Cellulose nanocrystals and cellulose nanofibrils based hydrogels for biomedical applications

Nanocellulose: A Fundamental Material for Science and Technology Applications

Recently, considerable interest has been focused on developing greener and biodegradable materials due to growing environmental concerns. Owing to their low cost, biodegradability, and good mechanical properties, plant fibers have substituted synthetic fibers in the preparation of composites. However, the poor interfacial adhesion due to the hydrophilic nature and high-water absorption limits the use of plant fibers as a reinforcing agent in polymer matrices. The hydrophilic nature of the plant fibers can be overcome by chemical treatments. Cellulose the most abundant natural polymer obtained from sources such as plants, wood, and bacteria has gained wider attention these days. Different methods, such as mechanical, chemical, and chemical treatments in combination with mechanical treatments, have been adopted by researchers for the extraction of cellulose from plants, bacteria, algae, etc. Cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and microcrystalline cellulose (MCC) have been extracted and used for different applications such as food packaging, water purification, drug delivery, and in composites. In this review, updated information on the methods of isolation of nanocellulose, classification, characterization, and application of nanocellulose has been highlighted. The characteristics and the current status of cellulose-based fiber-reinforced polymer composites in the industry have also been discussed in detail.

A Critical Review on Modification Methods of Cement Composites with Nanocellulose and Reaction Conditions during Nanocellulose Production

Nanocellulose (NC) is a natural polymer that has driven significant progress in recent years in the study of the mechanical properties of composites, including cement composites. Impressive mechanical properties, ability to compact the cement matrix, low density, biodegradability, and hydrophilicity of the surface of nanocellulose particles (which improves cement hydration) are some of the many benefits of using NCs in composite materials. The authors briefly presented a description of the types of NCs (including the latest, little-known shapes), showing the latest developments in their manufacture and modification. Moreover, NC challenges and opportunities are discussed to reveal its hidden potential, as well as the use of spherical and square/rectangular nanocellulose to modify cement composites. Intending to emphasize the beneficial use of NC in cementitious composites, this article discusses NC as an eco-friendly, low-cost, and efficient material, particularly for recycling readily available cellulosic waste. In view of the constantly growing interest in using renewable and waste materials in a wide range of applications, the authors hope to provide progress in using nanocellulose (NC) as a modifier for cement composites. Furthermore, this review highlights a gap in research regarding the preparation of new types of NCs, their application, and their impact on the properties of cementitious composites. Finally, the authors summarize and critically evaluate the type, dosage, and application method of NC, as well as the effects of these variables on the final properties of NC-derived cement composites. Nevertheless, this review article stresses up-to-date challenges for NC-based materials as well as future remarks in light of dwindling natural resources (including building materials), and the principles of a circular economy.

A novel Nanocellulose-Gelatin-AS-IV external stent resists EndMT by activating autophagy to prevent restenosis of grafts

Vein grafts are widely used for coronary artery bypass grafting and hemodialysis access, but restenosis remains the "Achilles' heel" of these treatments. An extravascular stent is one wrapped around the vein graft and provides mechanical strength; it can buffer high arterial pressure and secondary vascular dilation of the vein to prevent restenosis. In this study, we developed a novel Nanocellulose-gelatin hydrogel, loaded with the drug Astragaloside IV (AS-IV) as an extravascular scaffold to investigate its ability to reduce restenosis. We found that the excellent physical and chemical properties of the drug AS-IV loaded Nanocellulose-gelatin hydrogel external stent limit graft vein expansion and make the stent biocompatible. We also found it can prevent restenosis by resisting endothelial-to-mesenchymal transition (EndMT) in vitro. It does so by activating autophagy, and AS-IV can enhance this effect both in vivo and in vitro. This study has added to existing research on the mechanism of extravascular stents in preventing restenosis of grafted veins. Furthermore, we have developed a novel extravascular stent for the prevention and treatment of restenosis. This will help optimize the clinical treatment plan of external stents and improve the prognosis in patients with vein grafts.

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The NC-Gelatin extravascular stent has suitable physicochemical properties to prevent restenosis of the grafted veins.

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The NC-Gelatin extravascular stent has excellent biocompatibility, which is critical for grafting veins.

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The NC-Gelatin extravascular stent prevents restenosis by activating autophagy against EndMT.

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AS-IV can enhance the effect of the stent to activate autophagy against EndMT.

Strong, flexible, and highly conductive cellulose nanofibril/PEDOT:PSS/MXene nanocomposite films for efficient electromagnetic interference shielding

Flexible and light weight electromagnetic interference (EMI) shielding materials with high electromagnetic shielding efficiency (SE) and excellent mechanical strength are highly demanded for wearable and portable electronics. In this work, for the first time, a freestanding and flexible cellulose nanofibril (CNF)/PEDOT:PSS/MXene (Ti₃C₂T_x) nanocomposite film with a ternary heterostructure was manufactured using a vacuum-assisted filtration process. The results show that compared with pure MXene films, the tensile strength of the optimized nanocomposite film increases from 8.88 MPa to 59.99 MPa, and the corresponding fracture strain increases from 0.87% to 4.60%. Intriguingly, the optimized nanocomposite film exhibited an impressive conductivity of 1903.2 S cm^-1, which is among the highest values reported for MXene and cellulose-based nanocomposites. Owing to the superior conductivity and unique heterostructure, the nanocomposite film exhibits a high EMI SE value of 76.99 dB at a thickness of only 58.0 μm. Taking into account the robust mechanical properties and remarkable EMI shielding performance, the CNF/PEDOT:PSS/MXene nanocomposite film could be a prospective EMI shielding material for a variety of high-end applications.

The therapeutic effect and targets of cellulose polysaccharide on coronary heart disease (CHD) and the construction of a prognostic signature based on network pharmacology

Cellulose is the first rich biological polysaccharide in nature and has many excellent properties, so it is being developed as a variety of drug carriers. Moreover, applications in drug delivery, biosensors/bioanalysis, immobilization of enzymes and cells, stem cell therapy, and skin tissue repair are also highlighted by many studies. Coronary heart disease, as one of the diseases with the highest incidence, is urgent to enhance the survival outcome and life quality of patients with coronary heart disease, whereas the mechanism of cellulose's interaction with the human body remains unclear. However, the mechanism of cellulose's interaction with the human body remains unclear. We obtained 92 genes associated with cellulose and coronary heart disease through the intersection of different databases. Ten key genes were identified: HRAS, STAT3, HSP90AA1, FGF2, VEGFA, CXCR4, TERT, IL2, BCL2L1, and CDK1. Molecular docking of the 10 genes revealed their association with their respective receptors. Analysis by KEGG and GO has discovered that these related targets were more enriched in metabolic- and activation-related functions, which further confirmed that cellulose polysaccharides can also interact with cardiovascular diseases as molecules. In the end, we screened out six key genes that were more associated with the prognosis (CDK1, HSP90AA1, CXCR4, IL2, VEGFA, and TERT) and constructed a signature, which has a good predictive effect and has significant statistical significance. Our study is the first study to explore the interaction targets of cellulose and CHD and to construct a prognostic model. Our findings provide insights for future molecular design, drug development, and clinical trials.

Nanocellulose/two dimensional nanomaterials composites for advanced supercapacitor electrodes

With the emerging of the problems of environmental pollution and energy crisis, the development of high-efficiency energy storage technology and green renewable energy is imminent. Supercapacitors have drawn great attention in wearable electronics because of their good performance and portability. Electrodes are the key to fabricate high-performance supercapacitors with good electrochemical properties and flexibility. As a biomass based derived material, nanocellulose has potential application prospects in supercapacitor electrode materials due to its biodegradability, high mechanical strength, strong chemical reactivity, and good mechanical flexibility. In this review, the research progress of nanocellulose/two dimensional nanomaterials composites is summarized for supercapacitors in recent years. First, nanocellulose/MXene composites for supercapacitors are reviewed. Then, nanocellulose/graphene composites for supercapacitors are comprehensively elaborated. Finally, we also introduce the current challenges and development potential of nanocellulose/two dimensional nanomaterials composites in supercapacitors.

Sprayable Antibacterial Hydrogels by Simply Mixing of Aminoglycoside Antibiotics and Cellulose Nanocrystals for the Treatment of Infected Wounds

Antibiotic hydrogels with sustained release profiles are recognized as promising candidates to treat local bacterial infections with reduced adverse effects. However, it still remains challenging for clinical translation of these antibiotic gels due to safety concern of gel ingredients, complicated synthesis and fabrication procedures, and unsatisfactory rheological properties for practical uses in vivo. Herein, the preparation of a type of sprayable hydrogels by ionic interactions between aminoglycosides and cellulose nanocrystals (CNC) is proposed for the treatment of local infections such as bacteria-infected wounds. The CNC-based hydrogels are applicable for all kinds of aminoglycoside antibiotics and show excellent gel stability and rheological behaviors such as shear thinning and fast self-healing, allowing facile administration by injection or spraying. The hydrogels exhibit efficient antibacterial activity both in vitro and in vivo, and accelerate bacteria-infected wounds by spraying on the infected area. The proposed hydrogels by simply mixing of aminoglycosides and CNC provide great prospects for clinical translation in the treatment of local infections.

Gellan Gum in Wound Dressing Scaffolds

Several factors, such as bacterial infections, underlying conditions, malnutrition, obesity, ageing, and smoking are the most common issues that cause a delayed process of wound healing. Developing wound dressings that promote an accelerated wound healing process and skin regeneration is crucial. The properties of wound dressings that make them suitable for the acceleration of the wound healing process include good antibacterial efficacy, excellent biocompatibility, and non-toxicity, the ability to provide a moist environment, stimulating cell migration and adhesion, and providing gaseous permeation. Biopolymers have demonstrated features appropriate for the development of effective wound dressing scaffolds. Gellan gum is one of the biopolymers that has attracted great attention in biomedical applications. The wound dressing materials fabricated from gellan gum possess outstanding properties when compared to traditional dressings, such as good biocompatibility, biodegradability, non-toxicity, renewability, and stable nature. This biopolymer has been broadly employed for the development of wound dressing scaffolds in different forms. This review discusses the physicochemical and biological properties of gellan gum-based scaffolds in the management of wounds.

Preparation of biodegradable carboxymethyl cellulose/dopamine/Ag NPs cryogel for rapid hemostasis and bacteria-infected wound repair

Massive hemorrhage caused by accident or surgery is a major factor in accidental death. In addition, bacterial infection is also an important threat after bleeding. Cryogels with interpenetrating macroporous structures pose great application prospects in rapid hemostasis and infected wound repair. In this study, cryogels with different pore size are prepared by carboxymethyl cellulose (CMC) and dopamine (DA). The CMC grafted with different DA amounts is crosslinked by free DA through oxidative polymerization at low temperatures to form cryogels with different pore sizes. And the CMC/DA-3 cryogel is chosen as the optimal group for its high porosity, suitable mechanical, and good hemostatic ability. CMC/DA-3 cryogel is loaded with silver nanoparticles (Ag NPs) to prepare hemostatic cryogel with antibacterial properties. Antibacterial tests and animal hemostasis experiments confirm that the CMC/DA-3/Ag cryogel has good antibacterial properties and can finish rapid hemostasis. In the S. aureus infection skin defect model, the wound healing is significantly improved compared with commercial gelatin sponge. In summary, the novel cryogel has great potential in rapid hemostasis and infected wound healing.

Cellulose nanofibrils-graphene hybrids: recent advances in fabrication, properties, and applications

With the fast-developing social economy and the acceleration of industrialization, seeking effective renewable, sustainable, and environmentally friendly resources that show promising properties is an urgent task and a crucial means to achieve sustainable progress in the face of the growing depletion of non-renewable resources and the deterioration of environmental issues. Cellulose nanofibrils (CNFs) are natural polymeric nanomaterials with excellent biocompatibility, biodegradability, good mechanical features, high strength, low density, high specific surface area, and tunable chemistry. Their combination with other nanomaterials, such as graphene derivatives (GNMs), has been demonstrated to be effective since they produce hybrids with outstanding physicochemical properties, tailorable functionality, and high performance. In this review, recent advances in the preparation, modification, and emerging application of CNFs/GNMs hybrids are described and discussed using the latest studies. First, the concise background of nanocellulose and graphene derivatives is provided, followed by the interfacial interactions between CNFs and GNMs. The different hybrids exhibit great promise in separation, adsorption, optics, flexible electronics, energy storage, thermal management, barrier and packaging, and electromagnetic shielding. The main challenges that inhibit the applicability of these hybrids are finally highlighted, and some perspectives for future research directions are provided.

Effects of taxifolin from enzymatic hydrolysis of Rhododendron mucrotulatum on hair growth promotion

Flavonoid aglycones possess biological activities, such as antioxidant and antidiabetic activities compared to glycosides. Taxifolin, a flavonoid aglycones, is detected only in trace amounts in nature and is not easily observed. Therefore, in this study, to investigate the hair tonic and hair loss inhibitors effect of taxifolin, high content of taxifolin aglycone extract was prepared by enzymatic hydrolysis. Taxifolin effectively regulates the apoptosis of dermal papilla cells, which is associated with hair loss, based on its strong antioxidant activities. However, inhibition of dihydrotestosterone (DHT), which is a major cause of male pattern hair loss, was significantly reduced with taxifolin treatment compared with minoxidil, as a positive control. It was also confirmed that a representative factor for promoting hair growth, IGF-1, was significantly increased, and that TGF-β1, a representative biomarker for hair loss, was significantly reduced with taxifolin treatment. These results suggest that taxifolin from enzymatic hydrolysis of RM is a potential treatment for hair loss and a hair growth enhancer.

Characterizations of Alpha-Cellulose and Microcrystalline Cellulose Isolated from Cocoa Pod Husk as a Potential Pharmaceutical Excipient

Cellulose is a non-toxic, bio-degradable, and renewable biopolymer which is abundantly available in nature. The most common source of commercial microcrystalline cellulose is fibrous wood pulp. Cellulose and its derivatives have found wide commercial applications in the pharmaceutical, cosmetic, food, paper, textile, and engineering industries. This study aims to isolate and characterize cellulose forms from cocoa pod husk (CPH) and to assess its mechanical and disintegration properties as a direct compression excipient in metronidazole tablets. Two isolated cellulose types (i.e., cocoa alpha-cellulose (CAC) and cocoa microcrystalline cellulose (C-MCC)) were compared with avicel (AV). CAC and C-MCC were characterized for their physicochemical properties using Scanning Electron Microscopy (SEM), FTIR spectroscopy, Differential Scanning Calorimetry (DSC), and X-Ray Powder Diffraction (XRD). Metronidazole tablets were produced by direct compression with cellulose. The mechanical and disintegration properties of the tablets were evaluated. CAC and C-MCC yield was 42.3% w/w and 38.25% w/w, respectively. Particle diameters were significantly different with CAC (282.22 μm) > C-MCC (161.32 μm) > AV (72.51 μm). CAC and C-MCC had a better flow than AV. SEM revealed the fibrous nature of the cellulose. FTIR and XRD analysis confirmed the presence of cellulose with crystallinity index of 69.26%, 43.83%, and 26.32% for AV, C-MCC, and CAC, respectively. C-MCC and AV are more crystalline and thermally stable at high temperatures compared to CAC. The mechanical and disintegration properties of C-MCC and AV tablets complied with pharmacopeia specifications. Taken together, C-MCC isolated from CPH displayed some fundamental characteristics suitable for use as a pharmaceutical excipient and displayed better properties compared to that of AV.

Formation of biocompatible MgO/cellulose grafted hydrogel for efficient bactericidal and controlled release of doxorubicin

In this study, MgO-doped CNC-g-PAA hydrogel was synthesized by grafting poly (acrylic acid) (PAA) onto cellulose nanocrystals (CNC) and then doped Magnesium oxide (MgO) using pH 7.0 and 12.0 to obtain an efficient nanocomposite hydrogel for antibacterial and anti-cancer activities. The synthesized nanocomposite hydrogels were evaluated by detailed characterization and confirmed the formation of a well-interconnected porous structure. MgO/CNC-g-PAA (pH = 12.0) exhibited improved bactericidal tendencies towards gram-negative and gram-positive bacteria, which was further investigated by in-silico molecular docking analyses and also examined the reactive oxygen species production by photocatalysis and free radical-scavenging assay. After this, Doxorubicin (DOX), a model anticancer drug, was successfully loaded into nanocomposites (~79 %) by electrostatic interaction and confirmed pH-triggered based release, which was over 53.7 % in 24 h. Finally, in vitro cytotoxicity-based analysis confirmed the improved antitumor efficacy of nanocomposite hydrogels. These findings revealed that MgO/CNC-g-PAA hydrogels might be prospective carriers for controlled drug delivery.

Recent Advances in Cellulose-Based Hydrogels for Tissue Engineering Applications

In recent years, cellulose has attracted much attention because of its excellent properties, such as its hydrophilicity, mechanical properties, biodegradability, biocompatibility, low cost and low toxicity. In addition, cellulose and its derivatives contain abundant hydrophilic functional groups (such as hydroxyl, carboxyl and aldehyde groups), which are good raw materials for synthesizing biocompatible hydrogels. In this paper, the application prospects of cellulose and its derivatives-based hydrogels in biomedical tissue engineering are summarized and discussed through the analysis of recent research. Firstly, we discuss the structure and properties of cellulose, nano celluloses (NC) from different sources (including cellulose nanocrystals (CNC), cellulose nanofibrils (CNF) and bacterial nano celluloses (BNC)) and cellulose derivatives (including cellulose ethers and cellulose esters) obtained by different modification methods. Then, the properties and preparation methods of physical and chemical cellulose hydrogels are described, respectively. The application of cellulose-based hydrogels as a tissue engineering scaffold (skin, bone and cartilage) in the biomedical field is introduced. Finally, the challenges and prospects of cellulose-based hydrogels in tissue engineering are summarized.

Recent insights into polysaccharide-based hydrogels and their potential applications in food sector: A review

Hydrogels are ideal for various food applications because of their softness, elasticity, absorbent nature, flexibility, and hygroscopic nature. Polysaccharide hydrogels are particularly suitable because of the hydrophilic nature, their food compatibility, and their non-immunogenic character. Such hydrogels offer a wide range of successful applications such as food preservation, pharmaceuticals, agriculture, and food packaging. Additionally, polysaccharide hydrogels have proven to play a significant role in the formulation of food flavor carrier systems, thus diversifying the horizons of newer developments in food processing sector. Polysaccharide hydrogels are comprised of natural polymers such as alginate, chitosan, starch, pectin and hyaluronic acid when crosslinked physically or chemically. Hydrogels with interchangeable, antimicrobial and barrier properties are referred to as smart hydrogels. This review brings together the recent and relevant polysaccharide research in these polysaccharide hydrogel applications areas and seeks to point the way forward for future research and interventions. Applications in carrying out the process of flavor carrier system directly through their incorporation in food matrices, broadening the domain for food application innovations. The classification and important features of polysaccharide-based hydrogels in food processing are the topics of the current review study.

Research Progress of Highly Efficient Noble Metal Catalysts for the Oxidation of 5-Hydroxymethylfurfural

5-hydroxymethylfurfural (HMF) is considered to be one of the most pivotal multifunctional biomass platform chemicals. This Review discusses recent advances in catalytic oxidation of HMF towards high-value products. The reaction mechanism of different noble metals and the path of HMF oxidation to high-value products have been deeply investigated in the noble metal catalytic system. The reaction mechanisms of different noble metals and HMF conversion paths were compared in detail. Moreover, the factors affecting the performance of different noble metal catalysts were summarized. Finally, effective strategies were put forward to improve the catalytic performance of noble metal catalysts. The purpose is to provide a valuable reference for the academic research on the preparation of oxidation products from biomass-based HMF and the industrial application of noble metal catalysts.

A Bibliometric and Visual Analysis of Nanocomposite Hydrogels Based on VOSviewer From 2010 to 2022

Background: Nanocomposite hydrogels (NHs) are stable composite materials formed by dispersing nanomaterials in hydrogels and have broad development prospects in the biomedical field. In this study, we aimed to systematically and comprehensively evaluate the trends and hot spots of biomedical applications of NHs from 2010 to 2022.

Methods: In total, 713 articles and reviews related to NH applications in the biomedical field from 2010 to 2022 were retrieved from the Web of Science Core Collection (WOSCC). Two scientometric software programs, VOSviewer and Microsoft Excel 2019, were used to visually perform bibliometric analysis in terms of research trends, sources, the contribution of journals, co-citation, and the co-occurrence of keywords.

Results: From 1 January 2010 to 3 February 2022, the number of annual scientific publications about NHs exhibited an upward trend, and research articles were published in a larger proportion (more than 77%). The top three countries in NH research were China, the United States, and India. Meanwhile, Tabriz University of Medical Sciences, the Chinese Academy of Sciences, and Tshwane University of Technology were the most active and contributive. In the contribution of journals, the journal Advanced Functional Materials had the highest number of publications, and the journal Int J Biol Macro had the most citations. Varaprasad K was the most prolific author, and Haraguchi K ranked first among co-cited authors. In the ranking of frequency in the co-cited references, Nanocomposite Hydrogels for Biomedical Applications, published by Gaharwar AK, was the most frequently cited reference. The keyword with the highest frequency was “drug delivery.”

Conclusion: This study performed a full overview of NHs using bibliometrics and identified current trends and hot spots. This information may help researchers focusing on NHs to identify developments in this field.

Use of Carbotrace 480 as a Probe for Cellulose and Hydrogel Formation from Defibrillated Microalgae

Carbotrace 480 is a commercially available fluorescent optotracer that specifically binds to cellulose’s glycosidic linkages. Herein, the use of Carbotrace 480 is reported as an analytical tool for linking cellulose content to hydrogel formation capability in defibrillated celluloses obtained from proprietary microalgae. Defibrillated celluloses obtained from acid-free hydrothermal microwave processing at low temperature (160 °C) showed poor hydrogel formation attributed to a low cellulose concentration as evidenced through the lack of Carbotrace fluorescence. High temperature (220 °C) processing afforded reasonable gels commensurate with a higher cellulose loading and stronger response to Carbotrace.

Lignin as a Natural Carrier for the Efficient Delivery of Bioactive Compounds: From Waste to Health

Lignin is a fascinating aromatic biopolymer with high valorization potentiality. Besides its extensive value in the biorefinery context, as a renewable source of aromatics lignin is currently under evaluation for its huge potential in biomedical applications. Besides the specific antioxidant and antimicrobial activities of lignin, that depend on its source and isolation procedure, remarkable progress has been made, over the last five years, in the isolation, functionalization and modification of lignin and lignin-derived compounds to use as carriers for biologically active substances. The aim of this review is to summarize the current state of the art in the field of lignin-based carrier systems, highlighting the most important results. Furthermore, the possibilities and constraints related to the physico–chemical properties of the lignin source will be reviewed herein as well as the modifications and processing required to make lignin suitable for the loading and release of active compounds.

Recent Advances in 3D Bioprinting: A Review of Cellulose-Based Biomaterials Ink

Cellulose-based biodegradable hydrogel proves to be excellently suitable for the medical and water treatment industry based on the expressed properties such as its flexible structure and broad compatibility. Moreover, their potential to provide excellent waste management from the unutilized plant has triggered further study on the advanced biomaterial applications. To extend the use of cellulose-based hydrogel, additive manufacturing is a suitable technique for hydrogel fabrication in complex designs. Cellulose-based biomaterial ink used in 3D bioprinting can be further used for tissue engineering, drug delivery, protein study, microalgae, bacteria, and cell immobilization. This review includes a discussion on the techniques available for additive manufacturing, bio-based material, and the formation of a cellulose-based hydrogel.

Tissue Adhesive, Conductive, and Injectable Cellulose Hydrogel Ink for On-Skin Direct Writing of Electronics

Flexible and soft bioelectronics used on skin tissue have attracted attention for the monitoring of human health. In addition to typical metal-based rigid electronics, soft polymeric materials, particularly conductive hydrogels, have been actively developed to fabricate biocompatible electrical circuits with a mechanical modulus similar to biological tissues. Although such conductive hydrogels can be wearable or implantable in vivo without any tissue damage, there are still challenges to directly writing complex circuits on the skin due to its low tissue adhesion and heterogeneous mechanical properties. Herein, we report cellulose-based conductive hydrogel inks exhibiting strong tissue adhesion and injectability for further on-skin direct printing. The hydrogels consisting of carboxymethyl cellulose, tannic acid, and metal ions (e.g., HAuCl4) were crosslinked via multiple hydrogen bonds between the cellulose backbone and tannic acid and metal-phenol coordinate network. Owing to this reversible non-covalent crosslinking, the hydrogels showed self-healing properties and reversible conductivity under cyclic strain from 0 to 400%, as well as printability on the skin tissue. In particular, the on-skin electronic circuit printed using the hydrogel ink maintained a continuous electrical flow under skin deformation, such as bending and twisting, and at high relative humidity of 90%. These printable and conductive hydrogels are promising for implementing structurally complicated bioelectronics and wearable textiles.

Cellulose-Based Nanomaterials Advance Biomedicine: A Review

There are various biomaterials, but none fulfills all requirements. Cellulose biopolymers have advanced biomedicine to satisfy high market demand and circumvent many ecological concerns. This review aims to present an overview of cellulose knowledge and technical biomedical applications such as antibacterial agents, antifouling, wound healing, drug delivery, tissue engineering, and bone regeneration. It includes an extensive bibliography of recent research findings from fundamental and applied investigations. Cellulose-based materials are tailorable to obtain suitable chemical, mechanical, and physical properties required for biomedical applications. The chemical structure of cellulose allows modifications and simple conjugation with several materials, including nanoparticles, without tedious efforts. They render the applications cheap, biocompatible, biodegradable, and easy to shape and process.

Enzymatic hydrolysis of lignocellulosic biomass using a novel, thermotolerant recombinant xylosidase enzyme from Clostridium clariflavum: a potential addition for biofuel industry

The present study describes the cloning, expression, purification and characterization of the xylosidase gene (1650 bp) from a thermophilic bacterium Clostridium clariflavum into E. coli BL21 (DE3) using the expression vector pET-21a(+) for utilization in biofuel production. The recombinant xylosidase enzyme was purified to homogeneity by heat treatment and immobilized metal ion affinity chromatography. SDS-PAGE determined that the molecular weight of purified xylosidase was 60 kDa. This purified recombinant xylosidase showed its maximum activity at a temperature of 37 °C and pH 6.0. The purified recombinant xylosidase enzyme remains stable up to 90 °C for 4 h and retained 54.6% relative activity as compared to the control. The presence of metal ions such as Ca²⁺ and Mg²⁺ showed a positive impact on xylosidase enzyme activity whereas Cu²⁺ and Hg²⁺ inhibit its activity. Organic solvents did not considerably affect the stability of the purified xylosidase enzyme while DMSO and SDS cause the inhibition of enzyme activity. Pretreatment experiments were run in triplicate for 72 h at 30 °C using 10% NaOH. Saccharification experiment was performed by using 1% substrate (pretreated plant biomass) in citrate phosphate buffer of pH 6.5 loaded with 150 U mL⁻¹ of purified recombinant xylosidase enzyme along with ampicillin (10  μg mL⁻¹). Subsequent incubation was carried out at 50 °C and 100 rpm in a shaking incubator for 24 h. Saccharification potential of the recombinant xylosidase enzyme was calculated against both pretreated and untreated sugarcane bagasse and wheat straw as 9.63% and 8.91% respectively. All these characteristics of the recombinant thermotolerant xylosidase enzyme recommended it as a potential candidate for biofuel industry.

The present study describes the cloning, expression, purification and characterization of a xylosidase gene from Clostridium clariflavum into E. coli BL21 (DE3) using the expression vector pET-21a(+) for utilization in biofuel production.