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1.
In order to improve biological and mechanical properties of hydroxyapatite, the concept of hydroxyapatite-included nanocomposite coatings was introduced. By judiciously choosing constituent ceramics for composites preparation, the biological and mechanical performance of coatings can be tailored in order to meet various clinical requirements. The aim of this work was fabrication, development and characterization of novel hydroxyapatite-forsterite-bioactive glass nanocomposite coatings. The sol-gel technique was used to prepare hydroxyapatite-forsterite-bioactive glass nanocomposite in order to apply coating on 316L stainless steel (SS) by dip coating technique. The X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were used to investigate the phase structure, microstructure and morphology of the coating. In order to evaluate the forsterite incorporation influence upon bioactivity, the changes on the surfaces of the prepared composite coatings after the predicted days of contact with simulated body fluid (SBF) were investigated by SEM. Results showed that the suitable calcined temperature for nanocomposite coatings with different amounts of forsterite was 600 °C. At this temperature, the homogenous and crack-free coating could attach to the 316L SS substrate. The crystallite sizes of the prepared coatings were lower than 100 nm. The EDX analysis of hydroxyapatite-forsterite-bioglass, coated 316L SS surface, indicated consisting elements of prepared coatings and the substrate. During immersion in the SBF at pre-determined time intervals, apatite layer was formed and stimulation for apatite formation was increased with increase in forsterite amounts. It seems that hydroxyapatite-forsterite-bioactive glass nanocomposite coatings might be good candidates for biomedical applications.  相似文献   

2.
Porous ceramic scaffolds are synthetic implants, which support cell migration and establish sufficient extracellular matrix (ECM) and cell-cell interactions to heal bone defects. Hydroxyapatite (HA) scaffolds is one of the most suitable synthetic scaffolds for hard tissue replacement due to their bioactivity, biocompatibility and biomimetic features. However, the major disadvantages of HA is poor mechanical properties as well as low degradability rate and apatite formation ability. In this study, we developed a new method to improve the bioactivity, biodegradability and mechanical properties of natural hydroxyfluorapatite (HFA) by applying two-step coating process including ceramic and polymer coats. The structure, morphology and bioactivity potential of the modified and unmodified nanocomposite scaffolds were evaluated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and energy dispersive spectroscopy (EDS). The scaffold with optimized mechanical properties was HFA-30?wt%HT (HT stands for hardystonite) with a total porosity and pore size of 89?±?1 and 900–1000?µm, respectively. The compressive modulus and strength of HFA (porosity ~ 93?±?1) were improved from 108.81?±?11.12–251.45?±?12.2?MPa and 0.46?±?0.1–1.7?±?0.3?MPa in HFA-30?wt%HT sample, respectively. After applying poly(ε-caprolactone fumarate) (PCLF) polymer coating, the compressive strength and modules increased to 2.8?±?0.15 and 426.1?±?15.14?MPa, respectively. The apatite formation ability of scaffolds was investigated using simulated body fluid (SBF). The results showed that applying the hardystonite coating improve the apatite formation ability; however, the release of ions increased the pH. Whereas, modified scaffolds with PCLF could control the release of ions and improve the apatite formation ability as well.  相似文献   

3.
In this study, scaffolds with polycaprolactone (PCL) and hydroxy apatite (HA) were produced. Their properties are not sufficient to be used alone. Oleic Acid (OA) and glycerol monooleate (GMO) as organic additives were selected for a homogeneous distribution of the ceramic material in the polymer matrix. Biocomposite materials were prepared with solvent casting‐salt leaching technique using dichloromethane as the solvent. Salt was used as the porosifier. Materials were kept in simulated body fluid (SBF) to determine the bioactivity in vitro conditions. FTIR and EDX analyses for chemical characterization, tensile and compressive tests for mechanical properties, SEM analyses for surface properties and BET analyses for pore sizes, total surface areas and total pore volumes of scaffolds were performed. FTIR, EDX, and SEM analyses were repeated after SBF treatment. Pore diameters were highly increased with 3 and 20 wt% HA addition. Small amount of GMO addition is more effective on pore size. Mechanical properties of scaffolds were suitable for soft tissue applications, as smooth muscle cells, skin and cancellous bone. The cytotoxicity and cell proliferation on scaffolds were studied with smooth muscle cells (SMC) and L929 fibroblastic cells in vitro. No cytotoxic effect was observed for the scaffolds in both cell types. J. VINYL ADDIT. TECHNOL., 24:248–261, 2018. © 2016 Society of Plastics Engineers  相似文献   

4.
A hydroxyapatite/poly(ethylene-co-acrylic acid) (HAp/EAA) nanocomposite has been synthesized by a solution-based method. p-Aminophenyl phosphonic acid has been used as a coupling agent in order to enhance the bonding between HAp and EAA, and hence to improve the mechanical properties of the composite. XRD study has indicated the development of compressive and tensile stresses in a nanocomposite due to thermal expansion mismatch between nano-hydroxyapatite (n-HAp) and EAA. Fourier-transform infrared spectrometry (FTIR) and thermal analysis have shown the presence of strong interfacial bonding between n-HAp and EAA. The surface roughness and the homogeneous dispersion of nanoparticles have been observed by field emission scanning electron microscopy (FESEM). A comparison of mechanical properties between phosphonic acid treated (cn-HAp/EAA) and untreated (un-HAp/EAA) nanocomposites has been made. The use of a phosphonic acid coupling agent promotes the uniform dispersion of n-HAp in the polymer matrix with a strong nanoparticle-polymer interfacial bonding, which provides a means of preparing a HAp/polymer nanocomposite for implant applications.  相似文献   

5.
The combination of biopolymer with a bioactive component takes advantage of the osteoconductivity and osteoinductivity properties. The studies on composites containing hydroxyapatite (HA), demineralized bone matrix (DBM) fillers and chitosan biopolymer are still conducted. In the present study, the bioactive fillers were loaded onto p(HEMA‐MMA) grafted chitosan copolymer to produce a novel biocomposites having osteoinductive and osteoconductive properties. The produced composites were assessed by TGA, XRD, FTIR, and SEM techniques to prove the interaction between both matrices. In vitro behavior of these composites was performed in SBF to verify the formation of apatite layer onto their surfaces and its enhancement. The results confirmed the formation of thick apatite layer containing carbonate ions onto the surface of biocomposites especially these containing HA‐DBM mixture and pMMA having bone cement formation in their structure. These a novel biocomposites have unique bioactivity properties can be applied in bone implants and tissue engineering applications as scaffolds in future. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   

6.
This paper describes the behaviour of bioactive wollastonite materials containing Malaysian limestone and silica sand. Wollastonite, which is also known as calcium silicate (CaSiO3), is an industrial mineral composed of calcium, silicon and oxygen. Pseudowollastonite, which is a primary crystal of wollastonite, was synthesised via a solid-state reaction at a temperature of 1450 °C. The in-vitro bioactivity of wollastonite was examined by soaking it in simulated body fluid (SBF) solution for 1–7 days at 36.5 °C. The soaked wollastonite samples were characterised using XRD, SEM-EDX, FTIR and ICP analyses. Apatite particles precipitated on the surface of the wollastonite sample after the sample was soaked in the SBF. The XRD analysis indicated the presence of an increasing amount of the hydroxyapatite phase as the soaking time increased. The SEM and EDX analyses indicated the formation of granules of agglomerated apatite particles on the surface of the soaked wollastonite sample. During the formation of apatite, phosphate ions from the SBF solution were consumed. This process was confirmed by ICP, which revealed a decrease in ion concentration after the soaking process. The FTIR analysis indicated that the peaks of the phosphate ions increase when the apatite layer forms on the surface of the wollastonite sample. After the soaking process, a calcium deficient hydroxyapatite layer was observed on the wollastonite sample. The study concludes that wollastonite produced from Malaysian limestone and silica sand is bioactive and may be used as an implantable biomaterial.  相似文献   

7.
《Ceramics International》2017,43(9):6868-6875
In this paper, the compressive strength and in vitro bioactivity of sintered 45S5 bioactive glass scaffolds produced by powder technology and polymer foaming were investigated. The sintering temperature of scaffolds was 975 °C. The characterization of scaffolds before immersion in SBF was performed by scanning electron microscopy (SEM) and microtomography (μCT). The scaffolds were also tested for compression, and their density and porosity were measured. After immersion, the samples were observed through SEM and analyzed using EDS, X-ray diffraction (XRD), and infrared spectroscopy (FT-IR). Mass variation was also estimated. The glass-ceramic scaffolds showed a 61.44±3.13% interconnected porosity and an average compressive strength of 13.78±2.43 MPa. They also showed the formation of a hydroxyapatite layer after seven days of immersion in SBF, demonstrating that partial crystallization during sintering did not suppress their bioactivity.  相似文献   

8.
《Ceramics International》2017,43(10):7573-7580
In this study, β-TCP/CNT nanocomposite has been synthesized by solution precipitation method. Then, the effects of the different percentage of CNT (CNT1β-TCP, CNT3β-TCP, CNT5β-TCP) and surfactant (CNT1β-TCP1SDBS, CNT1β-TCP2SDBS, CNT1β-TCP3SDBS) on β-TCP/CNT nanocomposite powder were studied. The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) analyses were used to characterize the samples. The observations revealed that the microstructure of 1 wt% CNT could provide dispersion without agglomeration in nanocomposite powder; however, a higher concentration of CNT powder in the nanocomposite resulted in the formation of Ca2PO7 phase. Implementing 2 wt% of SDBS as a surfactant modified the shape, size, and distribution of CNT particles on nanocomposites. Finally, the nanocomposite sample was immersed in simulated body fluid (SBF) to evaluate the in vitro bioactivity. It obviously showed an apatite layer on the surface after 7 days of immersion in SBF. Taken together, this nanocomposite might be potentially to be used as bone repair biomaterial.  相似文献   

9.
This research aims to evaluate the mechanical properties, biocompatibility, and degradation behavior of scaffolds made of pure hydroxyapatite (HA) and HA-modified by ZnO for bone tissue engineering applications. HA and ZnO were developed using sol-gel and precipitation methods respectively. The scaffolds properties were characterized using X-ray diffraction (XRD), Fourier transform spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), atomic absorption (AA), and atomic force microscopy (AFM). The interaction of scaffold with cells was assessed using in vitro cell proliferation and alkaline phosphatase (ALP) assays. The obtained results indicate that the HA/ZnO scaffolds possess higher compressive strength, fracture toughness, and density—but lower hardness—when compared to the pure HA scaffolds. After immersing the scaffold in the SBF solution, more deposited apatite appeared on the HA/ZnO, which results in the rougher surface on this scaffold compared to the pure HA scaffold. Finally, the in vitro biological analysis using human osteoblast cells reveals that scaffolds are biocompatible with adequate ALP activity.  相似文献   

10.
The aim of this research was to evaluate the mechanical properties, biocompatibility, and degradation behavior of scaffolds made of pure hydroxyapatite (HA) and HA-modified by MnO2 for bone tissue engineering applications. HA and MnO2 were developed using sol-gel and precipitation methods, respectively. The scaffolds properties were characterized using X-ray diffraction (XRD), Fourier transform spectroscopy (FTIR), scanning electron microcopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The interaction of scaffold with cells was assessed using in vitro cell proliferation and alkaline phosphatase (ALP) assays. The obtained results indicate that the HA/MnO2 scaffolds possess higher compressive strength, toughness, hardness, and density when compared to the pure HA scaffolds. After immersing the scaffold in the SBF solution, more deposited apatite appeared on the HA/MnO2, which results in the rougher surface on this scaffold compared to the pure HA scaffold. Finally, the in vitro biological analysis using human osteoblast cells reveals that scaffolds are biocompatible with adequate ALP activity.  相似文献   

11.
Bioactive glass of the type CaO–P2O5–SiO2 was obtained by the sol–gel processing method. The obtained material was characterized by X-ray powder diffraction (XRD). Composite samples of hydroxyapatite with synthesized bioglass were prepared at 1000 °C and characterized by XRD, Fourier transform infrared spectroscopy (FTIR), and surface electron microscopy (SEM). The bioactivity was examined in vitro with respect to the ability of hydroxyapatite layer to form on the surface as a result of contact with simulated body fluid (SBF). XRD, FTIR and SEM studies were conducted before and after contact of the material with SBF. It could be detected that the bioglass was crystallized partly. Furthermore, silicated hydroxyapatite may have formed due to the diffusion of silicate groups to the apatite phase and these may have substituted for the phosphate groups. It can be concluded from SEM and FTIR results that apatite phase formed after 14 days in SBF.  相似文献   

12.
计陈红  郭亚军  褚联峰 《广州化工》2010,38(12):176-179,181
以多孔聚氨酯泡沫为基体,经过预处理、电化学沉积等工艺制备了具有三维多孔网状结构的、高空隙率的羟基磷灰石泡沫复合材料,将羟基磷灰石涂层浸泡在模拟体液SBF中进行浸泡实验,通过扫描电子显微镜(SEM)、X射线衍射(XRD)和红外分析仪(FTIR)等技术对羟基磷灰石涂层进行了表征。实验结果表明:在合适的条件下可得到纯羟基磷灰石涂层;随着温度的升高,晶体端面边长和长度逐渐增大;涂层在模拟体液SBF中浸泡24h后,涂层表面生成了很多球状磷灰石颗粒相互堆积,磷灰石颗粒尺寸明显增大。  相似文献   

13.
Summary  The effect of shear or time of shearing – as exerted by different screw configurations – upon the nano hydroxyapatite (n-HA) dispersion, during the twin screw extrusion processing for the preparation of PA6-66/n-HA composites, was investigated. Three different screw configurations, designated as medium, high and very high shear, were used. A noticeable improvement in the n-HA dispersion, attributed to the increasing shear exerted upon the melt during mixing in the TSE, was observed. Crystallization and thermal behavior of n-HA reinforced PA6-66 composites were studied by X-Ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). An increase in the crystallization temperature, accompanied by a decrease in percent crystallinity with the addition of n-HA to the PA6-66 matrix was observed. That is, n-HA acted as a nucleating agent and enhanced the crystallization rate. In addition, it was observed that the n-HA promoted the occurrence of the Brill transition. The decomposition temperature increased with the addition of n-HA. The PA6-66/ n-HA nanocomposite was thereafter, immersed in simulated body fluid (SBF) and the generation of a new calcium phosphate layer on the nanocomposite surface was monitored by SEM, FTIR and Atomic Absorption. The Ca/P ratio in the forming apatite layer started at a low value, ca. 1.3, which corresponds to octacalcic phosphate, but increased with the immersion time to 1.6, which corresponds to carbonated apatite.  相似文献   

14.
The aim of this work was to develop bioactive chitosan scaffolds reinforced with monetite‐containing whisker‐like fibers. The fibers synthesized by homogeneous precipitation were characterized as monetite/hydroxyapatite short fibers (MAFs), using XRD, FTIR and SEM. The pure chitosan and MAFs/chitosan composite scaffolds were produced by freeze‐drying, and characterized with respect to porosity, pore size, swelling behavior, compressive strength and modulus, and in vitro bioactivity. The incorporation of MAFs in chitosan matrices led to increase the pore size, according to the evaluation by FE‐SEM, and decrease the porosity of composite scaffolds. The swelling ratio decreased as MAFs content of scaffolds increased. The compressive strength and modulus of scaffolds were improved by an increase in MAFs content. The noncross‐linked scaffolds with a chitosan: MAFs weight ratio of 1:1 (CW3) showed a porosity of 75.5%, and the strength and modulus of 259 kPa and 2.8 MPa in dry state, respectively. The crosslinking by glutaraldehyde resulted in improved mechanical properties. The strength and modulus of cross‐linked CW3 scaffolds in wet state reached to 345 kPa and 1.8 MPa, respectively. The in vitro bioactivity of the reinforced scaffolds, evaluated by FE‐SEM/EDS, XRD, and ATR‐FTIR, was confirmed by the formation of a carbonated apatite layer on their surfaces when they soaked in simulated body fluid (SBF). The results of this initial study indicate that the monetite‐containing whisker‐like fibers may be an appropriate reinforcement of chitosan scaffolds.  相似文献   

15.
Biocomposite of bioactive glass (BG) with chitosan polymer (CH) is prepared by freeze-drying technique. Obtained material is investigated by using several physico-chemical methods. The XRD and FTIR show the interface bonding interactions between glass and polymer. The specific surface and porosity of biocomposite were determined. In vitro assays were employed to evaluate the effect of chitosan addition on the glass by studying the chemical reactivity and bioactivity of the BG and BG/CH biocomposite after soaking in a simulated body fluid (SBF). The obtained results show the formation of a bioactive hydroxycarbonate apatite (HCA) layer and highlight the bioactivity and the kinetics of chemical reactivity of bioactive glass, particularly after association with chitosan. The BG/CH biocomposite has excellent ability to form an apatite layer. Inductively coupled plasma-optical emission spectrometry (ICP-OES) highlights the negative effect of chitosan on the silicon release toward the SBF of bioactive glass when in vitro assays.  相似文献   

16.
In this study, porous scaffolds were prepared from chitosan (2% w/v in acetic acid and deacetylation degree: DD > 85%) by freeze‐drying method, and freshly lyophilized scaffolds were stabilized with ethanol solutions. Bone‐like apatite formation on chitosan scaffolds was achieved by immersing the scaffolds into a novel concentrated simulated body fluid (10× SBF‐like solution) for different periods, i.e., 6 and 24 h. Scanning electron microscope views showed that the 6‐h treatment in 10× SBF‐like solution led to the formation of calcium phosphate nucleation sites on chitosan scaffolds, whereas the apatite particles showed characteristic cauliflower‐like morphology at the end of 24‐h treatment. X‐ray diffraction results supported the fact that mineral phase was made of hydroxyapatite. Osteogenic activities of untreated and SBF‐treated chitosan scaffolds were examined by preosteoblastic MC3T3 cell culture studies. The mitochondrial activity test showed that apatite‐coated scaffolds stimulated cell proliferation compared with uncoated scaffolds. Alkaline phosphatase and osteocalcine levels indicated that the differentiation of the cells on all scaffolds increased significantly from 15th day of culture to the 21th day of culture, especially for the cells on 24‐h SBF‐treated scaffolds. The results of this study indicated that 10× SBF‐like solution‐treated chitosan scaffolds may be evaluated for bone tissue engineering. POLYM. COMPOS., 31:1418–1426, 2010. © 2009 Society of Plastics Engineers  相似文献   

17.
Thermoplastic starch (TPS), as a natural based polymer, is known to have the capability to be used in biological applications due to its biocompatibility and biodegradability. In this study, mechanical properties of TPS are enhanced by incorporating bioactive β-tricalcium phosphate (β-TCP) particles for bone tissue engineering applications. Starch-based nanocomposites containing 3, 5, and 10 wt% of β-TCP nanoparticles (TT3, TT5, TT10) were made using a co-rotating twin-screw extruder. Dynamic light scattering (DLS) and X-ray diffraction (XRD) techniques were employed to analyze the nanocomposites. Moreover, degradability, swelling degree, and biomineralization in a simulated body fluid (SBF) were studied. To investigate the dispersion of β-TCP nanoparticles in the composite and biomineralization of the nanocomposites after incubation in SBF, scanning electron microscopy (SEM) and energy dispersive X-Ray analysis (EDX) were performed. Evaluation of mechanical properties of TPS and nanocomposites demonstrated that increase in β-TCP content enhanced mechanical properties. Besides, the bioactivity of these three nanocomposite materials was proven by nucleation of hydroxyapatite on the samples’ surface after incubation in simulated body fluid (SBF). Cytotoxicity test was done as well. Results of the current study have paved the way for the application of TPS/β-TCP composite as bone tissue engineering material.  相似文献   

18.
In this research, the synthesis of nanocrystalline merwinite (2SiO2-3CaO-MgO) bioactive ceramic was carried out by the sol-gel method. After crushing, obtained sol-gel derived bioceramic powder pressed uniaxially to produce cylindrical-like pellets, followed by sintering at 1300 °C. Via immersion in simulated body fluid (SBF) for various time intervals, the formation of apatite was characterized. Scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and Fourier transform infrared spectroscopy (FT-IR) studies were conducted both before and after immersion in SBF. The crystallization temperature of the merwinite was determined by thermal analysis. Attained results confirmed formation of apatite layer within the first day of soaking. Accordingly it can be concluded that merwinite is bioactive and might be used for preparation of implantable biomaterials.  相似文献   

19.
In this study, gelatin/beta tricalcium phosphate (β-TCP) nanocomposite scaffolds were prepared by solvent casting method. The cross-linking method was carried out by adding formaldehyde to gelatin. The microparticles of sodium chloride were used as porogen agent. Characterization of nano β-TCP was performed using XRD, FTIR, and SEM. Results showed that the size of the particles is about 100 nm with spherical morphology. In addition, the scaffold characterization was carried out using FTIR and SEM techniques. Observations showed a porous texture with pore size between 100 and 400 μm. The biodegradability and bioactivity evaluations of the scaffolds were done by immersing them in a simulated body fluid solution for different time periods. The biodegradability studies demonstrated a reduction in the degradation rate of gelatin/β-TCP nanocomposite scaffolds due to the presence of β-TCP nanoparticles. The obtained results of bioactivity tests confirmed the formation of apatite layer on the surface of the scaffolds. Furthermore, the effects of porosity, cross-linking agent, and β-TCP nanoparticles on the bending and compressive properties of the composite scaffolds were examined. According to the mechanical examinations of the scaffolds, the best bending and compressive properties occurred in the presence of 10 and 20 wt% of β-TCP nanoparticles, respectively. The appropriate mechanical properties and biodegradation rate for tissue engineering applications obtained at 1 g of the formaldehyde solution.  相似文献   

20.
《Ceramics International》2017,43(13):10071-10079
Calcium aluminate cement (CAC) blends show great potential as biomaterial when compared to commercial products used in odontology and orthopedics. Mixtures of CAC +4 wt% of different additives (alumina, zirconia, zinc oxide, tricalcium phosphate or hydroxyapatite) containing compositions, resulted in samples with low porosity levels and smaller pore sizes after their contact with simulated body fluid (SBF) solution, which was associated with apatite precipitation on the materials’ surface. In order to certify these aspects, the in vitro apatite-formation ability (bioactivity) of CAC blends was evaluated by pH and calcium concentration measurements in SBF for samples previously treated (or not) with sodium silicate (SS) solution. The surface of the samples after immersion in SBF or SBF/SS was analyzed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and confocal Raman spectroscopy. In addition, the in vitro apatite deposition and the osteoblastic cell viability were also evaluated. SEM results showed that the precipitation of phases was detected on the CAC blend samples’ surfaces. The presence of calcium and mainly phosphorus by EDX indicated the formation of calcium phosphate phases. Moreover, the presence of a more homogeneous apatite-like layer on the samples’ surface was observed after treatment with sodium silicate solution. The detection of the Raman signature at 960 cm−1, confirmed the presence of an apatite-like layer on the surface of the compositions after immersion in SBF or SBF/SS. Regarding the osteoblastic cell viability results, blends with collagen, zinc oxide and zirconia presented better results when compared to commercial products.  相似文献   

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