Preparation and properties of conductive bacterial cellulose-based graphene oxide-silver nanoparticles antibacterial dressing

Enhanced electrical conductivity and antibacterial properties of bacterial cellulose composite membrane decorated with hydroxypropyl-β-cyclodextrin/magnetic particle/alpha-lipoic acid/nano silver

The electrical conductivity and antibacterial properties are crucial characteristics for bacterial cellulose (BC) based membranes to be broadly applied in the field of wearable electronics. In the study, to achieve these aims, alpha-lipoic acid (LA) was utilized as anchoring groups and reducing agent, hydroxypropyl-β-cyclodextrin (HP-β-CD) capped magnetic particles (Fe3O4 NPs) and the in-situ formed silver nanoparticles (AgNPs) were sequentially incorporated into the BC matrix to fabricate BC based nanocomposite membranes (HP-β-CD/Fe3O4/LA@BC and HP-β-CD/Fe3O4/LA/Ag@BC). Fourier transform attenuated total reflectance infrared spectroscopy (FTIR-ATR) and field emission scanning electron microscopy (FE-SEM) analysis proved the dense networks were formed in the modified BC membranes. The HP-β-CD/Fe3O4/LA@BC possessed significantly enhanced mechanical strength and electrical conductivity. The electrical conductivity of HP-β-CD/Fe3O4/LA/Ag@BC was optimized at treatment temperature of 50 °C and treatment time of 2 h, and increased with the increase in concentration of silver ion, adsorption temperature, and adsorption time. Freezing treatment at the low temperature of -45 °C did not affect the electrical conductivity of modified membranes. Inhibition rate of 99.99 % against Staphylococcus aureus and Escherichia coli demonstrated the excellent antimicrobial properties of the HP-β-CD/Fe3O4/LA/Ag@BC membrane. This work offers an ecofriendly way for fabricating bacterial cellulose-based soft smart electronic materials with good antimicrobial effect.

Bacterial nanocelluloses as sustainable biomaterials for advanced wound healing and dressings

Wound healing remains a significant clinical challenge, calling for innovative approaches to expedite the recovery process and improve patient outcomes. Bacterial nanocelluloses (BNCs) have emerged as a promising solution in the field of wound healing and dressings due to their unique properties such as high crystallinity, mechanical strength, high purity, porosity, high water absorption capacity, biodegradability, biocompatibility, sustainability, and flexibility. BNC-based materials can be applied for the treatment of different types of wounds, from second-degree burns to skin tears, biopsy sites, and diabetic and ischemic wounds. BNC-based dressings have exceptional mechanical properties such as flexibility and strength, which ensure proper wound coverage and protection. The renewable nature, eco-friendly production process, longer lifespan, and potential for biodegradability of BNCs make them a more sustainable alternative to conventional wound care materials. This review aims to provide a detailed overview on the application of BNC-based composites for wound healing and dressings via highlighting their ability as a carrier for delivery of different types of antimicrobial compounds as well as their direct effect on the healing process. Besides, it mentions some of the in vivo and clinical studies using BNC-based dressings and describes challenges related to the application of these materials as well as their future directions.

Molecular modeling analyses of functionalized cellulose

Functionalization of cellulose with nanomaterials and functional groups is essential for enhancing its properties for specific applications, such as flexible sensors and printed electronics. This study employs Hartree Fock (HF) and Density Functional Theory (DFT) calculations to investigate the vibrational spectra of cellulose, identifying DFT: B3LYP/3-21 g** as the optimal model aligning with experimental spectra. Using this model, we examined the impact of functionalizing cellulose with various groups (OH, NH2, COOH, CH3, CHO, CN, SH) and graphene oxide (GO) on its electronic properties. The results indicate that cellulose functionalized with GO (Cellulose-GO) has the lowest bandgap energy (0.1687 eV), and improvements in reactivity, stability, and electronic properties were confirmed through Molecular Electrostatic Potential (MESP) and Total Dipole Moment (TDM) analyses. The spectrum of Density of States (DOS) for the cellulose functionalized with different groups shows several peaks, indicating various energy levels where electronic states are concentrated. The Projected Density of States (PDOS) analysis reveals how different functional groups affect the electronic structure of cellulose. Moreover, the (Cellulose-GO) composite was characterized using an Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectrometer, revealing interaction through the OH group of CH2OH, as indicated by a new band at 1710 cm-1, consistent with theoretical predictions. Overall, this study demonstrates that functionalization with GO enhances cellulose's responsiveness, degradation, and electrical properties, making it suitable for applications in flexible electronic devices and protective barriers against corrosion.

Graphene-Based Wound Dressings for Wound Healing: Mechanism, Technical Analysis, and Application Status

The development of novel wound dressings is critical in medical care. Graphene and its derivatives possess excellent biomedical properties, making them highly suitable for various applications in medical dressings. This review provides a comprehensive technical analysis and the current application status of graphene-based medical dressings. Initially, we discuss the chemical structure and the fabrication method of graphene and its derivatives. We then provide a detailed summary of the mechanisms by which graphene materials promote wound repair across the four stages of wound healing. Subsequently, we categorize the types of graphene-based wound dressings and analyze corresponding characteristics. Finally, we analyze the challenges encountered at present and propose solutions regarding future development trends. This paper aims to serve as a reference for further research in skin tissue engineering and the development of innovative graphene-based medical dressings.

3D printing of bacterial cellulose for potential wound healing applications: Current trends and prospects

Several advances in skin tissue engineering have been made to restore skin damage, facilitating wound healing. Bacterial cellulose (BC), a naturally occurring polymer, has gained attention as a potential material in wound healing due to its unique physical and biological properties. In recent years, with the advent of 3D bio-printing technology, new avenues have opened for fabricating customized wound dressings and scaffolds for tissue engineering purposes. The existing literature in this field mainly focuses on the ways of modifications of bacterial cellulose to make it printable. Still, the applicability of 3D printed scaffolds for wound healing needs to be explored more. This review article focuses on the current research on using 3D-printed BC for skin regeneration, including its production methods and physical and biological properties, making it a better choice than traditional dressings. Furthermore, it also highlights the limitations and future directions for using BC in wound healing and tissue engineering applications. This review provides a comprehensive and up-to-date exploration of the applications of 3D-printed BC in wound healing, drawing insights from pre-existing studies and emphasizing patient compliance, clinical outcomes, and economic viability.

Biopolymer hydrogels and synergistic blends for tailored wound healing

Biopolymers have a transformative role in wound repair due to their biocompatibility, ability to stimulate collagen production, and controlled drug and growth factor delivery. This article delves into the biological parameters critical to wound healing emphasizing how combinations of hydrogels with reparative properties can be strategically designed to create matrices that stimulate targeted cellular responses at the wound site to facilitate tissue repair and recovery. Beyond a detailed examination of various biopolymer types and their functionalities in wound dressings acknowledging that the optimal choice depends on the specific wound type and application, this evaluation provides concepts for developing synergistic biopolymer blends to create next-generation dressings with enhanced efficiencies. Furthermore, the incorporation of therapeutic agents such as medications and wound healing accelerators into dressings to enhance their efficacy is examined. These agents often possess desirable properties such as antibacterial activity, antioxidant effects, and the ability to promote collagen synthesis and tissue regeneration. Finally, recent advancements in conductive hydrogels are explored, highlighting their capabilities in treatment and real-time wound monitoring. This comprehensive resource emphasizes the importance of optimizing ingredient efficiency besides assisting researchers in selecting suitable materials for personalized wound dressings, ultimately leading to more sophisticated and effective wound management strategies.

A Review on Recently Developed Antibacterial Composites of Inorganic Nanoparticles and Non-Hydrogel Polymers for Biomedical Applications

Development of new antibacterial materials for solving biomedical problems is an extremely important and very urgent task. This review aims to summarize recent articles (from the last five and mostly the last three years) on the nanoparticle/polymer composites for biomedical applications. Articles on polymeric nanoparticles (NPs) and hydrogel-based systems were not reviewed, since we focused our attention mostly on the composites of polymeric matrix with at least one inorganic filler in the form of NPs. The fields of application of newly developed antibacterial NPs/polymer composites are described, along with their composition and synthetic approaches that allow researchers to succeed in preparing effective composite materials for medical and healthcare purposes.

Fabrication and properties of conductive films based on bacterial cellulose and poly-N-isopropylacrylamide-modified graphene oxide

A conductive film (PNIPAM-rGO/BC) was fabricated combining bacterial cellulose (BC) with poly-N-isopropylacrylamide-modified graphene oxide (PNIPAM-GO) through vacuum filtration and steam reduction techniques. The conductivity and performance of PNIPAM-GO composite and the resulting conductive film were studied. The key findings revealed that PNIPAM-GO composite exhibited a reversible temperature-sensitive behavior. Specifically, the lower critical solution temperature (LCST) increased upon the introduction of graphene oxide (GO). Detailed analyses confirmed uniform dispersion of GO nanosheets within the BC matrix. The incorporation of 10.0 % PNIPAM-GO (containing 7.0 % GO) led to a remarkable 19.6 % increase in tensile strength and approximately 37.0 % enhancement in elongation at break for the conductive film (PNIPAM-rGO/BC) compared to BC. After steam reduction, the electrical conductivity of PNIPAM-rGO/BC exhibited significant improvement over BC. Furthermore, the conductive film demonstrated temperature-dependent conductivity, with a resistivity value approximately 5.2 ± 0.2 KΩ at 25 °C. As the test temperature above the LCST of PNIPAM-GO composite, the resistance decreased. These intriguing temperature-sensitive conductive properties position PNIPAM-rGO/BC as a promising material for smart switches.

Bioinspired multifunctional cellulose film: In situ bacterial capturing and killing for managing infected wounds

Bacterial infection of cutaneous wounds can easily lead to occurrence of chronic wounds and even more serious diseases. Therefore, multifunctional, biodegradable, and reusable wound dressings that can quickly manage wound infection and promote wound healing are urgently desired. Herein, inspired by the "capturing and killing" action of Drosera peltata Thunb., a biomimetic cellulose film was constructed to capture the bacteria (via the rough structure of the film) and kill them (via the combination of photodynamic therapy and chemotherapy) to promote wound tissue remodeling. The film (termed OBC-PR) was simply prepared by chemically crosslinking the oxidized bacterial cellulose (OBC) with polyhexamethylene guanidine hydrochloride (PHGH) and rose bengal (RB). Notably, it could effectively capture Escherichia coli and Staphylococcus aureus bacterial cells with capture efficiencies of ∼99 % and ∼96 %, respectively, within 10 min. Furthermore, the in vivo experiments showed that OBC-PR could effectively promote the macrophage polarization toward the M2 phenotype and adequately induce the reconstruction of blood vessels and nerves, thus promoting wound healing. This study provides a potential direction for designing multifunctional wound dressings for managing infected skin wounds in the future.

The regulation of CuSNPs' interface for further enhancing mechanical and photothermal conversion properties of chitosan/@CuSNPs hybrid fibers

Our previous study has demonstrated that the microstructure of copper sulfide nanoparticles (CuSNPs) can be controlled to enhance mechanical and photothermal conversion properties of chitosan (CS)/CuSNPs hybrid fibers. However, achieving optimal dispersion and compatibility of CuSNPs within a CS matrix remains a challenge, this study aims to improve dispersion and compatibility by modifying the CuSNPs' interface, thereby enhancing mechanical and photothermal conversion properties of hybrid fibers. The interfaces of @CuSNPs (CuS@Xylan NPs, CuS@SA NPs, and CuS@PEG NPs) contain hydroxyl groups, facilitating the hydrogen bonds formation with the CS matrix. The dispersibility is further enhanced by the synergistic effect of xylan and SA's anionic charges with cationic chitosan. Notably, the viscosity of the CS/@CuSNPs hybrid spinning solution is significantly enhanced, resulting in improved breaking strength for initial hybrid fibers. Specifically, the breaking strength of CS/CuS@Xylan NPs hybrid fibers reaches 1.4 cN/dtex, exhibiting a 42.86 % and 20.6 % increase over CS and CS/CuSNPs hybrid fibers. Simultaneously, the CS/CuS@Xylan NPs hybrid fibers exhibit exceptional photothermal conversion performance, surpassing that of CS fibers by 5.2 times and CS/CuSNPs hybrid fibers by 1.4 times. The regulation of interface modification is an efficient approach to enhance the tensile strength and photothermal conversion properties of CS/CuSNPs hybrid fibers.

Engineering Bacterial Biofilm Development and Structure via Regulation of Silver Nanoparticle Density in Graphene Oxide Composite Coating

Graphene-based composites have shown significant potential in the treatment of biofilm infections in clinical settings due to their exceptional antimicrobial properties and specific mechanisms. Nevertheless, a comprehensive understanding of the influence exerted by nanoparticles embedded in the composites on the development and structure of biofilms is still lacking. Here, we fabricate different graphene oxide-silver nanoparticle (GAg) composite-modified substrates (GAgS) with varying densities of silver nanoparticles (AgNPs) and investigate their effects on planktonic bacterial adhesion, subsequent biofilm formation, and mature biofilm structure. Our findings indicate that the initial attachment of Pseudomonas aeruginosa cells during biofilm formation is determined by the density of AgNPs on the GAgS surface. In contrast, the subsequent transition from adherent bacteria to the biofilm is determined by GAgS's synergistic antimicrobial effect. There exists a threshold for the inhibitory performance of GAgS, where the 20 μg/cm2 GAg composite completely prevents biofilm formation; below this concentration, GAgS delays the development of the biofilm and causes structural changes in the mature biofilm with enhanced bacterial growth and increased production of extracellular polymeric substance. More importantly, GAgS have minimal impact on mammalian cell morphology and proliferation while not inducing hemolysis in red blood cells. These results suggest that GAg composites hold promise as a therapeutic approach for addressing medical devices and implant-associated biofilm infections.

A review of carbon nanomaterials/bacterial cellulose composites for nanomedicine applications

Carbon nanomaterials (CNMs) mainly include fullerene, carbon nanotubes, graphene, carbon quantum dots, nanodiamonds, and their derivatives. As a new type of material in the field of nanomaterials, it has outstanding physical and chemical properties, such as minor size effects, substantial specific surface area, extremely high reaction activity, biocompatibility, and chemical stability, which have attracted widespread attention in the medical community in the past decade. However, the single use of carbon nanomaterials has problems such as self-aggregation and poor water solubility. Researchers have recently combined them with bacterial cellulose to form a new intelligent composite material to improve the defects of carbon nanomaterials. This composite material has been widely synthesized and used in targeted drug delivery, biosensors, antibacterial dressings, tissue engineering scaffolds, and other nanomedicine fields. This paper mainly reviews the research progress of carbon nanomaterials based on bacterial cellulose in nanomedicine. In addition, the potential cytotoxicity of these composite materials and their components in vitro and in vivo was discussed, as well as the challenges and gaps that need to be addressed in future clinical applications.

Ag-lignin hybrid nanoparticles for high-performance solar absorption in photothermal antibacterial chitosan films

There is an urgent need for antimicrobial films based on sustainable resources and production methods. In this study, we present a bio-based nanocomposite film composed of chitosan (∼60 wt %), lignin nanoparticles (LNPs, ∼40 wt %), a small amount of glutaraldehyde (1.5 wt %), and a trace level of silver nanoparticles (AgNPs, 0.072 wt %). The uniform dispersion with LNPs prevented aggregation of metallic silver, resulting in small (diameter 3.3 nm) AgNPs. The nanocomposite film absorbs 89% of radiation across the entire solar spectrum and exhibits a remarkable photothermally triggered antibacterial effect, which is further enhanced by the dark color of lignin. Under simulated solar light illumination, the nanocomposite films demonstrated a significant reduction in viable Escherichia coli count compared to control scenarios. The potential applications of these nanocomposites extend to sunlight-activated antimicrobial films and coatings, addressing the growing demand for sustainable and effective antimicrobial materials.

Nano Ag/PPy Biocomposites Based on Graphene Oxide Modified Bacterial Cellulose from the Juice of Xinhui Citrus and Its Antibacterial Activity

Bacterial cellulose (BC) is a green, natural biopolymer with excellent biocompatibility and a film-forming ability. However, its lack of inherent antibacterial activity restricts its application in medical materials and food preservation. In this study, BC derived from the juice of discarded Xinhui citrus was obtained through fermentation and further modified in situ with graphene oxide (GO) to obtain BC(GO). Subsequently, BC(GO) was loaded with cell-compatible polypyrrole (PPy) and antibacterial agent silver nanoparticles (AgNPs) to prepare Ag-PPy/BC(GO) composite films. Composite films were characterized using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) to evaluate their chemical structure and morphology. The results demonstrate effective adsorption of PPy and AgNPs onto the surface of BC nanofibers modified with GO. Antibacterial experiments reveal synergistic antibacterial effects of PPy and AgNPs. The Ag-PPy/BC(GO) membranes exhibit strong antibacterial activity against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with 48-h growth inhibition rates of 75-84% and 82-84%, respectively.

Recent advances in bacterial cellulose-based antibacterial composites for infected wound therapy

Wound infection arising from pathogenic bacteria brought serious trouble to the patient and medical system. Among various wound dressings that are effective in killing pathogenic bacteria, antimicrobial composites based on bacterial cellulose (BC) are becoming the most popular materials due to their success in eliminating pathogenic bacteria, preventing wound infection, and promoting wound healing. However, as an extracellular natural polymer, BC is not inherently antimicrobial, which means that it must be combined with other antimicrobials to be effective against pathogens. BC has many advantages over other polymers, including nano-structure, significant moisture retention, non-adhesion to the wound surface, which has made it superior to other biopolymers. This review introduces the recent advances in BC-based composites for the treatment of wound infection, including the classification and preparation methods of composites, the mechanism of wound treatment, and commercial application. Moreover, their wound therapy applications include hydrogel dressing, surgical sutures, wound healing bandages, and patches are summarized in detail. Finally, the challenges and future prospects of BC-based antibacterial composites for the treatment of infected wounds are discussed.

Homogeneous silver nanoparticle loaded polydopamine/polyethyleneimine-coated bacterial cellulose nanofibers for wound dressing

Utilizing mussel-inspired chemistry is an advanced strategy for surface modification, because dopamine (DA) can form a material-independent adhesive coating and further functionalization can be achieved, including the production of silver nanoparticles (AgNPs). Nevertheless, DA easily aggregates in the nanofiber network structure of bacterial cellulose (BC), which not only blocks the pores in the BC structure but also leads to the formation of large silver particles and the burst release of highly cytotoxic silver ions. Herein, a homogeneous AgNP-loaded polydopamine (PDA)/polyethyleneimine (PEI) coated BC was constructed via a Michael reaction between PDA and PEI. Under the action of PEI, the PDA/PEI coating was uniformly attached to the BC fiber surface with a thickness of approximately 4 nm, and homogeneous AgNPs were produced on the uniform PDA/PEI/BC (PPBC) fiber surface. The sustained release of silver ions was better from AgNPs@PPBC than from AgNPs@PDA/BC. The obtained AgNPs@PPBC exhibited excellent antibacterial activities and cytocompatibility. The results of the in vivo assay indicated that the AgNPs@PPBC dressing could inhibit S. aureus infection and inflammation, promote hair follicle growth, enhance collagen deposition, and accelerate wound healing within 12 days compared with BC. These results illustrate that the homogeneous AgNPs@PPBC dressing has great potential for treating infected wounds.

AS1411-conjugated doxorubicin-loaded silver nanotriangles for targeted chemo-photothermal therapy of breast cancer

Background: Combination therapy has attracted tremendous interest for its great potential in treating cancers. Materials & methods: Based on chitosan-coated silver nanotriangles, polyethylene glycol, AS1411 aptamer and doxorubicin, a multifunctional nanocomposite (AS1411-DOX-AgNTs) was constructed and characterized. Then the photothermal properties, ability to target breast cancer cells and anti-breast cancer effect of AS1411-DOX-AgNTs were evaluated. Results: AS1411-DOX-AgNTs were successfully fabricated and showed excellent photothermal conversion efficiency, breast cancer cell and tumor targeting ability. Compared with single treatments, the combination of AS1411-DOX-AgNTs with near-infrared irradiation possessed the strongest anti-breast cancer effect in vitro and in vivo. Conclusion: AS1411-DOX-AgNTs hold great potential in targeted DOX delivery and combined chemo-photothermal therapy for breast cancer.

Bacterial cellulose-based hydrogel with antibacterial activity and vascularization for wound healing

Skin wounds need an appropriate wound dressing to help prevent bacterial infection and accelerate wound closure. Bacterial cellulose (BC) with a three-dimensional (3D) network structure is an important commercial dressing. However, how to effectively load antibacterial agents and balance the antibacterial activity is a lingering issue. Herein, this study aims to develop a functional BC hydrogel containing silver-loaded zeolitic imidazolate framework-8 (ZIF-8) antibacterial agent. The tensile strength of the prepared biopolymer dressing is >1 MPa, the swelling property is over 3000 %, the temperature can reach 50 °C in 5 min with near-infrared (NIR) and the release of Ag⁺ and Zn²⁺ is stable. In vitro investigation shows that the hydrogel displays enhanced antibacterial activity, and the bacteria survival ratios are only 0.85 % and 0.39 % against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In vitro cell experiments present that BC/polydopamine/ZIF-8/Ag (BC/PDA/ZIF-8/Ag) shows satisfactory biocompatibility and promising angiogenic ability. In vivo study, the full-thickness skin defect on rats demonstrates remarkably wound healing ability and accelerated skin re-epithelialization. This work presents a competitive functional dressing with effective antibacterial properties and accelerative angiogenesis activities for wound repair.

Microwave-Assisted Incorporation of AgNP into Chitosan-Alginate Hydrogels for Antimicrobial Applications

Herein, improving the antibacterial activity of a hydrogel system of sodium alginate (SA) and basic chitosan (CS) using sodium hydrogen carbonate by adding AgNPs was investigated. SA-coated AgNPs produced by ascorbic acid or microwave heating were evaluated for their antimicrobial activity. Unlike ascorbic acid, the microwave-assisted method produced uniform and stable SA-AgNPs with an optimal reaction time of 8 min. Transmission electron microscopy (TEM) confirmed the formation of SA-AgNPs with an average particle size of 9 ± 2 nm. Moreover, UV-vis spectroscopy confirmed the optimal conditions for SA-AgNP synthesis (0.5% SA, 50 mM AgNO₃, and pH 9 at 80 °C). Fourier transform infrared (FTIR) spectroscopy confirmed that the -COO^- group of SA electrostatically interacted with either the Ag⁺ or -NH₃⁺ of CS. Adding glucono-δ-lactone (GDL) to the mixture of SA-AgNPs/CS resulted in a low pH (below the pKa of CS). An SA-AgNPs/CS gel was formed successfully and retained its shape. This hydrogel exhibited 25 ± 2 mm and 21 ± 1 mm inhibition zones against E. coli and B. subtilis and showed low cytotoxicity. Additionally, the SA-AgNP/CS gel showed higher mechanical strength than SA/CS gels, possibly due to the higher crosslink density. In this work, a novel antibacterial hydrogel system was synthesized via 8 min of microwave heating.

Conductive bacterial cellulose: From drug delivery to flexible electronics

Bacterial cellulose (BC) is a chemically pure, non-toxic, and non-pyrogenic natural polymer with high mechanical strength and a complex fibrillar porous structure. Due to these unique biological and physical properties, BC has been amply used in the food industry and, to a somewhat lesser extent, in medicine and cosmetology. To expand its application the BC structure can be modified. This review presented some recent developments in electrically conductive BC-based composites. The as-synthesized BC is an excellent dielectric. Conductive polymers, graphene oxide, nanoparticles and other materials are used to provide it with conductive properties. Conductive bacterial cellulose (CBC) is currently investigated in numerous areas including electrically conductive scaffolds for tissue regeneration, implantable and wearable biointerfaces, flexible batteries, sensors, EMI shielding composites. However, there are several issues to be addressed before CBC composites can enter the market, namely, composite mechanical strength reduction, porosity decrease, change in chemical characteristics. Some of them can be addressed both at the stage of synthesis, biologically, or by adding (nano)materials with the required properties to the BC structure. We propose several solutions to meet the challenges and suggest some promising BC applications.

The green synthesis of environmentally friendly magnetic silver complex stabilized on MnCoFe2O4@sodium alginate nanoparticles (MCF@S-ALG/Ag) and evaluation of their antibacterial activity

Magnetic nanoparticles with green cover sodium alginate and Ag, MnCoFe₂O₄@Sodium alginate/Ag (MCF@S-ALG/Ag) MNPs were prepared by a simple and clean method from Sargassum Vulgare brown algae. The structure of these nanoparticles was characterized by the Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), field emission-scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Furthermore, the antibacterial activity of MCF@S-ALG/Ag MNPs was tested for two bacteria of gram-negative (Escherichia coli (E. coli)) bacteria and gram-positive (Staphylococcus aureus (S. aureus)) bacteria. The MCF@S-ALG/Ag MNPs showed the inhibition zone 16.32 mm for S. aureus and 12.84 mm for E. coli bacteria. The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of MCF@S-ALG/Ag MNPs for both bacteria were found 20 µg/mL and 40 µg/mL, respectively.

Magnetic Bacterial Cellulose Biopolymers: Production and Potential Applications in the Electronics Sector

Bacterial cellulose (BC) is a biopolymer that has been widely investigated due to its useful characteristics, such as nanometric structure, simple production and biocompatibility, enabling the creation of novel materials made from additive BC in situ and/or ex situ. The literature also describes the magnetization of BC biopolymers by the addition of particles such as magnetite and ferrites. The processing of BC with these materials can be performed in different ways to adapt to the availability of materials and the objectives of a given application. There is considerable interest in the electronics field for novel materials and devices as well as non-polluting, sustainable solutions. This sector influences the development of others, including the production and optimization of new equipment, medical devices, sensors, transformers and motors. Thus, magnetic BC has considerable potential in applied research, such as the production of materials for biotechnological electronic devices. Magnetic BC also enables a reduction in the use of polluting materials commonly found in electronic devices. This review article highlights the production of this biomaterial and its applications in the field of electronics.

Graphene-Based Materials for Inhibition of Wound Infection and Accelerating Wound Healing

Bacterial infection of the wound could potentially cause serious complications and an enormous medical and financial cost to the rapid emergence of drug-resistant bacteria. Nanomaterials are an emerging technology, that has been researched as possible antimicrobial nanomaterials for the inhibition of wound infection and enhancement of wound healing. Graphene is 2-dimensional (2D) sheet of sp² carbon atoms in a honeycomb structure. It has superior properties, strength, conductivity, antimicrobial, and molecular carrier abilities. Graphene and its derivatives, Graphene oxide (GO) and reduced GO (rGO), have antibacterial activity and could damage bacterial morphology and lead to the leakage of intracellular substances. Besides, for wound infection management, Graphene-platforms could be functionalized by different antibacterial agents such as metal-nanoparticles, natural compounds, and antibiotics. The Graphene structure can absorb near-infrared wavelengths, allowing it to be used as antimicrobial photodynamic therapy. Therefore, Graphene-based material could be used to inhibit pathogens that cause serious skin infections and destroy their biofilm community, which is one of the biggest challenges in treating wound infection. Due to its agglomerated structure, GO hydrogel could entrap and stack the bacteria; thus, it prevents their initial attachment and biofilm formation. The sharp edges of GO could destroy the extracellular polymeric substance surrounding the biofilm and ruin the biofilm biomass structure. As well as, Chitosan and different natural and synthetic polymers such as collagen and polyvinyl alcohol (PVA) also have attracted a great deal of attention for use with GO as wound dressing material. To this end, multi-functional polymers based on Graphene and blends of synthetic and natural polymers can be considered valid non-antibiotic compounds useful against wound infection and improvement of wound healing. Finally, the global wound care market size was valued at USD 20.8 billion in 2022 and is expected to expand at a compound annual growth rate (CAGR) of 5.4% from 2022 to 2027 (USD 27.2 billion). This will encourage academic as well as pharmaceutical and medical device industries to investigate any new materials such as graphene and its derivatives for the treatment of wound healing.

Advances in the Physico-Chemical, Antimicrobial and Angiogenic Properties of Graphene-Oxide/Cellulose Nanocomposites for Wound Healing

Graphene oxide (GO) and its reduced form (rGO) have recently attracted a fascinating interest due to their physico-chemical properties, which have opened up new and interesting opportunities in a wide range of biomedical applications, such as wound healing. It is worth noting that GO and rGO may offer a convenient access to its ready dispersion within various polymeric matrices (such as cellulose and its derivative forms), owing to their large surface area, based on a carbon skeleton with many functional groups (i.e., hydroxyl, carboxyl, epoxy bridge, and carbonyl moieties). This results in new synergic properties due to the presence of both components (GO or rGO and polymers), acting at different length-scales. Furthermore, they have shown efficient antimicrobial and angiogenic properties, mostly related to the intracellular formation of reactive oxygen species (ROS), which are advantageous in wound care management. For this reason, GO or rGO integration in cellulose-based matrixes have allowed for designing highly advanced multifunctional hybrid nanocomposites with tailored properties. The current review aims to discuss a potential relationship between structural and physico-chemical properties (i.e., size, edge density, surface chemistry, hydrophilicity) of the nanocomposites with antimicrobials and angiogenic mechanisms that synergically influence the wound healing phenomenon, by paying particular attention to recent findings of GO or rGO/cellulose nanocomposites. Accordingly, after providing a general overview of cellulose and its derivatives, the production methods used for GO and rGO synthesis, the mechanisms that guide antimicrobial and angiogenic processes of tissue repair, as well as the most recent and remarkable outcomes on GO/cellulose scaffolds in wound healing applications, will be presented.

Efficacy of Graphene-Based Nanocomposite Gels as a Promising Wound Healing Biomaterial

The development of biocompatible nanocomposite hydrogels with effective wound healing/microbicidal properties is needed to bring out their distinguished characteristics in clinical applications. The positive interaction between graphene oxide/reduced graphene oxide (GO/rGO) and hydrogels and aloe vera gel represents a strong strategy for the advancement of therapeutic approaches for wound healing. In this study, the synthesis, characterization, and angiogenic properties of graphene-based nanocomposite gels have been corroborated and substantiated through several in vitro and in vivo assays. In this respect, graphene oxide was synthesized by incorporating a modified Hummer's method and ascertained by Raman spectroscopy. The obtained GO and rGO were uniformly dispersed into the aloe vera gel and hydrogel, respectively, as wound healing materials. These formulations were characterized via in vitro bio-chemical techniques and were found suitable for the appropriate cell viability, attachment, and proliferation. In addition, in vivo experiments were conducted using male Wistar rats. This revealed that the GO/rGO-based gels stimulated wound contraction and re-epithelialization compared to that of the non-treatment group. From the study, it is suggested that GO/rGO-based aloe vera gel can be recommended as a promising candidate for wound healing applications.

A comprehensive review on the applications of carbon-based nanostructures in wound healing: from antibacterial aspects to cell growth stimulation

A wound is defined as damage to the integrity of biological tissue, including skin, mucous membranes, and organ tissues. The treatment of these injuries is an important challenge for medical researchers. Various materials have been used for wound healing and dressing applications among which carbon nanomaterials have attracted significant attention due to their remarkable properties. In the present review, the latest studies on the application of carbon nanomaterials including graphene oxide (GO), reduced graphene oxide (rGO), carbon dots (CDs), carbon quantum dots (CQDs), carbon nanotubes (CNTs), carbon nanofibers (CNFs), and nanodiamonds (NDs) in wound dressing applications are evaluated. Also, a variety of carbon-based nanocomposites with advantages such as biocompatibility, hemocompatibility, reduced wound healing time, antibacterial properties, cell-adhesion, enhanced mechanical properties, and enhanced permeability to oxygen has been reported for the treatment of various wounds.

Antimicrobial Activity and Sorption Behavior of Al2O3/Ag Nanocomposites Produced with the Water Oxidation of Bimetallic Al/Ag Nanoparticles

The water oxidation of bimetallic Al/Ag nanoparticles has been shown to yield nanoscale structures whose morphology, phase composition and textural characteristics are determined by the synthesis conditions. Flower-like nanoscale structures with silver nanoparticles, with an average size of 17 nm, are formed in water at 60 °C. Under hydrothermal conditions at temperatures of 200 °C and a pressure of 16 MPa, boehmite nanoplatelets with silver nanoparticles, with an average size of 22 nm, are formed. The oxidation of Al/Ag nanoparticles using humid air at 60 °C and 80% relative humidity results in the formation of rod-shaped bayerite nanoparticles and Ag nanoparticles with an average size of 19 nm. The thermal treatment of nanoscale structures obtained at a temperature of 500 °C has been shown to lead to a phase transition into γ-Al2O3, while maintaining the original morphology, and to a decrease in the average size of the silver nanoparticles to 12 nm and their migration to the surface of nanoscale structures. The migration of silver to the nanoparticle surface influences the formation of a double electric layer of particles, and leads to a shift in the pH of the zero-charge point by approximately one, with the nanostructures acquiring pronounced antimicrobial properties.

Bacterial Cellulose as a Versatile Biomaterial for Wound Dressing Application

Chronic ulcers are among the main causes of morbidity and mortality due to the high probability of infection and sepsis and therefore exert a significant impact on public health resources. Numerous types of dressings are used for the treatment of skin ulcers-each with different advantages and disadvantages. Bacterial cellulose (BC) has received enormous interest in the cosmetic, pharmaceutical, and medical fields due to its biological, physical, and mechanical characteristics, which enable the creation of polymer composites and blends with broad applications. In the medical field, BC was at first used in wound dressings, tissue regeneration, and artificial blood vessels. This material is suitable for treating various skin diseases due its considerable fluid retention and medication loading properties. BC membranes are used as a temporary dressing for skin treatments due to their excellent fit to the body, reduction in pain, and acceleration of epithelial regeneration. BC-based composites and blends have been evaluated and synthesized both in vitro and in vivo to create an ideal microenvironment for wound healing. This review describes different methods of producing and handling BC for use in the medical field and highlights the qualities of BC in detail with emphasis on biomedical reports that demonstrate its utility. Moreover, it gives an account of biomedical applications, especially for tissue engineering and wound dressing materials reported until date. This review also includes patents of BC applied as a wound dressing material.

Bioinspired aligned wrinkling dressings for monitoring joint motion and promoting joint wound healing

Joint skin wounds are difficult to treat because of the frequent large motion of these active wounds; thus, dressings capable of simultaneous real-time monitoring of joint motion and promoting joint wound healing are highly needed. Herein, inspired by the aligned wrinkling microstructure and sensing functions of normal joint skins, we combine the electrospinning technique with a water-induced self-assembly approach to prepare bioinspired conductive dressings with aligned wrinkles for achieving the above-mentioned bifunctions. The results indicate that both the wavelength and height of the bioinspired aligned wrinkles can be facilely tuned by adjusting the thickness ratio of the two layers and the loading amount of conductive microparticles. Owing to the unique aligned wrinkling structure and good conductivity, the bioinspired dressing can monitor the donor student's diverse joint motions. Interestingly, the dressing can also accurately monitor different types of mouse neck motion, including up/down and left/right movements. The in vivo wound repairing results confirm that the bioinspired dressing can accelerate the healing of active wounds on the mouse neck by promoting collagen deposition, hair follicle regeneration, and epithelialization. The bioinspired dressing with the integration of real-time motion monitoring features and wound repairing functions will open a new avenue to improve the management of joint wounds.

An IFI6-based hydrogel promotes the healing of radiation-induced skin injury through regulation of the HSF1 activity

Radiation-induced skin injury (RISI) is a common complication of radiotherapy. Interferon-alpha inducible protein 6 (IFI6) significantly reduces the radiation sensitivity of HaCaT cells. Sodium alginate (SA) has substantial moisturizing properties. Graphene oxide (GO) is a suitable substrate with physical antibacterial properties. Therefore, we designed materials to modify IFI6 using the biogule of polydopamine (PDA) connected to GO/SA. The structure, size, morphology, and elemental compositions of IFI6-PDA@GO/SA were analyzed. Cytological studies suggested that IFI6-PDA@GO/SA is non-toxic to HaCaT cells, with antibacterial properties. It promotes migration and vascularization and inhibits apoptosis. These cells express IFI6 after irradiation. The mouse model suggested that IFI6-PDA@GO/SA promotes wound healing and reduces reactive oxygen species expression. IFI6-PDA@GO/SA accelerates RISI healing, possibly by initiating the SSBP1/HSF1 signaling pathway. In addition, IFI6-PDA@GO/SA improves the immune microenvironment. This study constitutes the first use of IFI6 as a RISI wound-healing material.

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.

Recent advances in the hybridization of cellulose and carbon nanomaterials: Interactions, structural design, functional tailoring, and applications

Due to the good biocompatibility and flexibility of cellulose and the excellent optical, electronic, as well as mechanical properties of carbon nanomaterials (CNMs), cellulose/CNM hybrid materials have been widely synthesized and used in energy storage, sensors, adsorption, biomedicine, and many other fields. In this review, we present recent advances (2016-current) in the design, structural design, functional tailoring and various applications of cellulose/CNM hybrid materials. For this aim, first the interactions between cellulose and CNMs for promoting the formation of cellulose/CNM materials are analyzed, and then the hybridization between cellulose with various CNMs for tailoring the structures and functions of hybrid materials is introduced. Further, abundant applications of cellulose/CNM hybrid materials in various fields are presented and discussed. This comprehensive review will be helpful for readers to understand the functional design and facile synthesis of cellulose-based nanocomposites, and to promote the high-performance utilization and sustainability of biomass materials in the future.

Investigation on visible light-driven antimicrobial and mechanistic activity of GO/TiO2(V–N) nanocomposite against wound pathogens

GO/TiO2(V–N) is fabricated as a visible light driven efficient antimicrobial material. In the presence of light, GO/TiO2(V–N) was employed as a photocatalytic active material against wound pathogens.

Multifunctional applications of natural polysaccharide starch and cellulose: An update on recent advances

The emergence of clinical complications and therapeutic challenges for treating various diseases necessitate the discovery of novel restorative functional materials. Polymer-based drug delivery systems have been extensively reported in the last two decades. Recently, there has been an increasing interest in the progression of natural biopolymers based controlled therapeutic strategies, especially in drug delivery and tissue engineering applications. However, the solubility and functionalisation due to their complex network structure and intramolecular bonding seem challenging. This review explores the current advancement and prospects of the most promising natural polymers such as cellulose, starch and their derivatives-based drug delivery vehicles like hydrogels, films and composites, in combating major ailments such as bone infections, microbial infections, and cancers. In addition, selective drug targeting using metal-drug (MD) and MD-based polymeric missiles have been exciting but challenging for its application in cancer therapeutics. Owing to high biocompatibility of starch and cellulose, these materials have been extensively evaluated in biomedical and pharmaceutical applications. This review presents a detailed impression of the current trends for the construction of biopolymer-based tissue engineering, drug/gene/protein delivery vehicles.

Conductive Biomaterials as Bioactive Wound Dressing for Wound Healing and Skin Tissue Engineering

Conductive biomaterials based on conductive polymers, carbon nanomaterials, or conductive inorganic nanomaterials demonstrate great potential in wound healing and skin tissue engineering, owing to the similar conductivity to human skin, good antioxidant and antibacterial activities, electrically controlled drug delivery, and photothermal effect. However, a review highlights the design and application of conductive biomaterials for wound healing and skin tissue engineering is lacking. In this review, the design and fabrication methods of conductive biomaterials with various structural forms including film, nanofiber, membrane, hydrogel, sponge, foam, and acellular dermal matrix for applications in wound healing and skin tissue engineering and the corresponding mechanism in promoting the healing process were summarized. The approaches that conductive biomaterials realize their great value in healing wounds via three main strategies (electrotherapy, wound dressing, and wound assessment) were reviewed. The application of conductive biomaterials as wound dressing when facing different wounds including acute wound and chronic wound (infected wound and diabetic wound) and for wound monitoring is discussed in detail. The challenges and perspectives in designing and developing multifunctional conductive biomaterials are proposed as well.

Performance of Polydopamine Complex and Mechanisms in Wound Healing

Polydopamine (PDA) has been gradually applied in wound healing of various types in the last three years. Due to its rich phenol groups and unique structure, it can be combined with a variety of materials to form wound dressings that can be used for chronic infection, tissue repair in vivo and serious wound healing. PDA complex has excellent mechanical properties and self-healing properties, and it is a stable material that can be used for a long period of time. Unlike other dressings, PDA complexes can achieve both photothermal therapy and electro activity. In this paper, wound healing is divided into four stages: antibacterial, anti-inflammatory, cell adhesion and proliferation, and re-epithelialization. Photothermal therapy can improve the bacteriostatic rate and remove reactive oxygen species to inhibit inflammation. Electrical signals can stimulate cell proliferation and directional migration. With low reactive oxygen species (ROS) levels, inflammatory factors are down-regulated and growth factors are up-regulated, forming regular collagen fibers and accelerating wound healing. Finally, five potential development directions are proposed, including increasing drug loading capacity, optimization of drug delivery platforms, improvement of photothermal conversion efficiency, intelligent electroactive materials and combined 3D printing.

Antibacterial polyvinyl alcohol/bacterial cellulose/nano-silver hydrogels that effectively promote wound healing

The lack of antibacterial properties limits the application of bacterial cellulose hydrogels in wound dressings. To overcome this deficiency, silver nanoparticles (AgNPs) were introduced as antibacterial agents into a polyvinyl alcohol (PVA)/bacterial cellulose (BC) solution. A freeze-thaw method promoted formation of PVA/BC/Ag hydrogels and improved their mechanical properties. The physicochemical and biological properties of this hydrogel were systematically characterized. Those results showed the hydrogels contained a porous three-dimensional reticulum structure and had high mechanical properties. Also, the hydrogels possessed outstanding antibacterial properties and good biocompatibilities. More importantly, it effectively repaired wound defects in mice models and wound healing reached 97.89% within 15 days, and far exceeded other groups and indicated its potential for use in wound treatment applications.