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BACKGROUND: There is a lack of small-caliber artificial blood vessels (< 6 mm) in clinical application. OBJECTIVE: To explore the potential of bacterial nanocellulose/polydopamine (BNC/PDA) composite tubes for small-caliber artificial blood vessels. METHODS: Bacterial nanocellulose small-caliber artificial blood vessel was prepared through an external silicone tube reactor, and the purified cellulose tube was immersed in dopamine solutions of different mass concentrations (0.1, 0.5, 1.0, 1.5, 2.0 g/L) for self polymerization reaction. After preparation of BNC/ PDA composite tubes, the microstructure, infrared spectrum, density, water holding capacity, water permeability, burst and suture strength, axial mechanical properties, and blood and cell compatibility of the bacterial nanocellulose tube and BNC/PDA composite tubes were characterized. RESULTS AND CONCLUSION: (1) The field emission scanning electron microscope showed that the inner surface of all tubes was a 3D network structure built by nanofibers, with uniform fiber distribution and compact structure. With the increase of dopamine mass concentration, the fiber diameter of artificial blood vessels increased. (2) As the mass concentration of dopamine increased, the density, burst and suture strength and axial mechanical properties of artificial blood vessels increased, and the water penetration and water holding capacity decreased. (3) The hemolysis rate and platelet adhesion test results showed that the hemolysis rate of the bacterial nanocellulose tube and the BNC/PDA composite tubes were both non-hemolytic grades. The composite tube adhered to platelets less than the bacterial nanocellulose tube. The whole blood coagulation test results showed that the composite tubes had stronger blood coagulation performance than the bacterial nanocellulose tube. (4) CCK-8 experiment results showed that compared with simple bacterial nanocellulose, the BNC/PDA0.1 composite tubes could promote the proliferation of human umbilical vein endothelial cells; the other four composite tubes inhibited cell proliferation; and BNC/PDA-1.5 and BNC/PDA-2.0 composite tube showed obvious cytotoxicity. The results of calcein fluorescence staining showed that the cells on the surface of the simple bacterial nanocellulose, BNC/PDA-0.1, BNC/PDA-0.5, and BNC/PDA-1.0 composite tubes could continue to proliferate, among which the number of cells on the surface of the BNC/PDA-0.1 composite tubes was more than that on simple bacterial nanocellulose. (5) The results show that the BNC/PDA composite tubes have certain potential to be used in small-caliber artificial blood vessels, and it can be further grafted with active macromolecules to achieve functionalization. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) is a novel nanomaterial known for its large surface area, biocompatibility, and non-toxicity. BNC contributes to regenerative processes in the skin but lacks antimicrobial and anti-inflammatory properties. Herein, the development of bioactive wound dressings by loading antibacterial povidone-iodine (PVI) or anti-inflammatory acetylsalicylic acid (ASA) into bacterial cellulose is presented. BNC is produced using Hestrin–Schramm culture media and loaded via immersion in PVI and ASA. Through scanning electron microscopy, BNC reveals open porosity where the bioactive compounds are loaded; the mechanical tests show that the dressing prevents mechanical wear. The loading kinetic and release assays (using the Franz cell method) under simulated fluids present a maximum loading of 589.36 mg PVI/g BNC and 38.61 mg ASA/g BNC, and both systems present a slow release profile at 24 h. Through histology, the complete diffusion of the bioactive compounds is observed across the layers of porcine skin. Finally, in the antimicrobial experiment, BNC/PVI produced an inhibition halo for Gram-positive and Gram-negative bacteria, confirming the antibacterial activity. Meanwhile, the protein denaturation test shows effective anti-inflammatory activity in BNC/ASA dressings. Accordingly, BNC is a suitable platform for the development of bioactive wound dressings, particularly those with antibacterial and anti-inflammatory properties. [ABSTRACT FROM AUTHOR]

The potential of nanomaterials in food technology is nowadays well-established. However, their commercial use requires a careful risk assessment, in particular concerning the fate of nanomaterials in the human body. Bacterial nanocellulose (BNC), a nanofibrillar polysaccharide, has been used as a food product for many years in Asia. However, given its nano-character, several toxicological studies must be performed, according to the European Food Safety Agency's guidance. Those should especially answer the question of whether nanoparticulate cellulose is absorbed in the gastrointestinal tract. This raises the need to develop a screening technique capable of detecting isolated nanosized particles in biological tissues. Herein, the potential of a cellulose-binding module fused to a green fluorescent protein (GFP–CBM) to detect single bacterial cellulose nanocrystals (BCNC) obtained by acid hydrolysis was assessed. Adsorption studies were performed to characterize the interaction of GFP–CBM with BNC and BCNC. Correlative electron light microscopy was used to demonstrate that isolated BCNC may be detected by fluorescence microscopy. The uptake of BCNC by macrophages was also assessed. Finally, an exploratory 21-day repeated-dose study was performed, wherein Wistar rats were fed daily with BNC. The presence of BNC or BCNC throughout the GIT was observed only in the intestinal lumen, suggesting that cellulose particles were not absorbed. While a more comprehensive toxicological study is necessary, these results strengthen the idea that BNC can be considered a safe food additive. [ABSTRACT FROM AUTHOR]

The strong need for the utilization of industrial by-products and biowaste increases as we transition towards a circular economy. On these grounds, the present research aims to explore the applicability of the Symbiotic Culture of Bacteria and Yeast (SCOBY), a by-product of a functional beverage industry, for applications in biomedicine. Herein, hydroxyapatite (HA)-coated SCOBY nanocellulose (SN) nanocomposite (SNHA) was synthesized via a novel biomimetic approach using Serratia marcescens strain by adopting two different in situ approaches. Characterization studies established the presence of functional groups corresponding to pure nanocellulose and HA. Microscopic analysis revealed SN fibers of the dimensions 30–50 nm surrounded by 10–15 nm rod-shaped HA crystals. The SNHA membranes were carbonated and harbored traces of metal ions. A deposition of nano-HA crystals as high as 30–50% was achieved. Overall, the synthesized SNHA membranes reflected increased stability, low crystalline nature and an ion-substituted structure resembling the natural bone; they are thereby suited for bone tissue engineering. [ABSTRACT FROM AUTHOR]

The research interest in sustainable and eco-friendly materials based on natural sources has increased dramatically due to their recyclability, biodegradability, compatibility, and nontoxic behavior. Nanocellulose contains chains of glucose residue and is an abundantly available green material. Recently, nanocellulose-based green composites are under extensive exploration and gained popularity among researchers owing to their lightweight, lost cost, low density, excellent mechanical and physical characteristics. These materials have also shown tremendous potential for applications in biomedical and numerous engineering fields. The mechanical properties of these materials play a vital role in effective utilization and their exploration for future applications. This review article comprehensively presents current developments, results, and findings in the arena of green and sustainable materials. Currently, the main problem is the large variability in their properties and qualities. Nanocellulose properties are influenced by various factors, including the fiber type, ecological conditions, manufacturing methods, and any alteration of the fiber surface. Finally, the review incorporates future challenges and opportunities in the field of nano cellulosic materials.

Oil spillage is one of the serious problems for sustainable environment. Bacterial nanocellulose (BNC), a hydrophilic and highly porous material holds a promising material for oil-water separation from contaminants. In the present work, a hydrophilic BNC produced from a sorbitol as the carbon source demonstrated the unique porous symmetrical arrangement having an oleophilic property. The BNC membrane obtained showed the highest water holding capacity (WHC) of ≈147 gg 1. The Brunauer-Emmett-Teller (BET) analysis of BNC revealed the unique characteristics of isothermic patterns, having macro sized pores with diameter of 121.3 nm and surface area of 40.6m2/g, which plays a vital role in separation of oil from water by allowing passage of only water through it. The separation efficiency of BNC membrane produced after 5th day of incubation has showed 99.0 % oil removal compared to 10 and 15th day incubated BNC membranes. a CFD model to investigate the possibilities of BNC membranes and clarify the dynamics of oil-water separation. The nanostructured network of BNC offers a tortuous path for oil molecules while allowing rapid permeation of water, leading to high separation selectivity and flux. Although BNC has been previously studied for oil water separation, this study provides new insights into the use of wet BNC membranes into its pristine state with sorbitol as carbon source for this application. [ABSTRACT FROM AUTHOR]

Abstract Bacterial nanocellulose (BNC) is usually produced as randomly‐organized highly pure cellulose nanofibers films. Its high water‐holding capacity, porosity, mechanical strength, and biocompatibility make it unique. Ordered structures are found in nature and the properties appearing upon aligning polymers fibers inspire everyone to achieve highly aligned BNC (A‐BNC) films. This work takes advantage of natural bacteria biosynthesis in a reproducible and straightforward approach. Bacteria confined and statically incubated biosynthesized BNC nanofibers in a single direction without entanglement. The obtained film is highly oriented within the total volume confirmed by polarization‐resolved second‐harmonic generation signal and Small Angle X‐ray Scattering. The biosynthesis approach is improved by reusing the bacterial substrates to obtain A‐BNC reproducibly and repeatedly. The suitability of A‐BNC as cell carriers is confirmed by adhering to and growing fibroblasts in the substrate. Finally, the thermal conductivity is evaluated by two independent approaches, i.e., using the well‐known 3ω‐method and a recently developed contactless thermoreflectance approach, confirming a thermal conductivity of 1.63 W mK−1 in the direction of the aligned fibers versus 0.3 W mK−1 perpendicularly. The fivefold increase in thermal conductivity of BNC in the alignment direction forecasts the potential of BNC‐based devices outperforming some other natural polymer and synthetic materials.

The persistent water treatment and separation challenge necessitates innovative and sustainable advances to tackle conventional and emerging contaminants in the aquatic environment effectively. Therefore, a unique three-dimensional (3D) network composite film (BNC-KC) comprised of bacterial nanocellulose (BNC) incorporated nano-kaolinite clay particles (KC) was successfully synthesized via an in-situ approach. The microscopic characterization of BNC-KC revealed an effective integration of KC within the 3D matrix of BNC. The investigated mechanical properties of BNC-KC demonstrated a better performance compared to BNC. Thereafter, the sorption performance of BNC-KC films towards basic blue 9 dye (Bb9) and norfloxacin (NFX) antibiotic from water was investigated. The maximum sorption capacities of BNC-KC for Bb9 and NFX were 127.64 and 101.68 mg/g, respectively. Mechanistic studies showed that electrostatic interactions, multi-layered sorption, and 3D structure are pivotal in the NFX/Bb9 sorption process. The intricate architecture of BNC-KC effectively traps molecules within the interlayer spaces, significantly increasing sorption efficiency. The distinctive structural configuration of BNC-KC films effectively addressed the challenges of post-water treatment separation while concurrently mitigating waste generation. The environmental evaluation, engineering, and economic feasibility of BNC-KC are also discussed. The cost estimation assessment of BNC-KC revealed the potential to remove NFX and Bb9 from water at an economically viable cost. [Display omitted] • Bacterial nanocellulose-kaolinite (BNC-KC) composite was successfully synthesized. • BNC-KC exhibited a unique three-dimensional network structure with high stability. • BNC-KC showed a maximum monolayer capacity of 101.68 (NFX) and 127.64 mg/g (Bb9). • Synergistic sorption mechanisms were confirmed for NFX and Bb9 sorption by BNC-KC. • Cost estimation and economic evaluation of BNC-KC were precisely presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pretreatment Drives Advances in BNC Research and Applications. • Using Lignocellulosic Waste as a Cultivation Medium in the Production of BNC. • BNC production from lignocellulosic waste promotes UN-aligned sustainable practices. • Lignocellulosic waste yields higher BNC production compared to synthetic media. The hydrothermal pretreatment process stands out as a pivotal step in breaking down the hemicellulosic fraction of lignocellulosic biomasses, such as sugarcane bagasse and eucalyptus sawdust. This pretreatment step is crucial for preparing these materials for subsequent processes, particularly in food applications. This technique aims to disintegrate plant wall components like cellulose, hemicellulose, and lignin, and facilitating access in later phases such as enzymatic hydrolysis, and ultimately making fermentable sugars available. In this study, sugarcane bagasse and eucalyptus sawdust biomass underwent hydrothermal pretreatment at specific conditions, yielding two key components: dry biomass and hemicellulose liquor. The primary focus was to assess the impact of hydrothermal pretreatment followed by enzymatic hydrolysis, using the Celic Ctec III enzyme cocktail, to obtain fermentable sugars. These sugars were then transformed into membranes via strain Gluconacetobacter xylinus bacterial biosynthesis. Notably, the addition of a nitrogen source significantly boosted production to 14.76 g/ in hydrolyzed sugarcane bagasse, underscoring its vital role in bacterial metabolism. Conversely, in hydrolyzed eucalyptus, nitrogen source inclusion unexpectedly decreased yield, highlighting the intricate interactions in fermentation media and the pivotal influence of nitrogen supplementation. Characterization of membranes obtained in synthetic and hydrolyzed media through techniques such as FEG-SEM, FTIR, and TGA, followed by mass balance assessment, gauged their viability on an industrial scale. This comprehensive study aimed not only to understand the effects of pretreatment and enzymatic hydrolysis but to also evaluate the applicability and sustainability of the process on a large scale, providing crucial insights into its feasibility and efficiency in practical food-related scenarios, utilizing nanocellulose bacterial (BNC) as a key component. [ABSTRACT FROM AUTHOR]

[Display omitted] • A smart indicator film based on myofibrillar protein (MP) has been developed. • The covalent and non-covalent interactions allow anthocyanin (ACN) to bind to MP. • The films containing 1% ACN have superior mechanical properties. • The films containing 1% ACN can accurately distinguish the freshness of fish meat. • This work provides the possibility to minimize the waste of MP by-products. A novel smart film MP/BNC/ACN for real-time monitoring of fish freshness was developed using myofibrillar protein (MP) and bacterial nanocellulose (BNC) as film raw materials and anthocyanin (Lycium ruthenicum, ACN) as an indicator. Firstly, the film containing 1 % ACN (MP/BNC/ACN1) was found to have a moderate thickness (0.44 ± 0.01 mm) and superior mechanical properties (tensile strength (TS) = 8.53 ± 0.11 MPa; elongation at break (EB) = 24.85 ± 1.38 %) by determining the physical structure. The covalent, electrostatic, and hydrogen bonding interactions between anthocyanin and the film matrix were identified and confirmed by FT-IR spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) analysis. A comprehensive evaluation concluded that MP/BNC/ACN1 exhibited excellent trimethylamine (TMA) sensitivity (total color difference (ΔE), ΔE TMA0-1000 = 4.47–31.05; limit of detection (LOD), LOD = 1.03) and UV stability (ΔE 96h = 4.16 ± 0.13). The performance of the films in assessing fish freshness was evaluated, principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed that MP/BNC/ACN1 (ΔE 2-10d = 16.84–32.05) could clearly distinguish between fresh (0–2 d), sub-fresh (4–6 d), and spoiled (8–10 d) stages of fish, which corresponded to the film colors of red, light red, and gray-black. In conclusion, this study addresses the limitation that intelligent films cannot visually discern real-time freshness during fish storage and provides a promising approach for real-time fish freshness monitoring. [ABSTRACT FROM AUTHOR]

Active bacterial nanocellulose (BNC) nanopapers containing Salvia officinalis essential oil (SEO) in free form and encapsulated with β-cyclodextrin (βCD) were prepared, and their effect on the shelf life extension of shrimp was investigated. The GC–MS analysis of the SEO indicated the presence of various active compounds such as Thujone (21.53 %), Ledol (12.51 %) and Eucalyptol (11.28 %) in the essential oil composition. The cytotoxicity of the SEO and SEO-βCD complexes in the L929 cell line was quite low. FTIR analysis revealed new interactions in the nanopapers containing SEO-βCD complexes. Microscopic images showed that SEO-βCD complexation improved the surface morphology of the BNC nanopapers, whereas free SEO had a negative effect. X-ray diffraction patterns of the nanopapers showed higher crystallinity of the SEO-βCD containing nanopapers than that of the SEO-incorporated nanopapers. Moreover, the addition of the SEO-βCD complex improved the thermal properties of the BNC nanopaper. Water contact angle analysis showed higher hydrophobicity of the samples containing free SEO than that of the other samples. Both SEO-βCD and free SEO increased the elongation at break and decreased the tensile strength of the nanopaper. The prepared active films showed a greater antimicrobial effect on L. monocytogenes than on E. coli. The results showed a higher antioxidant capacity of the free SEO-containing nanopapers (58–78 %). The desirable effects of the active nanopapers on shrimp preservation were demonstrated by the results obtained for the microbial load, pH, and volatile nitrogen content of the product. The results demonstrate the potential of the prepared BNC active nanopapers for use in active antioxidant/antimicrobial food packaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly sensitive, flexible and scalable 3D AgNRs@BNC SERS sensor is developed by a simple vacuum-assisted filtration. • The flexible 3D AgNRs@BNC SERS sensor is used to detect trace 4-ATP with a detection sensitivity of 1.0 × 10-12 M. • A rapid, direct and on-site identification of thiram residues on the uneven food surface was realized by AgNRs@BNC SERS sensor cooperated with portable Raman spectrometer. Owing to good flexibility, prominent mechanical properties, three-dimensional (3D) nanofibrous structure and low background interference, sustainable bacterial nanocellulose (BNC) is a highly attractive matrix material for surface-enhanced Raman scattering (SERS) sensor. Herein, a highly sensitive, flexible and scalable silver nanorod-decorated BNC (AgNRs@BNC) SERS sensor is developed by a simple vacuum-assisted filtration. The AgNRs were firmly locked in the 3D nanofibrous network of cellulose nanofibers upon vacuum drying process, resulting in the formation of 3D SERS hotspots with a depth of more than 10 μm on the sensor. With 4-aminothiophenol (4-ATP) as a target molecule, a lowest distinguishable level of 10-12 M and a high enhancement factor of 1.1 × 109 were realized by the optimal AgNRs1.5@BNC SERS sensor. Moreover, the AgNRs@BNC SERS sensor exhibits high detectable level of 10-9 M for thiram molecules by integrating with a portable Raman spectrometer. Besides, toxic thiram residues on grape surface could be directly on-site identified by the combination of AgNRs@BNC SERS sensors and a portable Raman spectrometer through a feasible press-and-peel method. The flexible AgNRs@BNC SERS sensor cooperated with portable Raman system demonstrates great potential for on-site detection of pesticide residues on irregular food surfaces. [ABSTRACT FROM AUTHOR]

The surface properties of cardiovascular biomaterials play a critical role in their biological responses. Although bacterial nanocellulose (BNC) materials have exhibited potential applications in cardiovascular implants, the impact of their surface characteristics on biocompatibility has rarely been studied. This study investigated the mechanism for the biocompatibility induced by the physicochemical properties of both sides of BNC. With greater wettability and smoothness, the upper BNC surface reduced protein adsorption by 25 % compared with the lower surface. This prolonged the plasma re-calcification time by 14 % in venous blood. Further, compared with the lower BNC surface, the upper BNC surface prolonged the activated partial thromboplastin time by 5 % and 4 % in arterial and venous blood, respectively. Moreover, the lower BNC surface with lesser rigidity, higher roughness, and sparser fiber structure promoted cell adhesion. The lower BNC surface enhanced the proliferation rate of L929 and HUVECs cells by 15 % and 13 %, respectively, compared with the upper BNC surface. With lesser stiffness, the lower BNC surface upregulated the expressions of CD31 and eNOS while down-regulating the ICAM-1 expression - This promoted the proliferation of HUVECs. The findings of this study will provide valuable insights into the design of blood contact materials and cardiovascular implants. [Display omitted] [ABSTRACT FROM AUTHOR]

The present study outlines a straightforward approach for designing a novel drug delivery system based on bacterial nanocellulose composites containing curcumin-loaded graphene quantum dots (BNC/CUR/GQDs) for antibacterial and wound healing applications. The nanocomposite was made of interconnected plates with uniform thicknesses around 2 mm. The scanning electron microscope (SEM) image of the prepared BNC nanocomposite showed a uniform and porous morphology composed of the microfibrils having an average diameter of 120 nm, which contributes to both drug inclusion and drug release in a controllable fashion. The designed system biosynthesized by Acetobacter xylinum demonstrated an optimum drug loading capacity and controlled release profile. The drug loading content and drug release efficiency were calculated around 31% and 61%. Agar diffusion test indicated that the introduction of GQDs into the BNC matrix conspicuously improved the growth inhibition of bacteria, and gram-negative and gram-positive bacterial strains were measured 21.6 mm and 21.5 mm, respectively. The cell viability of 92.3% was obtained for the BNC, while the cell viability of the designed system was measured at around 88.07%. Consequently, the incorporation of curcumin-loaded graphene quantum dots into bacterial nanocellulose matrices can open up a new insight into the production of high-performance wound dressing supplies. An antibacterial nanocomposite that could be used in wound healing and drug delivery application is synthesized. Bacterial nanocellulose was synthesized successfully by Acetobacter xylinium, then a loaded solution including GQD and Cur was added to its structure. The final composition shows a good capacity for loading and sustaining release of Cur as model drug and antibacterial efficacy. [ABSTRACT FROM AUTHOR]

Cellulose is the most abundant biopolymer on earth and offers versatile applicability in biotechnology. Bacterial cellulose, especially, is an attractive material because it represents pure microcrystalline cellulose. The cellulose synthase complex of acetic acid bacteria serves as a model for general studies on (bacterial) cellulose synthesis. The genome of Komagataeibacter hansenii ATCC 23769 encodes three cellulose synthase (CS) operons of different sizes and gene compositions. This implies the question of which role each of the three CS-encoding operons, bcsAB1, bcsAB2, and bcsAB3, plays in overall cellulose synthesis. Therefore, we constructed markerless deletions in K. hansenii ATCC 23769, yielding mutant strains that expressed only one of the three CSs. Apparently, BcsAB1 is the only CS that produces fibers of crystalline cellulose. The markerless deletion of bcsAB1 resulted in a nonfiber phenotype in scanning electron microscopy analysis. Expression of the other CSs resulted in a different, nonfibrous extracellular polymeric substance (nfEPS) structure wrapping the cells, which is proposed to contain acetylated cellulose. Transcription analysis revealed that all CSs were expressed continuously and that bcsAB2 showed a higher transcription level than bcsAB1. Moreover, we were able to link the expression of diguanylate cyclase B (dgcB) to cellulose production. [ABSTRACT FROM AUTHOR]

Development in many areas of engineering and technology are closely linked to the development of new or improvement of existing materials. Having in mind wide use of bacterial nanocellulose (BNC) in various areas of everyday life, from biomedicine, ecology to electronics, BNC-based composites are becoming widely used and attracting the attention of the scientific community. It is especially important to examine in detail the synthesis parameters that affect the changes in the crystal structure and morphology of the obtained composites, having in mind that these changes have a crucial influence on their final functional properties. In this paper, a composite material based on bacterial nanocellulose BNC (as the matrix) and ferromagnetic Fe3O4 was studied. BNC was obtained by the activity of acetic fermentation bacteria after 7 days of growth in a suitable medium. The research is aimed to optimization of the Fe3O4 precipitation conditions. It's especially considering the time interval of BNC films spend in the iron salt solution. The influence of the performed synthesis conditions was considered by the SEMEDS, FTIR and XRD methods.

Nanocellulose is an emerging material for which several food-related applications are foreseen, for example, novel food, functional food, food additive or in food contact materials. Nanocellulose materials can display a range of possible shapes (fibers, crystals), sizes and surface modifications. For food-related applications in the EU, information on the safety of substances must be assessed. The present review summarizes the current knowledge on (possible) adverse health effects of nanocellulose upon oral exposure, keeping EU regulatory aspects in mind. The overview indicates that toxicity data, especially from in vivo studies, are limited and outcomes are not unambiguous. The hazard assessment is further complicated by: the diversity in morphologies and surface modifications, lack of standard reference materials, limited knowledge about intestinal fate and absorption, analytical difficulties in biological matrices, dispersion issues, the possible presence of impurities and interferences within biological assays. Two subchronic in vivo toxicity studies show no indications of toxicity for two specific nanocellulose materials, even at high doses. However, these studies may have missed certain early or nano-specific toxic effects, such as inflammation potential, for which other, subacute studies provide some indications. Most in vitro studies show no cytotoxicity; however, several indicate that effects on oxidative stress and inflammatory responses depend on differences in size or surface treatments. Further, too few studies assessed genotoxicity of nanocelluloses. Therefore, immunotoxicity, oxidative stress and genotoxicity require further attention, as do absorption and effects on nutrient uptake. Recommendations for future research facilitating the safety assessment and safe-by-design of nanocellulose in food-related applications are provided. [ABSTRACT FROM AUTHOR]

A new intelligent pH-sensitive colorimetric label was fabricated by immobilizing Ixiolirion tataricum anthocyanins (ITA) into biocellulose (bacterial nanocellulose; BNC) film and was then studied to determine how it can be used as a label for monitoring freshness/spoilage of shrimp during storage at 4 °C. The formation of new interactions between ITA and BNC film and disruption of crystalline structure of BNC after anthocyanins immobilization were approved by FT-IR and XRD analyses, respectively. According to FE-SEM observations, the porosity of the BNC network decreased after ITA incorporation. The fabricated BNC-ITA label showed a distinct color change from violet to green over the pH range of 4–12. The pH, total volatile basic nitrogen (TVB-N), total psychrophiles count (TPC), and the quantity of biogenic amines (histamine, cadaverine, putrescine, and tyramine) in the shrimp samples and their correlation with color changes on the label were measured over a 4-day storage period. Consistent with changes in levels of TVB-N, TPC, pH, and biogenic amines, a visually distinguishable color change occurred on the BNC-ITA label as blue (fresh), dark green (medium fresh), and kelly green (spoiled). This research showed that ITA as a novel pH-sensitive dye is a promising candidate for developing pH labels for seafood intelligent packaging. • Colorimetric pH indicator was prepared by Ixiolirion tataricum anthocyanins (ITA). • ITA was immobilized into bacterial nanocellulose (BNC) as solid support. • Effect of ITA on morphological and structural characteristics of BNC was evaluated. • The BNC-ITA label showed color change from violet to green at pH range of 4–12. • Color change of the label had correlation with spoilage indices of packaged shrimp. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) is a fibrillar nanomaterial composed of β-(1 → 4) glucan chains, with <100 nm widths. Usually, the BNC is produced by mechanical disintegration of the cellulose fibrils network biosynthesized by several bacterial species, both gram-negative bacteria such as acetic acid bacteria, agrobacteria, rhizobia, and gram-positive bacteria from Sarcina and Bacillus genera. One dimension of BC is still micrometric; therefore, it is considered a 1D nanomaterial. BNC presents suitable mucoadhesive formulation features - biocompatibility and biodegradability, water retention, shear-thinning, good interaction with mucin. In this review, we focus mainly on the non-Newtonian behavior / shear-thinning characteristic of the BNC hydrogel. Due to this characteristic, BNC could be used as an in-situ thickener for the mucoadhesive formulations, which generate low viscosity gel and droplets. [ABSTRACT FROM AUTHOR]

The demand for bio-degradable lubricants is continuously increasing due to environmental concerns. One of the methods to achieve the bio-degradability property of lubricants is by using nanoparticles from bio-resources as additives in bio-degradable oils. Among the nanomaterials are nanofibers, cellulose, and graphene nanoplatelets. They can be mixed in Polyolester (POE) oil to produce lubricants for tribological applications. In a previous study, it has been confirmed that friction and wear of the tribo-pair reduced from 5 to 10% by mixing various volume percentages of bacterial cellulose (BC) into PEO as the base lubricant. The tribological performance BC containing POE base lubricant can further be enhanced by incorporating graphene nanoplatelets. This study shows that the specific wear rate of the material decreased by 20% by adding graphene nanoplatelets in BC containing POE oil. The friction and wear improvement can be related to the formation of tribofilm on the contact interface. EDS analysis indicates that oxygen played an important role in the friction and wear performance of the POE oil-based lubricant with BC and graphene additives. The tribofilm shows significant traces of oxygen elements. The presence of graphene nanoplatelets in POE oil removed the oxygen-rich layer but could not reduce the wear rate. However, incorporating both graphene and BC in POE oil significantly improved friction and wear, although the oxygen element was still traceable on the contact interface.

The potential of cellulose nanocomposites in the new-generation super-performing nanomaterials is huge, primarily in medical and environment sectors, and secondarily in food, paper, and cosmetic sectors. Despite substantial illumination on the molecular aspects of cellulose synthesis, various process features, namely, cellular export of the nascent polysaccharide chain and arrangement of cellulose fibrils into a quasi-crystalline configuration, remain obscure. To unleash its full potential, current knowledge on nanocellulose dispersion and disintegration of the fibrillar network and the organic/polymer chemistry needs expansion. Bacterial cellulose biosynthesis mechanism for scaled-up production, namely, the kinetics, pathogenicity, production cost, and product quality/consistency remain poorly understood. The bottom-up bacterial cellulose synthesis approach makes it an interesting area for still wider and promising high-end applications, primarily due to the nanosynthesis mechanism involved and the purity of the cellulose. This study attempts to identify the knowledge gap and potential wider applications of bacterial cellulose and bacterial nanocellulose. This review also highlights the manufacture of bacterial cellulose through low-cost substrates, that is, mainly waste from brewing, agriculture, food, and sugar industries as well as textile, lignocellulosic biorefineries, and pulp mills.

A comparative study was conducted on the efficiency of mercury removal using bacterial nanocellulose (BNC) membranes obtained from the fermentation of the microorganism Komagataeibacter medellinensis, in contrast with its oxidized analog obtained by modifying the bacterial nanocellulose membranes via oxidation with 2,2,6,6-Tetramethylpiperidine-1-oxyl. Both types of membranes (modified and unmodified) were characterized to identify variations in the Physico-chemical parameters after modification. FTIR spectra confirmed the chemical modification of cellulose in all reaction conditions by the presence of a new characteristic band at ∼1730 cm−1, corresponding to the new carboxylic groups produced by the oxidative process, and the decline of the band at ∼1,650 cm−1, corresponding to the hydroxyl groups of the C6 carbon. While the XRD profiles indicated that the percentage of BNC crystallinity decreased and the SEM images showed that the nanoribbon network was interrupted as the amount of oxidizing agent increased. The kinetics of mercury removal from both types of membrane was evaluated by calculating the concentration of mercury at different times and establishing a mathematical model to describe the kinetics of this process. The modified membranes improved significantly the adsorption process of the metal ion and it was found that the modification that results in the greatest adsorption efficiency was BNC-m 7.5 with a value of 92.97%. The results obtained suggest that the modification of the bacterial nanocellulose membranes by oxidation transcendentally improves the mercury removal capacity, outlining the modified membranes as an excellent material for mercury removal in wastewater.

To gain insight into the trend of bacterial nanocellulose research, a bibliometric analysis was performed using the Science Citation Index Expanded database from 2005 to 2020. The study concentrated on the publication’s performance in terms of annual outputs and citations, mainstream journals, categories of the Web of Sciences, leading countries, prominent institutions, and trends in research. Current research priorities and future trends were analyzed after summarizing the most commonly used keywords extracted from words in the paper title analysis, authors’ keyword analysis, and KeyWords Plus. The findings revealed that the annual output in the form of scholarly articles on bacterial nanocellulose research steadily increased during the first quartile of the study period, followed by a very rapid increase in the last five-years of the study. Increasing mechanical strength would remain the main future focus of bacterial nanocellulose research to create its scope in different field of applications.

Bacterial nanocellulose has been widely investigated in drug delivery, but the incorporation of lipophilic drugs and controlling release kinetics still remain a challenge. The inclusion of polymer particles to encapsulate drugs could address both problems but is reported sparely. In the present study, a formulation approach based on in situ precipitation of poly(lactic-co-glycolic acid) within bacterial nanocellulose was developed using and comparing the conventional solvent N-methyl-2-pyrrolidone and the alternative solvents poly(ethylene glycol), CyreneTM and ethyl lactate. Using the best-performing solvents N-methyl-2-pyrrolidone and ethyl lactate, their fast diffusion during phase inversion led to the formation of homogenously distributed polymer microparticles with average diameters between 2.0 and 6.6 µm within the cellulose matrix. Despite polymer inclusion, the water absorption value of the material still remained at ~50% of the original value and the material was able to release 32 g/100 cm2 of the bound water. Mechanical characteristics were not impaired compared to the native material. The process was suitable for encapsulating the highly lipophilic drugs cannabidiol and 3-O-acetyl-11-keto-β-boswellic acid and enabled their sustained release with zero order kinetics over up to 10 days. Conclusively, controlled drug release for highly lipophilic compounds within bacterial nanocellulose could be achieved using sustainable solvents for preparation.

Electrochemical biosensing devices are known for their simple operational procedures, low fabrication cost, and suitable real-time detection. Despite these advantages, they have shown some limitations in the immobilization of biochemicals. The development of alternative materials to overcome these drawbacks has attracted significant attention. Nanocellulose-based materials have revealed valuable features due to their capacity for the immobilization of biomolecules, structural flexibility, and biocompatibility. Bacterial nanocellulose (BNC) has gained a promising role as an alternative to antifouling surfaces. To widen its applicability as a biosensing device, BNC may form part of the supports for the immobilization of specific materials. The possibilities of modification methods and in situ and ex situ functionalization enable new BNC properties. With the new insights into nanoscale studies, we expect that many biosensors currently based on plastic, glass, or paper platforms will rely on renewable platforms, especially BNC ones. Moreover, substrates based on BNC seem to have paved the way for the development of sensing platforms with minimally invasive approaches, such as wearable devices, due to their mechanical flexibility and biocompatibility.

Bacterial nanocellulose (BNC) is characterized by high purity and excellent mechanical properties; however, its production is constrained by low yield. Therefore, efforts aimed at improving its yield and material properties are imperative. This study investigated the effect of adding different concentrations (0%, 0.5%, and 1.0%) of cellulose nanocrystal (CNC) in Hestrin–Schramm modified medium on the yield and properties of BNC produced by Komagataeibacter sp. SFCB22-18. The BNC yield increased as following an increase in added CNC concentration. Also, the morphology, structure, crystallinity, thermal stability, and mechanical properties of BNC improved after CNC incorporation. A low CNC concentration (0.1%) favored mechanical strength, whereas 0.5% gave the optimum morphology, structural, and thermal stability. These results showed that modifying BNC with CNC could help increase yield and improve its properties, and thus; the potentiality of BNC in various applications would be much enhanced. [ABSTRACT FROM AUTHOR]

Nanocellulose derived from microorganism is crucial bio-based products due to its unique physicochemical and mechanical properties for material science. Thus, optimizing bacterial cellulose (BNC) production is essential to widen applications and reduce production cost. Using various carbon sources derive from fruits as alternatives for synthesizing BNC could produce a low-cost BNC with comparable properties. Although Komagataeibacter xylinus grown in different natural juices, including clarified juice (CJ), sugarcane juice (SC) and coconut juice (CN) demonstrated a lower yield than that of control medium (HS), FTIR confirmed no change in chemical functional groups of BNCs. Similarly, different sugar sources have slightly effects on mechanical and thermal properties of BNC. However, the internal morphology illustrated the pore structure in oval shape for HS and CN while CJ and SC resulted in irregular pores which could lead to the highest crystallinity index value for BNC from HS compared to that from alternative media. [ABSTRACT FROM AUTHOR]

The objectives of innovation are often diametrically opposed to industrially standardized practices. The burgeoning field of Biofabrication represents one type of challenge that falls outside the norms of not only standardized industrial practices, but also those of Health Authorities. Biofabrication produces complex "biological products from raw materials such as living cells, molecules, extracellular matrices, and biomaterials" Mironov V, et al. Biofabrication, 2009, 1, 1–16. One such material is Bacterial Nanocellulose, a biologically derived cellulose structure with tissue like qualities, which does not fit within standardized manufacturing methods nor the well‐established parameters of medical device quality system regulations found within 21 CFR 820. Materials like this are necessary to address the hidden risks associated with their contending products, animal derived tissues, to move to a more sustainable manufacturing, and an animal cruelty free approach to medical device production. The goal of this manuscript, therefore, is to provide an example roadmap for navigating established quality system parameters while highlighting the need for Health Authorities to provide guidance to both industry and themselves as the field of advanced manufacturing continues to rapidly progress. [ABSTRACT FROM AUTHOR]

In this work, a novel Bacterial NanoCellulose (BNC) producing strain, from Kombucha tea, was isolated and characterized. Based on 16S rRNA analysis the strain was identified as Komagataeibacter rhaeticus. Under static culture, K. rhaeticus K3 produces membranes with a relaxed structure, as observed by Scanning Electron Microscopy (SEM). The addition of 2% (v/v) ethanol to the culture media enhanced by more than 3-fold of the BNC yield.Response surface methodology (RSM) was performed with K. rhaeticus K3, using a new low cost Eucalyptus Biomass Hydrolysate (EBH). The maximum experimental BNC yield was of 5.46 g/L, obtained with the following composition: 31.4 g/L of EBH; 2.89% (v/v) of ethanol and 10.8 g/L of Yeast extract/peptone.Texture Profile Analysis (TPA) of BNC membranes obtained using Hestrin-Schramm culture (HS) medium and optimized medium from EBH showed that membranes from EBH had higher resistance to compression, higher cohesiveness and resilience.

Development of effective drug delivery systems by the exploitation of biocompatible, inert nanomaterials has become the thrust areas of research in medicinal chemistry. Out of various materials of significance, one is nanocrystalline cellulose due to its biocompatibility and inertness. Further its surface modification can also be accomplished using variety of methods. In the present review we have compiled different types of nanocellulose and their use as drug delivery systems. The review recapitulate the literature not reported in recent reviews of 2019 and 2020. The review is focused on method of preparation of nanocellulose and its application in oral, transdermal and local drug delivery systems. Limitations and advantages of surface modified nanocellulose is also discussed.

Genistein is an isoflavone with antioxidant, anti-inflammatory, and anticancer properties. That said, its use in the industry is limited by its low solubility in aqueous systems. In this work, bacterial nanocellulose (BNC) and BNC modified with cetyltrimethylammonium (BNC-CTAB) were evaluated as genistein-encapsulating materials for their controlled release in cancer chemoprevention. Thin films were obtained and characterized by contact angle, AFM, TEM, UV–Vis spectroscopy FTIR, and TGA techniques to verify surface modification and genistein encapsulation. The results show a decrease in hydrophilization degree and an increase in diameter after BNC modification. Furthermore, the affinity of genistein with the encapsulating materials was determined in the context of monolayer and multilayer isotherms, thermodynamic parameters and adsorption kinetics. Spontaneous, endothermic and reversible adsorption processes were found for BNC-GEN and BNC-CTAB-GEN. After two hours, the maximum adsorption capacity corresponded to 4.59 mg GEN∙g−1 BNC and 6.10 mg GEN∙g−1 BNC-CTAB; the latter was a more stable system. Additionally, in vitro release assays performed with simulated gastrointestinal fluids indicated controlled and continuous desorption in gastric and colon fluids, with a release of around 5% and 85%, respectively, for either system. Finally, the IC50 tests made it possible to determine the amounts of films required to achieve therapeutic concentrations for SW480 and SW620 cell lines.

This study aims to examine the effect of ethanol and lactic acid on the production of bacterial cellulose, and determine the optimal composition of a co-supplemented culture using response surface methodology. Both ethanol and lactic acid, when added separately or jointly, affected the yield and properties of the biomaterial. Optimization resulted in an increase of 470% in the yield, compared to the Schramm-Hestrin medium. Culture growth profiles, substrate consumption and by-products generation, were examined. The growth rate was increased for cultures supplemented with lactic acid and both lactic acid and ethanol, while the production of gluconic acid was diminished for all modified cultures. The properties of BNC, such as the structure, crystallinity, water holding capacity and tensile strength, were also determined. BNC produced in optimal conditions is more porous and characterized by wider fibers. Despite a decrease in crystallinity, by the addition of ethanol, lactic acid and both additives, the ratio of cellulose Iα was almost unchanged. The stress, strain, young modulus and toughness were improved 2.8-4.2 times, 1–1.9 times, 2.4-3.5 times and 2.5-6.8 times, respectively. The new approach to improving BNC yields and properties presented here could contribute to more economical production and wider application of this biopolymer. • Ethanol and lactic acid influences the metabolism of K. xylinus E25. • Either ethanol or lactic acid improves the yield of bacterial cellulose. • Optimization of the co-supplemented medium enhances the yield by 470%. • The mechanical properties of BNC produced in the modified media were improved. • Physical properties of BNC differ significantly in dependence on culture condition. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) is a homopolymer of ß-1,4 linked glycose, which is synthesized by Acetobacter using simple culturing methods to allow inexpensive and environmentally friendly small- and large-scale production. Depending on the growth media and types of fermentation methods, ultra-pure cellulose can be obtained with different physio-chemical characteristics. Upon biosynthesis, bacterial cellulose is assembled in the medium into a nanostructured network of glucan polymers that are semitransparent, mechanically highly resistant, but soft and elastic, and with a high capacity to store water and exchange gasses. BNC, generally recognized as safe as well as one of the most biocompatible materials, has been found numerous medical applications in wound dressing, drug delivery systems, and implants of heart valves, blood vessels, tympanic membranes, bones, teeth, cartilages, cornea, and urinary tracts. [ABSTRACT FROM AUTHOR]

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This work presents a comparison of physicochemical and in vitro active wound healing properties of two distinct Graphene Oxides (GOs) from graphite and coal. These GOs are incorporated in Bacterial Nanocellulose (BNC) to form hydrogels. The performance and limitations of the loading fraction of both GOs in BNC are controlled by the processing technology and the source materials from which GOs are derived. Edge functionalization with C-GO offers the advantage of facilitating face-to-edge assembly in the hydrogel leading to better dispersion than the face-to-face assembly of basal functionalized G-GO. The latter leads to more aggregation of G-GO, resulting in a lower optimal loading fraction. Our investigation into the antibacterial properties of the BNC and BNC/GO hydrogels against gram-negative E. coli revealed inhibitory effects of the BNC/GO hydrogels that intensified with an increase in the concentration of GO. Furthermore, an in vitro wound scratch assay demonstrated that BNC/C-GO hydrogels promote better cell migration, confirming their superior biocompatibility and suitability as active wound dressings, albeit limited by loading fraction due to agglomeration. These findings shed light on the performance and limitations of GOs for diverse applications, emphasizing the significance of exploring the influence of different methods and source materials of GOs. • G-GO suspension exhibits a larger mean size of crystallites with higher lateral size than C-GO. • G-GO has many basal functional groups and assembles face-to-face with BNC. • C-GO has mainly edge functional groups and assembles face-to-edge with BNC. • Hence, -OH groups of C-GO bind with the cytoplasmic membrane and inhibit bacterial enzymes, enhancing antibacterial activity. [ABSTRACT FROM AUTHOR]

Maintaining wound moisture and monitoring of infection are crucial aspects of chronic wound treatment. The development of a pH-sensitive functional hydrogel dressing is an effective approach to monitor, protect, and facilitate wound healing. In this study, beet red pigment extract (BRPE) served as a native and efficient pH indicator by being grafted into silane-modified bacterial nanocellulose (BNC) to prepare a pH-sensitive wound hydrogel dressing (S-g-BNC/BRPE). FTIR confirmed the successful grafting of BRPE into the BNC matrix. The S-g-BNC/BRPE showed superior mechanical properties (0.25 MPa), swelling rate (1251 % on average), and hydrophilic properties (contact angle 21.83°). The composite exhibited a notable color change as the pH changed between 4.0 and 9.0. It appeared purple-red when the pH ranged from 4.0 to 6.0, and appeared light pink at pH 7.0 and 7.4, and appeared ginger-yellow at pH 8.0 and 9.0. Subsequently, the antioxidant activity and cytotoxicity of the composite was evaluated, its DPPH·, ABTS+, ·OH scavenging rates were 32.33 %, 19.31 %, and 30.06 %, respectively, and the cytotoxicity test clearly demonstrated the safety of the dressing. The antioxidant hydrogel dressing, fabricated with a cost-effective and easy method, not only showed excellent biocompatibility and dressing performance but could also indicated the wound state based on pH changes. • The S-g-BNC/BRPE hydrogel showed significant color changes in the pH range associated with chronic or infected wounds. • The S-g-BNC/BRPE hydrogel exhibited superior mechanical properties and hydrophilic properties than unmodified BNC. • The S-g-BNC/BRPE hydrogel showed excellent biocompatibility and certain antioxidant activity. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) exhibits promising application in the biomedical sector due to its distinctive physico-chemical attributes. However, the current challenges of high expenses and low productivity associated with existing techniques for BNC production necessitate attention. Consequently, this investigation utilized marine bacteria from the Pichavaram mangrove forest for the production of BNC. Among the various marine bacterial isolates, NCB8 demonstrated a notable capacity for BNC production and was identified through 16S rRNA sequencing as belonging to the Bacillus sp. The study systematically examined the impact of carbon source, incubation temperature, and pH on BNC production, resulting in an optimal yield of approximately 9.32 g/L when sucrose was employed as the carbon source at pH 5 and an incubation temperature of 35 °C. Additionally, the strain underwent kinetic analysis using first-order reaction kinetics for BNC production rate, sugar uptake rate, and BNC conversion yield, revealing values of 0.58 g/L/day, 0.10 g/L/day, and 5.45 g/g, respectively, with an R2 value of 0.94. Characterization of the produced BNC involved Fourier Transform Infrared Spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD) analyses. FTIR analysis confirmed characteristic cellulose structure peaks, while FE-SEM displayed a uniform arrangement of thin, thread-like cellulose nanofibrils that were densely packed and randomly oriented. XRD analysis identified characteristic peaks at 2ϴ values of 14.2, 16.9, and 21.6, corresponding to crystalline planes of cellulose lattice (1‾10), (110), and (200). In conclusion, the marine bacteria Bacillus sp. emerges as an excellent source for efficient BNC synthesis for possible applications including bio-packaging, wound dressing material and drug delivery system. • Marine bacteria Bacillus sp. was identified as potential bacterial nanocellulose (BNC) producer. • The optimised parameters viz., sucrose as the carbon source, at pH 5 and an incubation temperature of 35 °C result in 9.32 g/L of BNC. • The BNC production rate, sugar uptake rate, and BNC conversion yield, revealing values of 0.58 g/L/day, 0.10 g/L/day, and 5.45 g/g respectively. • The characterisation studies indicate BNC are cellulose-I, crystalline and thread-like structure. • This is the first report on the production of BNC from marine bacteria from India. [ABSTRACT FROM AUTHOR]

The bacterial nanocellulose (BnC) membranes were produced extracellularly by a novel aerobic acetic acid bacterium Komagataeibacter melomenusus. The BnC was modified in situ by adding carboxymethyl cellulose (CMC) into the culture media, obtaining a BnC-CMC product with denser fibril arrangement, improved rehydration ratio and elasticity in comparison to BnC. The proteolytic enzyme bromelain (Br) and antimicrobial peptide nisin (N) were immobilized to BnC matrix by ex situ covalent binding and/or adsorption. The optimal Br immobilization conditions towards the maximized specific proteolytic activity were investigated by response surface methodology as factor variables. At optimal conditions, i.e. , 8.8 mg/mL CMC and 10 mg/mL Br, hyperactivation of the enzyme was achieved, leading to the specific proteolytic activity of 2.3 U/mg and immobilization efficiency of 39.1 %. The antimicrobial activity was observed against Gram-positive bacteria (S. epidermidis , S. aureus and E. faecalis) for membranes with immobilized N and was superior when in situ modified BnC membranes were used. N immobilized on the BnC or BnC-CMC membranes was cytocompatible and did not cause changes in normal human dermal fibroblast cell morphology. BnC membranes perform as an efficient carrier for Br or N immobilization, holding promise in wound debridement and providing antimicrobial action against Gram-positive bacteria, respectively. [ABSTRACT FROM AUTHOR]

Diseases caused by pathogens severely hampered the development of aquaculture, especially largemouth bass virus (LMBV) has caused massive mortality and severe economic losses to the culture of largemouth bass (Micropterus salmoides). Considering the environmental hazards and human health, effective and environmentally friendly therapy strategy against LMBV is of vital importance and in pressing need. In the present study, a novel nanobody (NbE4) specific for LMBV was selected from a phage display nanobody library. Immunofluorescence and indirect ELISA showed that NbE4 could recognize LMBV virions and had strong binding capacity, but RT-qPCR evidenced that NBE4 did not render the virus uninfectious. Besides, antiviral drug ribavirin was used to construct a targeted drug system delivered by bacterial nanocellulose (BNC). RT-qPCR revealed that NbE4 could significantly enhance the antiviral activity of ribavirin in vitro and in vivo. The targeted drug delivery system (BNC-Ribavirin-NbE4, BRN) reduced the inflammatory response caused by LMBV infection and improved survival rate (BRN-L, 33.3 %; BRN-M, 46.7 %; BRN-H, 56.7 %)compared with control group (13.3 %), ribavirin group (RBV, 26.7 %) and BNC-ribavirin (BNC-R, 40.0 %), respectively. This research provided an effective antiviral strategy that improved the drug therapeutic effect and thus reduced the dosage. • A novel nanobody (NbE4) specific for largemouth bass virus (LMBV) was selected. • NbE4 can enhance the antiviral effect of ribavirin against LMBV by targeting effects. • The nano targeted drug system can improve the survival rate of LMBV-infected fish. • The treatment means reduced the inflammatory response caused by LMBV infection. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) is a promising dietary fiber with potential as a functional food additive. We evaluated BNC fibers (BNCf) in the Caenorhabditis elegans model to obtain insight into the BNCf's biointeraction with its gastrointestinal tract while reducing the variables of higher complex animals. BNCf were uptaken and excreted by worms without crossing the intestinal barrier, confirming its biosafety regarding survival rate, reproduction, and aging for concentrations up to 34 μg/ml BNCf. However, a slight decrease in the worms' length was detected. A possible nutrient shortage or stress produced by BNCf was discarded by measuring stress and chemotactic response pathways. Besides, we detected a lipid-lowering effect of BNCf in N2 C. elegans in normal and high-caloric diets. Oxidative damage was computed in N2 worms and Rac1/ced-10 mutants. The GTPase Rac1 is involved in neurological diseases, where its dysregulation enhances ROS production and neuronal damage. BNCf reduced the lipid oxidative markers produced by ROS species in this worm strain. Finally, we detected that BNCf activated the genetic expression of the immunological response and lipid catabolic process. These results strengthen the use of BNCf as a functional dietary fiber and encourage the potential treatment of neurological disease by modulating diet. [Display omitted] [ABSTRACT FROM AUTHOR]

Objective. To analyze publications devoted to the possibility of using bacterial nanocellulose as a plastic material for defects in the dura mater associated with spine and spinal cord pathology. Material and Methods. The PubMed database was searched with keywords “bacterial cellulose properties” and “bacterial cellulose”. The search was limited to articles published in English- and Russian-language journals in 2009–2019. The limitation was caused by the need for up-to-date evaluation of the properties of bacterial nanocellulose. The search with keywords “bacterial cellulose properties” returned a list of 963 articles and with key words “bacterial cellulose” – a list of 3908 articles. The Google search engine was also used, in which articles were found actually reflecting properties of bacterial nanocellulose without which complete understanding of its nature is impos- sible. After assessing the found data, 76 articles were selected that reflect this issue to the fullest extent. More than fifty percent of the reviewed articles were published within the last 10 years. Evidence level: IV; recommendation grade: C, though randomized trials with evidence level Ib and recommendation level A are used. Results. Implants made of bacterial nanocellulose are able to perform the function of the extracellular matrix by providing a barrier function, creating conditions for the circulation of metabolites and oxygen, and preventing the achievement of excess cell concentration. Conclusion. The use of bacterial nanocellulose as an implant for closure of the dura mater defects associated with the spinal cord pathology is a promising direction in neurosurgery, since nanocellulose does not cause adhesions to the nervous tissue and performs a barrier function.

Bacterial nanocellulose (BNC) is a novel nanomaterial known for its large surface area, biocompatibility, and non-toxicity. BNC contributes to regenerative processes in the skin but lacks antimicrobial and anti-inflammatory properties. Herein, the development of bioactive wound dressings by loading antibacterial povidone-iodine (PVI) or anti-inflammatory acetylsalicylic acid (ASA) into bacterial cellulose is presented. BNC is produced using Hestrin–Schramm culture media and loaded via immersion in PVI and ASA. Through scanning electron microscopy, BNC reveals open porosity where the bioactive compounds are loaded; the mechanical tests show that the dressing prevents mechanical wear. The loading kinetic and release assays (using the Franz cell method) under simulated fluids present a maximum loading of 589.36 mg PVI/g BNC and 38.61 mg ASA/g BNC, and both systems present a slow release profile at 24 h. Through histology, the complete diffusion of the bioactive compounds is observed across the layers of porcine skin. Finally, in the antimicrobial experiment, BNC/PVI produced an inhibition halo for Gram-positive and Gram-negative bacteria, confirming the antibacterial activity. Meanwhile, the protein denaturation test shows effective anti-inflammatory activity in BNC/ASA dressings. Accordingly, BNC is a suitable platform for the development of bioactive wound dressings, particularly those with antibacterial and anti-inflammatory properties.

The potential of nanomaterials in food technology is nowadays well-established. However, their commercial use requires a careful risk assessment, in particular concerning the fate of nanomaterials in the human body. Bacterial nanocellulose (BNC), a nanofibrillar polysaccharide, has been used as a food product for many years in Asia. However, given its nano-character, several toxicological studies must be performed, according to the European Food Safety Agency’s guidance. Those should especially answer the question of whether nanoparticulate cellulose is absorbed in the gastrointestinal tract. This raises the need to develop a screening technique capable of detecting isolated nanosized particles in biological tissues. Herein, the potential of a cellulose-binding module fused to a green fluorescent protein (GFP–CBM) to detect single bacterial cellulose nanocrystals (BCNC) obtained by acid hydrolysis was assessed. Adsorption studies were performed to characterize the interaction of GFP–CBM with BNC and BCNC. Correlative electron light microscopy was used to demonstrate that isolated BCNC may be detected by fluorescence microscopy. The uptake of BCNC by macrophages was also assessed. Finally, an exploratory 21-day repeated-dose study was performed, wherein Wistar rats were fed daily with BNC. The presence of BNC or BCNC throughout the GIT was observed only in the intestinal lumen, suggesting that cellulose particles were not absorbed. While a more comprehensive toxicological study is necessary, these results strengthen the idea that BNC can be considered a safe food additive.

Bacterial nanocellulose (BNC) is a natural biopolymer obtained by gram-negative bacteria by means of a green and inexhaustible biotechnological process using glucose as producing source. BCN hydrogels is formed by cellulose nanofibrils that maintain an open network structure, an ideal matrix to produce new class of organic-inorganic nanocomposites (OIN) for multifunctional applications. The polyoxometalates (POMs) are complex molecules with several metallic ions sharing oxide ions, forming a highly symmetrical metal oxide cluster. Phosphotungstic acid (PWA), H3PW12O40 photoreduction process activated under ultraviolet irradiation, promoting color change. In this work, photochromic organic-inorganic nanocomposites were prepared by soaking phosphotungstic acid (H3PW12O40) in wet BNC membranes mats at room temperature. Semi-transparent and free-standing BNC/PWA nanocomposite with paper-like aspect were obtained. BNC network was able to control, stabilize and disperse PWA particles in a narrow nanometric distribution, and FTIR spectra indicated that the primary Keggin structure was also preserved in the nanocomposites, independently on the PWA content. The nanoparticles present a narrow distribution of around 16 nm, independently on the PWA concentration. BNC/PWA nanocomposites showed reversible photochromic behavior characteristic of the equilibrium between different tungsten oxidation states. PWA reduction (W6+→ W5+) and organic matrix oxidation is proposed to occur through a radical process involving the interaction of one electron from the oxygen atom of the PWA and one hydrogen from BNC matrix. The photochromic effect vanishes almost completely after 5 h. This mechanism is real in the presence of oxygen, however, if the membranes are left in nitrogen or under vacuum the blue color remains longer than 45 days. Photo-electrochemical behavior was studied by spectroelectrochemistry measurements. It is worth noting that all processes were still reversible in the timescale of the experiment and color changes were observed in several cycles.

There is an emerging environmental awareness and social concern regarding the environmental impact of the textile industry, highlighting the growing need for developing green and sustainable approaches throughout this industry’s supply chain. Upstream, due to population growth and the rise in consumption of textile fibers, new sustainable raw materials and processes must be found. Cellulose presents unique structural features, being the most important and available renewable resource for textiles. The physical and chemical modification reactions yielding fibers are of high commercial importance today. Recently developed technologies allow the production of filaments with the strongest tensile performance without dissolution or any other harmful and complex chemical processes. Fibers without solvents are thus on the verge of commercialization. In this review, the technologies for the production of cellulose-based textiles, their surface modification and the recent trends on sustainable cellulose sources, such as bacterial nanocellulose, are discussed. The life cycle assessment of several cellulose fiber production methods is also discussed.

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Boluses characterize materials with an electromagnetic radiation attenuation coefficient similar to biological tissue and used to restrict the penetration of high energy photons and electrons used in radiotherapy for the treatment of superficial tumors. The development of new materials, mainly from sustainable biotechnological routes, will contribute to increase efficiency and expand the use of these technologies. The objective of this research was to develop the "proof of concept" regarding the use of the bacterial nanocellulose membrane (BNCm) as a bolus. For this purpose, BNCm were produced, purified and subjected to the physical–chemical characterization. The radiological density (RD) and radiation attenuation potential (RAP) of the BNCm were established and compared to a commercial bolus (CB). The moldability of BNCm was established and compared to the virtual bolus of dosimetric planning. The physical–chemical analysis demonstrated the constitution of a pure, highly hydrated, homogeneous and nanostructured network of cellulose fibers. BNCm showed superiority in relation to RD and similar RAP values when compared to CB. Moldability analysis showed a profile identical to a virtual bolus. The results validate the concept of using BNCm as a highly efficient biotechnological device, aligned with the idea of sustainability, as a bolus for use in radiotherapy. [ABSTRACT FROM AUTHOR]

Although used in a wide range of medical and pharmaceutical applications, the potential of the natural biopolymer bacterial nanocellulose (BNC) as drug delivery system is by far not fully exploited. Particularly, the incorporation of lipophilic drugs is still considered as an unsolved task. In the present study, the homogeneous incorporation of the lipophilic coenzyme Q10 (CoQ10) into BNC was accomplished by several post-synthesis techniques utilizing different nanoemulsions and liposomes. All colloidal carriers were in the range of about 90–120 nm with negative zeta potentials and storage stabilities up to 30 days. The biphasic drug release profiles of loaded BNC were found to be dependent on the type of colloidal carrier and the loading technique. Favorable characteristics such as high mechanical stability and high loading capacity were retained after the incorporation of the lipophilic components. Penetration studies using excised porcine skin revealed CoQ10 distributions also in deeper skin layers dependent on the type of the colloidal carrier system. In conclusion, hydrophilic BNC could be loaded with water-insoluble drugs as shown for the model drug CoQ10 by the use of lipidic colloidal carriers which offers new possibilities of application in pharmacy and medicine. [ABSTRACT FROM AUTHOR]