Showing 11 results for Scaffold
M. Raz, F. Moztarzadeh, M.a. Shokrgozar, M. Ashuri, M. Tahriri,
Volume 32, Issue 2 (12-2013)
Abstract
In this project, we prepared biomimetic nanocomposite scaffolds from gelatin and chitosan and hydroxyapatite and subsequently the scaffolds were evaluated by common used bulk technique. For this purpose, the nanocomposite hydrogel/apatite bone tissue engineering scaffolds were fabricated using applied biomimetic method accompanied with freeze drying technique. The apatite was precipitated using double diffusion mechanism within gelatin hydrogel in similar pH and temperature to the human body. Chitosan initial percentage (20, 30 and 40%) was set as variables. Nanocomposites were soaked in glutaraldehyde solution in order to enhance mechanical properties and make them insoluble in water. Diffusion of calcium and phosphate from lateral hydrogel into the middle hydrogel caused formation of parallel white layer-formed precipitate. Analysis of precipitates formed within middle hydrogel for the samples, showed that detected materials are composed of carbonated hydroxyapatite and dicalcium phosphate dihydrate (DCPD, brushite). Also, mechanical behavior obtained for the scaffolds were comparable with spongy bone. With increasing chitosan in the composite scaffold, the water up-take was increased from 379 to 661%. Phase composition, microstructure and structural groups in the composite samples were also characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR) analyses. Eventually, the obtained results showed that the composite contains 20% chitosan had appropriate properties for fabricating bone scaffold.
A. Abdolahi, M. R. Saeri, F. Tirgir, A. Doostmohammadi, H. Sharifi,
Volume 35, Issue 1 (6-2016)
Abstract
In this study, NBG was successfully achieved through a sol-gel technique, and to further improve its dispersibility, a crylate coupling agent was coupled onto the surface of the NBG. The 3-(Trimethoxysilyl)Propylmethacrylate coupling agent was used to the surface modification of the synthesized NBG by a wet-chemical method in a dynamic inert nitrogen atmosphere. The surface properties of the biomaterials before and after modification were characterized and compared using FTIR and AFM techniques. The characteristic peaks in FTIR spectra indicated that –CH2, –CH3 and C=O groups appeared on the surface of modified NBG, and also, AFM analysis revealed that the dispersibility of surface modified NBG was improved, significantly. The above results proved that the desired groups of 3-(Trimethoxysilyl)Propyl methacrylate had been covalently bonded onto the surface of NBG. Besides, a nanocomposite scaffold was synthesized using the synthesized NBG and polyurethane foam as raw materials. The morphology of pores, porosity contents, compress strength and bioactivity of the scaffold were studied. The results showed that the biological scaffolds for use in bone tissue engineering with the basic requirements (90% porosity and 200-600 μm pore diameter) were successfully prepared. The polymer component had no effect on the relationship between the scaffold pores and bioactivity of bioglass nanoparticles. Improvement of compressive strength and proper bioactivity of the resulted scaffold showed that it is an acceptable candidate for biomaterials applications.
M. Baradaran, S.s. Shafiei, F. Moztarzadeh, S.z. Mortazavi,
Volume 35, Issue 3 (12-2016)
Abstract
In recent years the use of nanomaterials in bone tissue engineering scaffold has been considered due to its imitating the structure of natural bone tissue which contains a nanocomposite structure mixed with a three-dimensional matrix. In the meantime, Polycaprol actone has been used as a bio-polymer in bone tissue engineering applications as a scaffold. The aim of this study is to develop porous scaffolds made of polycaprol actone/layered double hydroxide biocomposite, with appropriate mechanical, bioactive and biological properties, for bone tissue engineering application. The nanocomposite scaffolds were fabricated by the particulate leaching method and freeze-drying method. In this study, MG63 cells (osteosarcoma) was investigated for cellular study. Energy dispersive X-ray analysis confirmed uniform distribution of ceramic phase in polycaprol actone matrix. The results of mechanical tests showed the increase in young’s modulus after addition of ceramic phase. The microscopic investigations demonstrated that the pores generated after addition of ceramic phase and the average size of pores was as large as 100-600μm. Also by the addition of LDH, the hydrophilicity of PCL increased but the rate of hydroxyapatite formation was delayed due to presence of magnesium ions. The cell culture experiments confirmed the attachment and proliferation of cells on the scaffolds. The results showed that the fabricated scaffolds have the potential to be used in cancellous bone tissue engineering.
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.
S. Sadeghzade, R. Emadi, Sh. Labbaf,
Volume 37, Issue 1 (6-2018)
Abstract
In the recent three decades, Ca-Si-based ceramics have received great attention as an appropriate candidate for tissue engineering applications due to their remarkable bioactivity, biocompatibility, and good bone formation ability. Hardystonite is currently recognized as a bioactive and biocompatible bio-ceramic material for a range of medical applications. In the present study, for the first time, hardystonite powder and 3D hardystonite scaffold with interconnected porosity were produced using mechanical alloying synthesis and the space holder method, respectively. It was found that pure nano-crystalline hardystonite powder formation occurred following 10 h of milling and subsequent sintering at 800 C° for 3 h. The measured crystallite size of particles and the hardystonite scaffold was found to be 28 ± 2 and 79 ± 1 nm, respectively. The results also showed that nanostructured hardystonite scaffolds with the compressive strength and modulus of 0.35 ± 0.02 and 10.49 ± 0.21 MPa, the porosity of 81 ± 1% , and pores size range of 200–500 μm were successfully synthesized after sintering at 1250 °C for 3 h. During the sintering process, NaCl (80wt%, 300-420 µm), as the spacer agent, gradually evaporated from the system,producing porosity in the scaffold. Simulated body fluid (SBF) was used to evaluate the apatite formation ability of the scaffolds. The results showed that the formation of an apatite layer on the scaffold surface could be considered as a bioactivity criterion.
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. Sohrabi, M. Abbasi, M. M Ansar,
Volume 38, Issue 1 (6-2019)
Abstract
In this study, using biodegradable polymers, nanofiberouse scaffolds were fabricated from the layer-by-layer electrospinning method, including two layer that poly (ε-caprolactone), polyvinylpyrrolidone deposited at first layer and poly (ε-caprolactone), polyvinyl alcohol , β-tricalcium phosphate at latter. After prepration of scaffolds, scanning electron microscopy (SEM), swelling, porosity, mechanical properties and biodegradability behavior in buffered saline phosphate solution were studied. The results confirmed the bioactivity and suitable mechanical properties of the layer-by-layer scaffold. The swelling increase with the addition of hydrophilic polymers and reache 811 ± 214 % in the layer-by-layer scaffold, which reveald a significant difference compared to pure PCL. The MTT test on the layer-by-layer scaffold, after 3, 5 and 7 days of rats bone marrow stem cells (rMSC) culture, showed the cell viability of above 80% moreover, cells morphology on the scafold indicated the optimal compatibility of cells on the scaffold.
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. Fareghdeli, M. Karimi, A. Novin, M. Solati-Hashjin,
Volume 40, Issue 3 (11-2021)
Abstract
One challenge in preparing polymer/ceramic composites is non-uniform ceramic particles distribution in a polymer matrix. This research evaluated the effect of stirring time and temperature on hydroxyapatite (HA) distribution through (polylactic acid) PLA matrix. Therefore, to mix the ceramic suspension with the polymer solution, three temperatures, namely 25, 37, and 45°C and four times including 6, 12, 24 and, 48 h were examined. Fourier-transform infrared spectroscopy (FTIR) analysis was used to investigate the bonds, which showed physical bond formation such as carboxyl-calcium-carboxyl between HA and polymer matrix, influenced on particles distribution. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS) were used to observe particles distribution and determine samples homogeneity. To fulfill this goal, each obtained photograph representing the calcium presentation was split into nine equal sections, and a method based on the newly defined index called dispersion factor “α” was used to analyze the distribution. Results showed that the sample prepared at 37°C and 48 h had the topmost homogeneity properties.
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.
