The use of bacterial polysaccharides in bioprinting

3D Printing of Polysaccharide-Based Hydrogel Scaffolds for Tissue Engineering Applications: A Review

In tissue engineering, 3D printing represents a versatile technology employing inks to construct three-dimensional living structures, mimicking natural biological systems. This technology efficiently translates digital blueprints into highly reproducible 3D objects. Recent advances have expanded 3D printing applications, allowing for the fabrication of diverse anatomical components, including engineered functional tissues and organs. The development of printable inks, which incorporate macromolecules, enzymes, cells, and growth factors, is advancing with the aim of restoring damaged tissues and organs. Polysaccharides, recognized for their intrinsic resemblance to components of the extracellular matrix have garnered significant attention in the field of tissue engineering. This review explores diverse 3D printing techniques, outlining distinctive features that should characterize scaffolds used as ideal matrices in tissue engineering. A detailed investigation into the properties and roles of polysaccharides in tissue engineering is highlighted. The review also culminates in a profound exploration of 3D polysaccharide-based hydrogel applications, focusing on recent breakthroughs in regenerating different tissues such as skin, bone, cartilage, heart, nerve, vasculature, and skeletal muscle. It further addresses challenges and prospective directions in 3D printing hydrogels based on polysaccharides, paving the way for innovative research to fabricate functional tissues, enhancing patient care, and improving quality of life.

Exploring the evolution of bacterial cellulose precursors and their potential use as cellulose-based building blocks

Natural polymers have found increased use in a wider range of applications due to their less harmful effects. Notably, bacterial cellulose has gained significant consideration due to its exceptional physical and chemical properties and its substantial biocompatibility, which makes it an attractive candidate for several biomedical applications. This study attempts to thoroughly unravel the microstructure of bacterial cellulose precursors, known as bioflocculants, which to date have been poorly characterised, by employing both electron and optical microscopy techniques. Here, starting from bioflocculants from Symbiotic Culture of Bacteria and Yeast (SCOBY), we proved that their microstructural features, such as porosity percentage, cellulose assembly degree, fibres' density and fraction, change in a spatio-temporal manner during their rising toward the liquid-air interface. Furthermore, our research identified a correlation between electron and optical microscopy parameters, enabling the assessment of bioflocculants' microstructure without necessitating offline sample preparation procedures. The ultimate goal was to determine their potential suitability as a novel cellulose-based building block material with tuneable structural properties. Our investigations substantiate the capability of SCOBY bioflocculants, characterized by distinct microstructures, to successfully assemble within a microfluidic device, thereby generating a cellulose sheet endowed with specific and purposefully designed structural features.

Versatile xanthan gum-based support bath material compatible with multiple crosslinking mechanisms: rheological properties, printability, and cytocompatibility study

Extrusion-based bioprinting is a promising technology for the fabrication of complex three-dimensional (3D) tissue-engineered constructs. To further improve the printing accuracy and provide mechanical support during the printing process, hydrogel-based support bath materials have been developed. However, the gel structure of some support bath materials can be compromised when exposed to certain bioink crosslinking cues, hence their compatibility with bioinks can be limited. In this study, a xanthan gum-based composite support material compatible with multiple crosslinking mechanisms is developed. Different support bath materials can have different underlying polymeric structures, for example, particulate suspensions and polymer solution with varying supramolecular structure) and these properties are governed by a variety of different intermolecular interactions. However, common rheological behavior can be expected because they have similar demonstrated performance and functionality. To provide a detailed exploration/identification of the common rheological properties expressed by different support bath materials from a unified perspective, benchmark support bath materials from previous studies were prepared. A comparative rheological study revealed both the structural and shear behavior characteristics shared by support bath materials, including yield stress, gel complex moduli, shear-thinning behavior, and self-healing properties. Gel structural stability and functionality of support materials were tested in the presence of various crosslinking stimuli, confirming the versatility of the xanthan-based support material. We further investigated the effect of support materials and the diameter of extrusion needles on the printability of bioinks to demonstrate the improvement in bioink printability and structural integrity. Cytotoxicity and cell encapsulation viability tests were carried out to confirm the cell compatibility of the xanthan gum-based support bath material. We propose and demonstrate the versatility and compatibility of the novel support bath material and provide detailed new insight into the essential properties and behavior of these materials that serve as a guide for further development of support bath-based 3D bioprinting.

Recent advances and biomedical application of 3D printed nanocellulose-based adhesive hydrogels: A review

Nanocellulose-based tissue adhesives show promise for achieving rapid hemostasis and effective wound healing. Conventional methods, such as sutures and staples, have limitations, prompting the exploration of bioadhesives for direct wound adhesion and minimal tissue damage. Nanocellulose, a hydrolysis product of cellulose, exhibits superior biocompatibility and multifunctional properties, gaining interest as a base material for bioadhesive development. This study explores the potential of nanocellulose-based adhesives for hemostasis and wound healing using 3D printing techniques. Nanocellulose enables the creation of biodegradable adhesives with minimal adverse effects and opens avenues for advanced wound healing and complex tissue regeneration, such as skin, blood vessels, lungs, cartilage, and muscle. This study reviews recent trends in various nanocellulose-based 3D printed hydrogel patches for tissue engineering applications. The review also introduces various types of nanocellulose and their synthesis, surface modification, and bioadhesive fabrication techniques via 3D printing for smart wound healing.

3-Dimentional printing of polysaccharides for water-treatment: A review

Biological polysaccharides such as cellulose, chitin, chitosan, sodium alginate, etc., serve as excellent substrates for 3D printing due to their inherent advantages of biocompatibility, biodegradability, non-toxicity, and absence of secondary pollution. In this review we comprehensively overviewed the principles and processes involved in 3D printing of polysaccharides. We then delved into the diverse application of 3D printed polysaccharides in wastewater treatment, including their roles as adsorbents, photocatalysts, biological carriers, micro-devices, and solar evaporators. Furthermore, we assessed the technical superiority and future potential of polysaccharide 3D prints, envisioning its widespread application. Lastly, we remarked the challenging scientific and engineering aspects that require attention in the scientific research, industrial production, and engineering utilization. By addressing these key points, we aimed to advance the field and facilitate the practical implementation of polysaccharide-based 3D printing technologies in wastewater treatment and beyond.

Research progress in the preparation, structural characterization, and biological activities of polysaccharides from traditional Chinese medicine

Traditional Chinese medicines are tremendous sources of polysaccharides, which are of great interest in the human welfare system as natural medicines, food, and cosmetics. This review aims to highlight the recent trends in extraction (conventional and non-conventional), purification and analytic techniques of traditional Chinese medicine polysaccharides (TCMPs), and the chemical structure, biological activities (anti-tumor, hypoglycemic, antioxidant, intestinal flora regulation, immunomodulatory, anti-inflammatory, anti-aging, hypolipidemic, hepatoprotective, and other activities), and the underlying mechanisms of polysaccharides extracted from 76 diverse traditional Chinese medicines were compared and discussed. With this wide coverage, a total of 164 scientific articles were searched from the database including Google Scholar, PubMed, Web of Science, and China Knowledge Network. This comprehensive survey from previous reports indicates that TCMPs are non-toxic, highly biocompatible, and good biodegradability. Besides, this review highlights that TCMPs may be excellent functional factors and effective therapeutic drugs. Finally, the current problems and future research advances of TCMPs are also introduced. New valuable insights for the future researches regarding TCMPs are also proposed in the fields of therapeutic agents and functional foods.

Bacterial Cellulose-Based Bandages with Integrated Antibacteria and Electrical Stimulation for Advanced Wound Management

Bandages for daily wounds are the most common medical supplies, but there are still ingrained defects in their appearance, comfort, functions, as well as environmental pollution. Here, novel bandages based on bacterial cellulose (BC) membrane for wound monitoring and advanced wound management are developed. The BC membrane is combined with silver nanowires (AgNWs) by using vacuum filtration method to achieve transparent, ultrathin (≈7 µm), breathable (389.98-547.79 g m-2  d-1 ), and sandwich-structured BC/AgNWs bandages with superior mechanical properties (108.45-202.35 MPa), antibacterial activities against Escherichia coli and Staphylococcus aureus, biocompatibility, and conductivity (9.8 × 103 -2.0 × 105  S m-1 ). Significantly, the BC/AgNWs bandage is used in the electrical stimulation (direct current, 600  microamperes for 1 h every other day) treatment of full-thickness skin defect in rats, which obviously promotes wound healing by increasing the secretion of vascular endothelial growth factor (VEGF). The BC bandage is used for monitoring wounds and achieve a high accuracy of 94.7% in classifying wound healing stages of hemostasis, inflammation, proliferation, and remodeling, by using a convolutional neural network. The outcomes of this study not only provide two BC-based bandages as multifunctional wound management, but also demonstrate a new strategy for the development of the next generation of smart bandage.

NMR analysis of the side-group substituents in welan gum in comparison to gellan gum

The physicochemical properties and applications of polysaccharides are highly dependent on their chemical structures, including the monosaccharide composition, degree of substitution, and position of substituent groups in the backbone. The occurrence of side groups or side chains in the chain backbone of polysaccharides is often an essential factor influencing their conformational and physicochemical properties. Welan gum produced by the fermentation of Sphingomonas sp. ATCC 31555 microorganisms has been widely used in food, construction, and oil drilling fields. While understanding the physicochemical properties of welan gum solution has been highly developed, there is still little information about the determination strategy of the glycosyl side groups in welan gum. In this study, the NMR method was established to quantitatively determine the substituent groups in the chain backbone of welan gum. The delicate chemical structures of welan gum obtained at different fermentation conditions were clarified. The composition and content of side substituents were also identified by high-performance liquid chromatography to confirm the accuracy of NMR analysis. The quantitative determination of substituent groups in gellan gum based on NMR analysis was also elaborated for comparison. This work provides insights for profoundly understanding the structure-function relationship of welan gum.

Controllable and biocompatible 3D bioprinting technology for microorganisms: Fundamental, environmental applications and challenges

3D bioprinting is a new 3D manufacturing technology, that can be used to accurately distribute and load microorganisms to form microbial active materials with multiple complex functions. Based on the 3D printing of human cells in tissue engineering, 3D bioprinting technology has been developed. Although 3D bioprinting technology is still immature, it shows great potential in the environmental field. Due to the precise programming control and multi-printing pathway, 3D bioprinting technology provides a high-throughput method based on micron-level patterning for a wide range of environmental microbiological engineering applications, which makes it an on-demand, multi-functional manufacturing technology. To date, 3D bioprinting technology has been employed in microbial fuel cells, biofilm material preparation, microbial catalysts and 4D bioprinting with time dimension functions. Nevertheless, current 3D bioprinting technology faces technical challenges in improving the mechanical properties of materials, developing specific bioinks to adapt to different strains, and exploring 4D bioprinting for intelligent applications. Hence, this review systematically analyzes the basic technical principles of 3D bioprinting, bioinks materials and their applications in the environmental field, and proposes the challenges and future prospects of 3D bioprinting in the environmental field. Combined with the current development of microbial enhancement technology in the environmental field, 3D bioprinting will be developed into an enabling platform for multifunctional microorganisms and facilitate greater control of in situ directional reactions.

Production of Bacterial Exopolysaccharides: Xanthan and Bacterial Cellulose

Recently, degradable biopolymers have become increasingly important as potential environmentally friendly biomaterials, providing a wide range of applications in various fields. Bacterial exopolysaccharides (EPSs) are biomacromolecules, which due to their unique properties have found applications in biomedicine, foodstuff, textiles, cosmetics, petroleum, pharmaceuticals, nanoelectronics, and environmental remediation. One of the important commercial polysaccharides produced on an industrial scale is xanthan. In recent years, the range of its application has expanded significantly. Bacterial cellulose (BC) is another unique EPS with a rapidly increasing range of applications. Due to the great prospects for their practical application, the development of their highly efficient production remains an important task. The present review summarizes the strategies for the cost-effective production of such important biomacromolecules as xanthan and BC and demonstrates for the first time common approaches to their efficient production and to obtaining new functional materials for a wide range of applications, including wound healing, drug delivery, tissue engineering, environmental remediation, nanoelectronics, and 3D bioprinting. In the end, we discuss present limitations of xanthan and BC production and the line of future research.

Polysaccharide-based antibacterial coating technologies

To tackle antimicrobial resistance, a global threat identified by the United Nations, is a common cause of healthcare-associated infections (HAI) and is responsible for significant costs on healthcare systems, a substantial amount of research has been devoted to developing polysaccharide-based strategies that prevent bacterial attachment and biofilm formation on surfaces. Polysaccharides are essential building blocks for life and an abundant renewable resource that have attracted much attention due to their intrinsic remarkable biological potential antibacterial activities. If converted into efficient antibacterial coatings that could be applied to a broad range of surfaces and applications, polysaccharide-based coatings could have a significant potential global impact. However, the ultimate success of polysaccharide-based antibacterial materials will be determined by their potential for use in manufacturing processes that are scalable, versatile, and affordable. Therefore, in this review we focus on recent advances in polysaccharide-based antibacterial coatings from the perspective of fabrication methods. We first provide an overview of strategies for designing polysaccharide-based antimicrobial formulations and methods to assess the antibacterial properties of coatings. Recent advances on manufacturing polysaccharide-based coatings using some of the most common polysaccharides and fabrication methods are then detailed, followed by a critical comparative overview of associated challenges and opportunities for future developments. STATEMENT OF SIGNIFICANCE: Our review presents a timely perspective by being the first review in the field to focus on advances on polysaccharide-based antibacterial coatings from the perspective of fabrication methods along with an overview of strategies for designing polysaccharide-based antimicrobial formulations, methods to assess the antibacterial properties of coatings as well as a critical comparative overview of associated challenges and opportunities for future developments. Meanwhile this work is specifically targeted at an audience focused on featuring critical information and guidelines for developing polysaccharide-based coatings. Including such a complementary work in the journal could lead to further developments on polysaccharide antibacterial applications.

Polysaccharide-based biomaterials in a journey from 3D to 4D printing

3D printing is a state-of-the-art technology for the fabrication of biomaterials with myriad applications in translational medicine. After stimuli-responsive properties were introduced to 3D printing (known as 4D printing), intelligent biomaterials with shape configuration time-dependent character have been developed. Polysaccharides are biodegradable polymers sensitive to several physical, chemical, and biological stimuli, suited for 3D and 4D printing. On the other hand, engineering of mechanical strength and printability of polysaccharide-based scaffolds along with their aneural, avascular, and poor metabolic characteristics need to be optimized varying printing parameters. Multiple disciplines such as biomedicine, chemistry, materials, and computer sciences should be integrated to achieve multipurpose printable biomaterials. In this work, 3D and 4D printing technologies are briefly compared, summarizing the literature on biomaterials engineering though printing techniques, and highlighting different challenges associated with 3D/4D printing, as well as the role of polysaccharides in the technological shift from 3D to 4D printing for translational medicine.

Bacterial cellulose: Biopolymer with novel medical applications

Due to the growing importance of green chemistry, the search for alternatives to cellulose has begun, leading to the rediscovery of bacterial cellulose (BC). The material is produced by Gluconacetobacter and Acetobacter bacteria, mainly Komagataeibacter xylinus. It is a pure biopolymer, without lignin or hemicellulose, forming a three-dimensional mesh, showing much lower organization than its plant counterpart. Thanks to its design, it has proven itself in completely unprecedented applications - especially in the field of biomedical sciences. Coming in countless forms, it has found use in applications such as wound dressings, drug delivery systems, or tissue engineering. The review article focuses on discussing the main structural differences between plant and bacterial cellulose, methods of bacterial cellulose synthesis, and the latest trends in BC applications in biomedical sciences.

Development of a bioink using exopolysaccharide from Rhizobium sp. PRIM17

Biopolymers play a significant role in tissue engineering, including in the formulation of bioinks that require careful selection of the biopolymers having properties ideal for printability and supporting biological entities such as cells. Alginate is one of the most widely explored natural biopolymers for tissue engineering applications due to its biocompatibility, cross-linking ability, hydrophilic nature, and easy incorporation with other polymers. Here, a succinoglycan-like exopolysaccharide (EPS-R17) produced by a bacterial strain Rhizobium sp. PRIM17 was incorporated with alginate for the development of a bioink. The physicochemical characterization of EPS-R17 was performed before formulating the bioink with alginate. The bioink formulation was prepared by mixing different concentrations of EPS with an alginate solution at room temperature under sterile atmosphere. The prepared bioink was characterized for rheological properties, biocompatibility, and a bioplotting experiment was also conducted to mimick the extrusion bioprinting. The EPS-R17 was composed of glucose, galactose, and rhamnose with a molecular weight of 69.98 kDa. It was thermally stable up to 260 °C and showed characteristic FT-IR peaks (1723.3 cm^-1) for succinyl groups. The EPS-R17 showed biocompatibility with keratinocytes (HaCaT), and fibroblasts (HDF) in vitro. The rheological properties of EPS-R17-alginate bioink at different combinations showed shear thinning behavior at 25 and 37 °C. Amplitude sweep measurements showed the gel-like nature of the polymer combinations in the solution system superior to alginate or EPS-R17 alone. The combination of 1 % EPS-R17 and 1.5 % alginate showed good compressive strength and swelling behavior. Extrusion bioprinting mimicked using a bioplotting experiment showed the sustained cell viability in the polymer matrix of EPS-R17-alginate bioink. The results indicate that the EPS-R17 can be used in combination with alginate for bioinks for bioprinting applications for providing physical properties and favorable bioactivities.

Biobased Nanomaterials─The Role of Interfacial Interactions for Advanced Materials

This review presents recent advances regarding biomass-based nanomaterials, focusing on their surface interactions. Plant biomass-based nanoparticles, like nanocellulose and lignin from industry side streams, hold great potential for the development of lightweight, functional, biodegradable, or recyclable material solutions for a sustainable circular bioeconomy. However, to obtain optimal properties of the nanoparticles and materials made thereof, it is crucial to control the interactions both during particle production and in applications. Herein we focus on the current understanding of these interactions. Solvent interactions during particle formation and production, as well as interactions with water, polymers, cells and other components in applications, are addressed. We concentrate on cellulose and lignin nanomaterials and their combination. We demonstrate how the surface chemistry of the nanomaterials affects these interactions and how excellent performance is only achieved when the interactions are controlled. We furthermore introduce suitable methods for probing interactions with nanomaterials, describe their advantages and challenges, and introduce some less commonly used methods and discuss their possible applications to gain a deeper understanding of the interfacial chemistry of biobased nanomaterials. Finally, some gaps in current understanding and interesting emerging research lines are identified.

Past, present and future of biomedical applications of dextran-based hydrogels: A review

This review extensively surveys the biomedical applications of hydrogels containing dextran. Dextran has gained much attention as a biomaterial due to its distinctive properties such as biocompatibility, non-toxicity, water solubility and biodegradability. It has emerged as a critical constituent of hydrogels for biomedical applications including drug delivery devices, tissue engineering scaffolds and biosensor materials. The benefits, challenges and potential prospects of dextran-based hydrogels as biomaterials are highlighted in this review.

Self-Adaptive Antibacterial Scaffold with Programmed Delivery of Osteogenic Peptide and Lysozyme for Infected Bone Defect Treatment

Bone defects caused by disease or trauma are often accompanied by infection, which severely disrupts the normal function of bone tissue at the defect site. Biomaterials that can simultaneously reduce inflammation and promote osteogenesis are effective tools for addressing this problem. In this study, we set up a programmed delivery platform based on a chitosan scaffold to enhance its osteogenic activity and prevent implant-related infections. In brief, the osteogenic peptide sequence (YGFGG) was modified onto the surface of cowpea chlorotic mottle virus (CCMV) to form CCMV-YGFGG nanoparticles. CCMV-YGFGG exhibited good biocompatibility and osteogenic ability in vitro. Then, CCMV-YGFGG and lysozyme were loaded on the chitosan scaffold, which exhibited a good antibacterial effect and promoted bone regeneration for infected bone defect treatment. As a delivery platform, the scaffold showed staged release of lysozyme and CCMV-YGFGG, which facilitates the regeneration of infected bone defects. Our study provides a novel and promising strategy for the treatment of infected bone defects.

Scaffolds in the microbial resistant era: Fabrication, materials, properties and tissue engineering applications

Due to microbial infections dramatically affect cell survival and increase the risk of implant failure, scaffolds produced with antimicrobial materials are now much more likely to be successful. Multidrug-resistant infections without suitable prevention strategies are increasing at an alarming rate. The ability of cells to organize, develop, differentiate, produce a functioning extracellular matrix (ECM) and create new functional tissue can all be controlled by careful control of the extracellular microenvironment. This review covers the present state of advanced strategies to develop scaffolds with antimicrobial properties for bone, oral tissue, skin, muscle, nerve, trachea, cardiac and other tissue engineering applications. The review focuses on the development of antimicrobial scaffolds against bacteria and fungi using a wide range of materials, including polymers, biopolymers, glass, ceramics and antimicrobials agents such as antibiotics, antiseptics, antimicrobial polymers, peptides, metals, carbon nanomaterials, combinatorial strategies, and includes discussions on the antimicrobial mechanisms involved in these antimicrobial approaches. The toxicological aspects of these advanced scaffolds are also analyzed to ensure future technological transfer to clinics. The main antimicrobial methods of characterizing scaffolds’ antimicrobial and antibiofilm properties are described. The production methods of these porous supports, such as electrospinning, phase separation, gas foaming, the porogen method, polymerization in solution, fiber mesh coating, self-assembly, membrane lamination, freeze drying, 3D printing and bioprinting, among others, are also included in this article. These important advances in antimicrobial materials-based scaffolds for regenerative medicine offer many new promising avenues to the material design and tissue-engineering communities.

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Antibacterial, antifungal and antibiofilm scaffolds.

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Antimicrobial scaffold fabrication techniques.

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Antimicrobial biomaterials for tissue engineering applications.

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Antimicrobial characterization methods of scaffolds.

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Bone, oral tissue, skin, muscle, nerve, trachea, cardiac, among other applications.

From Classical to Advanced Use of Polymers in Food and Beverage Applications

Polymers are extensively used in food and beverage packaging to shield against contaminants and external damage due to their barrier properties, protecting the goods inside and reducing waste. However, current trends in polymers for food, water, and beverage applications are moving forward into the design and preparation of advanced polymers, which can act as active packaging, bearing active ingredients in their formulation, or controlling the head-space composition to extend the shelf-life of the goods inside. In addition, polymers can serve as sensory polymers to detect and indicate the presence of target species, including contaminants of food quality indicators, or even to remove or separate target species for later quantification. Polymers are nowadays essential materials for both food safety and the extension of food shelf-life, which are key goals of the food industry, and the irruption of smart materials is opening new opportunities for going even further in these goals. This review describes the state of the art following the last 10 years of research within the field of food and beverage polymer's applications, covering present applications, perspectives, and concerns related to waste generation and the circular economy.

Preparation of 3D Printed Polylactic Acid/Bacterial Cellulose Composite Scaffold for Tissue Engineering Applications

Bacterial cellulose (BC) has become a universal biomaterial owing to its intrinsic properties. BC fibers are composed of microfibers with a diameter of 3-4 nm into fiber bundles with a thickness of 40-60 nm, and interweave with each other to form a well-developed ultra-fine network structure. Polylactic acid (PLA) has good mechanical properties and excellent biocompatibility and biodegradability. Therefore, PLA has been widely applied in tissue engineering. Addressed herein is a novel type of PLA/BC (PLA/BC) composite scaffold prepared by 3D printing (3D), 3D modeling of the required porous membrane material support established in the computer, and decomposition of the model into 5 layer 20 μM sheets. The range of PLA loadings assessed in this work was 1.0 wt.%, 1.5 wt.%, and 2.0 wt.%, and its physicochemical properties and biological properties were characterized and evaluated. Tensile strength of PLA/BC composite scaffolds increased to 66.49 MPa compared to that of a pure BC film (25.61 MPa). Hydrophilicity was tunable with the amount of added PLA. In this paper, the effects of 3D round hole and stripe surface topology on cell growth behavior were characterized. Schwann cells (SCs) adhered to the surface of the 3D composite membrane successfully, and their proliferation rate on the surface of the regular circular pore and stripe structure was better than that of the smooth surface. Erythrocyte fixation and platelet adhesion experiments showed that the 3D composite scaffold had excellent blood compatibility. Further degradation studies showed that loose structures appeared after 1 week, and structural defects began after 3 weeks. The in vitro degradation results showed that the degradation rate of the BC membrane in simulated body fluid after 6 weeks was 14.38%, while the degradation rate of the PLA/BC composite scaffold was 18.75%.

Properties and Hydrolysis Behavior of Celluloses of Different Origin

The present paper is a fundamental study on the physicochemical properties and hydrolysis behavior of cellulose samples differing in origin: bacterial, synthetic, and vegetal. Bacterial cellulose was produced by Medusomyces gisevii Sa-12 in an enzymatic hydrolyzate derived from oat-hull pulp. Synthetic cellulose was obtained from an aqueous glucose solution by electropolymerization. Plant-based cellulose was isolated by treatment of Miscanthus sacchariflorus with dilute NaOH and HNO₃ solutions. We explored different properties of cellulose samples, such as chemical composition, degree of polymerization (DP), degree of crystallinity (DC), porosity, and reported infrared spectroscopy and scanning electron microscopy results. The hydrolysis behavior was most notable dependent on the origin of cellulose. For the bacterial cellulose sample (2010 DP, 90% DC, 89.4% RS yield), the major property affecting the hydrolysis behavior was its unique nanoscale reticulate structure promoting fast penetration of cellulases into the substrate structure. The study on enzymatic hydrolysis showed that the hydrolysis behavior of synthetic and Miscanthus celluloses was most influenced by the substrate properties such as DP, DC and morphological structure. The yield of reducing sugars (RS) by hydrolysis of synthetic cellulose exhibiting a 3140 DP, 80% DC, and highly depolymerization-resistant fibers was 27%. In contrast, the hydrolysis of Miscanthus-derived cellulose with a 1030 DP, 68% DC, and enzyme-accessible fibers provided the highest RS yield of 90%. The other properties examined herein (absence/presence of non-cellulosic impurities, specific surface, pore volume) had no considerable effect on the bioconversion of the cellulosic substrates.

Cost-Effective Synthesis of Bacterial Cellulose and Its Applications in the Food and Environmental Sectors

Bacterial cellulose (BC), also termed bio-cellulose, has been recognized as a biomaterial of vital importance, thanks to its impressive structural features, diverse synthesis routes, high thermomechanical properties, and its ability to combine with multiple additives to form composites for a wide range of applications in diversified areas. Its purity, nontoxicity, and better physico-mechanical features than plant cellulose (PC) make it a better choice for biological applications. However, a major issue with the use of BC instead of PC for various applications is its high production costs, mainly caused by the use of expensive components in the chemically defined media, such as Hestrin–Schramm (HS) medium. Furthermore, the low yield of BC-producing bacteria indirectly accounts for the high cost of BC-based products. Over the last couple of decades, extensive efforts have been devoted to the exploration of low-cost carbon sources for BC production, besides identifying efficient bacterial strains as well as developing engineered strains, developing advanced reactors, and optimizing the culturing conditions for the high yield and productivity of BC, with the aim to minimize its production cost. Considering the applications, BC has attracted attention in highly diversified areas, such as medical, pharmaceutics, textile, cosmetics, food, environmental, and industrial sectors. This review is focused on overviewing the cost-effective synthesis routes for BC production, along with its noteworthy applications in the food and environmental sectors. We have made a comprehensive review of recent papers regarding the cost-effective production and applications of BC in the food and environmental sectors. This review provides the basic knowledge and understanding for cost-effective and scaleup of BC production by discussing the techno-economic analysis of BC production, BC market, and commercialization of BC products. It explores BC applications as food additives as its functionalization to minimize different environmental hazards, such as air contaminants and water pollutants.

Advances in 3D Gel Printing for Enzyme Immobilization

Incorporating enzymes with three-dimensional (3D) printing is an exciting new field of convergence research that holds infinite potential for creating highly customizable components with diverse and efficient biocatalytic properties. Enzymes, nature’s nanoscale protein-based catalysts, perform crucial functions in biological systems and play increasingly important roles in modern chemical processing methods, cascade reactions, and sensor technologies. Immobilizing enzymes on solid carriers facilitates their recovery and reuse, improves stability and longevity, broadens applicability, and reduces overall processing and chemical conversion costs. Three-dimensional printing offers extraordinary flexibility for creating high-resolution complex structures that enable completely new reactor designs with versatile sub-micron functional features in macroscale objects. Immobilizing enzymes on or in 3D printed structures makes it possible to precisely control their spatial location for the optimal catalytic reaction. Combining the rapid advances in these two technologies is leading to completely new levels of control and precision in fabricating immobilized enzyme catalysts. The goal of this review is to promote further research by providing a critical discussion of 3D printed enzyme immobilization methods encompassing both post-printing immobilization and immobilization by physical entrapment during 3D printing. Especially, 3D printed gel matrix techniques offer mild single-step entrapment mechanisms that produce ideal environments for enzymes with high retention of catalytic function and unparalleled fabrication control. Examples from the literature, comparisons of the benefits and challenges of different combinations of the two technologies, novel approaches employed to enhance printed hydrogel physical properties, and an outlook on future directions are included to provide inspiration and insights for pursuing work in this promising field.

A Synthetic Gene Library Yields a Previously Unknown Glycoside Phosphorylase That Degrades and Assembles Poly-β-1,3-GlcNAc, Completing the Suite of β-Linked GlcNAc Polysaccharides

The considerable utility of glycoside phosphorylases (GPs) has led to substantial efforts over the past two decades to expand the breadth of known GP activities. Driven largely by the increase of available genomic DNA sequence data, the gap between the number of sequences in the carbohydrate active enzyme database (CAZy DB) and its functionally characterized members continues to grow. This wealth of sequence data presented an exciting opportunity to explore the ever-expanding CAZy DB to discover new GPs with never-before-described functionalities. Utilizing an in silico sequence analysis of CAZy family GH94, we discovered and then functionally and structurally characterized the new GP β-1,3-N-acetylglucosaminide phosphorylase. This new GP was sourced from the genome of the cell-wall-less Mollicute bacterium, Acholeplasma laidlawii and was found to synthesize β-1,3-linked N-acetylglucosaminide linkages. The resulting poly-β-1,3-N-acetylglucosamine represents a new, previously undescribed biopolymer that completes the set of possible β-linked GlcNAc homopolysaccharides together with chitin (β-1,4) and PNAG (poly-β-1,6-N-acetylglucosamine). The new biopolymer was denoted acholetin, a combination of the genus Acholeplasma and the polysaccharide chitin, and the new GP was thus denoted acholetin phosphorylase (AchP). Use of the reverse phosphorolysis action of AchP provides an efficient method to enzymatically synthesize acholetin, which is a new biodegradable polymeric material.

Bacterial cellulose as a potential biopolymer in biomedical applications: a state-of-the-art review

Throughout history, natural biomaterials have benefited society. Nevertheless, in recent years, tailoring natural materials for diverse biomedical applications accompanied with sustainability has become the focus. With the progress in the field of materials science, novel approaches for the production, processing, and functionalization of biomaterials to obtain specific architectures have become achievable. This review highlights an immensely adaptable natural biomaterial, bacterial cellulose (BC). BC is an emerging sustainable biopolymer with immense potential in the biomedical field due to its unique physical properties such as flexibility, high porosity, good water holding capacity, and small size; chemical properties such as high crystallinity, foldability, high purity, high polymerization degree, and easy modification; and biological characteristics such as biodegradability, biocompatibility, excellent biological affinity, and non-biotoxicity. The structure of BC consists of glucose monomer units polymerized via cellulose synthase in β-1-4 glucan chains, creating BC nano fibrillar bundles with a uniaxial orientation. BC-based composites have been extensively investigated for diverse biomedical applications due to their similarity to the extracellular matrix structure. The recent progress in nanotechnology allows the further modification of BC, producing novel BC-based biomaterials for various applications. In this review, we strengthen the existing knowledge on the production of BC and BC composites and their unique properties, and highlight the most recent advances, focusing mainly on the delivery of active pharmaceutical compounds, tissue engineering, and wound healing. Further, we endeavor to present the challenges and prospects for BC-associated composites for their application in the biomedical field.

Fabrication strategies and biomedical applications of three-dimensional bacterial cellulose-based scaffolds: A review

Bacterial cellulose (BC), an extracellular polysaccharide, is a versatile biopolymer due to its intrinsic physicochemical properties, broad-spectrum applications, and remarkable achievements in different fields, especially in the biomedical field. Presently, the focus of BC-related research is on the development of scaffolds containing other materials for in-vitro and in-vivo biomedical applications. To this end, prime research objectives concern the biocompatibility of BC and the development of three-dimensional (3D) BC-based scaffolds. This review summarizes the techniques used to develop 3D BC scaffolds and discusses their potential merits and limitations. In addition, we discuss the various biomedical applications of BC-based scaffolds for which the 3D BC matrix confers desired structural and conformational features. Overall, this review provides comprehensive coverage of the idea, requirements, synthetic strategies, and current and prospective applications of 3D BC scaffolds, and thus, should be useful for researchers working with polysaccharides, biopolymers, or composite materials.

Nanomaterials for application in wound Healing: current state-of-the-art and future perspectives

Nanoparticles are the gateway to the new era in drug delivery of biocompatible agents. Several products have emerged from nanomaterials in quest of developing practical wound healing dressings that are nonantigenic, antishear stress, and gas-exchange permeable. Numerous studies have isolated and characterised various wound healing nanomaterials and nanoproducts. The electrospinning of natural and synthetic materials produces fine products that can be mixed with other wound healing medications and herbs. Various produced nanomaterials are highly influential in wound healing experimental models and can be used commercially as well. This article reviewed the current state-of-the-art and briefly specified the future concerns regarding the different systems of nanomaterials in wound healing (i.e., inorganic nanomaterials, organic and hybrid nanomaterials, and nanofibers). This review may be a comprehensive guidance to help health care professionals identify the proper wound healing materials to avoid the usual wound complications.

Rational integration of defense and repair synergy on PEEK osteoimplants via biomimetic peptide clicking strategy

Polyetheretherketone (PEEK) has been widely used as orthopedic and dental materials due to excellent mechanical and physicochemical tolerance. However, its biological inertness, poor osteoinduction, and weak antibacterial activity make the clinical applications in a dilemma. Inspired by the mussel adhesion mechanism, here we reported a biomimetic surface strategy for rational integration and optimization of anti-infectivity and osteo-inductivity onto PEEK surfaces using a mussel foot proteins (Mfps)-mimic peptide with clickable azido terminal. The peptide enables mussel-like adhesion on PEEK biomaterial surfaces, leaving azido groups for the further steps of biofunctionalizations. In this study, antimicrobial peptide (AMP) and osteogenic growth peptide (OGP) were bioorthogonally clicked on the azido-modified PEEK biomaterials to obtain a dual-effect of host defense and tissue repair. Since bioorthogonal clicking allows precise collocation between AMP and OGP through changing their feeding molar ratios, an optimal PEEK surface was finally obtained in this research, which could long-term inhibit bacterial growth, stabilize bone homeostasis and facilitate interfacial bone regeneration. In a word, this upgraded mussel surface strategy proposed in this study is promising for the surface bioengineering of inert medical implants, in particular, achieving rational integration of multiple biofunctions to match clinical requirements.

Surface Modification of Bacterial Cellulose for Biomedical Applications

Bacterial cellulose is a naturally occurring polysaccharide with numerous biomedical applications that range from drug delivery platforms to tissue engineering strategies. BC possesses remarkable biocompatibility, microstructure, and mechanical properties that resemble native human tissues, making it suitable for the replacement of damaged or injured tissues. In this review, we will discuss the structure and mechanical properties of the BC and summarize the techniques used to characterize these properties. We will also discuss the functionalization of BC to yield nanocomposites and the surface modification of BC by plasma and irradiation-based methods to fabricate materials with improved functionalities such as bactericidal capabilities.

The Application Status of Nanoscale Cellulose-Based Hydrogels in Tissue Engineering and Regenerative Biomedicine

As a renewable, biodegradable, and non-toxic material with moderate mechanical and thermal properties, nanocellulose-based hydrogels are receiving immense consideration for various biomedical applications. With the unique properties of excellent skeletal structure (hydrophilic functional groups) and micro-nano size (small size effect), nanocellulose can maintain the three-dimensional structure of the hydrogel to a large extent, providing mechanical strength while ensuring the moisture content. Owing to its unique features, nanocellulose-based hydrogels have made excellent progress in research and development on tissue engineering, drug carriers, wound dressings, development of synthetic organs, 3D printing, and biosensing. This review provides an overview of the synthesis of different types of nanocellulose, including cellulose nanocrystals, cellulose nanofibers, and bacterial nanocellulose, and describes their unique features. It further provides an updated knowledge of the development of nanocellulose-based functional biomaterials for various biomedical applications. Finally, it discusses the future perspective of nanocellulose-based research for its advanced biomedical applications.

Recent Advancements in Microbial Polysaccharides: Synthesis and Applications

Polysaccharide materials are widely applied in different applications including food, food packaging, drug delivery, tissue engineering, wound dressing, wastewater treatment, and bioremediation sectors. They were used in these domains due to their efficient, cost-effective, non-toxicity, biocompatibility, and biodegradability. As is known, polysaccharides can be synthesized by different simple, facile, and effective methods. Of these polysaccharides are cellulose, Arabic gum, sodium alginate, chitosan, chitin, curdlan, dextran, pectin, xanthan, pullulan, and so on. In this current article review, we focused on discussing the synthesis and potential applications of microbial polysaccharides. The biosynthesis of polysaccharides from microbial sources has been considered. Moreover, the utilization of molecular biology tools to modify the structure of polysaccharides has been covered. Such polysaccharides provide potential characteristics to transfer toxic compounds and decrease their resilience to the soil. Genetically modified microorganisms not only improve yield of polysaccharides, but also allow economically efficient production. With the rapid advancement of science and medicine, biosynthesis of polysaccharides research has become increasingly important. Synthetic biology approaches can play a critical role in developing polysaccharides in simple and facile ways. In addition, potential applications of microbial polysaccharides in different fields with a particular focus on food applications have been assessed.

Clay Minerals as Bioink Ingredients for 3D Printing and 3D Bioprinting: Application in Tissue Engineering and Regenerative Medicine

The adaptation and progress of 3D printing technology toward 3D bioprinting (specifically adapted to biomedical purposes) has opened the door to a world of new opportunities and possibilities in tissue engineering and regenerative medicine. In this regard, 3D bioprinting allows for the production of tailor-made constructs and organs as well as the production of custom implants and medical devices. As it is a growing field of study, currently, the attention is heeded on the optimization and improvement of the mechanical and biological properties of the so-called bioinks/biomaterial inks. One of the strategies proposed is the use of inorganic ingredients (clays, hydroxyapatite, graphene, carbon nanotubes and other silicate nanoparticles). Clays have proven to be useful as rheological and mechanical reinforcement in a wide range of fields, from the building industry to pharmacy. Moreover, they are naturally occurring materials with recognized biocompatibility and bioactivity, revealing them as optimal candidates for this cutting-edge technology. This review deals with the use of clays (both natural and synthetic) for tissue engineering and regenerative medicine through 3D printing and bioprinting. Despite the limited number of studies, it is possible to conclude that clays play a fundamental role in the formulation and optimization of bioinks and biomaterial inks since they are able to improve their rheology and mechanical properties, thus improving printability and construct resistance. Additionally, they have also proven to be exceptionally functional ingredients (enhancing cellular proliferation, adhesion, differentiation and alignment), controlling biodegradation and carrying/releasing actives with tissue regeneration therapeutic activities.

Efficacy of Bacterial Nanocellulose in Hard Tissue Regeneration: A Review

Bacterial nanocellulose (BNC, as exopolysaccharide) synthesized by some specific bacteria strains is a fascinating biopolymer composed of the three-dimensional pure cellulosic nanofibrous matrix without containing lignin, hemicellulose, pectin, and other impurities as in plant-based cellulose. Due to its excellent biocompatibility (in vitro and in vivo), high water-holding capacity, flexibility, high mechanical properties, and a large number of hydroxyl groups that are most similar characteristics of native tissues, BNC has shown great potential in tissue engineering applications. This review focuses on and discusses the efficacy of BNC- or BNC-based biomaterials for hard tissue regeneration. In this review, we provide brief information on the key aspects of synthesis and properties of BNC, including solubility, biodegradability, thermal stability, antimicrobial ability, toxicity, and cellular response. Further, modification approaches are discussed briefly to improve the properties of BNC or BNC-based structures. In addition, various biomaterials by using BNC (as sacrificial template or matrix) or BNC in conjugation with polymers and/or fillers are reviewed and discussed for dental and bone tissue engineering applications. Moreover, the conclusion with perspective for future research directions of using BNC for hard tissue regeneration is briefly discussed.

Development and Characterization of Yeast-Incorporated Antimicrobial Cellulose Biofilms for Edible Food Packaging Application

The unique properties and advantages of edible films over conventional food packaging have led the way to their extensive exploration in recent years. Moreover, the incorporation of bioactive components during their production has further enhanced the intrinsic features of packaging materials. This study was aimed to develop edible and bioactive food packaging films comprising yeast incorporated into bacterial cellulose (BC) in conjunction with carboxymethyl cellulose (CMC) and glycerol (Gly) to extend the shelf life of packaged food materials. First, yeast biomass and BC hydrogels were produced by Meyerozyma guilliermondii (MT502203.1) and Gluconacetobacter xylinus (ATCC53582), respectively, and then the films were developed ex situ by mixing 30 wt.% CMC, 30 wt.% Gly, 2 wt.% yeast dry biomass, and 2 wt.% BC slurry. FE-SEM observation showed the successful incorporation of Gly and yeast into the fibrous cellulose matrix. FTIR spectroscopy confirmed the development of composite films through chemical interaction between BC, CMC, Gly, and yeast. The developed BC/CMC/Gly/yeast composite films showed high water solubility (42.86%). The yeast-incorporated films showed antimicrobial activities against three microbial strains, including Escherichia coli, Pseudomonas aeruginosa, and Saccharomyces aureus, by producing clear inhibition zones of 16 mm, 10 mm, and 15 mm, respectively, after 24 h. Moreover, the films were non-toxic against NIH-3T3 fibroblast cells. Finally, the coating of oranges and tomatoes with BC/CMC/Gly/yeast composites enhanced the shelf life at different storage temperatures. The BC/CMC/Gly/yeast composite film-coated oranges and tomatoes demonstrated acceptable sensory features such as odor and color, not only at 6 °C but also at room temperature and further elevated temperatures at 30 °C and 40 °C for up to two weeks. The findings of this study indicate that the developed BC/CMC/Gly/yeast composite films could be used as edible packaging material with high nutritional value and distinctive properties related to the film component, which would provide protection to foods and extend their shelf life, and thus could find applications in the food industry.

Toward Fabrication of Bioactive Papers: Covalent Immobilization of Peptides and Proteins

Herein, we report a novel two-step method for the covalent, site-directed, and efficient immobilization of proteins on lab-made paper sheets. First, paper fibers were modified with a peptidic anchor comprising enzyme recognition motifs. Four different conjugation strategies for peptide immobilization were evaluated with respect to reproducibility and fiber loading efficiency. After manufacturing of the peptide-preconditioned paper, oriented conjugation of the model protein tGFP containing a C-terminal recognition sequence for either sortase A or microbial transglutaminase was assessed semiquantitatively by fluorescence measurement and inspected by confocal laser scanning microscopy (CLSM). The two enzymes utilized for protein conjugation used the same oligoglycine peptide anchor, and both proved to be suitable for controlled oriented linkage of substrate proteins at physiological conditions.

Embracing Additive Manufacturing Technology through Fused Filament Fabrication for Antimicrobial with Enhanced Formulated Materials

Antimicrobial materials produced by 3D Printing technology are very beneficial, especially for biomedical applications. Antimicrobial surfaces specifically with enhanced antibacterial property have been prepared using several quaternary salt-based agents, such as quaternary ammonium salts and metallic nanoparticles (NPs), such as copper and zinc, which are incorporated into a polymeric matrix mainly through copolymerization grafting and ionic exchange. This review compared different materials for their effectiveness in providing antimicrobial properties on surfaces. This study will help researchers choose the most suitable method of developing antimicrobial surfaces with the highest efficiency, which can be applied to develop products compatible with 3D Printing Technology.

Perspective Applications and Associated Challenges of Using Nanocellulose in Treating Bone-Related Diseases

Bone serves to maintain the shape of the human body due to its hard and solid nature. A loss or weakening of bone tissues, such as in case of traumatic injury, diseases (e.g., osteosarcoma), or old age, adversely affects the individuals quality of life. Although bone has the innate ability to remodel and regenerate in case of small damage or a crack, a loss of a large volume of bone in case of a traumatic injury requires the restoration of bone function by adopting different biophysical approaches and chemotherapies as well as a surgical reconstruction. Compared to the biophysical and chemotherapeutic approaches, which may cause complications and bear side effects, the surgical reconstruction involves the implantation of external materials such as ceramics, metals, and different other materials as bone substitutes. Compared to the synthetic substitutes, the use of biomaterials could be an ideal choice for bone regeneration owing to their renewability, non-toxicity, and non-immunogenicity. Among the different types of biomaterials, nanocellulose-based materials are receiving tremendous attention in the medical field during recent years, which are used for scaffolding as well as regeneration. Nanocellulose not only serves as the matrix for the deposition of bioceramics, metallic nanoparticles, polymers, and different other materials to develop bone substitutes but also serves as the drug carrier for treating osteosarcomas. This review describes the natural sources and production of nanocellulose and discusses its important properties to justify its suitability in developing scaffolds for bone and cartilage regeneration and serve as the matrix for reinforcement of different materials and as a drug carrier for treating osteosarcomas. It discusses the potential health risks, immunogenicity, and biodegradation of nanocellulose in the human body.

Challenges and opportunities for the biodegradation of chlorophenols: Aerobic, anaerobic and bioelectrochemical processes

Chlorophenols (CPs) are highly toxic and refractory contaminants which widely exist in various environments and cause serious harm to human and environment health and safety. This review provides comprehensive information on typical CPs biodegradation technologies, the most green and benign ones for CPs removal. The known aerobic and anaerobic degradative bacteria, functional enzymes, and metabolic pathways of CPs as well as several improving methods and critical parameters affecting the overall degradation efficiency are systematically summarized and clarified. The challenges for CPs mineralization are also discussed, mainly including the dechlorination of polychlorophenols (poly-CPs) under aerobic condition and the ring-cleavage of monochlorophenols (MCPs) under anaerobic condition. The coupling of functional materials and degraders as well as the operation of sequential anaerobic-aerobic bioreactors and bioelectrochemical system (BES) are promising strategies to overcome some current limitations. Future perspective and research gaps in this field are also proposed, including the further understanding of microbial information and the specific role of materials in CPs biodegradation, the potential application of innovative biotechnologies and new operating modes to optimize and maximize the function of the system, and the scale-up of bioreactors towards the efficient biodegradation of CPs.

Ex situ Synthesis and Characterization of High Strength Multipurpose Bacterial Cellulose-Aloe vera Hydrogels

The innate structural and functional properties of bacterial cellulose (BC) have been greatly improved by developing its composites with other materials for its applications in different fields. In the present study, BC-Aloe vera (BCA) gel composite with high tensile strength was ex situ developed and characterized for its potential applications in environmental and medical fields. FE-SEM micrographs showed the impregnation of Aloe vera gel into the fibril network of BC. The dry weight analysis showed the addition of 40 wt.% Aloe vera contents into the BC matrix. The addition of Aloe vera resulted in a 3-fold increase in the mechanical strength of BCA composite. The critical strain or stress concentration points were accurately identified in the composite using a three-dimensional digital image correlation (3D-DIC) system. The BCA composite retained water for an extended period of up to 70 h. The BCA composite effectively adsorbed Cu, Co, Fe, and Zn metals. Moreover, the BCA composite supported the adhesion and proliferation of MC3T3-E1 cells. The findings of this study suggest that the developed BCA composite could find multipurpose applications in different fields.

Permeation of Silver Sulfadiazine Into TEMPO-Oxidized Bacterial Cellulose as an Antibacterial Agent

Surface oxidation of bacterial cellulose (BC) was done with the TEMPO-mediated oxidation mechanism system. After that, TEMPO-oxidized bacterial cellulose (TOBC) was impregnated with silver sulfadiazine (AgSD) to prepare nanocomposite membranes. Fourier transform infrared spectroscopy (FTIR) was carried out to determine the existence of aldehyde groups on BC nanofibers and X-ray diffraction (XRD) demonstrated the degree of crystallinity. FESEM analysis revealed the impregnation of AgSD nanoparticles at TOBC nanocomposites with the average diameter size ranging from 11 nm to 17.5 nm. The sample OBCS3 showed higher antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli by the disc diffusion method. The results showed AgSD content, dependent antibacterial activity against all tested bacteria, and degree of crystallinity increases with TOBC and AgSD. The main advantage of the applications of TEMPO-mediated oxidation to BC nanofibers is that the crystallinity of BC nanofibers is unchanged and increased after the oxidation. Also enhanced the reactivity of BC as it is one of the most promising method for cellulose fabrication and functionalization. We believe that the novel composite membrane could be a potential candidate for biomedical applications like wound dressing, BC scaffold, and tissue engineering.

3D printed hydrogels with oxidized cellulose nanofibers and silk fibroin for the proliferation of lung epithelial stem cells

A novel biomaterial ink consisting of regenerated silk fibroin (SF) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized bacterial cellulose (OBC) nanofibrils was developed for 3D printing lung tissue scaffold. Silk fibroin backbones were cross-linked using horseradish peroxide/H₂O₂ to form printed hydrogel scaffolds. OBC with a concentration of 7wt% increased the viscosity of inks during the printing process and further improved the shape fidelity of the scaffolds. Rheological measurements and image analyses were performed to evaluate inks printability and print shape fidelity. Three-dimensional construct with ten layers could be printed with ink of 1SF-2OBC (SF/OBC = 1/2, w/w). The composite hydrogel of 1SF-1OBC (SF/OBC = 1/1, w/w) printed at 25 °C exhibited a significantly improved compressive strength of 267 ± 13 kPa and a compressive stiffness of 325 ± 14 kPa at 30% strain, respectively. The optimized printing parameters for 1SF-1OBC were 0.3 bar of printing pressure, 45 mm/s of printing speed and 410 μm of nozzle diameter. Furthermore, OBC nanofibrils could be induced to align along the print lines over 60% degree of orientation, which were analyzed by SEM and X-ray diffraction. The orientation of OBC nanofibrils along print lines provided physical cues for guiding the orientation of lung epithelial stem cells, which maintained the ability to proliferate and kept epithelial phenotype after 7 days' culture. The 3D printed SF-OBC scaffolds are promising for applications in lung tissue engineering.