Showing 16 results for Subject: Biomaterials
M. Kouhi, M. Shamanian, M. Fathi, Molamma Prabhakaran, Seeram Ramakrishna,
Volume 36, Issue 3 (11-2017)
Abstract
In this work, poly (hydroxybutyrate co hydroxyvalerate) (PHBV) composite nanofibrous scaffold containing hydroxyapatite/bredigite (HABR) nanoparticles was fabricated through electrospining method. The morphology of prepared nanofibers and the state of the nanoparticles dispersion in nanofiber matrix were investigated using scanning and transmission electron microscopy, respectively. Evaluation of the mechanical properties of the nanofibrous scaffolds revealed that there is a limit to the nanoparticle concentration at which nanoparticles can improve the mechanical properties of the nanofibrous scaffolds. According to the results, PHBV/HABR nanofibers showed higher wettability compared to PHBV nanofibers. In vitro cell culture assay was done using human fetal osteoblast cells on nanofibrous scaffold. MTS assay revealed that cell proliferation on the composite nanofibrous scaffold was significantly higher than those on the pure scaffold after 10 and 15 days. Scanning electron microscopy- Energy dispersive X-ray spectroscopy and CMFDA colorimeter assay analysis showed that the cells on the PHBV/HABR scaffolds acquired higher mineral deposition than the cells on the pure PHBV and control sample scaffold. Based on the results we concluded that PHBV/HABR nanofibers scaffold with higher wettability, improved mechanical properties and cell behavior hold great potential in bone regeneration applications.
M. H. Barounian, S. Hesaraki, A. Kazemzadeh,
Volume 37, Issue 1 (6-2018)
Abstract
In this study, a new bioactive and light-cure polymeric calcium phosphate nanocomposite containing a powder phase consisting of pure TetraCalciumPhosphate was synthesized by solid state sintering. By using indomethacin, a non-steroidal anti-inflammatory drug, and a liquid phase including polyhydroxy-based resin, Ethyl Methacrylate was prepared and evaluated after curing with the high-intensity blue light. Phase changes in the cement composition after soaking in phosphate buffered saline (PBS) were investigated using X-ray diffraction (XRD). Morever, changes in the chemical groups in the cement and the microstructure of the cement after soaking in the PBS were investigated by Fourier transform spectroscopy (FTIR) and electronscanning microscopic (SEM) images, respectively. XRD patterns and SEM images showed that after soaking the samples in. the PBS solution, a new calcium phosphate phase with a shape like needle and polka appeared on the surface, which was formed more in the drug-containing sample at a concentration of 5% wt. of these nanostructures. Other results also showed that with the passage of time, the structural degradation in the PBS was due to the conversion of the initial phases to the calcium phosphate phase (apatite). Also, the results of the mechanical strength test of polymeric cement samples containing the drugshowed that the mean compressive strength of the samples after the fixation was about 56 MPa, and it was decreased by 26 MPa with continuous immersion after 21 days.
S. Ghadiri, A. Hassanzadeh-Tabrizi,
Volume 37, Issue 1 (6-2018)
Abstract
In this study, the synthesis of nano-porous calcium magnesium silicate was performed and studied to improve drug properties and drug release. This synthesis was carried out by using the tetraethyl ortho silicate precursor (TEOS) and the Cetyltrimethyl ammonium bromide surfactant (CTAB) in a sol-gel alkaline environment; and the product was heat treated at 600° C and 800° C temperatures. The purpose of this study is to investigate the effect of the calcination temperature on the potential for ibuprofen release by the production produced compound. The product was studied using X-ray diffraction patterns (XRD), Nitrogen adsorption / desorption, Fourier-transform infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV) and Transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). The results of Nitrogen absorption-desorption assay showed a surface area of 42-140 m2 /g The drug release after 240 hours showed that the calcite sample had a lower release at 600 ° C, temperature that which was is due to the smaller size of the cavities and the more surface area, as compared tothan the other specimens. Also, calcium and magnesium elements increased the loading capacity, and createcreating a suitable substrate for for the slower drug release. Overall, This this study showed that nano-porous magnesium silicate calcium has had the ability to load and release the ibuprofen and can could be, therefore, used as a modern drug delivery system in the bone tissue engineering field.
S. F. Shams, M. Ebrahimian-Hosseinabadi,
Volume 37, Issue 2 (9-2018)
Abstract
The purpose of this paper was modeling and mechanical analysis of the biodegradable biphasic calcium phosphate/silk (BCP/Silk) laminated composite bone plate for fractured tibia healing; to this aim,ABAQUS 6.13 was employed for modeling and mechanical analysis. First, the tibia bone was considered based on the anthropometric measurements of an average person as a two-layer cylinder; the inner part was the bone marrow and the outer one was the cortical bone. Then, the bone plate and screws were designed according to the defined standards and the properties of new composite in the ABAQUS software. The mesh of bone plate and other equipments were selected to be tetragonal and cubic, respectivelly. After that, the bone plate was placed on the bone while the bone was bounded along the Y axis and the force of around 400 N was loaded. The results showed that the biocompatible and biodegradable composite bone plate had the elastic modulus of about 21 GPa, which was close to the bone modulus.
Sh. Tavakoli Dehaghi, S. Darvishi, Sh. Nemati, M. Kharaziha,
Volume 37, Issue 3 (12-2018)
Abstract
Abstract: With the advances in the development of biomaterials for tissue replacement, the attention of scientists has been focused on the improvement of clinical implant properties. In this regard, despite the appropriate properties of the stainless steel, the application of stainless steel as implants has been limited due to the weak corrosion resistivity. The purpose of this paper was preparation and characterization of hydrophobic polydimethylsiloxane (PDMS)-SiO2-CuO nanocomposite coating on the 316L stainless steel surface. The 316L stainless steel was coated by SiO2 nanoparticles (20 wt. %), CuO nanoparticles (0.5, 1 and 2 wt. %) and biocompatible PDMS. In this research, x-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the coating. Moreover, the roughness and water contact angle of the coatings consisting of various amounts of CuO nanopowder were estimated. Finally, the effects of various amounts of the CuO nanopowder on the corrosion resistivity of nanocomposite coatings were investigated. XRD patterns confirmed the presence of crystalline CuO nanoparticles on the substrate. Due to the non-crystalline nature of silica nanoparticles and the semi-crystalline PDMS polymer, no peak confirming the presence of these phases was detected on the XRD pattern of the nanocomposite coating. SEM images showed the formation of a lotus leaf-like layer on the surface of the nanocomposite coating containing 1 and 2 wt. % CuO. Moreover, water contact angle evolution revealed that while contact angle was 81 degree without CuO nanoparticles, it was enhanced to 146 degree in the presence of 1 wt. % CuO. Moreover, the corrosion study showed the nanocomposite containing 2 wt.% CuO had the best corrosion resistance, the corrosion current density of 2.1E-7 A.cm-2, and the corrosion potential of 0.22 V.
M. Akbari Taemeh, B. Akbari, J. Nourmohammadi,
Volume 37, Issue 3 (12-2018)
Abstract
In gradient scaffolds, changes in porosity, pore size or chemical composition occur gradually. Recently, different methods have been applied to create gradient in the scaffolds, but they have some disadvantages such as high cost and control. The main purpose of this research was to fabricate porous gradient scaffolds by a novel, functional, simple, and low-cost method. Two homogenous scaffolds (Homog 1 and Homog 2) and two gradient scaffolds (Grad 1 and Grad 2) were fabricated and compared. Polycaprolactone scaffolds with the pore size gradient along the radial direction were fabricated by combining layer-by-layer assembly and porogen leaching techniques. Paraffin micro particles were used as porogen in two size ranges: 250 to 420 µm and 420 to 600 µm. The average pore size of Homog 1 and Homog 2 was 278.48 ± 11.23 µm and 417.79 ± 14.62, which were suitable for bone tissue engineering. The porosity of the samples was: Homog 1: 77.5 ± 1.25 %, Homog 2: 61.3 ± 3.5 %, Grad 1: 74 ± 0.5 % and Grad 2: 79.8 ± 4 %. It should be stated that the required porosity for cell survival and growth was above 70 %. Compressive strength at 80% strain and compressive modulus for Homog 1, Homog 2, Grad 1 and Grad 2 were 0.16 ± 0.16 MPa and 0.25 ± 0.11 MPa, 0.26 ± 0.20 MPa and 0.53 ± 0.34 MPa, 0.19 ± 0.34 MPa and 0.33 ± 0.43 MPa, 0.12 ± 0.28 MPa and 0.16 ± 0.51 MPa, respectively. The results showed that pore size gradient had a negligible effect on the mechanical properties of the scaffolds and using polycaprolactone (PCL) as the only material of scaffold was not appropriate. The structure of gradient scaffolds showed the radial pore size gradient with a good adhesion between layers without any detectable interface; the result of the compression test also confirmed it.
M. Afrashi, D. Semnani, Z. Talebi,
Volume 38, Issue 2 (9-2019)
Abstract
In this study, adsorption of fluconazole on silica aerogel was performed successfully by the immersion method in the 1% solution of fluconazole-ethanol at the ambient condition and without using the supercritical method. The hydrophobic and hydrophilic silica aerogels were synthesized by the two-stage sol-gel method and dried at the ambient temperature. This method had most of drug loading at 24 h. It was 1.92% and 1.98% for the hydrophilic and hydrophobic silica aerogels, respectively. Physical properties of the synthesized aerogels were studied by the nitrogen absorption and desorption tests. The presence of fluconazole and the chemical structure of the samples were determined by fourier-transform infrared spectroscopy (FTIR). As well, the loading and release of the drug were investigated using a spectrophotometer. The results showed the structure of the synthesized aerogels had a pore diameter of 6-8 nm and a surface area of about 800-100 m2/g. The study of the drug release also revealed that the release rate of fluconazole in the hydrophilic silica aerogel was higher than that of the hydrophobic sample.
F. Soleimani, R. Emadi,
Volume 38, Issue 3 (12-2019)
Abstract
In this study, polycaprolactone/chitosan/1% baghdadite composite coating was applied on anodized AZ91 alloy to improve the corrosion rate of AZ91 alloy in simulated body fluid (SBF) solution for long immersion times, control its degradability and enhance its bioactivity. By applying the composite coating and after seven days of immersion in a phosphate buffer solution, the corrosion rate decreased from 0.21 mg/h.cm2 (for AZ91 sample) to 0.1 mg/h.cm2 (for anodized AZ91 sample). Formation of apatite layer on the surface of specimens is considered a criterion for bioactivity. In order to evaluate the ability of specimens to get covered by an apatite, the SBF test was used. Application of the composite coating yielded the highest ability for apatite formation, controlled release of ions, and the lowest corrosion rate in the SBF so that it could be considered a good choice for bone implants.
N. Safari, M. Toroghinejad, M. Kharaziha, V. Saeedi,
Volume 38, Issue 3 (12-2019)
Abstract
The aim of this study was to fabricate the Mg-1Al-Cu alloys with various amounts of Cu content (0, 0.25, 0.5 and 1 wt.%) using spark plasma sintering (SPS) approach and evaluation of their degradation rate and biological properties. The results indicated that Cu incorporation (0.25 wt.%) significantly diminish degradation rate from 0.039 cm/h in pure Mg to 0.00584 cm/h in Mg-1Al-0.25Cu alloy. In addition, Mg-1Al-0.25Cu alloy could noticeably (1.25 times) promote viability of MG63 cells compared to pure Mg, owing to the optimized ion release. Moreover, the antibacterial activity of Mg-1Al-0.25Cu was considerable. In summary, Mg-1Al-0.25Cu alloy with appropriate degradation rate, good biocompatibility and antibacterial properties can be introduced as a biodegradable orthopedic implant.
N. Bahremandi Tolou, H. R. Salimi Jazi, M. Kharaziha, N. Lisi, G. Faggio, A. Tamburrano,
Volume 39, Issue 1 (5-2020)
Abstract
In recent years, graphene has been considered in various tissue engineering applications such as nerve guide conduits because of its unique properties such as high electrical and mechanical properties, porous structure for exchange of nutritious and waste materials, biocompatible, capability of drug and growth factor delivery. In the current study, nerve guide conduits based on a 3D graphene were synthesized by induction heating chemical vapor deposition (ICVD). Graphene was synthesized on Ni foam template at 1080 ͦC. Fabricated samples were characterized by Raman analysis and Scanning Electron Microscopy. Raman analysis showed that the synthesized graphene is in the form of a turbostratic multilayered graphene with little defects. Cyclododecane (CD) as a temporary protective layer was used to remove nickel. After removing nickel, the free-standing 3D-graphene structure was coated with a polymer (PCL) by drop and dip coating methods to obtain the composite conduit. A comparison of the electromechanical results of the 3D-graphene/PCL conduit and PCL conduit indicated that firstly, grapheme increased the electrical conductivity of the composite conduit which will help promote nerve regeneration and axon growth. Secondly, tensile strength and flexibility of the 3D-graphene/PCL conduit was improved compared to the PCL conduit.
S. Torabi, S. Khorshidi, A. Karkhaneh,
Volume 39, Issue 2 (8-2020)
Abstract
For many years, dexamethasone has been used as an anti-inflammatory drug and is still one of the safest glucocorticoids for treating various diseases. Due to the wide range of the side effects of this drug, it is essential to find a suitable delivering system for reduction in dosage with increased effectiveness. Electrospinning is one of the fiber fabrication methods which is widely used to develop drug carriers due to its ability to load various drugs and biological components and control their release. In this research, neat poly (lactic acid) electrospun fibers and dexamethasone loaded fibers were prepared. To evaluate the effect of polymer concentration on morphology, mechanical properties and drug release profile of the resulting fibers, three polymer concentrations of 10%, 14% and 18% w/v were processed. Thereafter, 5% w/v dexamethasone was added to solutions. The scanning electron microscopy images were investigated to obtain the average diameter of fibers and the average area of pores in each sample. In neat samples, by moving from 10% to 18% composition, the average diameter of the fibers increased by 63.21%. However, in drug loaded samples this increased by 51/19%. After evaluating mechanical properties, an increase of 81/34% in Elastic modulus by moving from 10% to 18% composition was observed. Moreover, the ultimate strength increased by 68/021% when increasing the polymer concentration from 10 to 18%. Drug release from the electrospun samples was continued up to 7 days. Linear release was observed in 10% and 14% compositions. The drug release pattern of these samples was of zero order. Considering the importance of zero order release in different applications of dexamethasone, these delivering systems could be useful. The maximum drug release rate belonged to 14% composition (0.044 1/h).
S. S. Shafiei, M. Shavandi , Y. Nickakhtar ,
Volume 39, Issue 4 (2-2021)
Abstract
Tissue-engineering scaffolds provide biological and mechanical frameworks for cell adhesion, growth, and differentiation. Nanofibrous scaffolds mimic the native extracellular matrix (ECM) and play a significant role in formation and remodeling of tissues and/or organs . One way to mimic the desired properties of fibrous ECM is adding nanoparticles into the polymer matrix. In the current study, the uniform fibers of poly (ε-caprolactone) (PCL) enriched with different layered double hydroxide (LDH) contents (ranging from 0.1 wt.% to 10 wt.%) were successfully fabricated by electrospinning method. The LDH nano particles were randomly dispersed in the fibers, as confirmed by Energy Dispersive X-ray analysis (EDX). Scaffolds were analyzed from morphological, physical and mechanical view. Biological assessments of scaffolds in terms of cellular attachment and adipogenic differentiation of mouse adipose derived stem cells (mADSCs) were performed. The results showed that inclusion of LDH nanoparticles reduced the average fiber diameter and enhanced the tensile strength and elongation at break values of the PCL scaffold. The LDH-enriched electrospun PCL scaffolds had remarkable effects on cell adhesion. Moreover, a significant increase in adipogenic differentiation of mADSCs was observed. The PCL/LDH nanofibrous scaffolds showed great potential in application for soft tissue engineering.
N. Zakeri, H.r. Rezaie, J. Javadpour, M. Kharaziha,
Volume 39, Issue 4 (2-2021)
Abstract
In recent years, nanoceramics have been used in scaffolds to emulate the nanocomposite with a three-dimensional structure of natural bone tissue. In this regard, polycaprolactone biopolymer is widely used as a scaffold in bone tissue engineering. The goal of this research is to produce porous scaffolds of polycaprolactone - zeolite biocomposite with suitable mechanical, bioactive and biological properties for bone tissue engineering applications. The nanocomposite scaffolds were synthesized by solvent casting/particulate leaching and freeze-drying approaches. Microscopic investigations showed generation of pores with an average size of 200-400μm after addition of ceramic phase. Energy dispersive X-ray analysis confirmed uniform distribution of ceramic phase in polycaprolactone matrix. FTIR results determined the binding type of zeolite nanoparticles to the polycaprolactone matrix as physical bonding. The results of mechanical tests showed the increase in young’s modulus after addition of ceramic phase (from 0.04 to 0.3 and 3 to 7 MPa, respectively). The hydrophilicity of polycaprolactone increased after adding nanozeolite and more weight loss was observed for scaffold containing 20% zeolite (53.52 6 1.6%) with an increase in the rate of hydroxyapatite formation. The results showed that the prepared scaffolds have potential for cancellous bone tissue engineering application.
F. Mofid Nakhae, M. Rajabi, H. R. Bakhsheshi-Rad,
Volume 40, Issue 3 (11-2021)
Abstract
Development of bioactive ceramic composite scaffold materials with enhanced mechanical strength has been a topic of great interest in bone tissue engineering. In the present study, β-tricalcium phosphate scaffolds with various amounts of bredigite and an interconnected pore network suitable for bone regeneration were fabricated by the space holder method. The effect of high concentrations of bredigite on the structure, mechanical properties (compressive strength), and in vitro bioactivity was investigated. According to the results, immersion in simulated body fluid (SBF) led to the apatite formation on the surface of the scaffold, but increasing the bredigite content caused the agglomeration of the bredigite phase at the grain boundaries and deteriorated the mechanical properties.
F. Rafati, N. Johari, F. Zohari,
Volume 40, Issue 4 (3-2022)
Abstract
In the present study, PCL/ZnO nanocomposite scaffolds containing 0, 5, and 15 wt.% of ZnO nanoparticles were prepared via the salt leaching/solvent casting method. The influence of ZnO nanoparticles on the morphology of prepared PCL/ZnO scaffolds was investigated using SEM images. The compressive strength test evaluated the effect of scaffolds’ morphology on mechanical properties. The XRD technique confirmed the desired phases in the scaffold composition. The results showed that the compressive strength and structural integrity of the scaffolds increased by increasing ZnO nanoparticles content as the reinforcement. However, the compressive strength and structural integrity decreased by increasing the amount of ZnO nanoparticles up to more than 5 wt.%. In summary, PCL/ZnO nanocomposite scaffold containing 5 wt.% of ZnO nanoparticles revealed the highest strength, compressive modulus, and structural integrity.
F. Dehghani Firoozabadi, A. Ramazani Saadatabadi, A. Asefnejad,
Volume 41, Issue 1 (8-2022)
Abstract
Today, many people need to use bone grafts and implants because of damage to bone tissue. Due to the stimulation of the immune system after implantation, infection at the operation site is very common, which causes swelling and pain in the operation area. The use of zinc oxide nanoparticles reduces infection at the operation site and reduces the patient's need for antibiotics. In the present study, the morphology of the scaffolds was investigated by field emission scanning electron microscope (FE-SEM). The toxicity of the samples was evaluated using MTT assay. The behavior of nanocomposites against Escherichia coli and Staphylococcus aureus was investigated by measuring the diameter of the growth inhibition zone. It was found that modification of scaffolds with nanoparticles caused a growth inhibition in bacterial culture medium. It was also observed that fibroblast cells on the surface of the modified scaffolds had longer survival than polymer scaffolds. This study showed that the addition of oxidizing nanoparticles improves the antibacterial properties of scaffolds and cell viability and reduces scaffold toxicity.
