Synthesis, characterization and biocompatible properties of novel silk fibroin/graphene oxide nanocomposite scaffolds for bone tissue engineering application

Silk-Based 3D Porous Scaffolds for Tissue Engineering

Silk fibroin, extracted from the silk of the Bombyx mori silkworm, stands out as a biomaterial due to its nontoxic nature, excellent biocompatibility, and adjustable biodegradability. Porous scaffolds, a type of biomaterial, are crucial for creating an optimal microenvironment that supports cell adhesion and proliferation, thereby playing an essential role in tissue remodeling and repair. Therefore, this review focuses on 3D porous silk fibroin-based scaffolds, first summarizing their preparation methods and then detailing their regenerative effects on bone, cartilage, tendon, vascular, neural, skin, hepatic, and tracheal epithelial tissue engineering in recent years.

Fabrication and investigation of a pentamerous composite based on calix[4]arene functionalized graphene oxide grafted with silk fibroin, cobalt ferrite, and alginate

This paper presents a new scaffold made from graphene oxide nanosheets, calix[4]arene supramolecules, silk fibroin proteins, cobalt ferrite nanoparticles, and alginate hydrogel (GO-CX[4]/SF/CoFe2O4/Alg). After preparing the composite, we conducted various analyses to examine its structure. These analyses included FTIR, XRD, SEM, EDS, VSM, DLS, and zeta potential tests. Additionally, we performed tests to evaluate the swelling ratio, rheological properties, and compressive mechanical strength of the material. The biological capability of the composite was tested through biocompatiblity, anticancer, hemolysis, antibacterial anti-biofilm assays. Besides, the rheological properties and swelling behaviour of the composite were studied. The results showed that the scaffold is biocompatible with Hu02 cells and the cell viability percentages of 85.23 %, 82.78 %, and 80.18 % for were acquired for 24, 48, and 72 h, respectively. In contrast, the cell viability percentage of BT549 cancer cells were obtained 65.79 %, 60.45 % and 58.16 % for same period which confirmed notable anticancer activity of the product composite. Moreover, a significant antibacterial growth inhibition against E. coli and S. aureus species highlights its potential as an effective antibacterial agent. Furthermore, the observed minimal hemolytic effect (6.56 %) and strong inhibition of P. aeruginosa biofilm formation with a low OD value (0.24) indicate notable hemocompatibility and antibacterial activity.

Effects of mechanical properties of carbon-based nanocomposites on scaffolds for tissue engineering applications: a comprehensive review

Mechanical properties, such as elasticity modulus, tensile strength, elongation, hardness, density, creep, toughness, brittleness, durability, stiffness, creep rupture, corrosion and wear, a low coefficient of thermal expansion, and fatigue limit, are some of the most important features of a biomaterial in tissue engineering applications. Furthermore, the scaffolds used in tissue engineering must exhibit mechanical and biological behaviour close to the target tissue. Thus, a variety of materials has been studied for enhancing the mechanical performance of composites. Carbon-based nanostructures, such as graphene oxide (GO), reduced graphene oxide (rGO), carbon nanotubes (CNTs), fibrous carbon nanostructures, and nanodiamonds (NDs), have shown great potential for this purpose. This is owing to their biocompatibility, high chemical and physical stability, ease of functionalization, and numerous surface functional groups with the capability to form covalent bonds and electrostatic interactions with other components in the composite, thus significantly enhancing their mechanical properties. Considering the outstanding capabilities of carbon nanostructures in enhancing the mechanical properties of biocomposites and increasing their applicability in tissue engineering and the lack of comprehensive studies on their biosafety and role in increasing the mechanical behaviour of scaffolds, a comprehensive review on carbon nanostructures is provided in this study.

Harnessing Natural Polymers for Nano-Scaffolds in Bone Tissue Engineering: A Comprehensive Overview of Bone Disease Treatment

Numerous surgeries are carried out to replace tissues that have been harmed by an illness or an accident. Due to various surgical interventions and the requirement of bone substitutes, the emerging field of bone tissue engineering attempts to repair damaged tissues with the help of scaffolds. These scaffolds act as template for bone regeneration by controlling the development of new cells. For the creation of functional tissues and organs, there are three elements of bone tissue engineering that play very crucial role: cells, signals and scaffolds. For the achievement of these aims, various types of natural polymers, like chitosan, chitin, cellulose, albumin and silk fibroin, have been used for the preparation of scaffolds. Scaffolds produced from natural polymers have many advantages: they are less immunogenic as well as being biodegradable, biocompatible, non-toxic and cost effective. The hierarchal structure of bone, from microscale to nanoscale, is mostly made up of organic and inorganic components like nanohydroxyapatite and collagen components. This review paper summarizes the knowledge and updates the information about the use of natural polymers for the preparation of scaffolds, with their application in recent research trends and development in the area of bone tissue engineering (BTE). The article extensively explores the related research to analyze the advancement of nanotechnology for the treatment of bone-related diseases and bone repair.

Design and fabrication of a magnetic nanobiocomposite based on flaxseed mucilage hydrogel and silk fibroin for biomedical and in-vitro hyperthermia applications

In this research work, a magnetic nanobiocomposite is designed and presented based on the extraction of flaxseed mucilage hydrogel, silk fibroin (SF), and Fe3O4 magnetic nanoparticles (Fe3O4 MNPs). The physiochemical features of magnetic flaxseed mucilage hydrogel/SF nanobiocomposite are evaluated by FT-IR, EDX, FE-SEM, TEM, XRD, VSM, and TG technical analyses. In addition to chemical characterization, given its natural-based composition, the in-vitro cytotoxicity and hemolysis assays are studied and the results are considerable. Following the use of highest concentration of magnetic flaxseed mucilage hydrogel/SF nanobiocomposite (1.75 mg/mL) and the cell viability percentage of two different cell lines including normal HEK293T cells (95.73%, 96.19%) and breast cancer BT549 cells (87.32%, 86.9%) in 2 and 3 days, it can be inferred that this magnetic nanobiocomposite is biocompatible with HEK293T cells and can inhibit the growth of BT549 cell lines. Besides, observing less than 5% of hemolytic effect can confirm its hemocompatibility. Furthermore, the high specific absorption rate value (107.8 W/g) at 200 kHz is generated by a determined concentration of this nanobiocomposite (1 mg/mL). According to these biological assays, this magnetic responsive cytocompatible composite can be contemplated as a high-potent substrate for further biomedical applications like magnetic hyperthermia treatment and tissue engineering.

Graphene oxide reinforced silk fibroin nanocomposite as an electroactive interface for the estimation of dopamine

The fabrication of 2D materials and polymer-based nanocomposites deposited on flexible conductive interfaces has unblocked new horizons to expedite reaction kinetics for developing highly selective and sensitive electrochemical biosensors. Herein, we developed a novel biosensing platform, comprising graphene oxide and a silk fibroin-based nanocomposite, drop-cast on a carbon cloth electrode. The fabricated interface was expected to be a robust and miniaturized sensing platform for precise detection of dopamine (DA). Characterization was performed by SEM, EDX, FTIR, XRD, UV-visible spectroscopy, contact angle measurement, fluorescence spectroscopy, particle size, and zeta potential analysis. CV, EIS, DPV, and chronoamperometry demonstrated the superior electrochemical properties of the working interface and revealed its enhanced active surface area, increased conductivity, and accelerated electron transfer rate. The designed interface exhibited low LoD (0.41 μM), admirable stability, good sensitivity (2.46 μA μM^-1 cm^-2), wide linearity ranging from 100-900 μM, excellent reproducibility, and superb selectivity against dopamine even in the presence of possible interfering analytes. These findings endorse the feasibility of the practical execution of such an integrated system in real sample analysis.

Application of Nano-Biomaterials Scaffold in Postoperative Nursing Care of Orthopedic Fractures

This article detects the drug-carrying capacity of the new chitosan/silk fibroin/nano-hydroxyapatite multilayer composite scaffold and analyzes its efficacy in postoperative care of orthopedic fractures. The article uses animal experiments for comparative analysis. All animals undergo fracture model establishment. One group uses nano three-dimensional scaffold materials loaded with antibiotics, one group is pure nano three-dimensional scaffold materials, and the last group is without any implantation treatment. Finally, it was found that the fracture recovery of the three groups of animals was different. In particular, all the antibiotic-loaded nano three-dimensional scaffold material group indicators are better than the other two groups. For this reason, we conclude that the new chitosan/silk fibroin/nano-hydroxyapatite multilayer composite scaffold has a strong drug-carrying capacity. The stent is worthy of clinical promotion and use in orthopedics.

Advancements and Applications in the Composites of Silk Fibroin and Graphene-Based Materials

Silk fibroin and three kinds of graphene-based materials (graphene, graphene oxide, and reduced graphene oxide) have been widely investigated in biomedical fields. Recently, the hybrid composites of silk fibroin and graphene-based materials have attracted much attention owing to their combined advantages, i.e., presenting outstanding biocompatibility, mechanical properties, and excellent electrical conductivity. However, maintaining bio-toxicity and biodegradability at a proper level remains a challenge for other applications. This report describes the first attempt to summarize the hybrid composites’ preparation methods, properties, and applications to the best of our knowledge. We strongly believe that this review will open new doors for coming researchers.

Development of Graphene-Based Materials in Bone Tissue Engineaering

Bone regeneration-related graphene-based materials (bGBMs) are increasingly attracting attention in tissue engineering due to their special physical and chemical properties. The purpose of this review is to quantitatively analyze mass academic literature in the field of bGBMs through scientometrics software CiteSpace, to demonstrate the rules and trends of bGBMs, thus to analyze and summarize the mechanisms behind the rules, and to provide clues for future research. First, the research status, hotspots, and frontiers of bGBMs are analyzed in an intuitively and vividly visualized way. Next, the extracted important subjects such as fabrication techniques, cytotoxicity, biodegradability, and osteoinductivity of bGBMs are presented, and the different mechanisms, in turn, are also discussed. Finally, photothermal therapy, which is considered an emerging area of application of bGBMs, is also presented. Based on this approach, this work finds that different studies report differing opinions on the biological properties of bGBMS due to the lack of consistency of GBMs preparation. Therefore, it is necessary to establish more standards in fabrication, characterization, and testing for bGBMs to further promote scientific progress and clinical translation.

Facile design and development of nano-clustery graphene-based macromolecular protein hydrogel loaded with ciprofloxacin to antibacterial improvement for the treatment of burn wound injury

Nowadays, awareness about the burn wound is often considered difficult due to bacterial and other organism infections. The facile and eco-friendly preparations of antibiotic-loaded hydrogel-based bio-composites have great attention in the field of wound dressing for burn wound therapy and nursing care. In the present investigation, we have developed ciprofloxacin (CF)-encapsulated graphene-silk fibroin macromolecular hydrogel dressings material with unique chemical and physical properties to achieve the desirable antibacterial efficacy and healing activity. The antibacterial activity of prepared hydrogel was evaluated against bacterial pathogens treated with different concentrations of CF, which have been provided improved antibacterial activity on burn wound infection. In vitro, cytocompatibility evaluations were performed to imply the suitability of hydrogel on fibroblast cells, which has been dramatically related to in vivo wound healing. Furthermore, an in vivo wound healing analysis was carried out using a rat to observe the capability of the CF-incorporated GH/SF hydrogel matrix. Thus, this investigation widely demonstrates the healing ability of prepared hydrogel matrix and could be a significant landmark in the research on burn wound healing applications.

Engineering a Bioactive Hybrid Coating for In Vitro Corrosion Control of Magnesium and Its Alloy

Magnesium (Mg) and its alloys are promising biodegradable metallic implant materials. However, their clinical applications are limited by their fast corrosion rate in the biological environment. In this work, with an outlook to improve the in vitro corrosion resistance of Mg and WE43 Mg alloy, a layer-by-layer interfacially engineered anticorrosive and bioactive coating consisting of a natural oxide lower layer, hydroxyapatite (HA) middle layer, and silk fibroin (SF) top layer was fabricated and investigated. Anodization was used to create natural oxide layer induced microroughness on substrates. The electrochemically deposited HA layer improved the surface microroughness and microhardness but significantly decreased Mg ion release, hydrogen gas evolution, and weight loss in simulated body fluid. The spin-coated SF layer further decreased hydrophilicity, in vitro degradation, and corrosion rate. The nonspecific and specific intermolecular interactions between fabricated layers along with their mechanical interlocking interface contributed to improved adhesion strength and integrity of the coating. The SF+HA-coated samples showed enhanced degradation and corrosion resistance due to a synergistic effect of the underlying HA layer, hindering the ingress of aggressive ions and the top hydrophobic SF layer, preventing the ingress of corrosive solution. The SF+HA-coated Mg and WE43 Mg alloy samples exhibited 50 and 26 times decreased corrosion rate, respectively, compared to uncoated samples. Moreover, in vitro cytotoxicity and cell culture studies using a mouse fibroblast cell showed that the SF+HA hybrid coating improved the cell viability, attachment, and proliferation, with cells exhibiting elongated morphology on coated samples as compared to a round shape on uncoated samples.

Silk-Based Materials for Hard Tissue Engineering

Hard tissues, e.g., bone, are mechanically stiff and, most typically, mineralized. To design scaffolds for hard tissue regeneration, mechanical, physico-chemical and biological cues must align with those found in the natural tissue. Combining these aspects poses challenges for material and construct design. Silk-based materials are promising for bone tissue regeneration as they fulfill several of such necessary requirements, and they are non-toxic and biodegradable. They can be processed into a variety of morphologies such as hydrogels, particles and fibers and can be mineralized. Therefore, silk-based materials are versatile candidates for biomedical applications in the field of hard tissue engineering. This review summarizes silk-based approaches for mineralized tissue replacements, and how to find the balance between sufficient material stiffness upon mineralization and cell survival upon attachment as well as nutrient supply.

Investigation of the biological activity, mechanical properties and wound healing application of a novel scaffold based on lignin–agarose hydrogel and silk fibroin embedded zinc chromite nanoparticles

Given the important aspects of wound healing approaches, in this work, an innovative biocompatible nanobiocomposite scaffold was designed and prepared based on cross-linked lignin–agarose hydrogel, extracted silk fibroin solution, and zinc chromite (ZnCr₂O₄) nanoparticles.

Spider Silk Fusion Proteins for Controlled Collagen Binding and Biomineralization

The development of biomaterials for the interface between tendon and bone is important for realizing functional tendon replacements. Toward the development of new materials for such applications, engineered recombinant spider silk proteins were modified with peptide tag sequences derived from noncollagenous proteins in bone, so-called SIBLING proteins, such as osteopontin and sialoprotein, which are known to interact with collagen and to initiate mineralization. Materials made of these spider silk-SIBLING hybrids were analyzed concerning mineralization and interaction with cells. They showed enhanced calcium phosphate formation upon incubation in mineralization agents. In gradient films, MC3T3-E1 mouse preosteoblasts adhered preferentially along the gradient toward the variant with a collagen binding motif.

Graphene oxide/alginate/silk fibroin composite as a novel bionanostructure with improved blood compatibility, less toxicity and enhanced mechanical properties

For biomedical applications, the design and synthesis of biocompatible nanostructures, are considered as critical challenges. In this study, graphene oxide (GO) was covalently modified by natural sodium alginate (Alg) polymer. By adding silk fibroin (SF) to this nanostructure, a hybrid nanobiocomposite (GO/Alg/SF) was resulted and its unique features were determined using FT-IR, EDX, FE-SEM, XRD and TG analyses. Because of using less toxic and high biocompatible materials, specific biological results were achieved. The cell viability of this novel nanostructure was 89.2 % and its hemolytic effect was less than 6% while the highest concentration (1000 μg/mL) of this nanostructure was chosen for these purposes. Also, high mechanical properties including the compressive strength (0.87 ± 0.034 (MPa)) and the compressive modulus (2.25 ± 0.091 (MPa)) were exposed. This nanostructure can be considered as a scaffold for wound dressing applications due to the mentioned properties.

The assembly of silk fibroin and graphene-based nanomaterials with enhanced mechanical/conductive properties and their biomedical applications

The assembly of silk fibroin and graphene-based nanomaterials would present fantastic properties and functions via optimizing the interaction between each other, and can be processed into various formats to tailor specific biomedical applications.