Search

Nanocellulose, a versatile and sustainable nanomaterial derived from cellulose fibers, has attracted considerable attention in various fields due to its unique properties. Similar to dietary fibers, nanocellulose is difficult to digest in the human gastrointestinal tract. The indigestible nanocellulose is fermented by gut microbiota, producing metabolites and potentially exhibiting prebiotic activity in intestinal diseases. Additionally, nanocellulose can serve as a matrix material for probiotic protection and show promising prospects for probiotic delivery. In this review, we summarize the classification of nanocellulose, including cellulose nanocrystals (CNC), cellulose nanofibers (CNF), and bacterial nanocellulose (BNC), highlighting their distinct characteristics and applications. We discuss the metabolism-related characteristics of nanocellulose from oral ingestion to colon fermentation and introduce the prebiotic activity of nanocellulose in intestinal diseases. Furthermore, we provide an overview of commonly used nanocellulose-based encapsulation techniques, such as emulsification, extrusion, freeze drying, and spray drying, as well as the delivery systems employing nanocellulose matrix materials, including microcapsules, emulsions, and hydrogels. Finally, we discuss the challenges associated with nanocellulose metabolism, prebiotic functionality, encapsulation techniques, and delivery systems using nanocellulose matrix material for probiotics. This review will provide new insight into the application of nanocellulose in the treatment of intestinal diseases and probiotic delivery., Competing Interests: Declaration of competing interest The authors declared no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Antimicrobial bacterial cellulose (BC) membranes incorporated with carbon dots (CDs) were developed to improve the shelf life and ensure the safety of minced beef during 9 days of storage at 4 °C. An ex-situ method was used to develop BC-CDs with different CDs loading capacities (16.50, 22.50, and 38.50 mg/cm 3 ). Only BC-CDs 38.50 membrane exhibited toxicity in human embryonic kidney cells, and BC-CDs membranes had the slowest release rate of CDs in 95% ethanol. Significant differences were noted in the chemical and sensory attributes of samples packaged with BC-CDs 16.50 and BC-CDs 22.50 , compared to the control. The microbial counts in samples with BC-CDs were significantly lower than those in samples with pristine BC membranes or the control. Notably, the BC-CDs 22.50 membrane exhibited a substantial reduction (4.7 log 10 CFU/g) in Escherichia coli counts by the end of storage. These findings highlight the potential of BC-CDs membranes as effective antimicrobial materials in meat packaging., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The use of nanocellulose (NC) has increased significantly in the food industry, as subtypes such as cellulose nanofibrils (CNF) or bacterial cellulose (BC) have been demonstrated to be a source of insoluble fiber with important benefits for human health. Despite these advantages, and due to its nanoscale size, NC must be assessed from a safety perspective that considers its exposure, fate, and biological effects in order to help more accurately estimate its potential hazards. The exposure routes of humans to NC include (i) ingestion during consumption of foods that contain cellulose as a food ingredient or (ii) contact of food with cellulose-containing materials, such as its packaging. That is why it is important to understand the potentially toxic effects that nanomaterials can have on human health, understanding that the different types of NC behave differently in terms of their ingestion, absorption, distribution, metabolism, and excretion. By analysing both in vitro and in vivo studies, the purpose of this paper is to present the most recent findings on the different types of NC and their safety when used in food. In addition, it provides an overview of relevant studies into NC and its health benefits when used as a food additive., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Author A. Cañas-Gutiérrez, received fees for research support from Instituto Tecnológico Metropolitano. The other authors declare having received hours in their work plan to carry out the investigation in your institution., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Bacterial nanocellulose (BNC), due to its inherent nanometric scale and strength properties, can be considered as a good candidate to be used in papermaking. This work explored the possibility of using it in the production of fine paper as a wet-end component and for the paper coating. Filler-containing handsheet production was performed with and without the presence of common additives typically used in the furnish of office papers. It was found that, under optimized conditions, BNC mechanically treated by high-pressure homogenization could improve all the evaluated paper properties (mechanical, optical and structural) without impairing the filler retention. However, paper strength was improved only to a small extent (increase in the tensile index of 8 % for a filler content of ca. 27.5 %). On the other hand, when used at the paper surface, remarkable improvements in the gamut area of >25 % in comparison to the base paper and of >40 % in comparison to starch-only coated papers were achieved for a formulation having 50 % BNC and 50 % of carboxymethylcellulose. Overall, the present results highlight the possibility of using BNC as a paper component, particularly when applied at the paper substrate as a coating agent aiming at improving printing quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Liquid metal (LM) nanodroplets and MXene nanosheets are integrated with sulfonated bacterial nanocellulose (BNC) and acrylic acid (AA). Upon fast sonication, AA polymerization leads to a crosslinked composite hydrogel in which BNC exfoliates Mxene, forming organized conductive pathways. Soft conducting properties are achieved in the presence of colloidally stable core-shell LM nanodroplets. Due to the unique gelation mechanism and the effect of Mxene, the hydrogels spontaneously undergo surface wrinkling, which improves their electrical sensitivity (GF = 8.09). The hydrogels are further shown to display interfacial adhesion to a variety of surfaces, ultra-elasticity (tailorable elongation, from 1000 % to 3200 %), indentation resistance and self-healing capabilities. Such properties are demonstrated in wearable, force mapping, multi-sensing and patternable electroluminescence devices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Oxidized bacterial nanocellulose (O-BNC) is a favorable material to subdue bacterial infection because of the carboxylate content that not only has a weak antibacterial activity but also is capable of bonding electrostatically to polycationic antibacterial agents. In this study, the 2,2,6,6-Tetramethylpiperidinyloxy radical (TEMPO)-mediated oxidation of BNC was optimized to achieve high carboxylate content while retaining an acceptable tensile profile. To develop an O-BNC-based functional wound dressing, ε-poly-l-lysine (PLL) was then covalently bonded with O-BNC via 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) reaction after homogeneous distribution by ultrasonication. The antibacterial activity of the obtained wound dressing was significantly higher (p < 0.05), and no toxicity was observed. The infected full-thickness wounds of rats were healed faster (p < 0.05) covered by the dressing due to less inflammation, faster blood vessel proliferation, and epidermal layer formation. The material is an effective and promising functional dressing for the treatment of infected wounds., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Bacterial nanocellulose (BNC) is an excellent candidate biomaterial for wound dressing applications, although its preparation should consider the differences in wound healing resulting from BNC biosynthesized by different bacterial strains. This study design aimed to characterize the BNC produced by three different bacterial strains and compare their effectiveness for wound healing applications. The results demonstrated that the upper surfaces of the BNC membranes were clearly denser and more compact than the lower surfaces, while all varieties were capable of serving as a physical barrier to the invasion of bacteria. The growth of fibroblasts demonstrated that the lower surfaces of BNC membranes exhibited biocompatibility superior to that of the upper surfaces. In vivo analysis indicated that, of all samples, wounds treated with the BNC membrane synthesized by DHU-WX-1 displayed the greatest wound repair efficacy. The results indicate that BNC biosynthesized by different strains displayed different wound healing effectiveness. Placing the lower surface of BNC membranes in contact with wounds, with the denser upper surface outward, satisfied the clinical requirements of a wound repair biomaterial., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Bacterial nanocellulose (BNC) is a natural biomaterial with a wide range of medical applications. However, it cannot be used as a biological implant of the circulatory system without checking whether it is biodegradable under human plasma conditions. This work aimed to investigate the BNC biodegradation by selected pathogens under conditions simulating human plasma. The BNC was incubated in simulated biological fluids with or without Staphylococcus aureus, Candida albicans and Aspergillus fumigatus, and its physicochemical properties were studied. The results showed that the incubation of BNC in simulated body fluid with A. fumigatus contributes more to its degradation than that under other conditions tested. The rearrangement of the hydrogen-bond network in this case resulted in a more compact structure, with an increased crystallinity index, reduced thermal stability and looser cross-linking. Therefore, although BNC shows great potential as a cardiovascular implant material, before use for this purpose its biodegradability should be limited., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Incorporation of chitosan (CS) into Bacterial nanocellulose (BNC) matrix is of great interests in biomedical field due to the advantageous properties of each material. However, the conventional strategies result in poor composite effect with low efficiency. In this study, the three-dimensional fibrillar network of BNC was utilized as a template for the first time to homogeneously disperse CS to form nanoparticles (CSNPs) in BNC matrix via ionic gelation method, to develop chitosan nanoparticles-embedded bacterial nanocellulose (CSNPs-BNC) composites. This composite method is simple and efficient, without introducing dispersants and crosslinking agents, while retaining the mechanical properties and native 3D network structure of BNC. The CSNPs-BNC composites had excellent antibacterial activity to support potential clinical application. The CSNPs-BNC composites could promote the adhesion and proliferation of Schwann cells, and demonstrate good biocompatibility both in vitro and in vivo. The results indicated that CSNPs-BNC can provide a promising candidate for biomedical applications., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

To date, the production of bacterial nanocellulose (BNC) by standard methods has been well known, while the use of low-cost feedstock as an alternative medium still needs to be explored for BNC commercialization. This study explores the prospect for the use of the different aqueous extract of fruit peel wastes (aE-FPW) as a nutrient and carbon source for the production of BNC. Herein, this objective was accomplished by the use of a novel, high- yielding strain, isolated from rotten apple and further identified as Komagataeibacter xylinus IITR DKH20 using 16 s rRNA sequencing analysis. The physicochemical properties of BNC matrix collected from the various aE-FPW mediums were similar or advanced to those collected with the HS medium. Statistical optimization of BNC based on Central Composite Design was performed to study the effect of significant parameters and the results demonstrated that the BNC yield (11.44 g L -1 ) was increased by 4.5 fold after optimization., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Biotech nanocellulose (bacterial nanocellulose, BNC) is a high potential natural polymer. Moreover, it is the only cellulose type that can be produced biotechnologically using microorganisms resulting in hydrogels with high purity, high mechanical strength and an interconnecting micropore system. Recently, the subject of intensive research is to influence this biosynthesis to create function-determining properties. This review reports on the progress in product design and today's state of technical and medical applications. A novel, dynamic, template-based technology, called Mobile Matrix Reservoir Technology (MMR Tech), is highlighted. Thereby, shape, dimensions, surface properties, and nanonetwork structures can be designed in a process-controlled manner. The formed multilayer materials open up new applications in medicine and technology. Especially medical materials for cardiovascular and visceral surgery, and drug delivery systems are developed. The effective production of layer-structured composites and coatings are important for potential applications in the electronics, paper, food and packaging technologies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In this study, the effect of bioreactor size was evaluated with respect to the production and characteristics of the nanocellulose membranes produced by two different bioreactors: one with an 1800 cm 2 cross-sectional area (BC-B44) and a lab-scale bioreactor with a 41 cm 2 cross-sectional area (BC-B1). The culture conditions were kept the same, and the substrate consisted of overripe bananas, which are inexpensive because they are unsuitable for human consumption. The X-ray diffraction pattern showed that the two samples had similar crystalline structures, but changes were observed at the morphological level in the nanofibers that make up the BNC membranes. These changes generated, in turn, variations in the mechanical and thermal properties of the samples. This result represents a novel scale-up effect related to the static mode fermentation of BNC., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A novel design of bioreactor G-BNC, in combination with two previously reported designs of bioreactor were used to fabricate three small caliber bacterial nanocellulose (BNC) conduits (G-BNC, S-BNC and D-BNC). They were compared systematically with a clinically-used ePTFE graft. S-BNC possessed a laminated structure, the lowest BNC content, roughest luminal surface and weakest mechanical properties, and so might not be sufficiently strong for use as an artificial blood vessel alone. The D-BNC conduit possessed an unstratified structure with a fiber network that was more dense and the greatest BNC content, providing the strongest mechanical properties. G-BNC possessed a looser network with the smoothest luminal surface and greater hemocompatibility. Following comprehensive evaluation of mechanical properties and performance, we judge that D-BNC and G-BNC should possess greater potential in application as small caliber vascular grafts, however the patency of the three BNC conduits need be further verified in animal studies in vivo., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

During the last two decades cellulosic nanomaterials have been the subject of much research around the world. Moreover, in the last few years, increasing industrial interest on the field enabled the setting-up of the first facilities producing commercial quantities of nanocelluloses; whereas a number of inventions involving cellulose nano-objects are claimed every year. In this context, the current article describes the recent evolution (from 2010 till 2017) of published patents which explicitly include in their title, abstract and/or claims references to cellulose nano-objects such as cellulose nanocrystals, cellulose nanofibrils and bacterial nanocellulose. Results evidence the astonishing increase in nanocellulose patents since 2010, and specially within the last three years surveyed (i.e. 2015-2017), when published documents accounted for ca. 70 % of the total number of patents published since 2010. Besides patent timelines, data is analysed in terms of patent owners, countries of application, and citing number., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest that are directly relevant to the content of this article., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Bacterial nanocellulose (BNC) is a natural biomaterial with a wide range of biomedical applications. BNC contains 99 % of water which makes it too thick to be used as a bioimplant material. The aim of the work was to determine the effect of the BNC dehydration followed by rehydration on its mechanical and physicochemical properties, in the context of the use of BNC as bio-prostheses in the cardiovascular system. Dehydration involved the convection-drying at 25 and 105 °C, and the freeze-drying, while rehydration - the soaking in water. All modified BNC samples had reduced thickness, and results obtained from FT-IR, XRD, and SEM analysis revealed that 25 °C BNC convection-dried after soaking in water was characterized by the highest: tensile strength (17.4 MPa), thermal stability (253 °C), dry mass content (4.34 %) and I α /I β ratio (1.10). Therefore, 25 °C convection-dried BNC followed by soaking in water can be considered as a material suitable for cardiovascular implants., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This study aimed to develop an eco-friendly flexible surface-enhanced Raman scattering (SERS) substrate for in-situ detection of pesticides using biodegradable bacterial nanocellulose (BNC). Plasmonic silver nanoparticle- bacterial nanocellulose paper (AgNP-BNCP) composites were prepared by vacuum-assisted filtration. After loading AgNPs into BNC hydrogel, AgNPs were trapped firmly in the network of nanofibrous BNCP upon ambient drying process, resulting in 3D SERS hotspots within a few-micron depth on the substrate. The fabricated AgNP-BNCPs exhibited high SERS activity with good reproducibility and stability as demonstrated by the detection of 4-aminothiophenol and methomyl pesticide. Due to the optical transparency of BNCP, a direct and rapid detection of methomyl on fruit peels using AgNP-BNCPs can be achieved, demonstrating a simple and effective 'paste-and-read' SERS approach. These results demonstrate potential of AgNP-BNCP composites for user-friendly in-situ SERS analysis., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Bacterial nanocellulose (BNC) has many advantages over plant cellulose, which make it widely used in many fields, especially in the food industry. In this study, three strains including BCA263, BCC529, and P1 were selected for characteristics analysis of BNCs under static and agitated culture conditions. The BNCs produced under static culture condition were in the shape of uniform membrane, while BNCs produced under agitated culture were in form of small agglomerates and fragments. BCA263 and BCC529 strains were more suitable for static culture, while P1 strain was more suitable for agitated culture. BNCs produced under static culture condition exhibited higher crystallinity, stronger tensile strength, denser network structure, higher temperature resistance and good flame retardancy; while BNCs produced under agitated culture condition exhibited larger porous and lower crystallinity. Furthermore, BNCs produced under agitated culture condition were more suitable as a stabilizer of coffee milk beverage., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Nonsense mutation in the bcsC gene occurred in the ethanol-adapted strain of Komagataeibacter oboediens MSKU 3, E3 strain, resulting in the loss of the function to produce BNC. In this study, we tried to restore the BNC-producing ability of E3 strain by the following adaptive mutation through repetitive static culture, and obtained four BNC-producing revertant strains, of which the bcsC gene had InDel mutations near the frameshift mutation region in E3 strain, resulting in several amino acid alterations compared with the BcsC of MSKU 3. Each revertant produced BNCs with different productivity on the static culture. Interestingly, one of the revertants, R37-9, produced BNC with a finer structure and narrower range of fibrils width, compared to others. The genome of R37-9 strain revealed only one amino acid substitution in the bcsC gene. Thus, we concluded that N713D mutation occurred in the bcsC gene is responsible for the finer fibrils structure., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The design of functional materials capable of fighting fungal infections is of paramount importance given the intricate problem of multidrug-resistant pathogenic fungi. Herein, nanocomposites consisting of cross-linked poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (PMETAC) and bacterial nanocellulose (BNC) were prepared, characterized and tested towards the polymorphic fungus Candida albicans. The BNC three-dimensional network enabled the in-situ polymerization of the non-toxic and bioactive quaternary-ammonium monomer, which originated transparent nanocomposites containing 10 and 40 wt.% of cross-linked PMETAC. Furthermore, the nanocomposites exhibit UV-A and UV-B blocking properties, high water-uptake capacity, thermal stability up to 200 °C, good viscoelastic (storage modulus > 1.7 GPa) and mechanical (Young's modulus ≥2.4 GPa) properties and are non-cytotoxic to human keratinocytes (HaCaT cells). The fungal inactivation reached a 4.4 ± 0.14-log CFU reduction for the nanocomposite containing only 10 wt.% of cross-linked PMETAC. Hence, these bioactive and non-cytotoxic materials can constitute potentially effective systems for the treatment of C. albicans infections., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The impact of strain selection and culture conditions on bacterial nanocellulose (BNC) productivity and quality was investigated by using four strains, static and agitated cultures, and an initial pH in the range 4-6. With agitation, strain DHU-ATCC-1 displayed highest productivity [1.14 g/(L × d)]. In static cultures, DHU-ZGD-1186 exhibited superior BNC yield on consumed glucose (0.79 g/g), and lowest by-product formation with respect to gluconic acids [≤0.07 g/(L × d)]. By-product formation typically decreased in the order gluconic acid >2-keto-gluconic acid >5-keto-gluconic acid, and was lowest in cultures with high initial pH. The BNC from DHU-ZGD-1186 exhibited higher average viscometric degree of polymerization (DP v ), higher crystallinity index, and higher tear index. In conclusion, both strain selection and cultivation conditions had an impact on BNC productivity and properties. Productivity, DP v , crystallinity, and mechanical strength of BNC from agitated cultures could be similar to or even higher than the corresponding values for static cultures., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Since anisotropic hydrogel membranes have great potential in tissue engineering and bioseparation, the aim of this study was to produce an anisotropic BNC hydrogel membrane for the first time with enhanced BNC productivity by using a newly designed 30-L horizontal rotary drum bioreactor. As compared with the traditional tray static cultivation, the BNC hydrogel from the rotary drum bioreactor showed anisotropic morphology, sparser network, lower dry matter content of 0.16 w/w%, thicker fiber diameter, and lower degree of polymerization that was still 1.8 times higher than cotton, and featured with much higher ultraviolet-visible light transmittance, as well as demonstrated anisotropic tensile properties, lower Young's modulus of 0.23 MPa and compressive modulus of 0.99 kPa. The productivity of dry and wet BNC was enhanced by 1.65 times and 3.73 times, respectively. The proposed technology may not only obtain anisotropic BNC hydrogel membranes with high transparency, but also promote the BNC productivity., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The synergy of the local delivery of nucleic acids using a hydrogel-based gene activated matrix (GAM) might support regenerative processes on a genetic level by concurrently providing a cell-friendly microenvironment. To investigate bacterial nanocellulose (BNC) as GAM, two plasmids (pSV-β-Gal and pGL3) were incorporated by reswelling and injection techniques forming matrix and core-shell systems as determined by SEM and staining experiments. The release was found to be dependent on the type of BNC, the plasmid and the loading technique, and lasted over at least 20 days. No morphological or mechanical changes of the BNC due to the presence of plasmids were observed. Immobilized plasmids especially in the matrix systems were protected against enzymatic degradation by maintaining the high biocompatibility of BNC and transfection efficacy of the plasmids. These results indicate that BNC can be used as a promising and renewable carrier for the application as local gene delivery system., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Bacterial nanocellulose/hydroxyapatite/cellulose nanocrystal (BHC) composites were synthesized via in-situ synthesis using cellulose nanocrystals (CNCs) to improve colloidal stability and the dispersion of hydroxyapatite (HA) during the bacterial nanocellulose (BNC) cultivation period. Transmission electron microscopy images and energy dispersive spectroscopy (EDS) results confirmed the dispersion of HA on the CNC particles with a Ca/P ratio of 1.66 corresponding to that of the stoichiometric HA. The SEM images and EDS results showed that the integration of the HA and BNC network without CNC assistance (BHA (0.25 and 0.5 wt.%) composites) was less than that for BHC at both concentrations. Fourier-transform infrared analysis, XRD and thermal degradation revealed the effect of HA on the BHC composites with a decreased CrI% and improved thermal property. Cytotoxicity proved the potential for using BHC composites for bone tissue engineering scaffold with cell viability up to 83.4 ± 3.6% compared to the negative control (99.2 ± 0.08%)., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Properties of bacterial nanocellulose (BNC) produced by four different strains were studied and compared for laccase immobilization. Scanning electron microscope inspection indicated the four types of BNC had obvious differences in fiber density, diameter and distribution. BNC hydrogel demonstrated the highest fracture stress of 2.44 Mpa and the highest Young's modulus of 12.76 Mpa. Brunauer-Emmett-Teller analysis suggested the four BNC had significant difference in specific surface area, total pore volume and average pore size. Laccase was immobilized on BNC carriers via adsorption. Kinetic studies showed that the four types of BNC-immobilized laccase had different affinity with substrate, and all types of immobilized laccase showed high operational stability after ten consecutive biocatalytic cycles of reaction. The results suggest that the structure diversity of BNC from various strains may directly result in different efficiency in laccase immobilization, and a looser fiber network in BNC with larger porosity is helpful for enzyme immobilization., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The present study reports the development of non-cytotoxic and pH-sensitive nanostructured membranes consisting of a polymer with amino acid pending moieties and bacterial nanocellulose (BC). The nanocomposites were prepared through a simple methodology under green reaction conditions. The obtained materials display good thermal stability (up to 200°C), viscoelastic (storage modulus>700MPa) and mechanical (Young's modulus=3.5-4.9GPa) properties, together with high water uptake capacity. The results of the in vitro MTT assay showed that the nanocomposites are non-cytotoxic to HaCaT cells for 72h. The in vitro release profile of diclofenac sodium salt (DCF) from the nanocomposites into simulated body fluids at different pH values demonstrates the pH-responsive behaviour of these materials. Besides, DCF is mainly retained in the nanocomposites at pH 2.1 and released at pH 7.4, revealing their potential for the controlled release of DCF in dermal as well as in oral drug delivery applications., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The study aimed at evaluation of various types of alkali rinsing with regard to their efficacy in terms of removal, not only of bacteria but also bacterial metabolites, from cellulose matrices formed by three Komagataeibacter xylinus strains. Moreover, we tested the type of alkali rinsing on membrane cytotoxicity in vitro in fibroblast and osteoblast cells and we compared matrices' ability to induce oxidative stress in macrophages. We identified 11 metabolites of bacterial origin that remained in cellulose after rinsing. Moreover, our results indicated that the type of alkali rinsing should be adjusted to specific K. xylinus strains that are used as cellulose producers to obtain safe biomaterials in the context of low cytotoxicity and macrophage induction. The findings have translational importance and may be of direct significance to cellulose dressing manufacturers., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A facile method for the preparation of cobalt ferrite nanotubes by use of bacterial cellulose nanoribbons as a template is described. The proposed method relays on a simple coprecipitation operation, which is a technique extensively used for the synthesis of nanoparticles (either isolated or as aggregates) but not for the synthesis of nanotubes. The precursors employed in the synthesis are chlorides, and the procedure is carried out at low temperature (90 °C). By the method proposed a homogeneous distribution of cobalt ferrite nanotubes with an average diameter of 217 nm in the bacterial nanocellulose (BC) aerogel (3%) was obtained. The obtained nanotubes are formed by 26-102 nm cobalt ferrite clusters of cobalt ferrite nanoparticles with diameters in the 9-13 nm interval. The nanoparticles that form the nanotubes showed to have a certain crystalline disorder, which could be attributed in a greater extent to the small crystallite size, and, in a lesser extent, to microstrains existing in the crystalline lattice. The BC-templated-CoFe2O4 nanotubes exhibited magnetic behavior at room temperature. The magnetic properties showed to be influenced by a fraction of nanoparticles in superparamagnetic state., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

For the loading of the natural biopolymer bacterial nanocellulose (BNC) with drugs, usually an adsorption method has been described. In the present study, a high-speed loading technique based on vortexing was established for the incorporation of proteins in BNC as drug delivery system. Compared to the conventional technique, vortexing accomplished in 10 min the same protein loading capacity as the adsorption method in 24h with comparable protein distribution and protein stability. Vortex loaded BNC demonstrated a retarded protein release with a lower total amount of released protein after 168 h compared to the adsorption loaded BNC. This was correlated with a densification of the fiber network as shown by electron microscopy and a reduced water holding capacity. These observations offer the possibility to control the drug release by selection of the preparation technique., (Copyright © 2014 Elsevier Ltd. All rights reserved.)