mg/L) and keeps 80% of the adsorption capacity after four cycles, indicating a great potential for uranium removal from wastewater. This work shows a suitable approach to explore the untreated biomass to prepare SAP with enhanced adsorption performance via a general and low-cost strategy.

Facile Fabrication of Lignin-Cellulose Green Nanogels

There has been increasing exploration of the development and production of biodegradable polymers in response to issues with petrol-based polymers and their impact on the environment. Here we report a new approach to synthesize a natural nanogel from lignin and nanocellulose. First lignin nanobeads were synthesized by a solvent-shifting method, which showed a spherical shape with a diameter of 159.7 nm. Then the lignin nanobeads were incorporated into a nanocellulose network to form the lignin/cellulose nanogels. The nanocellulose fibrils (CNF-C) nanogels reveal a higher storage modulus than the nanocellulose crystal (CNC-C) ones due to the denser network with self-entanglement of longer cellulose chains. The presence of lignin nanobeads in the nanogels helped to increase the viscoelasticity of the nanogels. This work highlights that the new kinds of green nanogels could be potentially utilized in a variety of biomedical applications such as drug delivery and wound dressing.

Comparative adsorptive behaviour of cow dung ash and starch as potential eco-friendly matrices for controlled organophosphorus pesticides delivery

The work reported herein explores the viability of cow dung ash (CDA) as a matrix for controlled pesticide delivery, by comparing its adsorptive characteristics towards two organophosphorus pesticides with those of starch, conventionally utilized in designing controlled pesticide delivery systems. CDA was characterized by Fourier transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD). Data for pesticide adsorption on the surfaces correlate well with Langmuir and Freundlich isotherms, with the former isotherm giving a slightly better fit (R² ≥ 0.90) than the latter (R² ≥ 0.81). Values of the adsorption parameters K_L and R_L indicate favourable pesticide adsorption on both surfaces. Desorption is the microscopic reverse of adsorption; both processes obey pseudo-second-order kinetics. The implication of this kinetic form is a mechanism in which adsorbate diffusion to the polymer surface and its transport into the polymer interior are important events. The isothermal and kinetic ratios, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{{K_{L}^{CDA} }}{{K_{L}^{Starch} }} = 3.8$$\end{document}KLCDAKLStarch=3.8 and 4.0, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{{k_{2}^{CDA} }}{{k_{2}^{Starch} }} = 1.3$$\end{document}k2CDAk2Starch=1.3 and 0.6, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{{k_{ - 2}^{CDA} }}{{k_{ - 2}^{Starch} }} = 5.2$$\end{document}k-2CDAk-2Starch=5.2 and 1.0 at pH 7.0 and 27 °C, compare the adsorptive behaviour of diazinon and dichlorvos, respectively, on CDA and starch. These parameters are of the same order of magnitude, signalling that CDA is as potentially viable as starch for use as a matrix for pesticide-controlled delivery.

Antimicrobial Properties of Bacterial Cellulose Films Enriched with Bioactive Herbal Extracts Obtained by Microwave-Assisted Extraction

The use of bacterial cellulose (BC) as scaffold for active biofilms is one of the most interesting applications, especially for the biomedical and food industries. However, there are currently few studies evaluating the potential of incorporating herbal extracts into various biomaterials, including BC. Thus, the aim of this study is to report a screening of the total phenolic content and antioxidant and antimicrobial activity of ethanolic extracts of oregano, rosemary, parsley, and lovage. At the same time, the bioactive potential of BC enriched with the four ethanolic extracts is described. Microwave-assisted extraction was used to extract bioactive compounds from the four selected herbs. The physical, mechanical, structural, and chemical properties of BC were also assessed. Next, BC was enriched with the extracts, and their effect against Escherichia coli, Staphylococcus aureus, and Candida albicans was evaluated. The results showed that the bioactivity of the herbs varied significantly, with rosemary extract being the most bioactive. The BC films possessed good mechanical properties, and a three-dimensional network fibrillar structure appropriate for ethanolic-extract incorporation. The BC samples enriched with rosemary extracts had the highest antibacterial activity against S. aureus, while E. coli. and C. albicans seemed to be resistant to all extracts, regardless of herbs.

Lignin-Based Porous Biomaterials for Medical and Pharmaceutical Applications

Over the past decade, lignin-based porous biomaterials have been found to have strong potential applications in the areas of drug delivery, tissue engineering, wound dressing, pharmaceutical excipients, biosensors, and medical devices. Lignin-based porous biomaterials have the addition of lignin obtained from lignocellulosic biomass. Lignin as an aromatic compound is likely to modify the materials’ mechanical properties, thermal properties, antioxidant, antibacterial property, biodegradability, and biocompatibility. The size, shape, and distribution of pores can determine the materials’ porous structure, porosity, surface areas, permeability, porosity, water solubility, and adsorption ability. These features could be suitable for medical applications, especially controlled drug delivery systems, wound dressing, and tissue engineering. In this review, we provide an overview of the current status and future potential of lignin-based porous materials for medical and pharmaceutical uses, focusing on material types, key properties, approaches and techniques of modification and fabrication, and promising medical applications.

Next generation applications of lignin derived commodity products, their life cycle, techno-economics and societal analysis

The pulp and biorefining industries produce their waste as lignin, which is one of the most abundant renewable resources. So far, lignin has been remained severely underutilized and generally burnt in a boiler as a low-value fuel. To demonstrate lignin's potential as a value-added product, we will review market opportunities for lignin related applications by utilizing the thermo-chemical/biological depolymerization strategies (with or without catalysts) and their comparative evaluation. The application of lignin and its derived aromatics in various sectors such as cement industry, bitumen modifier, energy materials, agriculture, nanocomposite, biomedical, H2 source, biosensor and bioimaging have been summarized. This comprehensive review article also highlights the technical, economic, environmental, and socio-economic variable that affect the market value of lignin-derived by-products. The review shows the importance of lignin, and its derived products are a platform for future bioeconomy and sustainability.

Recent Progress in Biopolymer-Based Hydrogel Materials for Biomedical Applications

Hydrogels from biopolymers are readily synthesized, can possess various characteristics for different applications, and have been widely used in biomedicine to help with patient treatments and outcomes. Polysaccharides, polypeptides, and nucleic acids can be produced into hydrogels, each for unique purposes depending on their qualities. Examples of polypeptide hydrogels include collagen, gelatin, and elastin, and polysaccharide hydrogels include alginate, cellulose, and glycosaminoglycan. Many different theories have been formulated to research hydrogels, which include Flory-Rehner theory, Rubber Elasticity Theory, and the calculation of porosity and pore size. All these theories take into consideration enthalpy, entropy, and other thermodynamic variables so that the structure and pore sizes of hydrogels can be formulated. Hydrogels can be fabricated in a straightforward process using a homogeneous mixture of different chemicals, depending on the intended purpose of the gel. Different types of hydrogels exist which include pH-sensitive gels, thermogels, electro-sensitive gels, and light-sensitive gels and each has its unique biomedical applications including structural capabilities, regenerative repair, or drug delivery. Major biopolymer-based hydrogels used for cell delivery include encapsulated skeletal muscle cells, osteochondral muscle cells, and stem cells being delivered to desired locations for tissue regeneration. Some examples of hydrogels used for drug and biomolecule delivery include insulin encapsulated hydrogels and hydrogels that encompass cancer drugs for desired controlled release. This review summarizes these newly developed biopolymer-based hydrogel materials that have been mainly made since 2015 and have shown to work and present more avenues for advanced medical applications.

Construction of Biomass-Derived Hybrid Organogel Electrodes with a Cross-Linking Conductive Network for High-Performance All-Solid-State Supercapacitors

The biomass-based inter-transmission network architecture is expected to act on all-solid-state supercapacitors (ASSSCs) by building excellent conductive paths and achieving high ionic conductivity to promote their development as future electronic devices. Here, biomass-derived hybrid organogel electrodes constructed by incorporating polyaniline (PANI) into cellulose/dealkaline lignin (C/DL) film architectures exhibit an impressive specific capacitance (582 F g^-1 at 1 A g^-1) due to the effective dispersion and doping of PANI. Moreover, the specific capacitance of the best C/DL-PANI electrode is nearly 19 times higher than that of a cellulose-PANI electrode, which is attributed to the contribution of DL to the pseudocapacitance. ASSSCs assembled using the C/DL-PANI electrodes and the DL gel electrolyte exhibit excellent specific capacitance (344 F g^-1 at 1 A g^-1), Coulombic efficiency (∼100% for 5000 cycles), cycle stability (85.7% for 5000 cycles at 1 A g^-1), and energy density (58.1 W h kg^-1 at 0.5 kW kg^-1). The ASSSCs showed a comparable or even higher electrochemical performance than the reported PANI-based or biomass-based ASSSCs, which can be due to the conductive network of the biomass-derived electrodes, the migration of ions between the electrodes through the gel electrolyte ion pathway, and the interfacial synergy. This innovative work paves the way for the development of ASSSC applications based on biomass materials.

Green and efficient in-situ biosynthesis of antioxidant and antibacterial bacterial cellulose using wine pomace

Biologically active bacterial cellulose (BC) was efficiently synthesized in situ using wine pomace and its hydrolysate. The structural and biomechanical properties together with the biological functions of the BC were investigated. Functional BC from wine pomace and its enzymatic hydrolysate were of high purity and had higher crystallinity indexes (90.61% and 89.88%, respectively) than that from HS medium (82.26%). FTIR results proved the in-situ bindings of polyphenols to the functionalized BC. Compared to BC from HS medium, wine pomace-based BC had more densely packed ultrafine fibrils, higher diameter range distributions of fiber ribbon, but lower thermal decomposition temperatures, as revealed by the SEM micrographs and DSC data. Meanwhile, wine pomace-based BC exhibited higher loads in tensile strength and higher hardness (4.95 ± 0.31 N and 5.13 ± 0.63 N, respectively) than BC in HS medium (3.43 ± 0.14 N). Furthermore, BC synthesized from wine pomace hydrolysate exhibited a slower release rate of phenolic compounds, and possessed more antioxidant activities and better bacteriostatic effects than BC from wine pomace. These results demonstrate that BC synthesized in situ from wine pomace (especially from enzymatic hydrolysate) is a promising biomolecule with a potential application in wound dressing, tissue engineering, and other biomedical fields.

Fabrication, Characterization and Toxicity Evaluation of Chemically Cross linked Polymeric Network for Sustained Delivery of Metoprolol Tartrate

Natural mucilages are auspicious biodegradable polymeric materials. The aim of the present research work was to elucidate the characteristics of quince mucilage-based polymeric network for sustained delivery of metprolol tartrate and its toxicity evaluation. Mucilage was extracted by hot water extraction, and characterization of quince mucilage was accomplished by using Fourier transform infrared (FTIR) spectroscopy. Different batches of quince mucilage polymeric network were prepared by free radical polymerization by utilizing varying ratios of quince mucilage, acrylamide and crosslinker. Degree of swelling depends on concentration of mucilage, monomer and also on crosslinking density of polymeric network. FTIR illustrates proficient grafting, and morphological (scanning electron microscopy) analysis signified porous design. Hence, quince mucilage-based design was encouraging for sustained delivery of metprolol tartrate and acute toxicity evaluation proved that mucilage-based network was safe for oral drug delivery system.

Injectable Lignin-co-Gelatin Cryogels with Antioxidant and Antibacterial Properties for Biomedical Applications

For several biomedical applications, it is essential to develop novel bioactive materials. Such biomaterials could potentially improve wound healing, prevent infections, or be used in immunoengineering. For example, bioactive materials that reduce oxidative stress without relying on antibiotics and other drugs could be beneficial. Hydrogel-based biomaterials, especially those derived from natural polymers, have been regarded as one of the most promising scaffolds for biomedical research. These multifunctional scaffolds can exhibit high water adsorption capacity, biocompatibility, and biomechanical properties that can match native tissues. Cryogels are a special type of hydrogels in which polymers are cross-linked around ice crystals. As a result, cryogels exhibit unique physical features, including a macroporous and interconnected network, flexibility, shape-memory properties, and syringe injectability. Herein, we developed a multifunctional, i.e., antibacterial, antioxidant, and injectable cryogel by combining lignin with gelatin. The cryogel with 0.2% lignin showed a compressive modulus of 25 kPa and a compressive stress of 140 kPa at 80% strain, which is, respectively, 1.8 and 7 times higher than those of the pure gelatin cryogels. Meanwhile, such a cryogel formulation could completely recover its shape after compression up to 90% and was needle-injectable. Additionally, the lignin-co-gelatin cryogel with 0.1-0.2 lignin showed 8-10 mm of inhibition zone against the most common surgical site infection-associated pathogenic bacteria. Furthermore, lignin-co-gelatin cryogel was found to scavenge free radicals and have good cytocompatibility, and the cryogels with up to 0.2% lignin minimally activate naïve mouse bone marrow-derived dendritic cells. Overall, the current approach shows great promise for the design of bioresource-based multifunctional cryogels for a wide range of biomedical applications.

Multifunctional lignin-based nanocomposites and nanohybrids

Significant progress in lignins valorization and development of high-performance sustainable materials have been achieved in recent years. Reports related to lignin utilization indicate excellent prospects considering green chemistry, chemical engineering, energy, materials and polymer science, physical chemistry, biochemistry, among others. To fully realize such potential, one of the most promising routes involves lignin uses in nanocomposites and nanohybrid assemblies, where synergistic interactions are highly beneficial. This review first discusses the interfacial assembly of lignins with polysaccharides, proteins and other biopolymers, for instance, in the synthesis of nanocomposites. To give a wide perspective, we consider the subject of hybridization with metal and metal oxide nanoparticles, as well as uses as precursor of carbon materials and the assembly with other biobased nanoparticles, for instance to form nanohybrids. We provide cues to understand the fundamental aspects related to lignins, their self-assembly and supramolecular organization, all of which are critical in nanocomposites and nanohybrids. We highlight the possibilities of lignin in the fields of flame retardancy, food packaging, plant protection, electroactive materials, energy storage and health sciences. The most recent outcomes are evaluated given the importance of lignin extraction, within established and emerging biorefineries. We consider the benefit of lignin compared to synthetic counterparts. Bridging the gap between fundamental and application-driven research, this account offers critical insights as far as the potential of lignin as one of the frontrunners in the uptake of bioeconomy concepts and its application in value-added products.

Waterproof-breathable films from multi-branched fluorinated cellulose esters

Cellulose ester films were prepared by esterification of cellulose with a multibranched fluorinated carboxylic acid, "BRFA" (BRanched Fluorinated Acid), at different anhydroglucose unit:BRFA molar ratios (i.e., 1:0, 10:1, 5:1, and 1:1). Morphological and optical analyses showed that cellulose-BRFA materials at molar ratios 10:1 and 5:1 formed flat and transparent films, while the one at 1:1 M ratio formed rough and translucent films. Degrees of substitution (DS) of 0.06, 0.09, and 0.23 were calculated by NMR for the samples at molar ratios 10:1, 5:1, and 1:1, respectively. ATR-FTIR spectroscopy confirmed the esterification. DSC thermograms showed a single glass transition, typical of amorphous polymers, at -11 °C. The presence of BRFA groups shifted the mechanical behavior from rigid to ductile and soft with increasing DS. Wettability was similar to standard fluoropolymers such as PTFE and PVDF. Finally, breathability and water uptake were characterized and found comparable to materials typically used in textiles.