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1.
During the last decades, there have been several attempts to combine bioactive materials with biocompatible and biodegradable polymers to create nanocomposite scaffolds with excellent biocompatibility, bioactivity, biodegradability and mechanical properties. In this research, the nanocomposite scaffolds with compositions based on PVA and HAp nanoparticles were successfully prepared using colloidal HAp nanoparticles combined with freeze-drying technique for tissue engineering applications. In addition, the effect of the pH value of the reactive solution and different percentages of PVA and HAp on the synthesis of PVA/HAp nanocomposites were investigated. The SEM observations revealed that the prepared scaffolds were porous with three dimensional microstructures, and in vitro experiments with osteoblast cells indicated an appropriate penetration of the cells into the scaffold's pores, and also the continuous increase in cell aggregation on the scaffolds with increase in the incubation time demonstrated the ability of the scaffolds to support cell growth. According to the obtained results, the nanocomposite scaffolds could be considered as highly bioactive and potential bone tissue engineering implants.  相似文献   

2.
Designing and fabricating nanocomposite scaffolds for bone regeneration from different biodegradable polymers and bioactive materials are an essential step to engineer tissues. In this study, the composite scaffold of gelatin/hyaluronic acid (Gel/HA) containing nano-bioactive glass (NBG) was prepared by using freeze-drying method. The biocompatibilities in-vitro of the Gel-HA/NBG composite scaffolds, including MTT assay, ALP activity, von Kossa staining and tetracycline staining, were investigated. The SEM observations revealed that the prepared scaffolds were porous with three-dimensional (3D) and interconnected microstructure, agglomerated NBG particles were uniformly dispersed in the matrix. MTT results indicated that the tested materials didn't show any cytotoxicity. The presence of NBG in the composite scaffold further enhanced the ALP activity in comparison with the pure Gel/HA scaffold. The von Kossa staining and tetracycline staining results also indicated that the NBG may improve the cell response. Therefore, the results indicated the nanocomposite scaffold made from Gel, HA and NBG particles could be considered as a potential bone tissue engineering implant.  相似文献   

3.
In this study, biodegradable polylactic acid (PLA) and PLA nanocomposite scaffolds reinforced with magnetic and conductive fillers, were processed via fused filament fabrication additive manufacturing and their bioactivity and biodegradation characteristics were examined. Porous 3D architectures with 50% bulk porosity were 3D printed, and their physicochemical properties were evaluated. Thermal analysis confirmed the presence of ~18 wt% of carbon nanostructures (CNF and GNP; nowonwards CNF) and ~37 wt% of magnetic iron oxide (Fe2O3) particles in the filaments. The in vitro degradation tests of scaffolds showed porous and fractured struts after 2 and 4 weeks of immersion in DMEM respectively, although a negligible weight loss is observed. Greater extent of degradation is observed in PLA with magnetic fillers followed by PLA with conductive fillers and neat PLA. In vitro bioactivity study of scaffolds indicate enhancement from ~2.9% (PLA) to ~5.32% (PLA/CNF) and ~ 3.12% (PLA/Fe2O3). Stiffness calculated from the compression tests showed decrease from ~680 MPa (PLA) to 533 MPa and 425 MPa for PLA/CNF and PLA/Fe2O3 respectively. Enhanced bioactivity and faster biodegradation response of PLA nanocomposites with conductive fillers make them a potential candidate for tissue engineering applications such as scaffold bone replacement and regeneration.  相似文献   

4.
采用一步水热法制备了还原氧化石墨烯-二氧化钛(RGO-P25)纳米复合物.通过透射电子显微镜(TEM)、傅里叶变换红外(FTIR)光谱、X射线光电子能谱(XPS)、X射线衍射(XRD)及紫外-可见漫反射谱(UVVisDRS)对复合材料的结构和光电性能进行了表征.在紫外光照和可见光照条件下,研究了不同复合比例的复合物的光催化降解甲基蓝(MB)的性能.结果表明:在水热过程中氧化石墨烯被还原,通过静电引力相互作用得到了具有较高缺陷的还原氧化石墨烯复合物.随着RGO含量的增加,复合物的禁带宽度由3.00 eV变到2.27eV,复合物的导电性增强.在可见光和紫外光光照条件下, 30 min内1%(w,质量分数)RGO-P25光催化降解甲基蓝的效率都超过了80%.紫外光照条件下, 1%RGO-P25纳米复合物催化降解N3染料, cis-Ru(H2dcbpy)2(NCS)2 (H2dcbpy = 4, 4'-二羧酸-2, 2'-联吡啶), 30 min内63%(摩尔分数)的染料被降解.与P25(75%锐钛矿, 25%金红石)相比,石墨烯的加入大大提高了光催化效率,有效抑制了电子-空穴对的复合.  相似文献   

5.
Bioactive PLLA/surface-grafted silica (g-SiO?) nanocomposite scaffolds were fabricated by solid-liquid phase separation method. And solid PLLA/g-SiO? nanocomposite films were prepared by solution casting method. A series of parallel tube-like morphology and internal ladder-like structure of PLLA/g-SiO? nanocomposite scaffolds were observed by SEM. The formation of bone-like apatite in the simulated body fluid (SBF) was characterized by XRD, IR, SEM, EDS and weight measurement. The silica incorporation favors the formation of apatite. The growth of apatite with immersion time is found on the surfaces of both the PLLA/g-SiO? nanocomposite scaffolds and the films. The potential mechanism is that silanol groups of g-SiO? in the nanocomposites serve as nucleation sites for the formation of bone-like apatite crystals.  相似文献   

6.
Biodegradable poly(lactic-co-glycolic acid) (PLGA)/carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) nanocomposites were successfully prepared via solvent casting technique. Rat bone marrow-derived mesenchymal stem cells (MSCs) were employed to assess the biocompatibility of the nanocomposites in vitro. Scanning electron microscopy (SEM) observations revealed that c-MWCNTs gave a better dispersion than unmodified MWCNTs in the PLGA matrix. Surface properties were determined by means of static contact angle, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) analysis. The presence of c-MWCNTs increased the mechanical properties of the nanocomposites. Seven-week period in vitro degradation test showed the addition of c-MWCNTs accelerated the hydrolytic degradation of PLGA. In addition, SEM proved that the cells could adhere to and spread on films via cytoplasmic processes. Compared with control groups, MSCs cultured onto PLGA/c-MWCNT nanocomposites exhibited better adhesion and viability and also displayed significantly higher production levels of alkaline phosphatase (ALP) over 21 days culture. These results demonstrated that c-MWCNTs modified PLGA films were beneficial for promoting cell growth and inducing MSCs to differentiate into osteoblasts. This work presented here had potential applications in the development of 3-D scaffolds for bone tissue engineering.  相似文献   

7.
In this research, the novel three-dimensional (3D) porous scaffolds made of poly(lactic-co-glycolic acid) (PLGA)/nano-fluorohydroxyapatite (FHA) composite microspheres was prepared and characterize for potential bone repair applications. We employed a microsphere sintering method to produce 3D PLGA/nano-FHA scaffolds composite microspheres. The mechanical properties, pore size, and porosity of the composite scaffolds were controlled by varying parameters, such as sintering temperature, sintering time, and PLGA/nano-FHA ratio. The experimental results showed that the PLGA/nano-FHA (4:1) scaffold sintered at 90 °C for 2 h demonstrated the highest mechanical properties and an appropriate pore structure for bone tissue engineering applications. Furthermore, MTT assay and alkaline phosphatase activity (ALP activity) results ascertained that a general trend of increasing in cell viability was seen for PLGA/nano-FHA (4:1) scaffold sintered at 90 °C for 2 h by time with compared to control group. Eventually, obtained experimental results demonstrated PLGA/nano-FHA microsphere-sintered scaffold deserve attention utilizing for bone tissue engineering.  相似文献   

8.
This study focused on the fabrication of calcium phosphate (Ca-P)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposite scaffolds loaded with biomolecules using the selective laser sintering (SLS) technique and their evaluation. Ca-P/PHBV nanocomposite microspheres loaded with bovine serum albumin (BSA) as the model protein were fabricated using the double emulsion solvent evaporation method. The encapsulation efficiency of BSA in PHBV polymer microspheres and Ca-P/PHBV nanocomposite microspheres were 18.06 ± 0.86% and 24.51 ± 0.60%, respectively. The BSA loaded Ca-P/PHBV nanocomposite microspheres were successfully produced into three-dimensional porous scaffolds with good dimensional accuracy using the SLS technique. The nanocomposite microspheres served as protective carriers and maintained the bioactivity of BSA during SLS. The effects of SLS parameters such as laser power and scan spacing on the encapsulation efficiency of BSA in the scaffolds and in vitro BSA release were studied. An initial burst release was observed, which was followed by a slow release of BSA. After 28-day release, The PHBV matrix was slightly degraded after 28-day in vitro release study. It was shown that nanocomposite scaffolds with controlled architecture obtained via SLS could be incorporated with biomolecules, enhancing them with more functions for bone tissue engineering application or making them suitable for localized delivery of therapeutics.  相似文献   

9.
In the present research, chitosan/collagen and chitosan/collagen/nano-hydroxyapatite (nHAP) hydrogel nanocomposites were prepared using naturally extracted chitosan from Persian Gulf shrimp wastes and rat tail-tendon collagen. Freeze-gelation method was used to prepare highly porous scaffolds. The morphology, chemical structure, water retainability, and thermal properties were characterized using SEM, FTIR, water content experiment, simultaneous thermal analysis (STA), respectively. Atomic force microscopy (AFM) nanoindentation and unconfined compression test were used to assess different feature of the mechanical properties of the hydrogels. The obtained results were so promising that the prepared nanocomposites can be considered as a potential candidate for cartilage tissue engineering.  相似文献   

10.
Three-dimensional biodegradable porous scaffolds play an important role in tissue engineering. The degradable scaffold material, based on 1,4-butanediamine-modified poly(lactide-co-glycolide) (BMPLGA), nano-bioactive glass (NBAG), and nano-β-tricalciumphosphate (β-TCP), was prepared by a solution-casting/salt-leaching method. The biological properties were studied by using cell cytotoxicity, von Kossa staining, alkaline phosphatase activity, hemolytic test, acute toxicity, and genetic toxicity test. The MTT results indicated that the BMPLGA/NBAG-β-TCP materials did not show any cytotoxicity. The result of von Kossa staining showed that the introduction of the NBAG and β-TCP promoted fibroblastic differentiation and improved the mineral deposition of the BMPLGA matrix. In addition, the presence of NBAG and β-TCP in the composite further enhanced the ALP activity in comparison with the sole BMPLGA material. The hemolytic potential showed that the nanocomposite scaffolds were non-hemolytic. The BMPLGA/NBAG-β-TCP scaffolds showed no acute systemic toxicity or mutagenic action. Therefore, the results indicated the BMPLGA/NBAG-β-TCP nanocomposite scaffold could be considered as a potential bone tissue engineering implant.  相似文献   

11.
Using polymer hydrogels and nanocomposites hydrogels still promising materials for many applications. Polyvinyl pyrrolidone (PVP) has been used with various polymers synthetic and natural for different applications. In this study PVP and hydroxyl ethyl methacrylate (HEMA) copolymer hydrogels were prepared by the aid of gamma radiation and the PVP/HEMA nanocomposite hydrogels were obtained by in situ adsorption and reduction method of iron salts and silver nitrates (AgNO3) to form PVP/HEMA-Fe3O4 and PVP/HEMA-Ag nanocomposites. The prepared hydrogels and the formed nanoparticles were studied by various techniques; FTIR, TEM, SEM and also the gel content and swelling behavior were evaluated. The prepared hydrogels and nanocomposites hydrogels were examined as drug delivery systems for Ciprofloxacin HCl as model drug. The PVP/HEMA-Fe3O4 nanocomposite gave the suitable load and release behavior towards Ciprofloxacin HCl.  相似文献   

12.
Calcium phosphate materials are widely used as bone-like scaffolds or coating for metallic hip and knee implants due to their excellent biocompatibility, compositional similarity to natural bone and controllable bioresorbability. Local delivery of drugs or osteogenic factors from scaffolds and implants are required over a desired period of time for an effectual treatment of various musculoskeletal disorders. Curcumin, an antioxidant and anti-inflammatory molecule, enhances osteoblastic activity in addition to its anti-osteoclastic activity. However, due to its poor solubility and high intestinal liver metabolism, it showed limited oral efficacy in various preclinical and clinical studies. To enhance its bioavailability and to provide higher release, we have used poly (ε-caprolactone) (PCL), poly ethylene glycol (PEG) and poly lactide co glycolide (PLGA) as the polymeric system to enable continuous release of curcumin from the hydroxyapatite matrix for 22 days. Additionally, curcumin was incorporated in plasma sprayed hydroxyapatite coated Ti6Al4V substrate to study in vitro cell material interaction using human fetal osteoblast (hFOB) cells for load bearing implants. MTT cell viability assay and morphological characterization by FESEM showed highest cell viability with samples coated with curcumin-PCL-PEG. Finally, 3D printed interconnected macro porous β-TCP scaffolds were prepared and curcumin-PCL-PEG was loaded to assess the effects of curcumin on in vivo bone regeneration. The presence of curcumin in TCP results in enhanced bone formation after 6 weeks. Complete mineralized bone formation increased from 29.6% to 44.9% in curcumin-coated scaffolds compared to pure TCP. Results show that local release of curcumin can be designed for both load bearing or non-load bearing implants with the aid of polymers, which can be considered an excellent candidate for wound healing and tissue regeneration applications in bone tissue engineering.  相似文献   

13.
Flammability of epoxy appears to be one of the greatest threats and hence limits its advanced applications. The present investigation, therefore, reports on vegetable oil-based self-extinguishing epoxy/clay nanocomposites for the first time. These nanocomposites were prepared by the ex-situ technique using mechanical shearing and ultrasonication at different loadings (1, 2.5 and 5 wt%) of nano-clay. Monoglyceride of Mesua ferrea L. seed oil, bisphenol-A and tetrabromobisphenol-A based epoxy resin was used as the matrix. XRD, TEM, SEM, FTIR and rheological studies confirmed partially exfoliated nanocomposites formation. The study demonstrates two fold improvements of tensile strength and scratch hardness, three-fold increase in adhesive strength and 20 units increase in gloss value without any change in impact resistance through nanocomposite formation. TG studied confirmed the enhancement of thermal stability of the nanocomposite by 25 °C. The limiting oxygen index values and UL 94 test indicated the self-extinguishing characteristic of the nanocomposites.  相似文献   

14.
《先进技术聚合物》2018,29(1):451-462
Scaffold, an essential element of tissue engineering, should provide proper physical and chemical properties and evolve suitable cell behavior for tissue regeneration. Polycaprolactone/Gelatin (PCL/Gel)‐based nanocomposite scaffolds containing hydroxyapatite nanoparticles (nHA) and vitamin D3 (Vit D3) were fabricated using the electrospinning method. Structural and mechanical properties of the scaffold were determined by scanning electron microscopy (SEM) and tensile measurement. In this study, smooth and bead‐free morphology with a uniform fiber diameter and optimal porosity level with appropriate pore size was observed for PCL/Gel/nHA nanocomposite scaffold. The results indicated that adding nHA to PCL/Gel caused an increase of the mechanical properties of scaffold. In addition, chemical interactions between PCL, gelatin, and nHA molecules were shown with XRD and FT‐IR in the composite scaffolds. MG‐63 cell line has been cultured on the fabricated composite scaffolds; the results of viability and adhesion of cells on the scaffolds have been confirmed using MTT and SEM analysis methods. Here in this study, the culture of the osteoblast cells on the scaffolds showed that the addition of Vit D3 to PCL/Gel/nHA scaffold caused further attachment and proliferation of the cells. Moreover, DAPI staining results showed that the presence and viability of the cells were greater in PCL/Gel/nHA/Vit D3 scaffold than in PCL/Gel/nHA and PCL/Gel scaffolds. The results also approved increasing cell proliferation and alkaline phosphatase (ALP) activity for MG‐63 cells cultured on PCL/Gel/nHA/Vit D3 scaffold. The results indicated superior properties of hydroxyapatite nanoparticles and vitamin D3 incorporated in PCL/Gel scaffold for use in bone tissue engineering.  相似文献   

15.
A nano-structured scaffold was designed for bone repair using collagen, hyaluronic acid (HYA) and nano-bioactive glass (NBaG) as its main components. The collagen-HYA/NBaG scaffold was prepared by using a freeze-drying technique and characterized by scanning electron microscopy (SEM). Osteoblastls were seeded on these scaffolds and their proliferation rate, alkaline phosphatase (ALP) activity and ability to form mineralized bone nodules were compared with those osteoblasts grown on cell culture plastic surfaces. The cross-section morphology shows that the collagen-HYA/NBaG scaffold possessed a three-dimensional (3D) interconnected homogenous porous structure. The results obtained from biological assessment show that this scaffold did not negatively affect osteoblasts proliferation rate and improves osteoblasts function as shown by increasing the ALP activity and calcium deposition and formation of mineralized bone nodules. Therefore, the composite scaffolds could provide a favorable environment for initial cell adhesion, maintained cell viability and cell proliferation, and had good in-vitro biocompatibility.  相似文献   

16.
BaTiO3/bismaleimide/epoxy/glass fiber reinforced composites were prepared using E-glass fiber (E-GF) and silane coated E-glass fiber (SC-EGF) separately as reinforcement. BaTiO3 nanoparticles were prepared by hydrothermal method. Results show that the addition of BaTiO3 nanoparticles has significant effects on the mechanical and dielectric properties of the composite. Both E-GF and SC-EGF reinforced BaTiO3/bismaleimide/epoxy composites with 2 wt percentages of BaTiO3 nanoparticles showed improved tensile strength, flexural strength and dielectric constant and those with 3% showed high dielectric strength indicating this composition is more adaptable for high voltage insulating applications. Dielectric constants and dielectric loss of the fabricated nanocomposites have been obtained at higher frequencies (in GHz) by using Vector Network Analyser at room temperature and was found to be highest for the BMI-Epoxy nanocomposite with 1% weight nanofiller.  相似文献   

17.
Novel ternary nanocomposites films of Polypyrrole/copper/graphene oxide (PPy/Cu/GO) showed enhanced optical and electronic properties. In this study, PPy/Cu/GO films were synthesized with different GO load (0.0, 0.4, 0.6, and 0.8 wt%) using electrochemical deposition technique. The structural, optical and electrical properties of the composites were evaluated using X-Ray Diffraction (XRD) spectroscopy, UV–visible spectroscopy, Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), and four-point probe methods. XRD results reveal that the GO was completely intercalated and dispersed uniformly in the nanocomposites. The results also revealed that the nanocomposite films are crystalline in nature, with distinct peaks corresponding to indexed miller indices. UV-visible analysis revealed that all of the nanocomposites showed good UV absorbance which was significant in the UV–Vis region of ≈450 nm. The energy band gap decreased with increase in GO load and was found within 3.46 to 2.25 eV, across the range of GO load which fall within the range of energy band gap for photovoltaic applications. The SEM results revealed that the nanocomposite films showed unevenly shaped structures with porous surface which increases with increasing GO loading, while the EDX result revealed the presence of carbon, oxygen nitrogen and copper as fundamental elements deposited. The nanocomposites' four-point probe analysis revealed slight increase in conductivity with low GO content. The incorporation of Cu and GO nanoparticles in PPy matrix provides a better balance and thus improved the photovoltaic properties of PPy/Cu/GO making them suitable for photovoltaic applications.  相似文献   

18.
The material surface must be considered in the design of scaffolds for bone tissue engineering so that it supports bone cells adhesion, proliferation and differentiation. A biomimetic approach has been developed as a 3D surface modification technique to grow partially carbonated hydroxyapatite (the bonelike mineral) in prefabricated, porous, polymer scaffolds using a simulated body fluid in our lab. For the rational design of scaffolding materials and optimization of the biomimetic process, this work focused on various materials and processing parameters in relation to apatite formation on 3D polymer scaffolds. The apatite nucleation and growth in the internal pores of poly(L-lactide) and poly(D,L-lactide) scaffolds were significantly faster than in those of poly(lactide-co-glycolide) scaffolds in simulated body fluids. The apatite distribution was significantly more uniform in the poly(L-lactide) scaffolds than in the poly(lactide-co-glycolide) scaffolds. After incubation in a simulated body fluid for 30 d, the mass of poly(L-lactide) scaffolds increased approximately 40%, whereas the mass of the poly(lactide-co-glycolide) scaffolds increased by about 15% (see Figure). A higher ionic concentration and higher pH value of the simulated body fluid enhanced apatite formation. The effects of surface functional groups on apatite nucleation and growth were found to be more complex in 3D scaffolds than on 2D films. Surprisingly enough, it was found that carboxyl groups significantly reduced the apatite formation, especially on the internal pore surfaces of 3D scaffolds. These findings are critically important in the rational selection of materials and surface design of 3D scaffolds for mineralized tissue engineering and may contribute to the understanding of biomineralization as well.SEM micrograph of a poly(L-lactide) scaffold.  相似文献   

19.
Mesoporous nanocomposite materials of magnetic iron oxide-containing MCM-41 (IO/MCM-41) were prepared by simple thermal oxidation of Fe-containing MCM-41 initially prepared by a direct synthesis route using Fe3+ salt. The magnetic saturation of the fabricated nanocomposite materials was measured using a vibrating sample magnetometer, while surface morphology and inner framework of the composite materials were studied using a field emission scanning electron microscope and a transmission electron microscope to confirm their mesoporous nanocomposite formation. The fabricated magnetic materials were then adopted as a magnetorheological (MR) fluid, where the IO/MCM-41 magnetic nanocomposites were dispersed in a nonmagnetic medium oil in addition to as an additive for carbonyl iron-based MR fluid. Their MR properties of flow curve along with yield stress and viscoelastic properties under applied magnetic fields were investigated using a rotational rheometer.  相似文献   

20.
Eco-friendly all cellulose composites were developed using cellulose as matrix and nanocomposite (in situ generated copper nanoparticles modified Napier Grass Fibers (NGFs)) as fillers for the antibacterial applications. The content of the nanocomposite filler was increased from 1?wt.% to 5?wt.% in the cellulose matrix. All these composites were characterized by Scanning Electron Microscopy (SEM), Tensile, Thermo Gravimetric Analysis (TGA), and antibacterial tests. SEM-EDX analysis revealed the in situ generation of copper nanoparticles on the surface of the films. Further, all cellulose composites showed good thermal stability. A minimum of 30% increase in char residue was observed in all cellulose nanocomposites compared to matrix. Antibacterial analysis indicated an excellent clear zone formation against both Gram Negative (Escherichia coli) and Gram Positive (Staphylococcus) bacteria. Hence, all these cellulose nanocomposite films can be considered as antibacterial packaging and dressing materials in medical field.  相似文献   

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