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This study shows the enhancement of glass ionomer cement (GIC) by incorporating hydroxyapatite (HA) and zinc oxide (ZnO) nanoparticles to improve its mechanical strength, biological activity, and antibacterial properties. GC is widely used in dental and orthopedic applications due to its bioactivity and biocompatibility, but it suffers from weak antibacterial properties and limited load-bearing capacity. HA, a calcium phosphate compound similar to natural bone, and ZnO, known for its antibacterial and bone-regenerative properties, were integrated into GIC to address these limitations. The modified GC exhibited improved compressive strength and bioactivity, particularly with the addition of 4 wt% ZnO nanoparticles, which showed the highest increase in mechanical performance while maintaining cytocompatibility. However, the fluoride release was reduced, indicating an exchange between enhanced mechanical properties and fluoride ion release. Antibacterial efficacy was assessed using well diffusion, MIC, and MBC tests, confirming that the modified GC has significant potential in dental and orthopedic applications. Future research should focus on the long-term effects of Zn2⁺ ion release to fully understand its impact on the antibacterial performance of the cement.

Due to the vital functions of bone tissue in the body, any change in its structure affects the balance of the body. Following a lesion, the body may be unable to repair it, and bone scaffolds may be implanted to stimulate bone cells and thus repair lost bone. This article aims to develop a scaffold with ideal properties that can be used to treat fractures and injuries. The technique used in this study is a hybrid of 3D printing and freeze-drying. Alginate (ALG), polyvinyl alcohol (PVA), and bioceramic-titanium nanoparticles were used to coat electroconductive polylactic acid (EC-PLA) using the freeze-drying method. The prepared samples were analyzed using a scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) for morphology functional group and phase characterizations. After coating the scaffolds with the freeze-drying method, the pore size was examined and correlated with the compressive strength values. For biological studies, a bioactivity test involving immersion of the samples in simulated body fluids (SBF) was performed for a specified period. The samples were then evaluated for water absorption, weight loss, and pH changes. Cell behavioral and antibacterial tests were performed to evaluate the growth of scaffolds in the body. Additionally, the compressive strength test results are incorporated into simulation and modeling analyses under static loading and micromechanical models. Finally, the circle-shaped scaffold containing titanium sample was chosen as a suitable scaffold due to its 78% porosity, 27% apatite formation, 75° wetting angle, 15% weight loss after 7 days, and 99% biocompatibility. Finally, the bio-nanocomposite scaffold can attach to the cell and then gradually degrade, preserving the implant's mechanical properties for the regeneration process.

Recently, the application of porous bio-nanocomposites has been considered by many researchers for orthopedic application. Since experimental tests for obtaining the mechanical and physical properties of these nanostructured biomaterials are very expensive and time-consuming, it is highly recommended to model and simulate these bio-nanoscale materials to predict their mechanical and physical properties. In this study, three-phase porous bio-nanocomposite membranes were fabricated with Titanium oxide (TiO2), Hydroxyapatite (HA) and Polycaprolactone (PCL) polymer. HA and TiO2 are both biocompatible and biodegradable. The samples were fabricated with various amounts of titanium oxide and the materials characterization has been performed on selected sample. The molecular dynamics technique (MD) have been used to predict the mechanical performance of the nanocomposite models. The MD simulations were performed for single phase material and the developed for two phases equivalent components as a new approach in using MD simulation results. The results indicated the close relationship between the experimental data and simulation values for the selected sample. Moreover, phase and morphology of these nanostructures have been investigated using SEM results. Therefore, based on the proposed approach, MD simulation can be applicable for predicting the properties of porous bio-nanocomposite membrane.

Bone fracture due to internal or external factors is one of the most common diseases in today's orthopedic society. One of the techniques to solve these problems is to use artificial porous bone grafts made by 3D printers and the Freeze-Drying (FD) techniques. In this study, a shapeless porous scaffold was first fabricated using Fused Deposition Modeling (FDM) with the electroconductive filament. The printed scaffold is inserted into the alginate solution composed of Magnetite Nanoparticles (MNPs) containing 0, 10, 20, and 30 wt% baghdadite nanoparticles. Then, the four samples are coated using an FD technique at −45 °C and 0.01 m bar. The mechanical and biological properties are investigated using compressive strength and Simulated Body Fluid (SBF) test. The samples are analyzed using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis to evaluate the morphology and phase of the fabricated specimens. The obtained results from the measurement of mechanical properties show that the scaffolds can maintain their strength in the dry state and terms of mechanical properties close to cortical bones at about 6.5 MPa for the sample with 20 wt% and 72% porosity. The swelling behavior of the scaffolds in the Phosphate Buffer Saline (PBS) is also investigated. The cytotoxicity of the porous scaffold is evaluated by direct measurement for three days and the result of the sample with 20 wt% was significantly better than the other samples. Finally, this research shows that the produced bio-nanocomposite scaffolds have potential application in tissue engineering.

Today, various commercial dressings have been developed and introduced to the market. The diversity makes it difficult for the nurse to choose the right type. Although the most important reason to use a wound dress is to protect the wound from infection and prevent infection, but in fact, the main purpose of using these materials is to speed up the wound healing process. Traumatic injuries result in an epithelial wound that disrupts the continuity of the skin surface. These differences reveal as abrasions, punctures, and injuries. Wounds are divided into two types; the skin is either cut or ruptured, including deep wounds and bruises, or surface wounds. Expedited wound healing has been considered since the archaic era of human civilization, with the earliest reported case from the Ancient Egyptians. Wound lesions in mummified humans were observed to be cover with animal skin, with signs of (primary/secondary) wound healing present. A "new wound dressing" is an advanced wound dress used in wound management as biocompatible and biodegradable biomaterials that heal wounds and burns. In the past, it was believed that dry wounds had expedited healing and wet wounds have been found to promote using re-epithelization and result in reduced scar formation. Wounds can be treated using various types of natural polymers and materials. Also, techniques like electrospinning and freeze-drying techniques can be used for the fabrication of standard wound dress. These wounds are associated with bandages, inflammation, bleeding, pain, and pus. In this work, we consider various types of wounds and techniques to treat the wound. Susceptibility to these areas, due to special symptoms for each of them. Products like hydrogels, hydrocolloids, films, sponges, and nano-fiber polymeric materials are used to promote healing. In this review, we examine the ideal products for the treatment of wounds in diabetic patients.

In recent decades, polymer composites are widely used in industry due to their good mechanical properties and their low specific weight. Also, the use of glass fibers and carbon nanotubes can strengthen and improve the mechanical performance of the polymer due to their good mechanical properties. In this study, incorporated glass/epoxy nanocomposite with carbon nanotubes (CNT) samples were fabricated using a hand lay-up process, and the effect of addition functionalized Single-Walled Carbon Nanotubes (F-SWCNT) with COOH and non-functionalized SWCNT was investigated. The tensile strength, elastic modulus, bending strength was obtained experimentally using SANTAM-STM50. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to investigate the phase and morphology of the fibers. The mechanical properties results showed that the highest elastic modulus and tensile strength are obtained for the sample reinforced with F-SWCNT which increased by 32% and 10%, respectively in comparison with pure epoxy. Also, the obtained results of the bending test indicate that the highest flexural modulus and the highest flexural strength are related to the sample reinforced with functionalized carbon nanotubes which are 16.9 GPa and 381.39 MPa, respectively. Then, the mechanical performance of the reinforcement in the epoxy matrix and the failure mechanism was monitored using SEM images. Finally, reinforced epoxy nanocomposites with functionalized and non-functionalized SWCNT were simulated using Molecular Dynamics (MD) simulation to examine the agreement with the trends of experimental results. The MD obtained results showed that the most appropriate mode of dispersion occurs when functionalized carbon nanotubes are used. Also, it was observed that the elastic modulus of incorporated nanocomposites with F-SWCNT increased by 17% compared to non-functionalized SWCNT which shows the agreement with the trends of experimental results.

Objective(s): Many patients die due to vascular, gastrointestinal lumen problems, and coronary heart diseases. Synthetic vessels that are made of biodegradable-nanofiber polymers have significant properties such as proper biodegradability and efficient physical properties such as high strength and flexibility. Some of the best options for supporting cells in soft tissue engineering and design are applications of thermoplastic polyurethane polymer in the venous tissue. In this study, the first nanoparticle-reinforced polymeric artificial prosthesis was designed and tested to be used in the human body.Materials and Methods: In this study, artificial gastrointestinal lumen were fabricated and prepared using a 3D printer. To improve cell adhesion, wettability properties and mechanical stability of elastin biopolymer with magnetic nanoparticles (MNPs) as well as single-walled carbon nanotubes (SWCNT) were prepared as separate filaments. MNPs were made in 5–7 mm sizes and then examined for mechanical, biological, and hyperthermia properties. Then, the obtained results of the gastrointestinal lumen were simulated using the Abaqus software package with a three-branch. The results were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) for morphology and phase analysis. Results: The obtained results of the designed vessels showed remarkable improvement in mechanical properties of the SWCNT vessels and hyperthermia properties of the vessels containing the MNPs. The results of computational fluid dynamics (CFD) analysis showed that the artificial vessels had lower shear stress at the output. Conclusion: Five-mm MNP containing vessels showed noticeable chemical and biological properties along with ideal magnetic results in the treatment of thrombosis and vascular obstruction.

Some pulsed tissues are replaced with non-pulsed damaged tissue, which jeopardizes heart function after a heart attack. The restoration is performed by a patch tissue to repair defective tissues. It is supposed to attach to the outside of the heart and connect to the wounded area. The above patch is made of a conductive polymer on which a separate electrical polymer called "alginate" through a process called 3D bioprinter. The mechanism of the following patch for biological and cell behavior has to be investigated. Besides, we explain the results of the combination of these polymers with natural and synthetic polymer composites. As a natural and biological soft patch for cardiovascular disease (CVD) the adhesion of cells to patch is more efficient and important. In this study, we used a novel technique to print sodium alginate for CVD problems with soft hydrogel patch loading with the restorative drug. In other words, by producing soft tissue patches, researchers and clinical surgeons can obtain more desirable properties made of natural and synthetic polymer composites for the treatment of heart disease. In this study, four CVD patches fabricated using 3D bioprinter X4bioFab with various amounts of drug on their surfaces containing 2%, 4%, 6%, and 8%. The obtained values for mechanical and biological performance present proper features for the sample containing a 6% drug. The results indicated the prepared patch can be a suitable candidate for heart disease with sufficient cell attachment after a while.

Cartilage tissue has a low cell population with a dense extracellular matrix (ECM) and is also devoid of neurons as well as blood and lymph vessels. Bone tissue is able to heal itself but in cases of serious damage and auxiliary treatment methods are necessary. Nevertheless, they have their own restrictions and downsides. Tissue engineering is working towards overcoming these challenges using 3D printing and freeze-drying technique. This research project aims to develop and study the properties of a freeze-dried antibacterial tissue based on alginate, hyaluronic acid and titanium dioxide nanoparticles using freeze drying technique. The mechanical evaluations showed that the addition of titanium dioxide improved tensile strength, hardness and wettability of the antibacterial nanocomposite scaffold. The biological assessments of the sample were evaluated in the simulated body fluid to stimulate the hard tissue reaction with biological environment. The samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The obtained results indicated that addition of titanium oxide nanoparticle improved the hyaluronic acid polymer for bone filler using for orthopedic applications. The XRD analysis did not detect the formation of any new unwanted chemicals in the composite samples. The microscopic assessments confirmed the formation of nanocomposite scaffold containing titanium dioxide nanoparticles, with a porosity percentage between 77% and 82%. The phase analysis confirmed the triploid amorphous structure showing a significant resemblance to natural human bone tissue, thus supporting the idea of using this biomaterial as a multilayer bone filler.

Nearly every 100 years, humans collectively face a pandemic crisis. After the Spanish flu, now the world is in the grip of coronavirus disease 2019 (COVID-19). First detected in 2019 in the Chinese city of Wuhan, COVID-19 causes severe acute respiratory distress syndrome. Despite the initial evidence indicating a zoonotic origin, the contagion is now known to primarily spread from person to person through respiratory droplets. The precautionary measures recommended by the scientific community to halt the fast transmission of the disease failed to prevent this contagious disease from becoming a pandemic for a whole host of reasons. After an incubation period of about two days to two weeks, a spectrum of clinical manifestations can be seen in individuals afflicted by COVID-19: from an asymptomatic condition that can spread the virus in the environment, to a mild/moderate disease with cold/flu-like symptoms, to deteriorated conditions that need hospitalization and intensive care unit management, and then a fatal respiratory distress syndrome that becomes refractory to oxygenation. Several diagnostic modalities have been advocated and evaluated; however, in some cases, diagnosis is made on the clinical picture in order not to lose time. A consensus on what constitutes special treatment for COVID-19 has yet to emerge. Alongside conservative and supportive care, some potential drugs have been recommended and a considerable number of investigations are ongoing in this regard.

Objective(s): Tissue engineering aims to achieve a tissue, which has highly interconnected porous microstructure concurrent with appropriate mechanical and biological properties. Materials and Methods: Therefore, the microstructure scaffolds are of great importance in this field. In the present study, an electroconductive poly-lactic acid (EC-PLA) filament used to fabricate a porous bone scaffold. For scaffolds model designed, solid-work software was used. Then, the designed modeled was transferred to simplify 3D to laminated with its G-Code file for fused deposition modeling (FDM) printer to create a scaffold with porosity around 65-75%. Two different shapes were designed and fabricated (cylindrical and cubic shape). The samples were coated with hydroxyapatite (HA) nanoparticle to enhance its chemical stability. In this study, the X-ray diffraction (XRD) confirmed that the EC-PLA is non-crystalized and scanning electron microscopy (SEM) used to present the apatite formation on the surface of porous scaffolds. The compression test, fracture toughness, and hardness were measured. The biological response in the physiological saline was performed to determine the rate of degradation of EC-PLA in phosphate buffer saline (PBS) and the apatite formation in the simulated body fluid (SBF) after 14 days. Results: Finally, the biocompatibility of the porous architecture was monitored using human gum (HuGu) cells. The ABAQUS modeling simulation was used to compare the experimental and analytical results. The obtained results showed that by applying force to both cylindrical and cubic scaffold, the Von Mises Stress (VMS) could withstand the scaffold mentioned above at 9.7-11 MPa. Conclusion: Therefore, it can be concluded that prepared porous scaffolds have a high potential in bone tissue engineering and probably the treatment of tumor-related bone defects as photothermal therapy. The porous EC-PLA scaffold was successfully fabricated and showed appropriate compressive strength (39.14 MPa), with controllable porosity of 60-70 %, which is a suitable candidate for replacing in bone tissues.

In Osteoporosis, bone mechanical strength decreases and as a result, the risk of bone fracture increases. Osteoporosis is also referred as a "silent illness" since it usually develops asymptomatic until it breaks a long bone, like the femur. In recent years, porous scaffolds have been utilized to repair damaged bone tissue. For bone tissue engineering, synthetic scaffolds should have acceptable mechanical properties, in addition to the required biological properties. In this regard, the finite element simulation is used to predict the mechanical properties of porous bone scaffolds as one of the most common methods for reducing the experimental tests, because the acquisition of mechanical properties of such scaffolds is very time-consuming and expensive. Due to the widespread use of hydroxyapatite (HA) in the manufacture of bone scaffold composites, the mechanical properties of HA-wollastonite scaffold composites are obtained by laboratory tests and finite element methods. Comparison of the simulation of finite element analysis (FEA) and the experimental results indicate the success of the FEA simulation. In conclusion, new finding satisfied expectations as being suitable for mechanical and biomaterial aspect of a porous scaffold which is proven by laboratory tests and FEA simulations. Due to that fact, the result of this study can be employed to obtain scaffolds well-suited for bone implementations.

Background: A study conducted on wound treatment by antibacterial wound dressings can reduce the need for using antibiotics to a minimum amount. These wound dressings can create a moist environment at the wound surface to speed the healing process up. In recent years, researchers have paid much attention to polymeric wound dressings. Chitosan can help heal the wounds because of its similar structure to glycosaminoglycans in the skin. In this regard, the aim of the present study was to fabricate and characterize a novel biolayer wound dressing based on the carboxymethyl chitosan polymer with ceramic nanoparticles as a reinforcement and antibacterial agent using the freeze-drying method. Methods: In this study, to make a flexible wound dressing from a biocompatible and biodegradable polymer, N-O-carboxymethyl chitosan, diopside was added to improve the mechanical and hydrophobic properties of the soft tissue and cell proliferation was fabricated. After making the samples, a variety of chemical and biological tests and analyses were performed on the samples, including scanning electron microscope and Fourier-transform infrared spectroscopy. Results: The results showed that the use of this wound dress significantly reduced the risk of infection at the wound site. Conclusions: An antibacterial product with the proper mechanical behavior as a soft tissue was produced and evaluated in this study. The chemical and biological investigation represented that the sample with 5 wt% magnetite nanoparticles has excellent characteristics and can be introduced as a wound dressing application.

Objective(s): Cardiovascular diseases (CVDs) are the leading cause of mortality in the elderly. A common medical procedure for the treatment of CVDs is the replacement of the blocked or narrowed arteries, which is currently the optimal vascular transplant associated with autograft transplantation. In general, the saphenous veins and radial arteries in the mammary gland are considered to be the selective vessels for vascular substitution. In many cardiac patients, artificial blood vessels (ABVs) are not used for several reasons, including the age of the patient, small size of the veins, previous impressions, and abnormally. Therefore, the consideration of vascular substitute demands is inevitable, especially regarding vascular transplantation with very small diameters and availability of proper alternatives. The present study aimed to develop a novel artificial bio-composite blood vessel using polymer-reinforced and bioceramic nanoparticles. Materials and Methods: The biomechanics and chemical properties of artificial vessels have been investigated to be used in coronary artery bypassing in atherosclerosis as a soft tissue engineering procedure. In this study, thermoplastic polyurethane (TPU) composed of nanocrystalline hydroxyapatite (HA) nanopowder was prepared using the extrusion technique to construct the ABVs. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the optimum specimen. An important feature of the ABVs was the ability to find the elastic modulus, wettability, and porosity of the veins, which were assessed by fused deposition modeling and 3D printing. Results: The sample containing five wt% of HA had superior mechanical and biological features over the pure sample. Conclusion: According to the results, the narrowed arteries composed of TPU composite with nanocrystalline HA nanopowder had proper chemical stability and mechanical characteristics.

The subcutaneous or hypodermic tissue is the innermost layer of the skin, which is essential for adipose tissue. The dermal attachment to the epidermis is a basal layer composed of collagen. This basal layer performs four different functions and acts as a scaffold for soft tissue organization. It is citing for regeneration that has selective permeability for serum filtration. Also, it is a barrier between different cell types, and cite where the epithelium subcutaneous to the cells. Untreated, bedsores can lead to serious complications, one of which is cellulite, a potentially life-threatening bacterial infection. As the bedsore wound spreads to the joints and bones, it may cause bone and joint infections that can damage the cartilage, tissue, and reduce joint function. The bacteria can then enter the bloodstream through wounds, leading to shock and life-threatening conditions. Stage II wounds can heal in one to six weeks, but wounds that lead to stage three or four may last several months or may never heal, especially in children with health problems. The purpose of this study was to design bio-based wounds with gelatin, Gum Arabic, and polyurethane. The wounds were made with different bio composite specimens. The procedure is gelatin, and gum Arabic was combined with certain percentages. The temperature of mixing and solubilization was set at 50°C. After complete fabrication of the material and complete dissolution of the samples in the solvent without any agglomeration, the samples were placed in a low-temperature freezer at -70°C and were placed in a freeze dryer. After the drying process is completed and the pores are ready on the wound heal sample, in the next stages, several tests are carried out to check the suitability of the produced wounds. The SEM analysis was performed on bio-based wounds in which the results showed the suitability and porosity of these wound dress were suitable. The presence of proper porosity and moisture level for wound healing and non-acidity, as well as the use of bed wound healing, have been distinguished from other conventional wound healing products in the market and research domain.

Objective (s): Artificial bone implants have been studied as a possible bone replacement for fractured and destroyed facial tissue; the techniques employed to determine the success of the dental implants. The stability, porosity and resistance of the bone implant which is subjected to varying forces and stresses within the surrounding bone is a subject of interest among the dentists. Materials and Methods: An experimental analysis was conducted on bio-nanocomposite scaffold using space holder methods. The reaction of the bio-nanocomposites deformation under load was determined using Abaqus software. Thereafter, an analytical solution was presented to express explicitly the deformation responses of the artificial bone implant. Results: It was seen that the vibrational behavior and mechanical performance of the sample containing 15 wt% additives have shown better mechanical characteristic compared to the pure specimen. On the other hand, the additive weight fraction has a significant effect on the compression test and porosity value. Also, the elastic modulus of the samples increases more than two times with the addition of additive (from 60 MPa to 145 MPa). From the results, it can be concluded that the highest vibration variation is seen in the sample with lower MNPs percentages.Conclusion: By observing the results of the stresses, it was seen that the stresses were in a small value in the bio-nanocomposites with highest amount of reinforcement.

Objective(s): Bioactive silicate ceramics have favorable features for applying as off-the-shelf bone and artificial tissue. Calcium silicate can enhance the generation of an immediate bond with host bone without an intervening rough surface in the bone layer. However, the silicate bioceramics have some drawback regarding their mechanical properties and chemical stabilities. Materials and Methods: In this study, magnetite nanoparticles (MNPs) as reinforcement were added to the three silicate bioceramics to investigate the physical and mechanical properties as well as their magnetic behavior as a case study and compare with other calcium silicate nanocomposite which are excellent candidates for hyperthermia applications. Then the artificial neural network (ANN) applied to the previous data to predict the mechanical and biological behavior of the bio-nanocomposite as output parameters. A predicted model was enhanced using ANN to measure the optimum size and reinforcement amount of the magnetite bio-nanocomposite. The results of the fabricated bio-nanocomposite were extracted experimentally corresponding to different MNPs weight fractions compared to the predicted model. Results: The X-ray diffraction (XRD), scan electron microscopy (SEM) technique were used to compare the porosity and porous tissue microstructure. Thereafter, an analytical solution is presented to express explicitly the physical and mechanical responses of the bulk/scaffold bio-nanocomposite. Conclusion: The obtained results showed the potential application of these calculations and analyses in a wide range of numerical studies. The comparison presented within the test and predicted values showed that the modeling outcomes were close to testing values.

Objecttive (s): Silicate bioceramics like Baghdadite with chemical formula Ca3ZrSi2O9, has attracted the attention of researchers in biomedical field due to its remarkable in-vitro and in-vivo bioactivity and mechanical properties.Materials and Methods: Therefore, in the current study the baghdadite powder with Sol-Gel method was synthesized. Then, hydroxyapatite/Baghdadite (HA/Bagh) scaffolds were prepared by the replacing the polyurethane polymeric sponge technique. Afterwhile, the ceramic scaffolds were sintered at 1150ºC for 3 h. The prepared scaffold was then coated by polycaprolactone/bioglass (PCL/BG) polymer nanocomposite. Results: Bioactivity and biomineralization in the simulated body fluid (SBF) revealed that the nanocomposite scaffolds coate with PCL/BG had significant bioactivity properties. The morophology and microstructure investigation of soaked samples in SBF indicate that bone-like apatite formed on the surfaces. Also, ion release in SBF containing the scaffolds was measured by inductively coupled plasma (ICP) analysis. The nucleation positions of apatite crystals were areas with high silicon containing, Si+4 ion positions.Conclusion: The study indicates that scaffold containing 30 wt. % baghdadite had proper bioactivity behaviordue to its ability to form bone-like apatite on the surface of specimens.

Background: Biopolymer scaffolds have received great interest in academic and industrial environment because of their supreme characteristics like biological, mechanical, chemical, and cost saving in the biomedical science. There are various attempts for incorporation of biopolymers with cheap natural micro- or nanoparticles like lignin (Lig), alginate, and gums to prepare new materials with enhanced properties. Methods: In this work, the electrospinning (ELS) technique as a promising cost-effective method for producing polymeric scaffold fibers was used, which mimics extracellular matrix structure for soft tissue engineering applications. Nanocomposites of Lig and polycaprolactone (PCL) scaffold produced with ELS technique. Nanocomposite containings (0, 5, 10, and 15 wt.%) of Lig were prepared with addition of Lig powder into the PCL solution while stirring at the room temperature. The bioactivity, swelling properties, morphological and mechanical tests were conducted for all the samples to investigate the nanocomposite scaffold features. Results: The results showed that scaffold with 10 wt.% Lig have appropriate porosity, biodegradation, minimum fiber diameter, optimum pore size as well as enhanced tensile strength, and young modulus compared with pure PCL. Degradation test performed through immersion of samples in the phosphate-buffer saline showed that degradation of PCL nanocomposites could accelerate up to 10% due to the addition of Lig. Conclusions: Electrospun PCL-Lig scaffold enhanced the biological response of the cells with the mechanical signals. The prepared nanocomposite scaffold can choose for potential candidate in the biomedical science.

Iranian Gum Tragacanth (IGT) is among the most natural polymers which has interesting properties such as nontoxic nature, biodegradability and high resistance to bacterial attacks making it applicable for tissue scaffolds, protective clothing, and wound healing. In the current work, polyvinyl alcohol (PVA)/IGT nanocomposite fibre is prepared by using the electrospinning (ELS) technique in an aqueous solution with different volume ratios of 60/40, 70/30, 80/20, and 90/10. To enhance the chemical and mechanical stability of the produced samples, different amounts of nanoclay powder (1% and 3%) are added also to the solution. The blended nanofibres are characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and bioactivity evaluation in phosphate buffered saline (PBS) and simulated body fluid (SBF) solutions. The FTIR analysis indicated that PVA and IGT may have H+ bonding interactions. The results revealed that with a higher amount of IGT, a superior degradation as well as a higher chemical and biological stability could be obtained in the nanobiocomposite blend fibres. Furthermore, the blend nanofibre samples of 80/20 and 3% nanoclay powder exhibit a significant improvement during evaluation of its properties.

Introduction: Bone tissue engineering proposes a suitable way to regenerate lost bones. Different materials have been considered for use in bone tissue engineering. Hydroxyapatite (HA) is a significant success of bioceramics as a bone tissue repairing biomaterial. Among different bioceramic materials, recent interest has been risen on fluorinated hydroxyapatites, (FHA, Ca 10 (PO 4 ) 6 F x (OH) 2−x ). Fluorine ions can promote apatite formation and improve the stability of HA in the biological environments. Therefore, they have been developed for bone tissue engineering. The aim of this study was to synthesize and characterize the FHA nanopowder via mechanochemical (MC) methods. Materials and Methods: Natural hydroxyapatite (NHA) 95.7 wt.% and calcium fluoride (CaF 2 ) powder 4.3 wt.% were used for synthesis of FHA. MC reaction was performed in the planetary milling balls using a porcelain cup and alumina balls. Ratio of balls to reactant materials was 15:1 at 400 rpm rotation speed. The structures of the powdered particles formed at different milling times were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: Fabrication of FHA from natural sources like bovine bone achieved after 8 h ball milling with pure nanopowder. Conclusion: F− ion enhances the crystallization and mechanical properties of HA in formation of bone. The produced FHA was in nano-scale, and its crystal size was about 80-90 nm with sphere distribution in shape and size. FHA powder is a suitable biomaterial for bone tissue engineering.

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