共查询到20条相似文献,搜索用时 31 毫秒
1.
Miranda P Pajares A Saiz E Tomsia AP Guiberteau F 《Journal of biomedical materials research. Part A》2008,85(1):218-227
The mechanical behavior under compressive stresses of beta-tricalcium phosphate (beta-TCP) and hydroxyapatite (HA) scaffolds fabricated by direct-write assembly (robocasting) technique is analyzed. Concentrated colloidal inks prepared from beta-TCP and HA commercial powders were used to fabricate porous structures consisting of a 3-D tetragonal mesh of interpenetrating ceramic rods. The compressive strength and elastic modulus of these model scaffolds were determined by uniaxial testing to compare the relative performance of the selected materials. The effect of a 3-week immersion in simulated body fluid (SBF) on the strength of the scaffolds was also analyzed. The results are compared with those reported in the literature for calcium phosphate scaffolds and human bone. The robocast calcium phosphate scaffolds were found to exhibit excellent mechanical performances in terms of strength, especially the HA structures after SBF immersion, indicating a great potential of this type of scaffolds for use in load-bearing bone tissue engineering applications. 相似文献
2.
Miranda P Pajares A Saiz E Tomsia AP Guiberteau F 《Journal of biomedical materials research. Part A》2007,83(3):646-655
The fracture modes of hydroxyapatite (HA) scaffolds fabricated by direct-write assembly (robocasting) are analyzed in this work. Concentrated HA inks with suitable viscoelastic properties were developed to enable the fabrication of prototype structures consisting of a 3-D square mesh of interpenetrating rods. The fracture behavior of these model scaffolds under compressive stresses is determined from in situ uniaxial tests performed in two different directions: perpendicular to the rods and along one of the rod directions. The results are analyzed in terms of the stress field calculated by finite element modeling (FEM). This analysis provides valuable insight into the mechanical behavior of scaffolds for bone tissue engineering applications fabricated by robocasting. 相似文献
3.
Francisco J. Martínez-Vázquez Fidel H. Perera Pedro Miranda Antonia Pajares Fernando Guiberteau 《Acta biomaterialia》2010,6(11):4361-4368
The effect of polymer infiltration on the compressive strength of β-tricalcium phosphate (TCP) scaffolds fabricated by robocasting (direct write assembly) is analyzed in this work. Porous structures consisting of a tetragonal three-dimensional mesh of interpenetrating rods were fabricated from concentrated TCP inks with suitable viscoelastic properties. Biodegradable polymers (polylactic acid (PLA) and poly(ε-caprolactone) (PCL)) were infiltrated into selected scaffolds by immersion of the structure in a polymer melt. Infiltration increased the uniaxial compressive strength of these model scaffolds by a factor of three (PCL) or six (PLA). It also considerably improved the mechanical integrity of the structures after initial cracking, with the infiltrated structure retaining a significant load-bearing capacity after fracture of the ceramic rods. The strength improvement in the infiltrated scaffolds was attributed to two different contributions: the sealing of precursor flaws in the ceramic rod surfaces and the partial transfer of stress to the polymer, as confirmed by finite element analysis. The implications of these results for the mechanical optimization of scaffolds for bone tissue engineering applications are discussed. 相似文献
4.
Dellinger JG Cesarano J Jamison RD 《Journal of biomedical materials research. Part A》2007,82(2):383-394
Model hydroxyapatite (HA) scaffolds with porosities spanning multiple length scales were fabricated by robocasting, a solid freeform fabrication technique based on the robotic deposition of colloidal pastes. Scaffolds of various architectures including periodic, radial, and superlattice structures were constructed. Macropores (100-600 microm) were designed by controlling the arrangement and spacing between rods of HA. Micropores (1-30 microm) and submicron pores (less than 1 microm) were produced within the rods by including polymer microsphere porogens in the HA pastes and by controlling the sintering of the scaffolds. These model scaffolds may be used to systematically study the effects of scaffold porosity on bone ingrowth processes both in vitro and in vivo. 相似文献
5.
The effect of composition of calcium phosphate composite scaffolds on the formation of tooth tissue from human dental pulp stem cells 总被引:1,自引:0,他引:1
Different approaches towards making 3-dimensional (3-D) bioengineered tooth for future replacement therapy have been developed including scaffold-based tooth regeneration. However, selection of optimal scaffold for future clinical application remains a challenge. In the present study, we tested biocompatibility of four different types of 3-D scaffolds for tooth-tissue regeneration, including a pure poly(lactide-co-glycolide) (PLGA) (70/30, mol/mol) scaffold and three types of calcium phosphate contained composites scaffolds that were 50 wt% of PLGA combined with 50 wt% of hydroxyapatite (HA), tricalcium phosphate (TCP) or calcium carbonate hydroxyapatite (CDHA) respectively. These scaffolds were fabricated by the particle leaching in combination with phase separation technology. Surface modification of these scaffolds was further performed by an ammonia plasma treatment and anchorage of collagen technology. Effect of composition of the composite scaffolds on proliferation of human dental pulp stem cells (DPSCs) was accessed using in vitro MTT assay and in vivo BrdU labeling. Differentiation capability of the DPSCs in the scaffolds was analyzed by measurement of the levels of calcified tissue formation and ALP activity. Our results showed that while the calcium phosphate contained compound is able to support regeneration of tooth tissue effectively, the PLGA/TCP scaffold is more appropriate for the proliferation and differentiation of DPSCs. Furthermore, seeding of dissociated 4-dpn rat tooth bud cells on the PLGA/TCP scaffold generated dentin- and pulp-like tissues. Our results demonstrate that the PLGA/TCP scaffold is superior to the other three scaffolds for tooth-tissue regeneration, especially for dentin formation. 相似文献
6.
Synthesis and characterization of macroporous chitosan/calcium phosphate composite scaffolds for tissue engineering 总被引:10,自引:0,他引:10
Chitosan scaffolds reinforced by beta-tricalcium phosphate (beta-TCP) and calcium phosphate invert glass were fabricated with a low-cost, bioclean freeze-drying technique via thermally induced phase separation. The microstructure, mechanical performance, biodegradation, and bioactivity of the scaffolds were studied. The composite scaffolds were macroporous, and the pore structures of the scaffolds with beta-TCP and the glass appeared very different. Both the compressive modulus and yield strength of the scaffolds were greatly improved, and reinforced microstructures were achieved. The bioactivity tests showed a continuous decrease in both Ca and P concentrations of a simulated body fluid (SBF) after the scaffolds with beta-TCP were immersed in the SBF for more than 20 h, which suggests that an apatite layer might be formed on the scaffolds. However, the same was not observed for the pure chitosan scaffolds or the scaffolds incorporated with the glass. This was further confirmed by micrographs from scanning electron microscopy. This study suggests that the desirable pore structure, biodegradation rate, and bioactivity of the composite scaffolds might be achieved through controlling the ratio of chitosan and calcium phosphates or beta-TCP and the glass. 相似文献
7.
聚酯/磷酸三钙人工骨载体的表面修饰及不同骨移植材料的比较研究 总被引:1,自引:0,他引:1
采用热致分相法(TIPS)与熔铸颗粒沥取法(SCPL),实验室条件下制备适宜组分配比(7:3)的聚乳酸-聚羟乙酸/磷酸三钙[PLGA/TCP]复合人工骨载体[PLGA/TCP(L)];另外采用先进快速成形技术(RP)制备相同组分配比(7:3)的PLGA/TCP(RP)复合材料.扫描电镜(SEM)观察人工骨载体的超微结构,并用I型胶原(Col I)对载体材料进行表面修饰.进而复合诱骨生长因子-牛骨形态发生蛋白(bBMP)以制备出仿生活性人工骨.将PLGA/TCP(L)、PLGA/TCP(RP)、牛松质骨脱钙骨基质(DBM)、仿生活性人工骨及OsteoSet(R)人工骨进行多种比较.结果发现,先进RP技术制备的PLGA/TCP(RP)大段人工骨载体结构明显优于实验室常规方法所制备的PLGA/TCP(L)载体.PLGA/TCP(L)载体、DBM、PLGA/TCP(RP)载体及OsteoSet(R)人工骨的孔隙率分别为21.5%、70.4%、58.6%和0%,其中DBM和PLGA/TCP(RP)载体的孔隙率最高(P<0.01).此外,RP制备的PLGA/TCP(RP)人工骨载体孔径大(350 μm),并与天然DBM的孔径最为接近.PLGA/TCP(L)、PLGA/TCP(RP)人工骨载体经I型胶原表面修饰后[PLGA/TCP(L)-Col I、PLGA/TCP(RP)-Col I],明显改善其对bBMP的亲和力,人工骨载体表面及孔隙内对bBMP的复合能力明显增强,仿生活性人工骨[PLGA/TCP(L)-Col I-bBMP、PLGA/TCP(RP)-Col I-bBMP]的制备效率亦显著提高.其中采用先进RP技术结合载体材料表面修饰新工艺研制的PLGA/TCP(RP)-Col I-bBMP仿生活性人工骨具有与天然骨最接近的空间三维结构,并含有关键的成骨活性因子,因此具有更为广阔的研究与应用前景. 相似文献
8.
Amaral R Ozcan M Valandro LF Balducci I Bottino MA 《Journal of biomedical materials research. Part B, Applied biomaterials》2008,87(1):1-9
Scaffold fabrication for regenerating functional human tissues has an important role in tissue engineering, and there has been much progress in research on scaffold fabrication. However, current methods are limited by the mechanical properties of existing biodegradable materials and the irregular structures that they produce. Recently, several promising biodegradable materials have been introduced, including poly(propylene fumarate) (PPF). The development of micro-stereolithography allows the fabrication of free-form 3D microstructures as designed. Since this technology requires a low-viscosity resin to fabricate fine structures, we reduced the viscosity of PPF by adding diethyl fumarate. Using our system, the curing characteristics and material properties of the resin were analyzed experimentally. Then, we fabricated waffle shape and 3D scaffolds containing several hundred regular micro pores. This method controlled the pore size, porosity, interconnectivity, and pore distribution. The results show that micro-stereolithography has big advantages over conventional fabrication methods. In addition, the ultimate strength and elastic modulus of the fabricated scaffolds were measured, and cell adhesion to the fabricated scaffold was observed by growing seeded cells on it. These results showed that the PPF/DEF scaffold is a potential bone scaffold for tissue engineering. 相似文献
9.
Chen SH Wang XL Xie XH Zheng LZ Yao D Wang DP Leng Y Zhang G Qin L 《Acta biomaterialia》2012,8(8):3128-3137
A local delivery system with sustained and efficient release of therapeutic agents from an appropriate carrier is desirable for orthopedic applications. Novel composite scaffolds made of poly (lactic-co-glycolic acid) with tricalcium phosphate (PLGA/TCP) were fabricated by an advanced low-temperature rapid prototyping technique, which incorporated either endogenous bone morphogenetic protein-2 (BMP-2) (PLGA/TCP/BMP-2) or phytomolecule icaritin (ICT) (PLGA/TCP/ICT) at low, middle and high doses. PLGA/TCP served as control. In vitro degradation, osteogenesis and release tests showed statistical differences among PLGA/TCP/ICT, PLGA/TCP and PLGA/TCP/BMP-2 groups, where PLGA/TCP/ICT had the desired slow release of bioactive icaritin in a dose-dependent manner, whereas there was almost no BMP-2 release from the PLGA/TCP/BMP-2 scaffolds. PLGA/TCP/ICT significantly increased more ALP activity, upregulated mRNA expression of osteogenic genes and enhanced calcium deposition and mineralization in rabbit bone marrow stem cells cultured on scaffolds compared with the other two groups. These results indicate the desired degradation rate, osteogenic capability and release property in PLGA/TCP/ICT composite scaffold, as icaritin preserved its bioactivity and structure after incorporation, while PLGA/TCP/BMP-2 did not show an initially expected osteogenic potential, owing to loss of the original bioactivity of BMP-2 during its incorporation and fabrication procedure. The results suggest that PLGA/TCP composite scaffolds incorporating osteogenic ICT might be a promising approach for bone tissue bioengineering and regeneration. 相似文献
10.
Promotion of bone formation using highly pure porous beta-TCP combined with bone marrow-derived osteoprogenitor cells 总被引:17,自引:0,他引:17
Beta-tricalcium phosphate (TCP) exhibits rapid degradation and weak mechanical properties, which has limited its application as bone graft substitutes, though it has good biocompatibility and osteoconductivity. We hypothesized that a composite of highly pure porous beta-TCP and bone marrow-derived osteoprogenitor cells (BMO) could improve bone formation, and slow down the degradation of beta-TCP. A highly pure porous beta-TCP with 75% porosity was fabricated. The pores averaged 200-400 microm in diameter, with interconnecting paths 100-200 microm. Blocks of beta-TCP 5 mm3 were combined with BMO, and incubated 2 weeks with (+) or without (-) osteogenic medium. They were then implanted into subcutaneous sites of syngeneic rats for 24 weeks. These composites were harvested at different time points. The alkaline phosphatase activity and bone osteocalcin content of the composites (+) were much higher than corresponding values in the composites (-) of the control group (p<0.01). Light microscopy revealed mature bone and lots of blood vessels only in the TCP/BMO composite (+). The amount of newly formed bone increased until week 24. Slow resorptive activity could be found. The mechanical parameters of the composites were much improved over those of dry beta-TCP blocks. These results showed that tissue engineering treatment on incubating the composites of beta-TCP and BMO cells in osteogenic medium results in a good osteogenic activity. 相似文献
11.
Hyun-Seung Ryu Hyuk-Joon Youn Kug Sun Hong Bong-Sun Chang Choon-Ki Lee Sung-Soo Chung 《Biomaterials》2002,23(3):909-914
The sintering behavior of calcium pyrophosphate (CPP, Ca2P2O7)-doped beta-tricalcium phosphate [TCP, Ca3(PO4)2], prepared by solid state reaction, was investigated in-situ, using dilatometry. Pure beta-TCP undergoes phase transition to alpha-TCP at about 1200 degrees C; hence pure beta-TCP ceramics should be sintered bclow 1200 degrees C. Pure beta-TCP sintered body can achieve a relative density of only 86% when sintered at 1150 degrees C. However, the addition of CPP in the range of 0.5-3 wt% delays phasc transition of beta-TCP and enables sintering of beta-TCP at 1200 degrees C without a phase transformation to alpha-TCP. Due to this effect of CPP added to TCP, CPP-doped beta-TCP ceramics with relative density over 95% could be obtained when sintered at 1200 degrees C for 2 h. 相似文献
12.
A.A. Sawyer S.J. Song E. Susanto P. Chuan C.X.F. Lam M.A. Woodruff D.W. Hutmacher S.M. Cool 《Biomaterials》2009,30(13):2479-2488
Bone morphogenetic proteins (BMPs) have been widely investigated for their clinical use in bone repair and it is known that a suitable carrier matrix to deliver them is essential for optimal bone regeneration within a specific defect site. Fused deposited modeling (FDM) allows for the fabrication of medical grade poly ?-caprolactone/tricalcium phosphate (mPCL–TCP) scaffolds with high reproducibility and tailor designed dimensions. Here we loaded FDM fabricated mPCL–TCP/collagen scaffolds with 5 μg recombinant human (rh)BMP-2 and evaluated bone healing within a rat calvarial critical-sized defect. Using a comprehensive approach, this study assessed the newly regenerated bone employing micro-computed tomography (μCT), histology/histomorphometry, and mechanical assessments. By 15 weeks, mPCL–TCP/collagen/rhBMP-2 defects exhibited complete healing of the calvarium whereas the non-BMP-2-loaded scaffolds showed significant less bone ingrowth, as confirmed by μCT. Histomorphometry revealed significantly increased bone healing amongst the rhBMP-2 groups compared to non-treated scaffolds at 4 and 15 weeks, although the % BV/TV did not indicate complete mineralisation of the entire defect site. Hence, our study confirms that it is important to combine microCt and histomorphometry to be able to study bone regeneration comprehensively in 3D. A significant up-regulation of the osteogenic proteins, type I collagen and osteocalcin, was evident at both time points in rhBMP-2 groups. Although mineral apposition rates at 15 weeks were statistically equivalent amongst treatment groups, micro-compression and push-out strengths indicated superior bone quality at 15 weeks for defects treated with mPCL–TCP/collagen/rhBMP-2. Consistently over all modalities, the progression of healing was from empty defect < mPCL–TCP/collagen < mPCL–TCP/collagen/rhBMP-2, providing substantiating data to support the hypothesis that the release of rhBMP-2 from FDM-created mPCL–TCP/collagen scaffolds is a clinically relevant approach to repair and regenerate critically-sized craniofacial bone defects. 相似文献
13.
《Journal of biomaterials science. Polymer edition》2013,24(12):1637-1652
In this study, a series of 3-D interconnected porous scaffolds with various pore diameters and porosities was fabricated by freeze-drying with non-toxic biodegradable waterborne polyurethane (WBPU) emulsions of different concentration. The structures of these porous scaffolds were characterized by scanning electron microscopy (SEM), and the pore diameters were calculated using CIAS 3.0 software. The pores obtained were 3-D interconnected in the scaffolds. The scaffolds obtained at different pre-freeze temperatures showed a pore diameter ranging from 2.8 to 99.9 μm with a pre-freezing temperature of ?60°C and from 13.1 to 229.1 μm with a pre-freezing temperature of ?25°C. The scaffolds fabricated with WBPU emulsions of different concentration at the same pre-freezing temperature (?25°C) had pores with mean pore diameter between 90.8 and 39.6 μm and porosity between 92.0 and 80.0%, depending on the emulsion concentration. The effect of porous structure of the scaffolds on adhesion and proliferation of human umbilical vein endothelial cells (HUVECs) cultured in vitro was evaluated using the MTT assay and environmental scanning electron microscopy (ESEM). It was found that the better adhesion and proliferation of HUVECs on 3-D scaffolds of WBPU with relative smaller pore diameter and lower porosity than those on scaffolds with larger pore and higher porosity and film. Our work suggests that fabricating a scaffold with controllable pore diameter and porosity could be a good method to be used in tissue-engineering applications to obtain carriers for cell culture in vitro. 相似文献
14.
Roy TD Simon JL Ricci JL Rekow ED Thompson VP Parsons JR 《Journal of biomedical materials research. Part A》2003,66(2):283-291
This study analyzed the in vivo performance of composite degradable bone repair products fabricated using the TheriForm process, a solid freeform fabrication (SFF) technique, in a rabbit calvarial defect model at 8 weeks. Scaffolds were composed of polylactic-co-glycolic acid (PLGA) polymer with 20% w/w beta-tricalcium phosphate (beta-TCP) ceramic with engineered macroscopic channels, a controlled porosity gradient, and a controlled pore size for promotion of new bone ingrowth. Scaffolds with engineered macroscopic channels and a porosity gradient had higher percentages of new bone area compared to scaffolds without engineered channels. These scaffolds also had higher percentages of new bone area compared to unfilled control defects, suggesting that scaffold material and design combinations could be tailored to facilitate filling of bony defects. This proof-of-concept study demonstrated that channel size, porosity, and pore size can be controlled and used to influence new bone formation and calvarial defect healing. 相似文献
15.
Ultrasound effect on osteoblast precursor cells in trabecular calcium phosphate scaffolds 总被引:3,自引:0,他引:3
This study investigated the in vitro effect of low-intensity pulsed ultrasound (LIPUS) on human embryonic palatal mesenchyme cells (HEPM, CRL-1486, ATCC, Manassas, VA), an osteoblast precursor cell line, during early adhesion to calcium phosphate scaffolds. Hydroxyapatite (HA) and beta-tricalcium phosphate (TCP) ceramic scaffolds were produced by a template coating method. Phospho-specific antibody cell-based ELISA (PACE) technique was utilized on stress activation proteins, including the extracellular signal-regulated kinase (ERK1/2), P38, c-Jun N-terminal kinase (JNK) and the anti-apoptosis mediator protein kinase B (PKB/AKT). Cell-based ELISAs were also performed on the membrane anchoring protein vinculin and alpha6beta4 integrin. LIPUS stimulated activation of PERK 1/2, PJNK, PP38 and vinculin in traditional two-dimensional (2-D) culture. Calcium release from the scaffolds was partially involved in the activation of PERK 1/2 when cell response was compared between culture on 2-D surfaces and three-dimensional (3-D) HA and TCP scaffolds. Effects of calcium extracted media from scaffolds alone could not account for the full activation of PJNK, PP38, PAKT, vinculin and alpha6beta4 integrin. LIPUS stimulation further increased PERK activity on TCP scaffolds corresponding with an increase in both vinculin and alpha6beta4 integrin levels. It was concluded from this study that LIPUS treatment can significantly affect stress signaling mediators and adhesion proteins in osteoblast precursor cells during the early cell-attachment phase to trabecular patterned scaffolds. 相似文献
16.
Three-Dimensional Plotter Technology for Fabricating Polymeric Scaffolds with Micro-grooved Surfaces
《Journal of biomaterials science. Polymer edition》2013,24(14):2089-2101
Various mechanical techniques have been used to fabricate biomedical scaffolds, including rapid prototyping (RP) devices that operate from CAD files of the target feature information. The three-dimensional (3-D) bio-plotter is one RP system that can produce design-based scaffolds with good mechanical properties for mimicking cartilage and bones. However, the scaffolds fabricated by RP have very smooth surfaces, which tend to discourage initial cell attachment. Initial cell attachment, migration, differentiation and proliferation are strongly dependent on the chemical and physical characteristics of the scaffold surface. In this study, we propose a new 3-D plotting method supplemented with a piezoelectric system for fabricating surface-modified scaffolds. The effects of the physically-modified surface on the mechanical and hydrophilic properties were investigated, and the results of cell culturing of chondrocytes indicate that this technique is a feasible new method for fabricating high-quality 3-D polymeric scaffolds. 相似文献
17.
Concentrated hydroxyapatite inks for direct-write assembly of 3-D periodic scaffolds 总被引:1,自引:0,他引:1
Hydroxyapatite (HA) scaffolds with a 3-D periodic architecture and multiscale porosity have been fabricated by direct-write assembly. Concentrated HA inks with tailored viscoelastic properties were developed to enable the construction of complex 3-D architectures comprised of self-supporting cylindrical rods in a layer-by-layer patterning sequence. By controlling their lattice constant and sintering conditions, 3-D periodic HA scaffolds were produced with a bimodal pore size distribution. Mercury intrusion porosimetry (MIP) was used to determine the characteristic pore size and volume associated with the interconnected pore channels between HA rods and the finer pores within the partially sintered HA rods. 相似文献
18.
Influence of three-dimensional scaffold on the expression of osteogenic differentiation markers by human dermal fibroblasts 总被引:6,自引:0,他引:6
Current research in the field of tissue engineering utilizes biomaterial scaffolds, cells, and growth factors for the creation of a functional, biologically active tissue. This study examined the effect of two commercially available, three-dimensional scaffolds, ultraporous beta-tricalcium phosphate ceramics (beta-TCP, Vitoss) and open-celled poly(lactic acid) foams (OPLA, Drilac), on the osteogenic differentiation potential of human dermal fibroblasts. Serum-free, chemically-defined medium containing the metabolic factor 1alpha,25-dihydroxyvitamin D3 was used to promote an osteogenic phenotype in these cells. Osteoblast differentiation was assessed using PCR and immunohistochemical methods to detect gene and protein expression for the osteoblast markers alkaline phosphatase, osteopontin, and osteocalcin. Dermal fibroblasts cultured on beta-TCP scaffolds in chemically-defined medium with vitamin D3 exhibited up-regulated gene and protein expression compared to cells cultured on OPLA scaffolds. These results suggest that Vitoss (beta-TCP) scaffolds seeded with dermal fibroblasts and maintained in chemically-defined medium with vitamin D3 are better suited for bone tissue engineering applications than Drilac (OPLA) foams. 相似文献
19.
Solid freeform fabrication (SFF) is recognized as a promising tool for creating tissue engineering scaffolds due to advantages such as superior interconnectivity and highly porous structure. Despite structural support for SFF-based three-dimensional (3-D) scaffolds that can lead to tissue regeneration, lack of cell recognition motifs and/or biochemical factors has been considered a limitation. Previously, recombinant mussel adhesive proteins (MAPs) were successfully demonstrated to be functional cell adhesion materials on various surfaces due to their peculiar adhesive properties. Herein, MAPs were applied as surface functionalization materials to SFF-based 3-D polycaprolactone/poly(lactic-co-glycolic acid) scaffolds. We successfully coated MAPs onto scaffold surfaces by simply dipping the scaffolds into the MAP solution, which was confirmed through X-ray photoelectron spectroscopy and scanning electron microscopy analyses. Through in vitro study using human adipose tissue-derived stem cells (hADSCs), significant enhancement of cellular activities such as attachment, proliferation, and osteogenic differentiation was observed on MAP-coated 3-D scaffolds, especially on which fused arginine-glycine-aspartic acid peptides were efficiently exposed. In addition, we found that in vivo hADSC implantation with MAP-coated scaffolds enhanced bone regeneration in a rat calvarial defect model. These results collectively demonstrate that facile surface functionalization of 3-D scaffolds using MAP would be a promising strategy for successful tissue engineering applications. 相似文献
20.
3D fiber-deposited scaffolds for tissue engineering: influence of pores geometry and architecture on dynamic mechanical properties 总被引:6,自引:0,他引:6
One of the main issues in tissue engineering is the fabrication of scaffolds that closely mimic the biomechanical properties of the tissues to be regenerated. Conventional fabrication techniques are not sufficiently suitable to control scaffold structure to modulate mechanical properties. Within novel scaffold fabrication processes 3D fiber deposition (3DF) showed great potential for tissue engineering applications because of the precision in making reproducible 3D scaffolds, characterized by 100% interconnected pores with different shapes and sizes. Evidently, these features also affect mechanical properties. Therefore, in this study we considered the influence of different structures on dynamic mechanical properties of 3DF scaffolds. Pores were varied in size and shape, by changing fibre diameter, spacing and orientation, and layer thickness. With increasing porosity, dynamic mechanical analysis (DMA) revealed a decrease in elastic properties such as dynamic stiffness and equilibrium modulus, and an increase of the viscous parameters like damping factor and creep unrecovered strain. Furthermore, the Poisson's ratio was measured, and the shear modulus computed from it. Scaffolds showed an adaptable degree of compressibility between sponges and incompressible materials. As comparison, bovine cartilage was tested and its properties fell in the fabricated scaffolds range. This investigation showed that viscoelastic properties of 3DF scaffolds could be modulated to accomplish mechanical requirements for tailored tissue engineered applications. 相似文献