Cellulose Matrices Research Articles

Preparation of energy-efficient, environmentally friendly and high-strength biocomposites from wood fibre ultramicro self-composite cellulose matrices

Considering the diminishing forest as a natural resource, the efficient use of small-diameter shrubs is crucial for global sustainable development. This approach has significant potential to prevent wasting forest resources and reduce carbon emissions. However, small-diameter timber has inherent drawbacks, such as the looseness of this material, susceptibility to cracking and deformation, and low strength, all of which significantly impact its range of applications. In this study, an efficient, green method was developed to prepare adhesive-free biocomposites from discarded small-diameter shrubs via ultrasonic pretreatment and thermoforming. After the ultrasonic pretreatment, the flexural and tensile strengths of the biocomposites increased by 145% and 132%, respectively. Ultrasonic pretreatment separated and destroyed chemical bonds among the lignocellulosic biomass macromolecules through high-speed shear and microjets. This process significantly increased the amount of binding sites on the cellulose fibres, and further densified the cell walls through hot pressing. Moreover, the ultrasonic pretreatment may remove components of the wood flour that act as fillers or density enhancers, resulting in a reduction in the density of the biocomposite. Simultaneously, lignin acted as a binder and improved fibre bonding through both physical and chemical cross-linking, resulting in a dense cellulose structure with a three-dimensional lattice structure and a less hydrophilic surface, as evidenced by a water contact angle of 81.72°. In addition, the high-quality, binder-free biocomposites did not emit harmful gases such as formaldehyde. Hence, they are expected to become sustainable materials for building decoration and furniture applications in the future.

Conductive Nanocomposites Based on Graphene and Natural Polymers

This thesis focuses on the development of conductive nanocomposite materials based on graphene and natural polymers such as cellulose and chitosan. Graphene, a single layer of carbon atoms arranged in a honeycomb lattice, exhibits exceptional electrical, mechanical, and thermal properties, making it an attractive filler for polymer composites. However, the challenge lies in effectively dispersing graphene sheets within polymer matrices. The work presented explores new strategies for grafting polysaccharide chains onto oxidized graphite (graphene oxide) to improve its compatibility and dispersion in cellulose and chitosan matrices. The resulting composites were doped with gold or nickel nanoparticles to further enhance their electrical and catalytic properties. Detailed characterization techniques, including spectroscopic and microscopic methods, were employed to analyze the structure, morphology, and properties of the developed nanocomposites. The thesis is organized into three main parts: 1) a literature review on graphene, polysaccharides, and their biocomposites; 2) a description of the experimental materials and methods; and 3) a scientific discussion of the results, presented in the form of three research publications. The findings demonstrate the successful synthesis of conductive nanocomposites with improved compatibility and performance, opening up new avenues for the application of these sustainable and multifunctional materials in areas such as electronics, catalysis, and electromagnetic shielding.

Enzymatic Production of Trehalose and Trehalulose by Immobilized Thermostable Trehalose Synthase.

Trehalose, a versatile disaccharide renowned for its unique physical and chemical properties, finds extensive application in the food, pharmaceutical, and cosmetic industries. While conventional extraction methods face challenges, enzymatic conversion offers a promising avenue for the industrial production of trehalose. This study delves into a novel synthetic approach utilizing a recombinant enzyme, merging the thermostable trehalose synthase domain from Thermus thermophiles with a cellulose binding domain. Immobilization of this enzyme on cellulose matrices enhances stability and facilitates product purification, opening avenues for efficient enzymatic synthesis. Notably, the engineered enzyme demonstrates additional activity, converting sucrose into trehalulose. This dual functionality, combined with immobilization strategies, holds immense potential for scalable and cost-effective production of trehalose and trehalulose, offering promising prospects in various industrial and biomedical applications.

Regenerated nanofibrous cellulose electrospun from ionic liquid: Tuning properties toward tissue engineering.

Regenerated fibrous cellulose possesses a unique set of properties, including biocompatibility, biodegradability, and high surface area potential, but its applications in the biomedical sector have not been sufficiently explored. In this study, nanofibrous cellulose matrices were fabricated via a wet-electrospinning process using a binary system of the solvent ionic liquid (IL) 1-butyl-3-methylimidazolium acetate (BMIMAc) and co-solvent dimethyl sulfoxide (DMSO). The morphology of the matrices was controlled by varying the ratio of BMIMAc versus DMSO in the solvent system. The most effective ratio of 1:1 produced smooth fibers with diameters ranging from 200 to 400 nm. The nanofibrous cellulose matrix showed no cytotoxicity when tested on mouse fibroblast L929 cells whose viability remained above 95%. Human triple-negative breast cancer MDA-MB-231 cells also exhibited high viability even after 7 days of seeding and were able to penetrate deeper layers of the matrix, indicating high biocompatibility. These properties of nanofibrous cellulose demonstrate its potential for tissue engineering and cell culture applications.

3D culture of ovarian follicles in granular and nanofibrillar hydrogels

3D culture of ovarian follicles in hydrogel matrices is an important emerging tool for basic scientific studies as well as clinical applications such as fertility preservation. For optimizing and scaling 3D culture of preantral follicles, there is a need for identifying biomaterial matrices that simplifies and improves the current culture procedures. At present, microencapsulation of follicles in alginate beads is the most commonly used approach. However, this technique involves notable manual handling and is best suited for encapsulation of single or several follicles. As a potential alternative, we here explore the suitability of different particle-based hydrogel matrices, where follicles can easily be introduced in tunable 3D environments, in large numbers. Specifically, we study the growth of secondary murine follicles in microgranular alginate and nanofibrillar cellulose matrices, with and without cell-binding cues, and map follicle growth against the viscoelastic properties of the matrices. We cultured follicles within the particle-based hydrogels for 10 days and continuously monitored their size, survival, and tendency to extrude oocytes. Interestingly, we observed that the diameter of the growing follicles increased significantly in the particle-based matrices, as compared to state-of-the-art alginate micro-encapsulation. On the other hand, the follicles displayed an increased tendency for early oocyte extrusion in the granular matrices, leading to a notable reduction in the number of intact follicles. We propose that this may be caused by impaired diffusion of nutrients and oxygen through thicker matrices, attributable to our experimental setup. Still, our findings suggest that viscoelastic, granular hydrogels represent promising matrices for 3D culture of early-stage ovarian follicles. In particular, these materials may easily be implemented in advanced culturing devices such as micro-perfusion systems.

Loading of bacterial cellulose dressing with frutalin, a lectin from Artocarpus incisa L.

Bacterial cellulose (BC), produced by bacterial fermentation, is a high-purity material. BC can be oxidized (BCOXI), providing aldehyde groups for covalent bonds with drugs. Frutalin (FTL) is a lectin capable of modulating cell proliferation and remodeling, which accelerates wound healing. This study aimed to develop an FTL-incorporated dressing based on BC, and to evaluate its physicochemical properties and biological activity in vitro. An experimental design was employed to maximize FTL loading yield onto the BC and BCOXI, where independent variables were FTL concentration, temperature and immobilization time. BCOXI-FTL 1 (44.96 % ± 1.34) had the highest incorporation yield (IY) at the experimental conditions: 6 h, 5 °C, 20 μg mL−1. The second highest yield was BCOXI-FTL 6 (23.28 % ± 1.43) using 24 h, 5 °C, 100 μg mL−1. Similarly, the same reaction parameters provided higher immobilization yields for native bacterial cellulose: BC-FTL 6 (16.91 % ± 1.05) and BC-FTL 1 (21.71 % ± 1.57). Purified FTL displayed no cytotoxicity to fibroblast cells (<50 μg mL−1 concentration) during 24 h. Furthermore, BCOXI-FTL and BC-FTL were non-cytotoxic during 24 h and stimulated fibroblast migration. BCOXI-FTL demonstrated neutrophil activation in vitro similar to FTL. These promising results indicate that the bacterial cellulose matrices containing FTL at low concentrations, could be used as an innovative biomaterial for developing wound dressings.

Metabolomics-based study of chemical compositions in cellulase additives derived from a tobacco-origin Bacillus subtilis and their impact on tobacco sensory attributes.

To enhance the quality of tobacco leaves and optimize the smoking experience, diverse strains of functional bacteria and their associated metabolites have been used in tobacco aging. Exogenous cellulase additives are frequently employed to facilitate the degradation of cellulose and other macromolecular matrices and enhance the quality of the tobacco product. However, little is known about how microbial metabolites present in exogenous enzyme additives affect tobacco quality. In this study, crude cellulase solutions, produced by a tobacco-originating bacterium Bacillus subtilis FX-1 were employed on flue-cured tobacco. The incorporation of cellulase solutions resulted in the reduction of cellulose crystallinity in tobacco and the enhancement of the overall sensory quality of tobacco. Notably, tobacco treated with cellulase obtained from laboratory flask fermentation demonstrated superior scent and flavor attributes in comparison to tobacco treated with enzymes derived from industrial bioreactor fermentation. The targeted and untargeted metabolomic analysis revealed the presence of diverse flavor-related precursors and components in the cellulase additives, encompassing sugars, alcohols, amino acids, organic acids, and others. The majority of these metabolites exhibited significantly higher levels in the flask group compared to the bioreactor group, probably contributing to a pronounced enhancement in the sensory quality of tobacco. Our findings suggest that the utilization of metabolic products derived from B. subtilis FX-1 as additives in flue-cured tobacco holds promise as a viable approach for enhancing sensory attributes, establishing a solid theoretical foundation for the potential development of innovative tobacco aging additives.

Development of novel carboxymethyl cellulose/gelatin-based edible films with pomegranate peel extract as antibacterial/antioxidant agents for beef preservation

Novel antioxidant and antibacterial composite films were fabricated by incorporating pomegranate peel extract (PPE) into gelatin and carboxymethyl cellulose matrices. Increasing PPE concentration significantly (p < 0.05) altered physical properties and improved UV (decrease in light transmission 87.30 % to 9.89 % at 400 nm) and water resistance, while FTIR and molecular docking results revealed hydrogen bonding between PPE and film matrix. PPE incorporation enhanced antioxidant activity up to 84.15 ± 0.12 % and also restricted gram-positive and gram-negative bacterial growth by 72.4 % and 65.9 % respectively after 24 h, measured by antimicrobial absorption assays. For beef packaging applications at refrigeration temperatures, PPE films were most effective at extending shelf-life up to 3 days, as evidenced by reduced total viable counts, total volatile basic nitrogen, weight loss, and pH changes compared to control films. Therefore, these antioxidant and antibacterial films have potential applications in food packaging to protect against mechanical stress, light exposure, microbial spoilage, and oxidative free radicals.

Characterization of DNA concentration in urine and dried blood samples to detect the c.577 deletion within the EPO gene.

The EPO gene variant, c.577del (VAR-EPO), was discovered in the Chinese population in 2021. The mutated protein is naturally present in urine from individuals heterozygous for the variant. Electrophoresis methods currently applied in anti-doping laboratories produce a pattern in samples from individuals carrying VAR-EPO that cannot be unambiguously distinguished from individuals who received recombinant EPO doses. Consequently, the analysis of blood samples is obligatory to facilitate interpretation of suspicious findings from urine samples. However, this complicates the process and delays the reporting. Objective of this study was to develop EPO c.577del detection in urine and dried blood samples (DBS) in order to facilitate and accelerate EPO results management. Moreover, estimation of the success rate of sequencing regarding concentration of DNA in urine and DBS was evaluated. Conclusive results regarding Sanger sequencing were obtained for all samples with DNA concentrations above 0.024 ng/μL DNA in 80% of urines samples from volunteers. The potential success of DNA sequencing rate in athletes' urines was investigated. A total of 191 urine samples were considered. DNA concentration exceeding 0.024 ng/μL was detected in 85% of the samples. Interestingly, in-competition samples had a significantly higher DNA concentration than out-of-competition male urine samples (0.330 vs. 0.084 ng/μL). Moreover, conclusive EPO sequences were obtained for 100% of DBS (cellulose and polymer matrices). In conclusion, method for detection of EPO gene variant was developed in urine and DBS. Characterization of DNA concentration was performed in order to evaluate the probability of success of sequencing EPO gene in anti-doping field.

Diethylaminoethyl cellulose and quaternary ammonium cellulose matrices as adsorbent materials for potentially toxic CrO42−, Cr2O72−, SeO32− and SeO42− anions: A theoretical study

The present study theoretically analysis the adsorptive capacities of diethylaminoethyl cellulose (DMC) and quaternary ammonium cellulose (QC) biopolymer matrices toward CrO42−, Cr2O72−, SeO32−, and SeO42− at the B3LYP/6-31+G(d,p)/LANL2DZ level of theory. The locations of possible sites of interaction between structures were verified using molecular electrostatic potentials, which revealed that these matrices have quaternary nitrogen atoms that are partially positively charged and can interact with Se and Cr anions. The frontier molecular orbitals show that interactions between chemical species are possible, while structural data reveal that interactions occur through hydrogen bonds that are 1.574–3.263 Å long. The calculated energies associated with these processes, namely interaction (ΔEint) and Gibbs (ΔG) energies as well as the enthalpy (ΔH) are all negative, demonstrating that the anions interact spontaneously with the matrices and release heat. Topological analysis revealed that almost all interactions are weak (∇2(r) > 0 ua and H > 0 ua). Non-covalent-interaction and reduced-density-gradient plots show that the weak interactions are mostly van der Waals in nature with some hydrogen bonds. These theoretical results show that the QC and DMC matrices are good materials for adsorbing CrO42−, Cr2O72−, SeO32−, and SeO42− and can be used to remediate these contaminants.

Characterization of carbon quantum dots obtained through citric acid pyrolysis

Carbon quantum dots (CQDs) were produced through citric acid (CA) pyrolysis. For the first time, we searched for the optimum CA pyrolysis duration and temperature. As a basic quality criterion of quantum dots, photoluminescence quantum yield (QY) was chosen. For this purpose, the pyrolysis products were analysed with UV–Vis spectroscopy and fluorescence (FL) spectroscopy. The optimum pyrolysis time was accepted to be 240 min, whereas the optimum pyrolysis temperature was approved as 200 °C. The pyrolysis products obtained at the optimum conditions were further subjected to dialysis. Finally, the purified CQDs were characterised with FL spectroscopy, transmission electron microscopy, dynamic light scattering, Raman spectroscopy, and Fourier transform infra-red spectroscopy. The produced CQDs were shown to be stable in water solution. Their PL QY (6.1%) was decreased to 1.2% after CQDs exposure to daylight for 90 days. Luminescent polymer composites were produced when CQDs were embedded in the poly(vinyl alcohol) and bacterial cellulose matrices. The prepared composites can be used for fabrication of transparent, flexible, and luminescent films and for production of anti-counterfeiting paper for confidential documents, labels, and banknotes.

New perspectives for maximizing sustainable bioethanol production from corn stover

In Egypt, the production of second-generation bioethanol from agricultural waste is a thriving method to compensate the excessive usage as a consequence of the outspread of Covid-19. The profusion and renewability of lignocellulosic biomass urge its utilization as a promising feedstock for bioethanol production. However, functional delignification without affecting the cellulose matrices remains the major obstacle to achieving effective enzyme accessibility. This paper highlights a novel physio-chemical combination for corn stover (CS) pretreatment for bioethanol production. The optimum pretreatment condition was achieved using a mixture of 5% maleic acid (MA) and 3% citric acid (CA) for 30 min at an autoclave temperature of 110 °C leading to produce a pretreated CS (MAC) with 99% hemicellulose removal, 90% cellulose recovery, and 80% lignin removal. Characteristics analyses such as; SEM, FTIR, TGA, EDX, elemental, proximate, ultimate, higher heating value (HHV), and functionalization analyses were performed to emphasize the property and structure change of CS before and after the pretreatment. Then, MAC was hydrolyzed by cellulase enzyme and produced 13.5 g/L glucose yield which was fermented by Saccharomyces cerevisiae and produced 10 g/L bioethanol.

Photocured Composite Films with Microfibrillated Cellulose: A Study of Water Vapor Permeability

Photocuring is a crosslinking process, widely employed to produce polymers in the form of film. As it is an environmentally friendly process, it is particularly interesting for the preparation of sustainable materials and composites. In this work, composite self-standing films were obtained combining microfibrillated cellulose (MFC) and photocured matrices. To understand the influence of the polarity and surface tension of the matrix on the properties of the composite, poly(ethylene glycol) diacrylate was selected as a hydrophilic matrix and soybean oil epoxidized acrylate as a hydrophobic matrix. Furthermore, the weight fraction of MFC also varied. The conversion and rate of the curing reaction, and the water vapor permeability were studied and discussed in the light of the morphology and composition of the composites.

Amplified circularly polarized luminescence enabled by photon upconversion in spin-coating cellulose matrix

It is of great significance to construct organic circularly polarized luminescence systems (CPL) with large luminescence dissymmetry factors (glum) for practical applications. Here we report organic CPL systems constructed by merging triplet-triplet annihilation upconversion chromophores in cellulose matrices. The chirality of the matrix is transferred to the achiral chromophores of photon upconversion and then the multistep energy transfer processes of upconversion amplify glum. The glum value of upconversion CPL in the left-handed ethyl cellulose and the right-handed (acetyl) ethyl cellulose are up to +0.1 and −0.15, respectively. The study provides a straightforward approach for constructing solid organic upconversion CPL materials with large glum, which may expand the application potentials of organic chiroptical materials.

STUDY OF TECHNICAL CELLULOSE AS A MATRIX-SORBENT TO DEVELOP EXPRESS ANALYTIC SYSTEM FOR WATER SAFETY CONTROL

The study presented by the authors is devoted to the study of the properties and the possibility of using technical cellulose from non-wood plant raw materials as a solid-phase matrix to obtain solid-phase reactive indicator systems by the following methods: synthesis method on the base of a hetarylformazane immobilized on a cellulose matrix and development of analytical systems based on preconcentration of the determined metal ion by a matrix with subsequent its «revealing» by the formazan («revealing» method).&#x0D; The article focuses on determination of optimal combinations of chromogenic organic reagents (hetarylformazanes) and cellulose-based matrices for developing solid-phase reaction-based indicator systems. Adsorption features of formazan reagents onto cellulose matrices was studied. It has been established the relation between the reagent molecule structure, composition of cellulose matrix and analytical properties of the test-systems synthesized to determine metal ions. Different approaches were developed and applied to reveal the visually observable and easily measured effect due to cellulose properties as well as properties of hetarylformazanes fixed on the surface of the matrix. This fact allows to control sensitivity and selectivity of solid-phase reactive indicator systems for water quality assessment.

Bodipy Based Fluorescent Materials in Cellulose Matrices: Synthesis, Spectral Properties and Vapochromic Fluorescent Recognition of Alcohols and Acetone.

This paper highlights advances made using the 4-bora-3a,4a-diaza-s-indacene (BODIPY) as a fluorophore in design and application of fluorescent sensors for microenvironment polarity. Sections of the paper cover broad analysis of a range of fluorescent indicators immobilized in ethyl- and methyl cellulose matrices. The present study demonstrates that BODIPY-based fluorescent materials could be successfully utilized for ratiometric detection of ethanol and acetone in gas phase. The achieved limit of detection value equals 0.02mg/ml for acetone and 0.08mg/ml for ethanol, whereas obtained sensoric materials are reusable without regeneration required.

Nanobioengineered Sensing Technologies Based on Cellulose Matrices for Detection of Small Molecules, Macromolecules, and Cells.

Recent advancement has been accomplished in the field of biosensors through the modification of cellulose as a nano-engineered matrix material. To date, various techniques have been reported to develop cellulose-based matrices for fabricating different types of biosensors. Trends of involving cellulosic materials in paper-based multiplexing devices and microfluidic analytical technologies have increased because of their disposable, portable, biodegradable properties and cost-effectiveness. Cellulose also has potential in the development of cytosensors because of its various unique properties including biocompatibility. Such cellulose-based sensing devices are also being commercialized for various biomedical diagnostics in recent years and have also been considered as a method of choice in clinical laboratories and personalized diagnosis. In this paper, we have discussed the engineering aspects of cellulose-based sensors that have been reported where such matrices have been used to develop various analytical modules for the detection of small molecules, metal ions, macromolecules, and cells present in a diverse range of samples. Additionally, the developed cellulose-based biosensors and related analytical devices have been comprehensively described in tables with details of the sensing molecule, readout system, sensor configuration, response time, real sample, and their analytical performances.

The Mould War: Developing an Armamentarium against Fungal Pathogens Utilising Thymoquinone, Ocimene, and Miramistin within Bacterial Cellulose Matrices.

An increase in antifungal resistance has seen a surge in fungal wound infections in patients who are immunocompromised resulting from chemotherapy, disease, and burns. Human pathogenic fungi are increasingly becoming resistant to a sparse repertoire of existing antifungal drugs, which has given rise to the need to develop novel treatments for potentially lethal infections. Bacterial cellulose (BC) produced by Gluconacetobacter xylinus has been shown to possess many properties that make it innately useful as a next-generation biopolymer to be utilised as a wound dressing. The current study demonstrates the creation of a pharmacologically active wound dressing by loading antifungal agents into a biopolymer hydrogel to produce a novel wound dressing. Amphotericin B is known to be highly hepatotoxic, which reduces its appeal as an antifungal drug, especially in patients who are immunocompromised. This, coupled with an increase in antifungal resistance, has seen a surge in fungal wound infections in patients who are immunodeficient due to chemotherapy, disease, or injury. Antifungal activity was conducted via Clinical & Laboratory Standards Institute (CLSI) M27, M38, M44, and M51 against Candida auris, Candida albicans, Aspergillus fumigatus, and Aspergillus niger. This study showed that thymoquinone has a comparable antifungal activity to amphotericin B with mean zones of inhibition of 21.425 ± 0.925 mm and 22.53 ± 0.969 mm, respectively. However, the mean survival rate of HEp-2 cells when treated with 50 mg/L amphotericin B was 29.25 ± 0.854% compared to 71.25 ± 1.797% when treated with 50 mg/L thymoquinone. Following cytotoxicity assays against HEp-2 cells, thymoquinone showed a 71.25 ± 3.594% cell survival, whereas amphotericin B had a mean cell survival rate of 29.25 ± 1.708%. The purpose of this study was to compare the efficacy of thymoquinone, ocimene, and miramistin against amphotericin B in the application of novel antifungal dressings.

CuO immobilized paper matrices: A green catalyst for conversion of CO2 to cyclic carbonates

Paper matrices immobilized with CuO nanoflakes (width 50−100 nm and length upto 200 nm) by an ultrafast (5 min) microwave assisted method have been used as catalyst for the conversion of CO2 and epoxides into cyclic carbonates with almost 100 % yield in 20 h at a comparatively low CO2 pressure of 4 bar. Additionally, some amount of polycarbonate is also formed. The moderate TON of 121 and excellent recyclability performance (98 % retention of the catalytic activity) even after seven catalytic cycles along with the non-detectable leaching of the CuO from the paper matrices and ease of separation of the catalyst, made the CuO immobilized paper matrices a superior catalyst. The cellulose matrices not only act as a support to immobilize the CuO nanoparticles but also acts as a co-catalyst due to the presence of ample amount of hydroxyl groups in this biodegradable natural polymer. The synergy of cellulose and CuO in the immobilized paper matrices for the formation of the products can be seen as only 7 or 40 % conversion were estimated when only paper matrices or CuO was used as the catalysts, respectively. Moreover, as substrate the paper matrices has shown great potential as the destruction and re-fabrication for five consecutive cycles could hold more than 95 % of the immobilized CuO in the paper matrices.

A Review of Bioactive Glass/Natural Polymer Composites: State of the Art.

Collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose are biocompatible and non-cytotoxic, being attractive natural polymers for medical devices for both soft and hard tissues. However, such natural polymers have low bioactivity and poor mechanical properties, which limit their applications. To tackle these drawbacks, collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose can be combined with bioactive glass (BG) nanoparticles and microparticles to produce composites. The incorporation of BGs improves the mechanical properties of the final system as well as its bioactivity and regenerative potential. Indeed, several studies have demonstrated that polymer/BG composites may improve angiogenesis, neo-vascularization, cells adhesion, and proliferation. This review presents the state of the art and future perspectives of collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose matrices combined with BG particles to develop composites such as scaffolds, injectable fillers, membranes, hydrogels, and coatings. Emphasis is devoted to the biological potentialities of these hybrid systems, which look rather promising toward a wide spectrum of applications.