Cellulose and cellulose derivatives: Different colloidal states and food-related applications

Fabrication of edible nanocellulose chitosan bi-component film based on a novel "swell-permeate" approach

The fabrication of multi-component film with colloidal particles could be inconvenient. A novel "swell-permeate" (SP) strategy was proposed to form homogeneous multi-component films. The SP strategy allows colloidal particles to fit into the polymer network by stretching the polymer chains assisted by water. We demonstrated the strategy by creating films with polysaccharide substrates as β-cyclodextrin grafted chitosan (CS) with nanocellulose. The addition of nanocellulose significantly increased the mechanical properties and the barrier performance of the films. The size of nanocellulose particles in affecting mechanical properties was investigated by applying different length of cellulose nanocrystal (CNC), the longer of which, due to denser physical entanglements, showed a better increase to the film in the elastic modulus and tensile strength to 4.54-fold and 5.71-fold, respectively. The films were also loaded with ethyl-p-coumarate (EpCA) and had an enhanced performance in anti-microbial for Altenaria alternata, Salmonella typhi, and Escherichia coli. The anti-oxidative property was increased as well, and both effects were valid both in vitro and in ready-to-eat apples. The strategy provides a practical and convenient method for fabricating colloidal particle containing films, and the novel idea of "swell-permeate" is potentially regarded as a new solution to the challenge of ready-to-eat food quality maintenance.

Advances in the preparation and application of cellulose-based antimicrobial materials: A review

The rise of polymer materials in modern life has drawn attention to renewable, easily biodegradable, environmentally-friendly bio-based polymers. Notably, significant research has been dedicated to creating green antimicrobial functional materials for the biomedical field using natural polymer materials. Cellulose is a rich natural biomass organic polymer material. Given its favorable attributes like film-forming capability, biodegradability, and biocompatibility, it is extensively employed to tackle a wide range of challenges confronting humanity today. However, its inherent drawbacks, such as insolubility in water and most organic solvents, hygroscopic nature, difficulty in melting, and limited antimicrobial properties, continue to pose challenges for realizing the high-value applications of cellulose. Achieving multifunctionality and more efficient application of cellulose still poses major challenges. In this regard, the current development status of cellulose materials was reviewed, covering the classification, preparation methods, and application status of cellulose-based antimicrobial materials. The application value of cellulose-based antimicrobial materials in biomedicine, textiles, food packaging, cosmetics and wastewater treatment was summarised. Finally, insights were provided into the developing prospects of cellulose-based antimicrobial materials were provided.

Application of bacterial-derived long cellulose nanofiber to suspension culture of mammalian cells as a shear protectant

Nanofibrillated bacterial cellulose (NFBC) is a bio-compatible long-fiber nanocellulose produced by cellulose-synthesizing bacteria. It forms an entangled network structure in the suspension state, thereby imparting greater viscosity than conventional media additives. In this study, we examined its application as a shear protectant in the suspension culture of mammalian cells to mitigate hydrodynamic stress imposed on the cells. The media supplemented with hydroxypropyl cellulose-adsorbed NFBC (HP-NFBC) exhibited an increase in shear viscosity according to rheometric analysis, similar to FP003, a commercially available medium additive. Suspension culture of Chinese hamster ovary cells in HP-NFBC-containing media under a high stirring rate (120 rpm) demonstrated higher cell growth and lower cell death compared to those in the medium without additives and in FP003. A 0.10 (w/v)% concentration of HP-NFBC showed the highest viable cell number among the tested concentrations. Computational fluid dynamics simulation revealed a decrease in shear rate and flow velocity within the spinner flask owing to the addition of HP-NFBC or FP003. It is suggested that the decline of these parameters in high-viscosity media suppresses the hydrodynamic stress on cells. This study highlights the potential of HP-NFBC as a shear protectant in mammalian cell suspension culture.

Preparation of cellulose-based nanoparticles via electrostatic self-assembly for the pH-responsive delivery of astaxanthin

Oral administration of astaxanthin (AST), a potent antioxidant, is limited owing to its low solubility, physicochemical stability, and bioavailability. This study developed pH-responsive nanocarriers by the electrostatic self-assembly of 2,2,6,6-tetramethylpiperidine-1-oxyradical (TEMPO)-oxidized cellulose nanofibers (TCNFs) and chitosan (CS) to enhance the intestinal delivery of AST. The TCNF/CS@AST nanoparticles were optimized through single-factor experiments and Box-Behnken design, subsequently overcoming the hydrophobicity of AST and demonstrating improved stability against environmental stressors and controlled release in the intestinal environment. Transmission electron microscopy confirmed the near-spherical shape of these nanoparticles, with an average hydrodynamic diameter of 64 nm. TCNF/CS@AST enhanced the antioxidant effectiveness of AST after digestion and in lipopolysaccharide-stimulated RAW 264.7 cells while demonstrating good cellular compatibility. These nanoparticles present a promising strategy for the oral delivery of hydrophobic bioactive compounds orally, with potential applications in precision nutrition.

Cellulose as a sustainable scaffold material in cultivated meat production

The rapid progress in cultivated meat research has engendered considerable attention towards the edible scaffolding biomaterials employed in the production. Cellulose has the advantages in availability, edibility, animal-free origin, etc., which show its potential in wide fields. This review begins by presenting the fundamental physical and chemical properties of cellulose from different sources, including plant and bacterial cellulose. Subsequently, we summarize the application of cellulose especially in cultivated meat and tissue engineering. Furthermore, we explore various methods for preparing cellulose-based scaffolds for cultivated meat, encompassing five specific structural variations. In the end, associated with utilizing cellulose in cultivated meat production, we address several primary challenges surrounding to cell adhesion, scaling up, processibility and mechanical properties, and provide potential innovations. This review underscores the potential of cellulose as a versatile biomaterial in the cultivated meat industry and provides insight into addressing critical challenges for its integration.

Recent advances in moisture-induced electricity generation based on wood lignocellulose: Preparation, properties, and applications

Moisture-induced electricity generation (MEG), which can directly harvest electricity from moisture, is considered as an effective strategy for alleviating the growing energy crisis. Recently, tremendous efforts have been devoted to developing MEG active materials from wood lignocellulose (WLC) due to its excellent properties including environmental friendliness, sustainability, and biodegradability. This review comprehensively summarizes the recent advances in MEG based on WLC (wood, cellulose, lignin, and woody biochar), covering its principles, preparation, performances, and applications. In detail, the basic working mechanisms of MEG are discussed, and the natural features of WLC and their significant advantages in the fabrication of MEG active materials are emphasized. Furthermore, the recent advances in WLC-based MEG for harvesting electrical energy from moisture are specifically discussed, together with their potential applications (sensors and power sources). Finally, the main challenges of current WLC-based MEG are presented, as well as the potential solutions or directions to develop highly efficient MEG from WLC.

A multifunctional biogenic films and coatings from synergistic aqueous dispersion of wood-derived suberin and cellulose nanofibers

Here, biogenic and multifunctional active food coatings and packaging with UV shielding and antimicrobial properties were structured from the aqueous dispersion of an industrial byproduct, suberin, which was stabilized with amphiphilic cellulose nanofibers (CNF). The dual-functioning CNF, synthesized in a deep eutectic solvent, functioned as an efficient suberin dispersant and reinforcing agent in the packaging design. The nanofibrillar percolation network of CNF provided a steric hindrance against the coalescence of the suberin particles. The low CNF dosage of 0.5 wt% resulted in dispersion with optimal viscosity (208.70 Pa.s), enhanced stability (instability index of <0.001), and reduced particle size (9.37 ± 2.43 μm). The dispersion of suberin and CNF was further converted into self-standing films with superior UV-blocking capability, good thermal stability, improved hydrophobicity (increase in water contact angle from 61° ± 0.15 to 83° ± 5.11), and antimicrobial properties against gram-negative bacteria. Finally, the synergistic bicomponent dispersions were demonstrated as fruit coatings for bananas and packaging for strawberries to promote their self-life. The coatings and packaging considerably mitigated fruit deterioration and improved their freshness by preventing moisture loss and microbial attack. This sustainable approach is expected to pave the way toward advanced, biogenic, and active food packaging based on widely available bioresources.

Composite starch films as green adsorbents for removing benzo[a]pyrene from smoked sausages

Benzo[a]pyrene (BaP), which is emitted during the processing of smoked sausages, accumulates in sausages and poses a serious threat to human health. This study focused on the removal of BaP from sausages and accompanying particulate matter (PM) during the smoking of sausages by films formed by combining corn starch (CS) with K-carrageenan (KC)/sodium alginate (SA). Initially, the effects of different additions of KC and SA on the rheological analysis, thermogravimetric analysis (TGA) and film-forming properties of the composite films were investigated. The BaP reduction capacities of CS-KC and CS-SA composite films in sausage were 41.1%-47.0% and 54.2%-56.5%, respectively, because the three-dimensional mesh structure of the composite films provided a large number of adsorption sites. Finally, kinetic studies demonstrated that BaP control in composite films is mainly achieved by intraparticle diffusion. Therefore, due to its excellent recyclability and biodegradability, composite starch film has a promising application in smoked meat products.

Modified polysaccharides for food packaging applications: A review

Development of new food packaging materials is crucial to reduce the use of single-use plastics and to limit their destructive impact on the environment. Polysaccharides provide an alternative solution to this problem. This paper summarizes and discusses recent research results on the potential of modifying polysaccharides as materials for film and coating applications. Modifications of polysaccharides significantly affect their properties, as well as their application usability. Although modifications of biopolymers for packaging applications have been widely studied, polysaccharides have attracted little attention despite being a prospective, environmentally friendly, and economically viable packaging alternative. Therefore, this paper discusses approaches to the development of biodegradable, polysaccharide-based food packaging materials and focuses on modifications of four polysaccharides, such as starch, chitosan, sodium alginate and cellulose. In addition, these modifications are presented not only in terms of the selected polysaccharide, but also in terms of specific properties, i.e. hydrophilic, barrier and mechanical properties, of polysaccharides. Such a presentation of results makes it much easier to select the modification method to improve the unsatisfactory properties of the material. Moreover, very often it happens that the applied modification improves one and worsens another property, which is also presented in this review.

Utilization of an aqueous two-phase emulsification to prepare bimodal porous cellulose monolith for efficient adsorption of bovine serum albumin

Cellulose monolith has garnered significant interest in the field of biochromatography, which lies in its interconnected porous structure, large surface area and biocompatibility. In this context, we propose a novel approach for preparing cellulose monoliths using an aqueous two-phase system devoid of any organic solvents and surfactants. In this strategy, emulsifying cellulose solution into PEG 20,000 solution gives bicontinuous aqueous phases and further porous cellulose monolith after regeneration of dissolved cellulose. And the macroporous channels are derived from the removal of the PEG 20,000 aqueous phase while the micropores are from the phase separation of the cellulose phase. Physical characterizations reveal the obtained cellulose monolith exhibits exceptional column permeability of 1.36 × 10-11 m2 and a substantial surface area of 39.34 m2/g. Furthermore, cellulose monolith is functionalized with diethyl ethylamine hydrochloride (DEAE-HCl) to evaluate its potential as an anion adsorbent. Experimental results reveal that the DEAE-modified cellulose monolith possesses of adsorptive capacity of 316.58 mg/g of bovine serum albumin, along with fast adsorption kinetic. This study introduces an innovative strategy for fabricating porous cellulose monoliths tailored for biochromatography applications.

The reduce of water vapor permeability of polysaccharide-based films in food packaging: A comprehensive review

Polysaccharide-based films are favored in the food packaging industry because of their advantages of green and safe characters, as well as natural degradability, but due to the structural defects of polysaccharides, they also have the disadvantages of high water vapor permeability (WVP), which greatly limits their application in the food packaging industry. To break the limitation, numerous methods, e.g., physical and/or chemical methods, have been employed. This review mainly elaborates the up-to-date research status of the application of polysaccharide-based films (PBFs) in food packaging area, including various films from cellulose and its derivatives, starch, chitosan, pectin, alginate, pullulan and so on, while the methods of reducing the WVP of PBFs, mainly divided into physical and chemical methods, are summarized, as well as the discussions about the existing problems and development trends of PBFs. In the end, suggestions about the future development of WVP of PBFs are presented.

Review on design strategies and applications of flexible cellulose‑carbon nanotube functional composites

Combining the excellent biocompatibility and mechanical flexibility of cellulose with the outstanding electrical, mechanical, optical and stability properties of carbon nanotubes (CNTs), cellulose-CNT composites have been extensively studied and applied to many flexible functional materials. In this review, we present advances in structural design strategies and various applications of cellulose-CNT composites. Firstly, the structural characteristics and corresponding treatments of cellulose and CNTs are analyzed, as are the potential interactions between the two to facilitate the formation of cellulose-CNT composites. Then, the design strategies and processing techniques of cellulose-CNT composites are discussed from the perspectives of cellulose fibers at the macroscopic scale (natural cotton, hemp, and other fibers; recycled cellulose fibers); nanocellulose at the micron scale (nanofibers, nanocrystals, etc.); and macromolecular chains at the molecular scale (cellulose solutions). Further, the applications of cellulose-CNT composites in various fields, such as flexible energy harvesting and storage devices, strain and humidity sensors, electrothermal devices, magnetic shielding, and photothermal conversion, are introduced. This review will help readers understand the design strategies of cellulose-CNT composites and develop potential high-performance applications.

Carboxymethyl cellulose/polyvinyl alcohol composite aerogel supported beta molecular sieve for CH4 adsorption and storage

Biomass aerogel is attractive in various applications due to their renewable, biodegradable and eco-friendly advantages. Herein, a novel beta molecular sieve/carboxymethyl cellulose/polyvinyl alcohol composite aerogel (beta/CP) is prepared by direct mixing and directional freeze-drying as an efficient gas adsorbent with hierarchical porosity. The beta molecular sieve is uniformly dispersed in the three-dimensional skeleton of the aerogel. By adjusting the loading mass of the beta molecular sieve to constitute a reasonable porosity and pore size distribution, the synergistic effect between pore structures of different scales improves the adsorption performance. The experiment results of beta/CP-4 show that the CH4 adsorption capacity can reach 60.33 cm3/g at 298 K and 100 bar, which is almost the same as that of the pure beta molecular sieve (62.09 cm3/g). The strong interaction between the aerogel and it prevents the molecular sieve agglomeration, improves the pore utilization, and also reduces the cost of using molecular sieve adsorbent. The above results indicate that the composite has good potential for application in the field of CH4 storage.

Melatonin treatment delays the softening of blueberry fruit by modulating cuticular wax metabolism and reducing cell wall degradation

The effects of postharvest melatonin (MT) treatment on cuticular wax and cell wall metabolism in blueberry fruit (Vaccinium spp.) were evaluated. The results revealed that MT treatment maintained the cuticular wax rod-like structure and delayed wax degradation. The gas chromatography-mass spectrometry analysis results revealed that MT application changed the cuticular wax composition in blueberries, and 25 metabolic components were screened. The metabolic regulation of wax quality in blueberry fruit may therefore be influenced by MT. Additionally, MT slowed down pectin and cellulose degradation by reducing the activities of cell wall degrading enzymes like pectin methyl esterase polygalacturonase, β-galactosidase, and cellulose in the later stages of storage. It also downregulated the transcriptional expression of related genes like VcPE, VcPG, VcBG6, and VcGAL1. Thus, MT prevented softening and senescence by postponing the degradation of the cell wall in postharvest blueberry fruit.

Eco-Friendly Methods for Extraction and Modification of Cellulose: An Overview

Cellulose is the most abundant renewable polymer on Earth and can be obtained from several different sources, such as trees, grass, or biomass residues. However, one of the issues is that not all the fractionation processes are eco-friendly and are essentially based on cooking the lignocellulose feedstock in a harsh chemical mixture, such as NaOH + Na₂S, and water, to break loose fibers. In the last few years, new sustainable fractionation processes have been developed that enable the obtaining of cellulose fibers in a more eco-friendly way. As a raw material, cellulose's use is widely known and established in many areas. Additionally, its products/derivatives are recognized to have a far better environmental impact than fossil-based materials. Examples are textiles and packaging, where forest-based fibers may contribute to renewable and biodegradable substitutes for common synthetic materials and plastics. In this review, some of the main structural characteristics and properties of cellulose, recent green extraction methods/strategies, chemical modification, and applications of cellulose derivatives are discussed.

Effects of Chitosan and Cellulose Derivatives on Sodium Carboxymethyl Cellulose-Based Films: A Study of Rheological Properties of Film-Forming Solutions

Bio-based packaging materials and efficient drug delivery systems have garnered attention in recent years. Among the soluble cellulose derivatives, carboxymethyl cellulose (CMC) stands out as a promising candidate due to its biocompatibility, biodegradability, and wide resources. However, CMC-based films have limited mechanical properties, which hinders their widespread application. This paper aims to address this issue by exploring the molecular interactions between CMC and various additives with different molecular structures, using the rheological method. The additives include O-carboxymethylated chitosan (O-CMCh), N-2-hydroxypropyl-3-trimethylammonium-O-carboxymethyl chitosan (HTCMCh), hydroxypropyltrimethyl ammonium chloride chitosan (HACC), cellulose nanocrystals (CNC), and cellulose nanofibers (CNF). By investigating the rheological properties of film-forming solutions, we aimed to elucidate the influencing mechanisms of the additives on CMC-based films at the molecular level. Various factors affecting rheological properties, such as molecular structure, additive concentration, and temperature, were examined. The results revealed that the interactions between CMC and the additives were dependent on the charge of the additives. Electrostatic interactions were observed for HACC and HTCMCh, while O-CMCh, CNC, and CNF primarily interacted through hydrogen bonds. Based on these rheological properties, several systems were selected to prepare the films, which exhibited excellent transparency, wettability, mechanical properties, biodegradability, and absence of cytotoxicity. The desirable characteristics of these selected films demonstrated the strong biocompatibility between CMC and chitosan and cellulose derivatives. This study offers insights into the preparation of CMC-based food packaging materials with specific properties.

High-performance homogeneous carboxymethylcellulose-stabilized Au@Ag NRs-CMC surface-enhanced Raman scattering chip for thiram detection in fruits

Cellulose material holds considerable promise for effective surface-enhanced Raman scattering (SERS) substrate construction due to its extensive availability, chemically modifying capacity, ease of manufacture, high flexibility and low optical activity. A large-area, high-sensitivity, stable and uniform Au@Ag nanorods (NRs)-CMC substrate was successfully developed via electrostatic repulsion by using negatively-charged core-shell Au@Ag NRs as SERS active plasmonic nanomaterial, combined with negatively-charged carboxymethylcellulose (CMC) hydrogel for nanoparticles stabilization, homodisperse and protection. The obtained Au@Ag NRs-CMC substrate showed excellent sensitivity for the detection of thiram residues in fruits containing low and abundant pigment interferents, such as apples and blueberries, with detection limits of 58 and 78 ppb, respectively. Additionally, it retained more than 80% SERS performance after storage for 9 months under ambient conditions, demonstrating its great potential in facilitating the commercialization of cellulose-based SERS technology for cost-effective detection of food contaminants with advantages of facile preparation procedure, uniformity, reproducibility and long-term stability.

Essential characteristics improvement of metallic nanoparticles loaded carbohydrate polymeric films - A review

Petroleum-based films have contributed immensely to various environmental issues. Developing green-based films from carbohydrate polymers is crucial for addressing the harms encountered. However, some limitations exist on their property, processibility, and applicability that prohibit their processing for further developments. This review discusses the potential carbohydrate polymers and their sources, film preparation methods, such as solvent-casting, tape-casting, extrusion, and thermo-mechanical compressions for green-based films using various biological polymers with their merits and demerits. Research outcomes revealed that the essential characteristics improvement achieved by incorporating different metallic nanoparticles has significantly reformed the properties of biofilms, including crystallization, mechanical stability, thermal stability, barrier function, and antimicrobial activity. The property-enhanced bio-based films made with nanoparticles are potentially interested in replacing fossil-based films in various areas, including food-packaging applications. The review paves a new way for the commercial use of numerous carbohydrate polymers to help maintain a sustainable green environment.

Insight into the composite assembly process, nanofibril structure and stability of undenatured type II collagen in the presence of different types of nanocelluloses

Four types of nanocelluloses (CNs), including cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), cationic etherified nanocellulose (CCNF) and TEMPO-oxidized nanocellulose (TOCNF), were incorporated into the assembly process of undenatured type II collagen (UC-II). In the presence of CNs, the kinetics of UC-II composite assembly slightly fluctuated and the magnitude of UC-II assembly increased (from 59.93 to 66.83-85.06 %). CNC and CNF disrupted the triple helix structure of UC-II while CCNF and TOCNF had weak impact on it. Hydrogen bonding and hydrophobic interactions were dominant driving forces of UC-II/CNs, and electrostatic interactions were also involved in the fabrication of UC-II/CCNF and UC-II/TOCNF. UC-II/CNs exhibited distinct nanostructures due to the differences in shape, level, and surface group of CNs. CCNF and TOCNF contributed to the enhanced physical stability due to the increased surface charge. In addition, the thermal stability and rheological properties of UC-II/CNs were also improved. The composite assembly process, nanofibril structure and stability of UC-II in the presence of different types and levels of CNs, which was useful to develop the novel composite nanofibrils for the application in functional foods.

Adsorption Process of Various Antimicrobial Peptides on Different Surfaces of Cellulose

Current antimicrobial challenges in hospitals, pharmaceutical production units, and food packaging have motivated the development of antimicrobial agents, among them the antimicrobial compounds based on cellulose and peptides. Herein, we develop molecular dynamics (MD) models to dissect and characterize the adsorption process of antimicrobial peptides (AMPs) such as protegrin 1, magainin 2, and cyclic indolicidin on various surfaces of cellulose including [-1-10], [1-10], [-100], [100], [-110], and [110]. Our results suggest that the magainin 2 antimicrobial peptide loses most of its initial helix form, spreads on the cellulose surface, and makes the most rigid structure with [110] surface. The cyclic indolicidin peptide has the lowest affinity to adsorb on the cellulose surfaces, and the protegrin 1 peptide successfully adsorbs on all the proposed cellulose surfaces. Our MD simulations confirmed that cellulose can improve the corresponding peptides' structural stability and change their secondary structures during adsorption. The [-1-10] and [100] surfaces of cellulose show considerable affinity against the AMPs, exhibiting greater interactions with and adsorption to the peptides. Our data imply that the stronger adsorptions are caused by a set of H-bonds, van der Waals, and electrostatic interactions, where van der Waals interactions play a prominent role in the stability of the AMP-cellulose structures. Our energy analysis results suggest that glutamic acid and arginine amino acids have key roles in the stability of AMPs on cellulose surfaces due largely to stronger interactions with the cellulose surfaces as compared with other residues. Our results can provide useful insight at the molecular level that can help design better antimicrobial biomaterials based on cellulose.

Flexible Au@AgNRs/CMC/qPCR film with enhanced sensitivity, homogeneity and stability for in-situ extraction and SERS detection of thiabendazole on fruits

In this study, a high-performance, stable and homogeneous Au@AgNRs/CMC/qPCR flexible film surface-enhanced Raman scattering (SERS) substrate was constructed by synergistically stabilizing and protecting bimetallic core-shell Au@Ag nanorods (Au@AgNRs) with carboxymethylcellulose (CMC) and fluorescent-quantitative-polymerase-chain-reaction (qPCR) film. The network structure of CMC immobilized and aligned Au@AgNRs through coordination of carboxyl groups with surface Ag atoms to provide intensive and stable 'hot spots', and the qPCR bilayer film performed as carrier and barrier to protect Au@AgNRs from oxidation, humidity and optical damage and improved the robustness and stability. The Au@AgNRs/CMC/qPCR film was used for in-situ extraction and SERS detection of thiabendazole on nectarine (0.24 ppm) and lemon (0.27 ppm) with low detection of limits. Furthermore, it retained 98.6% SERS performance after storage for 90 days under ambient conditions, revealing the great potential in promoting the commercialization of the SERS technique for sensitive contaminants sensing with simple fabrication procedures, homogeneity, reproducibility and long-term stability.

Facile preparation of cellulose nanocrystals/ZnO hybrids using acidified ZnCl2 as cellulose hydrolytic media and ZnO precursor

Hybridization of nanocellulose with zinc oxide nanoparticles can improve the dispersibility of the zinc oxide and bring new functions to the bio-based products. In this study, cellulose nanocrystal/zinc oxide (CNC/ZnO) nanohybrids with reinforcing and antibacterial properties were prepared via a facile one-pot route. Microcrystalline cellulose (MCC) was first treated with acidified zinc chloride and hydrolyzed into CNCs, which then served as a stabilizing and supporting agent for the in-situ growth of ZnO nanoparticles during subsequent chemical precipitation. The acidified ZnCl₂ solution played a dual role, acting both as cellulose hydrolytic media and as ZnO precursor. By adjusting the pH of the zinc precursor solution (pH = 9-12), well-dispersed rod-like (length: 137.0-468.0 nm, width: 54.1-154.1 nm) and flower-like (average diameter: 179.6 nm) ZnO nanoparticles with hexagonal wurtzite structure were obtained. CNC/ZnO nanohybrids were incorporated into waterborne polyurethane (WPU) films. The Young's modulus and tensile strength of the nanocomposite films increased gradually from 154.8 to 509.0 MPa and from 16.5 to 29.9 MPa, respectively, with increasing CNC/ZnO nanofiller content up to 10 wt%. The 10 % CNC/ZnO composites showed inhibition rates to both E. coli and S. aureus above 88.8 %.

Superchaotropic Nano-ion Binding as a Gelation Motif in Cellulose Ether Solutions

Nanometer-sized anions (nano-ions) like polyoxometalates and boron clusters exhibit so-called superchaotropic behavior, which describes their strong binding to hydrated non-ionic matter in water. We show here that nano-ions, at millimolar concentrations, dramatically enhance the viscosity and induce gelation of aqueous solutions of non-ionic cellulose ethers (CEs), a class of widely utilized polymers known for their thickening and gel-forming ability. These phenomena arise from an interplay of attractive forces and repulsive electrostatic forces between CE-chains upon nano-ion binding. The attractive forces manifest themselves as aggregation of CE-chains into a physically crosslinked polymer network (gel). In turn, the electrostatic repulsions hamper the viscosity increase and gelation. Superchaotropic nano-ion binding emerges as a novel and general physical crosslinking motif for CE-solutions and exceeds by far the conventional thickening effects of classical salts and ionic surfactants.

Effects of adding methods and modification types of cellulose on the physicochemical properties of starch/PBAT blown films

This study revealed the relationship between cellulose types/adding methods and film properties, in which sodium carboxymethyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC), and microcrystalline cellulose (MCC) were added into starch/PBAT blown films in powder, aqueous solution, and emulsion forms, respectively. Cellulose interacted with starch networks via hydrogen bonds, and those added in emulsion form made more homogeneous film morphologies. MCC emulsion enhanced the film strength (40%) and modulus (149%) to the greatest extent, while comprehensively, HPMC emulsion possessed better reinforcement effects on the films, which increased mechanical properties (31% ~ 100%), moisture barrier (20%), oxygen barrier (93%), surface hydrophobicity (20%), as well as water resistance (12% ~ 76%). Findings supported the application of cellulose in high-throughput biodegradable films, and the high-content starch/PBAT blown films reinforced by HPMC emulsion had great potential in commercial packaging fields.

Gastrointestinal Effects and Tolerance of Nondigestible Carbohydrate Consumption

Nondigestible carbohydrates (NDCs) are food components, including nonstarch polysaccharides and resistant starches. Many NDCs are classified as dietary fibers by the US FDA. Because of their beneficial effects on human health and product development, NDCs are widely used in the food supply. Although there are dietary intake recommendations for total dietary fiber, there are no such recommendations for individual NDCs. NDCs are heterogeneous in their chemical composition and physicochemical properties-characteristics that contribute to their tolerable intake levels. Guidance on tolerable intake levels of different NDCs is needed because overconsumption can lead to undesirable gastrointestinal side effects, further widening the gap between actual and suggested fiber intake levels. In this review, we synthesize the literature on gastrointestinal effects of NDCs that the FDA accepts as dietary fibers (β-glucan, pectin, arabinoxylan, guar gum, alginate, psyllium husk, inulin, fructooligosaccharides and oligofructose, galactooligosaccharides, polydextrose, cellulose, soy fiber, resistant maltodextrin/dextrin) and present tolerable intake dose recommendations for their consumption. We summarized the findings from 103 clinical trials in adults without gastrointestinal disease who reported gastrointestinal effects, including tolerance (e.g., bloating, flatulence, borborygmi/rumbling) and function (e.g., transit time, stool frequency, stool consistency). These studies provided doses ranging from 0.75-160 g/d and lasted for durations ranging from a single-meal tolerance test to 28 wk. Tolerance was NDC specific; thus, recommendations ranged from 3.75 g/d for alginate to 25 g/d for soy fiber. Future studies should address gaps in the literature by testing a wider range of NDC doses and consumption forms (solid compared with liquid). Furthermore, future investigations should also adopt a standard protocol to examine tolerance and functional outcomes across studies consistently.

Natural carriers: Recent advances in their use to improve the stability and bioaccessibility of food active compounds

In the last decades, the incorporation of bioactive compounds in food supplements aroused the attention of scientists. However, these ingredients often exhibit both low solubility and stability and their poor bioaccessibility within the gastrointestinal tract limits their effectiveness. To overcome these drawbacks, many carriers have been investigated for encapsulating nutraceuticals and enhancing their bioavailability. It is note that several different vegetable wall materials have been applied to build delivery systems. Considering their encapsulation mechanism, lipid and protein-based carriers display specific interaction patterns with bioactives, whereas polysaccharidic-based carriers can entrap them by creating porous highly stable networks. To maximize the encapsulation efficiency, mixed systems are very promising. Following the current goal of using natural and sustainable ingredients, only a limited number of studies about the isolation of new ingredients from agro-food waste are available. In this review, a comprehensive overview of the state of art in the development of innovative natural lipid-, protein- and polysaccharide-based plant carriers is presented, focusing on their application as food active compounds. Different aspects to be considered in the design of delivery systems are discussed, including the carrier structure and chemical features, the interaction between the encapsulating and the core material, and the parameters affecting bioactives entrapment.

Recent Developments on Bioinspired Cellulose Containing Polymer Nanocomposite Cation and Anion Exchange Membranes for Fuel Cells (PEMFC and AFC)

Hydrogen fuel cell (FC) technologies are being worked on as a possible replacement for fossil fuels because they produce a lot of energy and do not pollute the air. In FC, ion-exchange membranes (IEMs) are the vital components for ion transport between two porous electrodes. However, the high production cost of commercialized membranes limits their benefits. Various research has focused on cellulose-based membranes such as IEM with high proton conductivity, and mechanical, chemical, and thermal stabilities to replace the high cost of synthetic polymer materials. In this review, we focus on and explain the recent progress (from 2018 to 2022) of cellulose-containing hybrid membranes as cation exchange membranes (CEM) and anion exchange membranes (AEM) for proton exchange membrane fuel cells (PEMFC) and alkaline fuel cells (AFC). In this account, we focused primarily on the effect of cellulose materials in various membranes on the functional properties of various polymer membranes. The development of hybrid membranes with cellulose for PEMFC and AFC has been classified based on the combination of other polymers and materials. For PEMFC, the sections are associated with cellulose with Nafion, polyaryletherketone, various polymeric materials, ionic liquid, inorganic fillers, and natural materials. Moreover, the cellulose-containing AEM for AFC has been summarized in detail. Furthermore, this review explains the significance of cellulose and cellulose derivative-modified membranes during fuel cell performance. Notably, this review shows the vital information needed to improve the ion exchange membrane in PEMFC and AFC technologies.

Progress in the application of sustained-release drug microspheres in tissue engineering

Sustained-release drug-loaded microspheres provide a long-acting sustained release, with targeted and other effects. There are many types of sustained-release drug microspheres and various preparation methods, and they are easy to operate. For these reasons, they have attracted widespread interest and are widely used in tissue engineering and other fields. In this paper, we provide a systematic review of the application of sustained-release drug microspheres in tissue engineering. First, we introduce this new type of drug delivery system (sustained-release drug carriers), describe the types of sustained-release drug microspheres, and summarize the characteristics of different microspheres. Second, we summarize the preparation methods of sustained-release drug microspheres and summarize the materials required for preparing microspheres. Third, various applications of sustained-release drug microspheres in tissue engineering are summarized. Finally, we summarize the shortcomings and discuss future prospects in the development of sustained-release drug microspheres. The purpose of this paper was to provide a further systematic understanding of the application of sustained-release drug microspheres in tissue engineering for the personnel engaged in related fields and to provide inspiration and new ideas for studies in related fields.

Formulation of Silk Fibroin Nanobrush-Stabilized Biocompatible Pickering Emulsions

Silk fibroin is widely believed to be sustainable, biocompatible, and biodegradable, providing promising features such as carriers to deliver drugs and functional ingredients in food, personal care, and biomedical areas, which are consistent with emulsion characteristics; especially, green, all-natural biopolymer-based stabilizers are in great demand to stabilize Pickering emulsions and match the multifunctional needs for developing ideal materials. Herein, an unprecedented three-dimensional (3D) nanostructure, namely a brush-like silk nanobrush (SNB), is applied as the stabilizer to formulate and stabilize Pickering emulsions. The size and interfacial tension are compared among the SNB, a regenerated silk nanofiber, and a nanowhisker. Additionally, optimization processes are conducted to determine the ideal ultrasonication intensity and SNB concentration required to prepare Pickering emulsions by analyzing the morphology, creaming index, mean oil droplet size, and rheological behavior. The results indicate that an SNB with the characteristic structure and suitable size shows superior potential to form sophisticated and interconnected networks in oil-water interfaces, and is proved to be able to resist creaming at a wide range of concentrations and subsequently stabilize Pickering emulsions from liquid-like emulsions to gel-like emulsions. Additionally, SNB is proved to be biocompatible according to cell experiments, providing a promising alternative in designing all-natural, green, and biocompatible emulsions with the aim of efficiently delivering nutrients or drugs associated with health benefits.

Novel Features of Cellulose-Based Films as Sustainable Alternatives for Food Packaging

Packaging plays an important role in food quality and safety, especially regarding waste and spoilage reduction. The main drawback is that the packaging industry is among the ones that is highly dependent on plastic usage. New alternatives to conventional plastic packaging such as biopolymers-based type are mandatory. Examples are cellulose films and its derivatives. These are among the most used options in the food packaging due to their unique characteristics, such as biocompatibility, environmental sustainability, low price, mechanical properties, and biodegradability. Emerging concepts such as active and intelligent packaging provides new solutions for an extending shelf-life, and it fights some limitations of cellulose films and improves the properties of the packaging. This article reviews the available cellulose polymers and derivatives that are used as sustainable alternatives for food packaging regarding their properties, characteristics, and functionalization towards active properties enhancement. In this way, several types of films that are prepared with cellulose and their derivatives, incorporating antimicrobial and antioxidant compounds, are herein described, and discussed.

Comparison of cellulose derivatives for Ca2+ and Zn2+ adsorption: Binding behavior and in vivo bioavailability

Cellulose with distinct colloidal states exhibited different adsorption capability for ions and whether the intake of cellulose would bring positive or negative influence on the mineral bioavailability is inconclusive. This work investigated the binding behavior of carboxymethyl cellulose (CMC), TEMPO-oxidized nanofibrillated/nanocrystalline cellulose (TOCNF/TOCNC), and microcrystalline cellulose (MCC) with Ca²⁺and Zn²⁺ and compared their effects on mineral bioavailability in vitro and in vivo. The results suggested that CMC displayed a higher adsorption capability (36.6 mg g^-1 for Ca²⁺ and 66.2 mg g^-1 for Zn²⁺) than the other types of cellulose because of the strong interaction between carboxyl groups of cellulose and the ions. Although the cellulose derivatives had adverse effects on ion adsorption in vitro, the fermentability endowed by TOCNF/TOCNC counterbalanced the negative impacts in vivo. The findings suggested that the colloidal states of cellulose affected the bioavailability of minerals and could provide useful guidance for applications of specific cellulose.

Application of traditional Chinese medicine in film drug delivery system

Film drug delivery systems have the advantages of precise administration, simple process and easy portability, compared with other traditional drug delivery systems such as tablets, capsules, syrups, ointments, etc. The traditional Chinese medicine (TCM) are normally developed in four categories of film agent like patch film, coating, spray film and gel film, which are applied to the treatment of oral ulcers, chronic diseases of lower limbs, burns, scalds, gynecological disease and body care. So the TCM film has great research value and prominent market prospect. In this review, we summarized the research progress of the material composition, pharmaceutical production, clinical application and pharmacology mechanism of various TCM film agents. It may provide a comprehensive reference for further development and utilization of TCM film agents.

Structural Insights into Cellulose-Coated Oil in Water Emulsions

Cellulose is a renewable biopolymer, abundant on Earth, with a multi-level supramolecular structure. There has been significant interest and advancement in utilizing natural cellulose to stabilize emulsions. In our research, we develop and examine oil in water emulsions surrounded by unmodified cellulose as microreactors for the process of transformation of cellulose into valuable chemicals such as biodiesel. This study presents morphological characterization of cellulose-coated emulsions that can be used for such purposes. Cryogenic-scanning electron microscopy imaging along with light microscopy and light scattering reveals a multi-layer inner structure: an oil core surrounded by a porous cellulose hydrogel shell, coated by an outer shell of regenerated cellulose. Measurements of small-angle X-ray scattering provide quantification of the nano-scale structure within the porous cellulose hydrogel inner shell of the emulsion particle. These characteristics are relevant to utilization of cellulose-coated emulsions in various applications such as controlled release and as hosts for enzymatic biotechnological reactions.

In Vitro Colonic Fermentation Profiles and Microbial Responses of Cellulose Derivatives with Different Colloidal States

Although cellulose derivatives are widely applied in the food industry, the effects of their structural properties on colonic health is unknown. Here, four types of cellulose derivatives, including microcrystalline cellulose (MCC), TEMPO-oxidized nanofibrillated cellulose (TOCNF), TEMPO-oxidized nanocrystalline cellulose (TOCNC), and carboxymethyl cellulose (CMC) were selected to investigate their in vitro fermentation profiles. TOCNF exhibited the highest production of total short-chain fatty acids (SCFAs), followed by TOCNC. The results suggested that reduced particle size and increased aspect ratio improved the fermentability of insoluble cellulose derivatives. MCC and CMC were barely fermented with similar total SCFAs production as the blank. 16S rRNA sequencing revealed that the fermentation of cellulose derivatives resulted in divergent microbial community structures. Moreover, Bacteroides cellulosilyticus showed high specificity to utilize TOCNF and TOCNC. The findings demonstrated that the colloidal states of cellulose derivatives, such as size and solubility, were important factors governing microbial community composition and metabolites.

Preparation of Cellulose Nanocrystals from Jujube Cores by Fractional Purification

Jujube cores are fiber-rich industrial waste. Dewaxing, alkali treatment, bleaching, and sulfuric acid hydrolysis were used to generate cellulose nanocrystals (CNCs) from the jujube cores in this study. The morphological, structural, crystallinity, and thermal properties of the fibers were investigated using FE-SEM, TEM, AFM, FT-IR, XRD, and TGA under various processes. CNCs’ zeta (ζ) potential and water contact angle (WAC) were also investigated. The findings demonstrate that non-fibrous components were effectively removed, and the fiber particles shrunk over time because of many activities. CNCs had a rod-like shape, with a length of 205.7 ± 52.4 nm and a 20.5 aspect ratio. The crystal structure of cellulose Iβ was preserved by the CNCs, and the crystallinity was 72.36%. The temperature of the fibers’ thermal degradation lowered during the operations, although CNCs still had outstanding thermal stability (>200 °C). Aside from the CNCs, the aqueous suspension of CNCs was slightly agglomerated; thus, the zeta (ζ) potential of the CNCs’ suspension was −23.72 ± 1.7 mV, and the powder had high hydrophilicity. This research will be valuable to individuals who want to explore the possibility for CNCs made of jujube cores.

Eco-Friendly and Complete Recycling of Waste Bamboo-Based Disposable Paper Cups for Value-Added Transparent Cellulose-Based Films and Paper Plastic Composites

Disposable paper cups are widely used in daily life and most of them are landfilled or incinerated after use, resulting in a serious ecological hazard and significant waste of resources due to the usage of thin polyethylene (PE) as their inner coating. Hence, converting these common solid domestic wastes into high-value added materials is attractive and meaningful. In this study, transparent cellulose-based films were achieved from old bamboo-based disposable paper cups after pretreatment through using the room ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as solvent. The cellulose-based film with a dense texture demonstrated a relatively nice mechanical and UV-shielding performances, and its tensile strength was as high as 48 MPa, much higher than that of commercial polyethylene (PE, 12 MPa) film. Thus, the resultant cellulose-based film showed a great potential in the packaging field. Besides, the flexible paper plastic composites (PPC) were also fabricated from the rest thin PE coating with the stuck fibers, and it was found that PPC showed excellent mechanical property and hydrophobicity. Consequently, a feasible and eco-friendly process of recycling and reusing waste disposable paper cups was developed to achieve a complete utilization and valorization of waste disposable paper cups.

Extraction and Characterization of Cellulose from Jerusalem Artichoke Residue and Its Application in Blueberry Preservation

The utilization of industrial by-products is becoming more and more important for resource utilization. In this study, soluble dietary fiber (SDF) was extracted from Jerusalem artichoke residue, and a series of characterizations of SDF were carried out. The results showed that SDF had good properties. SDF (0%, 0.1%, 0.2%, 0.3%, and 0.4%) and chitosan (2%) were further used to prepare the coating that was used for the preservation of blueberry. The chemical structure of the film was obtained by FT-IR and XRD analysis. The microstructure of the film was analyzed by SEM, and the properties of the film were tested. The blueberry fresh-keeping test proved that the SDF-added film could effectively prolong the quality of blueberries in storage for 16 days. After 16 days of storage, compared with the control group, the decay rate of the coating group with 0.2% SDF decreased by 16.3%, the consumption of organic acids decreased by 43.7%, and the content of anthocyanin increased by 29.3%. SDF has a potential application in food preservation.

Cellobiose phosphorylase from Caldicellulosiruptor bescii catalyzes reversible phosphorolysis via different kinetic mechanisms

In the process of yielding biofuels from cellulose degradation, traditional enzymatic hydrolysis, such as β-glucosidase catalyzing cellobiose, can barely resolve the contradiction between cellulose degradation and bioenergy conservation. However, it has been shown that cellobiose phosphorylase provides energetic advantages for cellobiose degradation through a phosphorolytic pathway, which has attracted wide attention. Here, the cellobiose phosphorylase gene from Caldicellulosiruptor bescii (CbCBP) was cloned, expressed, and purified. Analysis of the enzymatic properties and kinetic mechanisms indicated that CbCBP catalyzed reversible phosphorolysis and had good thermal stability and broad substrate selectivity. In addition, the phosphorolytic reaction of cellobiose by CbCBP proceeded via an ordered Bi Bi mechanism, while the synthetic reaction proceeded via a ping pong Bi Bi mechanism. The present study lays the foundation for optimizing the degradation of cellulose and the synthesis of functional oligosaccharides.

Wood-Sourced Polymers as Support for Catalysis by Group 10 Transition Metals

Despite providing interesting solutions to reduce the number of synthetic steps, to decrease energy consumption or to generate less waste, therefore contributing to a more sustainable way of producing important chemicals, the expansion of the use of homogeneous catalysis in industrial processes is hampered by several drawbacks. One of the most important is the difficulty to recycle the noble metals generating potential high costs and pollution of the synthesized products by metal traces detrimental to their applications. Supporting the metals on abundant and cheap biosourced polymers has recently appeared as an almost ideal solution: They are much easier to recover from the reaction medium and usually maintain high catalytic activity. The present bibliographical review focuses on the development of catalysts based on group 10 transition metals (nickel, palladium, platinum) supported on biopolymers obtained from wood, such as cellulose, hemicellulose, lignin, and their derivatives. The applications of these catalysts in organic synthesis or depollution are also addressed in this review with examples of C-C couplings, oxidation, or hydrogenation reactions.

Plant-Based Structures as an Opportunity to Engineer Optical Functions in Next-Generation Light Management

This review addresses the reconstruction of structural plant components (cellulose, lignin, and hemicelluloses) into materials displaying advanced optical properties. The strategies to isolate the main building blocks are discussed, and the effects of fibrillation, fibril alignment, densification, self-assembly, surface-patterning, and compositing are presented considering their role in engineering optical performance. Then, key elements that enable lignocellulosic to be translated into materials that present optical functionality, such as transparency, haze, reflectance, UV-blocking, luminescence, and structural colors, are described. Mapping the optical landscape that is accessible from lignocellulosics is shown as an essential step toward their utilization in smart devices. Advanced materials built from sustainable resources, including those obtained from industrial or agricultural side streams, demonstrate enormous promise in optoelectronics due to their potentially lower cost, while meeting or even exceeding current demands in performance. The requirements are summarized for the production and application of plant-based optically functional materials in different smart material applications and the review is concluded with a perspective about this active field of knowledge.