Search Results (328)

The article is devoted to the study of the physico-mechanical properties and oxygen permeability of the examined conduits based on bacterial cellulose (BC) obtained using the Komagataeibacter sucrofermentans B-11267 strain. BC is considered a promising material for regenerative biomedicine. The chemical structure, crystallinity degree and porosity of BC-based conduits were characterized by means of infrared spectroscopy (IR-spectroscopy), scanning electron microscopy (SEM) and atomic-force microscopy (AFM). Both the Young’s modulus and determined tension showed the high strength of the obtained conduits. Their oxygen permeability exceeded the values for the existing analogues, and lack of cytotoxicity indicated biocompatibility, confirming that BC-based conduits may be used for biomedical purposes. Full article

Developing innovative, low-cost halochromic materials for diagnosing microbial contamination in wounds and burns can effectively facilitate tissue regeneration. Here, we combine the pH-sensing capability of highly colorful red cabbage anthocyanins (RCAs) with their healing potential within a unique cellulose polymer film that mimics the skin matrix. Biological activities of RCA extract in bacterial cellulose (BC) showed no cytotoxicity and skin-sensitizing potential to human cells at concentrations of RCAs similar to those released from BC/RCA dressings (4.0–40.0 µg/mL). A decrease in cell viability and apoptosis was observed in human cancer cells with RCAs. The invisible eye detection of the early color change signal from RCAs in response to pH alteration by bacteria was recorded with a smartphone application. The incorporation of RCAs into BC polymer has altered the morphology of its matrix, resulting in a denser cellulose microfibril network. The complete coincidence of the vibrational modes detected in the absorption spectra of the cellulose/RCA composite with the modes in RCAs most likely indicates that RCAs retain their structure in the BC matrix. Affordable, sensitive halochromic BC/RCA hydrogels can be recommended for online monitoring of microbial contamination, making them accessible to patients. Full article

This study explored the potential of chitosan (CH)/bacterial cellulose (BC) complexes (0.5% w/v) as novel emulsifiers to stabilize oil-in-water (o/w) Pickering emulsions (20% v/v sunflower oil), with a focus on their gel-like behavior. Emulsions were prepared using CH combined with BNC derived via H₂SO₄ (BNC1) or H₂SO₄-HCl (BNC2) hydrolysis. Increasing BNC content improved stability by reducing phase separation and enhancing viscosity, while CH contributed interfacial activity and electrostatic stabilization. CH/BNC1_25:75 emulsions showed the highest stability, maintaining an emulsion stability index (ESI) of up to 100% after 3 days, with minimal change in droplet size (R_h ~8.5–8.8 μm) and a positive ζ-potential (15.1–29.8 mV), as confirmed by dynamic/electrophoretic light scattering. pH adjustment to 4 and 10 had little effect on their ESI, while ionic strength studies showed that 0.1 M NaCl caused only a slight increase in droplet size combined with the highest ζ-potential (−35.2 mV). Higher salt concentrations led to coalescence and disruption of their gel-like structure. Rheological analysis of CH/BNC1_25:75 emulsions revealed shear-thinning behavior and dominant elastic properties (G′ > G″), indicating a soft gel network. Incorporating sunflower-seed protein isolates into CH/BNC1 (25:75) emulsions led to coacervate formation (three-layer system), characterized by a decrease in droplet size and an increase in ζ-potential (up to 32.8 mV) over 7 days. These findings highlight CH/BNC complexes as sustainable stabilizers for food-grade Pickering emulsions, supporting the development of biopolymer-based emulsifiers aligned with bioeconomy principles. Full article

Superparamagnetic magnetite nanoparticles (Fe₃O₄) have garnered considerable interest due to their unique magnetic properties and potential for integration into multifunctional biomaterials. In particular, their incorporation into bacterial cellulose (BC) matrices offers a promising route for developing sustainable and high-performance magnetic composites. Numerous studies have explored BC-magnetite systems; however, innovations combining ex situ coprecipitation synthesis within BC matrices, tailored reagent molar ratios, stirring protocols, and purification processes remain limited. This study aimed to optimize the ex situ coprecipitation method for synthesizing superparamagnetic magnetite nanoparticles embedded in BC membranes, focusing on enhancing particle stability and crystallinity. BC membranes containing varying concentrations of magnetite (40%, 50%, 60%, and 70%) were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). The resulting magnetic BC membranes demonstrated homogenous dispersion of nanoparticles, improved crystallite size (6.96 nm), and enhanced magnetic saturation (Ms) (50.4 emu/g), compared to previously reported methods. The adoption and synergistic optimization of synthesis parameters—unique to this study—conferred greater control over the physicochemical and magnetic properties of the composites. These findings position the optimized BC-magnetite nanocomposites as highly promising candidates for advanced applications, including electromagnetic interference (EMI) shielding, electronic devices, gas sensors, MRI contrast agents, and targeted drug delivery systems. Full article

Dialdehyde bacterial cellulose (DBC) has been implemented in versatile applications. DBC was prepared from bacterial cellulose (BC) through periodate oxidation with varying parameters, including the mole ratio of BC and NaOI₄, temperature, and reaction time. The relationship between the degree of oxidation (DO)/aldehyde content and these parameters was proposed as a quadratic equation to predict the oxidation conditions needed to achieve a specific DO using Response Surface Methodology (RSM). The chemical structure and morphology of DBC were influenced by DO. DBC with different DO levels was used as a crosslinker and a reinforcing agent for gelatin sponge fabrication. Results indicated that a high DO of DBC could enhance the tensile strength and structural stability of the gelatin matrix. Selecting the proper DO level could control the morphological structure of the gelatin sponge, which is crucial for biomedical applications. Full article

Bacterial cellulose (BC), an extracellular polysaccharide synthesized by various bacterial strains. It exhibits high tensile strength, water retention, crystallinity, and biocompatibility, making it valuable in biomedical, cosmetic, food, textile, and paper industries. This study examined the effects of six carbon sources on BC production by Komagataeibacter sucrofermentans, identifying fructose as the most effective. A Box–Behnken experimental design was employed to investigate the effects of three variables (fructose concentration, temperature, and cultivation time) on cellulose yield. The optimized cultivation conditions were: fructose concentration of 227.5 g/L, temperature of 28.0 °C, and cultivation time of 295 h, resulting in a BC yield of 63.07 ± 2.91 g/L. Subsequently, BC’s potential as a bacteriophage carrier was assessed. Escherichia coli phage T4 and Staphylococcus aureus phage vB_SauS_CS1 (CS1) were immobilized within BC hydrogels, and their antibacterial activities were assessed through in vitro experiments. These findings suggest BC’s promise as a phage delivery platform for biomedical applications. Full article

Environmentally sustainable methods for producing flexible electronics, such as paper-based energy harvesters in nanogenerators, are a major objective in materials science. In this frame, the present study investigated two different Komagataeibacter sp. strains (K2G30 and K2G44), never tested as biocatalysts for the production of bacterial cellulose (BC) functionalized with iron particles to provide potential electrical conductivity. Two functionalization strategies (ex situ and in situ) were evaluated using two iron compounds FeCl₂ and FeSO₄, individually and in combination (up to 0.1% w/v), to assess efficiency and feasibility. In addition, a Design of Experiment approach was implemented to calculate quantitative mathematical models to correlate the functionalization methods with the iron amount in the BC. Among the tested conditions, BC produced by strain K2G44 using the ex situ method with FeCl₂ showed the most promising results, achieving the highest iron content (~37% atomic weight) with a highly homogeneous dispersion of iron nanoparticles. Moreover, the in situ BC functionalization using FeSO₄ led to the formation of iron gluconate. FeSO₄ alone significantly enhanced BC production in the in situ process, with yields of 2.62 ± 0.15 g/L for K2G30 and 2.05 ± 0.09 g/L for K2G44. Full article

Cellulose has been identified as a medium for heavy metal removal due to its high adsorption capacity in relation to these contaminants. Furthermore, cellulose is abundant and can be obtained in a practical and easy way. A notable example is E. crassipes biomass, which is abundant in wetlands and has not yet been efficiently and sustainably removed. Another biomass that has been used in heavy metal removal projects is bacterial cellulose. Generating this biomass in a laboratory setting is imperative, given its 100% cellulose composition, which ensures optimal adsorption capacities during the development of heavy metal adsorbent systems. Therefore, the objective of this project was to design biomass adsorbents that combine the properties of bacterial and E. crassipes cellulose for Cr(VI) removal. The rationale for combining these two materials is based on the premise that it will produce optimal results, a hypothesis supported by the documented efficiency of bacterial cellulose and the formidable resilience of E. crassipes biomass to elution processes. The second-order model and the Langmuir isotherm fit proved to be the most suitable, indicating that there an occurred interaction between the adsorption sites of these biomasses and Cr (VI). This suggests the presence of a significant number of active sites on the surface of these materials. The EC(50)+BC(50) biomass, with an adsorption capacity of 42 g of Cr(VI) per dollar, is the most cost-effective due to the low cost of E. crassipes and the high capacity of bacterial cellulose. It is a mixture that guarantees high adsorption capacities and facilitates up to seven reuse cycles through elutions with ethylenediaminetetraacetic acid (EDTA). This finding emphasizes the potential of this material for implementation in environmental sustainability initiatives, particularly those focused on the removal of heavy metals, including Cr(VI). Full article

Cellulose-based paper products derived from agro-industrial waste have attracted considerable interest due to their potential in sustainable material development. In this study, bacterial cellulose (BC) residue from the food and beverage industry was employed as a reinforcing agent to fabricate high-performance paper composites by blending with eucalyptus pulp (EP) at various ratios and basis weights. These papers were coated with a cationic modified starch solution (MS) using a rod coater, followed by hot pressing. Mechanical strengths (TAPPI Standard), water resistance (Cobb test and water contact angle), and air permeability (ASTM D737) were evaluated to assess material performance. The results showed that incorporating 50 wt% BC produced paper with outstanding mechanical performance, characterized by a high tensile index and excellent tear resistance. The application of the MS coating significantly boosted water resistance and air barrier performance, underscoring the effectiveness of this approach in creating high-performance paper materials. The resulting coated composites demonstrated excellent mechanical strength and barrier properties, positioning them as promising candidates for filtration applications such as personal protective face mask membranes. Full article

Microorganisms metabolising low-value carbon sources can produce a diverse range of bio-based and biodegradable materials compatible with circular economy principles. One such material is bacterial cellulose (BC), which can be obtained in high purity through the fermentation of sweetened tea by a Symbiotic Culture of Bacteria and Yeast (SCOBY). In recent years, there has been a growing research interest in SCOBYs as a promising solution for sustainable material design. In this work, we have explored a novel method to grow SCOBYs vertically using a waste-based scaffold system. Waste sheep wool and cotton fabric were soaked in a SCOBY infusion to serve as scaffolds, carrying the infusion and facilitating vertical growth through capillary forces. Remarkably, vertical membrane growth up to 5 cm above the liquid–air interface (LAI) was observed after just one week. Membranes with different microstructures were found in sheep wool and cotton, randomly oriented between the scaffold fibre, resulting in a high surface area. This study demonstrated that vertical growth in scaffolds is possible, proving the concept of a new method of growing composite materials with potential high-value applications in biomedicine, energy storage, or filtration. Full article

Background/Objectives: The rise of bacterial resistance and the search for alternative, biocompatible antimicrobial materials have driven interest in natural-based nanocomposites. In this context, silver nanoparticles (AgNPs) have shown broad-spectrum antibacterial activity, and bacterial cellulose (BC) is widely recognized for its high purity, hydrophilicity, and biocompatibility. This study aimed to develop a bio-based BC–AgNP nanocomposite via green synthesis using Astrocaryum aculeatum (tucumã) extract and assess its antimicrobial performance for wound dressing applications. Methods: BC was biosynthesized via green tea fermentation (20 g/L tea and 100 g/L sugar) and purified prior to use. AgNPs were obtained by reacting aqueous tucumã extract with silver nitrate (0.1 mmol/L) at pH (9) and temperature (40 °C). BC membranes were immersed in the AgNPs dispersion for 7 days to form the nanocomposite. Characterization was performed using UV–Vis, DLS, TEM, SEM–EDS, FTIR, XRD, ICP–OES, and swelling analysis. Antibacterial activity was evaluated using the disk diffusion method against Staphylococcus aureus and Escherichia coli (ATCC 6538 and 4388). Results: The UV–Vis spectra revealed a gradual decrease in the surface plasmon resonance (SPR) band over 7 days of incubation with BC, indicating progressive incorporation of AgNPs into the membrane. ICP analysis confirmed silver incorporation in the BC membrane at 0.00215 mg/mL, corresponding to 15.5% of the initial silver content. Antimicrobial assays showed inhibition zones of 6.5 ± 0.5 mm for S. aureus and 4.3 ± 0.3 mm for E. coli. Conclusions: These findings validate the successful formation and antimicrobial performance of the BC–AgNP nanocomposite, supporting its potential use in wound care applications. Full article

Developing scaffolds with a three-dimensional porous structure and adequate mechanical properties remains a key challenge in tissue engineering of bone. These scaffolds must be biocompatible and biodegradable to effectively support osteoblastic cell attachment, metabolic activity, and differentiation. This study successfully fabricated a chitosan–bacterial cellulose (CS–BC) composite scaffold using the solvent casting/particle leaching (SCPL) technique, with NaOH/urea solution and sodium chloride crystals as the porogen. The scaffold exhibited a well-distributed porous network with pore sizes ranging from 300 to 500 µm. Biodegradation tests in PBS containing lysozyme revealed a continuous degradation process, while in vitro studies with MC3T3-E1 cells (pre-osteoblastic mouse cell line) demonstrated excellent cell attachment, as observed through SEM imaging. The scaffold also promoted increased metabolic activity (OD values) in the MTT assay, and enhanced alkaline phosphatase (ALP) activity and upregulated expression of osteogenic-related genes. These findings suggest that the CS–BC composite scaffold, fabricated using the SCPL method, holds great potential as a candidate for bone tissue engineering applications. Full article

Bacterial cellulose (BC) is a polysaccharide produced by Gram-positive and Gram-negative bacteria with a strictly aerobic metabolism, having a huge number of significant applications in the biomedical field. This study investigates the development of bacterial cellulose (BC)-based composite systems that incorporate cerium dioxide nanoparticles (CeO₂ NPs) used as antibacterial agents to enhance wound healing, particularly for burn treatments. The innovation of this study resides in the integration of CeO₂ NPs synthesized by using a precipitation method using both chemical and green reducing agents, ammonium hydroxide (NH₄OH) and turmeric extract (TE), in BC membranes composed of ultrathin nanofibers interwoven into a three-dimensional network appearing as a hydrogel mass. Characterization by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FTIR) confirmed the effective deposition of this agent onto the BC matrix. Antibacterial activity tests against E. coli and B. subtilis indicated strong inhibition for the composites synthesized following these routes, particularly for the BC-CeO₂-TE-OH sample, processed by employing both precipitating agents. Cytotoxicity evaluations showed no inhibition of cell activity. Additionally, loading the composites with dexamethasone endowed them with analgesic release over 4 h, as observed through ultraviolet–visible spectroscopy (UV-Vis), while the FTIR spectra revealed a sustained drug presence post-release. These findings highlight BC-based films as promising candidates for advanced wound care and tissue engineering applications. Full article

Bacterial cellulose (BC) is a highly pure and crystalline cellulose produced via bacterial fermentation. However, due to its chemical structure made of strong hydrogen bonds and its high molecular weight, BC can neither be melted nor dissolved by common solvents. Therefore, processing BC implies the use of very strong, often toxic and dangerous chemicals. In this study, we proved a green method to produce electrospun BC fibers by testing different ionic liquids (ILs), namely, 1-butyl-3-methylimidazolium acetate (BmimAc), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EmimTFSI) and 1-ethyl-3-methylimidazolium dicyanamide (EmimDCA), either individually or as binary mixtures. Moreover, γ-valerolactone (GVL) was tested as a co-solvent derived from renewable sources to replace dimethyl sulfoxide (DMSO), aimed at making the viscosity of the cellulose solutions suitable for electrospinning. A BmimAc and BmimAc/EmimTFSI (1:1 w/w) mixture could dissolve BC up to 3 w%. GVL was successfully applied in combination with BmimAc as an alternative to DMSO. By optimizing the electrospinning parameters, meshes of continuous BC fibers, with average diameters ~0.5 μm, were produced, showing well-defined pore structures and higher water absorption capacity than pristine BC. The results demonstrated that BC could be dissolved and electrospun via a BmimAc/GVL solvent system, obtaining ultrafine fibers with defined morphology, thus suggesting possible greener methods for cellulose processing. Full article

Probiotics have gained prominence and consumer appreciation due to their potential health benefits. However, maintaining their viability and stability during gastric transit remains a challenge. This study aims to enhance the viability of microencapsulated Lactobacillus plantarum in composite microcapsules exposed to simulated gastric juice. The independent variables investigated were low-acyl gellan gum (LAG), bacterial cellulose (BC), and calcium concentrations. The microcapsules were prepared using the internal ionic gelation method. The resulting microcapsules exhibited a uniform size distribution, with a diameter of approximately between 15 to 120 μm, making them suitable for food applications. Response surface methodology (RSM) based on the Box–Behnken design was successfully employed to optimize the concentrations of LAG, BC, and calcium. Under optimal conditions—0.63% w/v LAG, 17.91% w/v BC, and 25.12 mM Ca—the highest L. plantarum viability reached 94.28% after exposure to simulated gastric juice, with an R² value of 99.64%. These findings demonstrate the feasibility of developing multicomponent microcapsules that effectively protect probiotic bacteria against gastric fluids, offering a promising alternative for the food industry in designing probiotic-enriched food systems. Full article