填充结构对3D打印聚己内酯支架力学性能的影响

背景:3D打印聚己内酯组织工程支架是近些年来研究的热点之一,选择合适的材料制备力学性能优良的多孔支架是当前研究的难点。目的:制备不同填充结构的三维多孔聚己内酯支架,研究其机械性能。方法:设计0°/90°、0°/60°、0°/60°/120°、0°/45°和0°/45°/90°/135°5种填充结构,采用生物3D打印机打印三维多孔聚己内酯支架,测试支架的孔隙率及压缩和拉伸性能。结果与结论:(1)5种支架的孔隙率比较差异无显著性意义(P> 0.05);(2)从Z方向压缩时,不同填充结构聚己内酯支架的压缩性能差异很小;(3)从Y方向压缩时,0°/45°、0°/60°、0°/90°三种支架的压缩性能随填充角度增加而增强,0°/45°/90°/135°支架的压缩模量和强度比0°/45°支架高,0°/60°/120°支架的压缩模量和强度比0°/60°支架强;(4)从X方向压缩时,支架压缩模量和强度的规律与Y方向压缩相反;在5种支架中,0°/45°/90°/135°支架的拉伸模量和强度最大,0°/90°支架的拉伸模量和强度最小,0°/45°、0°/60°、0°/90°支架的拉伸强度和模量随角度...     

基于3D打印的Ⅰ型胶原涂覆β-TCP骨组织工程支架研究

根据骨缺损形态构建个性化的组织工程支架在骨组织工程应用中有巨大需求。基于3D打印技术制备个性化的I型胶原涂覆的β-磷酸三钙(β-TCP)骨支架。通过比较0/90°、0/60°、0/45°的填充角度,0.10、0.25、0.50 mg/m L涂覆胶原的浓度对β-TCP支架孔径、孔隙率、力学性能的影响,选定最优填充角度为0/90°及最佳涂覆胶原的浓度为0.50 mg/m L的β-TCP/胶原支架。所得支架能准确地再现设计的三维模型,具有多级孔结构,大孔平均直径为315μm,微孔直径为3~5μm,孔隙率为84%。β-TCP/胶原支架的抗压能力为(12.29±0.88)MPa,压缩弹性模量为(116.74±27.75)MPa,与成人松质骨相似。体外大鼠骨髓间充质干细胞(m BMSCs)支架培养实验结果显示,涂覆胶原的支架具有更好的生物相容性,能有效促进m BMSCs的粘附增殖,β-TCP/胶原支架上细胞具有更高的碱性磷酸酶(ALP)活性和Collagen-I、BSP相关成骨基因的表达。研究结果显示,3D打印制备的I型胶原涂覆的β-TCP支架具有匹配的外形,良好可控的孔隙率,对m BMSCs有良好成骨活性,为骨组织支架在临床上应用提供新的技术。     

基于三维打印的磷酸三钙骨组织工程支架烧结工艺研究

磷酸三钙(TCP)是构建骨组织工程支架常用的生物陶瓷材料。三维(3D)打印的TCP支架具有精确可控的孔隙结构,但存在力学性能不足的问题。由于烧结工艺对生物陶瓷支架力学性能的影响至关重要,本文详细探讨了不同烧结温度对3D打印TCP支架的力学性能的影响,测试了不同烧结温度制备的支架的表观形貌、质量和体积收缩率、孔隙率、力学性能以及降解性能。结果表明,当烧结温度为1150℃时,晶粒生长充分、气孔最少,支架具有最大的体积收缩率、最小的孔隙率以及最优的力学性能,压缩模量和抗压强度可以分别达到(100.08±18.6)MPa和(6.52±0.84)MPa,能够满足人体松质骨力学强度的要求。此外,与其他烧结温度下制备的支架相比,1150℃下烧结制备的支架在酸性环境中降解最慢,进一步说明其在长期植入时具有更佳的力学稳定性。该支架可支持骨髓间充质干细胞(BMSCs)黏附和快速增殖,具有良好的生物相容性。综上,本文优化了3D打印TCP支架的烧结工艺,提高了其力学性能,为其作为承重骨的应用奠定了基础。     

基于高温挤出打印的PLGA/β-TCP人工骨支架制备及其性能研究

目的制备具有较优力学性能和细胞增殖特性的聚乳酸-羟基乙酸共聚物/β-磷酸三钙[poly(lactic-co-glycolic acid)/β-tricalcium phosphate,PLGA/β-TCP]人工骨支架,为骨组织工程支架材料和结构的选择提供实验依据。方法以PLGA和纳米β-TCP为原材料,先将PLGA在加热筒中高温熔融,再将β-TCP混合搅拌均匀进行打印。采用高温挤出打印方法制备人工骨支架,研究不同材料配比(PLGA与β-TCP配比为4∶1、3∶1、2∶1)、不同孔径(200μm、300μm和400μm)、不同层高(4.2 mm、5.4 mm和6.6 mm)以及不同孔形(方形、45°倾斜和60°倾斜)对支架力学性能和细胞增殖性能的影响。打印9组支架,利用扫描电镜分析支架的形貌特征,用万能材料试验机测试支架的抗压强度、弹性模量,用CCK-8试剂盒进行细胞增殖性能测试。最后对实验数据进行极差分析,得出最优组合,并制作相应的支架,对其进行力学性能和生物性能的测试。结果在力学性能实验中,S5组支架显示出最好的抗压强度(7.23 MPa),S9组支架显示出最好的杨氏模量(356.1 MPa),与骨小梁相当;在细胞增殖实验中,S1组支架显示出最好的增殖特性。通过正交实验法,分析并实验验证,得出综合性能最优的支架参数为材料配比为4∶1、层高为6.6 mm、孔型为45°倾斜以及孔径为200μm。结论材料配比为4∶1、层高为6.6mm、孔型为45°倾斜以及孔径为200μm的支架基本能够满足某些松质骨(如骨小梁)的力学性能和细胞增殖性能,并可为后续相关研究提供实验和理论基础。     

3D打印多孔钛支架微观孔隙结构和力学性能

目的研究3D打印技术制造的钻石分子结构多孔钛支架的微观孔隙结构和力学性能,指导3D打印多孔钛骨科植入物的开发。方法采用选择性激光熔化(selective laser melting,SLM)和电子束熔化(electron beam melting,EBM)两种金属3D打印制造工艺,制造钻石分子结构多孔Ti6Al4V支架。使用光学显微镜和扫描电镜观察其微观孔隙结构,并使用万能材料试验机对这些支架进行压缩测试。结果两种3D打印制造工艺都会存在加工误差,并且在表面存在半熔融金属颗粒。SLM工艺相对误差为20.9%~35.8%。EBM工艺相对误差为-9.1%~46.8%,且制造不出杆件宽度为0.2 mm的支架。SLM工艺制造的支架抗压强度为99.7~192.6 MPa,弹性模量为2.43~4.23 GPa。EBM工艺制造的支架抗压强度为39.5~96.9 MPa,弹性模量为1.44~2.83 GPa。结论 SLM工艺比EBM工艺制造精度高。支架的孔隙率是影响其抗压强度和弹性模量的主要因素,相同工艺的情况下,孔隙率越大,抗压强度越小,弹性模量也越小;相近孔隙率的情况下,SLM工艺比EBM工艺强度高,弹性模量也高。     

3D打印PLA﹑PDS及PLGA材料的力学性能及软组织再生潜能

3D打印技术在组织工程支架的个性化制备方面体现出明显优势,不仅可精细成型复杂结构,而且可以极大地节约原材料。该文选择3种可降解生物医用高分子材料,聚乳酸(PLA)、聚对二氧环己酮(PDS)及聚乙交酯-丙交酯(PLGA),利用3D打印技术制备了标准测试样品,对其分别进行了单轴拉伸性能、压缩性能、三点弯曲性能测试。通过与文献中模压样品测试数据的比较发现,3D打印技术制备的样品孔隙率及力学性能可控,综合性能优异。而且,可控的力学性能对体内不同软组织的再生具有重要意义。     

3D打印胶原/壳聚糖支架改善大鼠脊髓损伤后神经功能恢复

文题释义：壳聚糖：为一种天然多糖,是虾蟹等低等动物外壳的重要成分,具有一定的机械强度,并且具有良好的生物相容性和抗菌性,在生物工程领域具有较好的应用前景。 3D生物打印：是组织工程中最重要的技术之一。目前常用的三维生物打印方法包括喷墨打印、挤压生物打印和激光生物打印,选择好合适的材料后,在计算机指导下根据所选择的生物材料和细胞类型逐层准确地打印出所设计的结构。 背景：3D打印技术可以根据需求制备出满足脊髓植入形状、大小和表面形态要求的生物支架。 目的：观察3D打印胶原/壳聚糖支架对脊髓损伤大鼠神经功能恢复的影响。 方法：将胶原和壳聚糖按2∶1的质量比混合,采用冷冻干燥法制备普通胶原/壳聚糖支架,采用3D打印机制备3D打印胶原/壳聚糖支架,分别测量两种支架的孔隙率和弹性模量,电镜观察支架形态。将神经干细胞分别与3D打印胶原/壳聚糖支架、普通胶原/壳聚糖支架共培养,进行扫描电镜观察与CCK-8检测。将40只雌性SD大鼠(由中国人民解放军医学科学院军事科学院提供)随机分成4组：假手术组、脊髓损伤组、普通胶    原/壳聚糖支架组和3D打印胶原/壳聚糖支架组,后3组制作脊髓全横断损伤模型,普通胶原/壳聚糖支架组和3D打印胶原/壳聚糖支架组损伤处填充对应的支架材料,术后相应时间点进行后肢功能BBB评分、斜坡实验、神经电生理检测与磁共振平扫。实验方案经天津市神经创伤重点实验室伦理委员会批准。 结果与结论：①扫描电镜显示,3D打印胶原/壳聚糖支架具有互连的多孔结构,普通胶原/壳聚糖支架内部结构紊乱;②神经干细胞在3D打印胶原/壳聚糖支架表面生长良好,完全伸展,且3D打印胶原/壳聚糖支架表面神经干细胞的活性显著高于普通胶原/壳聚糖支架组(P < 0.05);③3D打印胶原/壳聚糖支架的孔隙率与弹性模量均高于普通胶原/壳聚糖支架组(P < 0.05);④3D打印胶原/壳聚糖支架组术后3-8周的BBB评分高于脊髓损伤组、普通胶原/壳聚糖支架组(P < 0.05),术后4,6,8周的斜坡实验角度大于脊髓损伤组、普通胶原/壳聚糖支架组(P < 0.05);⑤3D打印胶原/壳聚糖支架组术后8周的运动诱发电位振幅、体感诱发电位振幅大于脊髓损伤组与普通胶原/壳聚糖支架组(P < 0.05),运动诱发电位潜伏期、体感诱发电位潜伏期短于脊髓损伤组与普通胶原/壳聚糖支架组(P < 0.05);⑥磁共振平扫显示与脊髓损伤组及普通胶原/壳聚糖支架组比较,3D打印胶原/壳聚糖支架组损伤处具有较好的连续性与较多的神经纤维束通过;⑦结果表明,3D打印胶原/壳聚糖支架可促进脊髓损伤大鼠神经功能的修复。 ORCID: 0000-0001-5771-8222(史新宇) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

基于有限元法的骨组织工程支架力学性能分析及改进设计

目的分析不同孔隙结构和孔隙率骨组织工程支架的力学性能,并对支架的孔隙结构进行改进设计使其性能提高。方法利用SolidWorks软件进行方形孔、球形孔和圆柱形孔3种结构55%～75%孔隙率的支架建模,计算得到各结构的表面积体积比;利用ANSYS Workbench软件进行结构受力的有限元计算,得到支架结构的应力分布和等效压缩模量;根据应力分布的特点,将方形孔的支架结构改进为长方形孔隙结构和长方体单元结构两种支架。结果随着孔隙率的增加,3种结构的表面积体积比均增大,对于相同的孔隙率,方形孔和球形孔的表面积体积比较大,圆柱形孔最小;3种结构的最大压应力总体趋势是随着孔隙率的增加而增大,对于同一孔隙率的3种结构,方形孔的最大压应力最小;3种结构的模量和孔隙率近似呈线性关系,方形孔和圆柱形孔的模量值相近;60%孔隙率的方形孔及两种改进结构应力分析表明,两种改进结构的平行于应力方向的4条棱侧壁应力可减小约15%。结论方形孔的表面积体积比和力学性能比相同孔隙率的球形孔和圆柱形孔结构要更有优势,而改进的两种结构又可以提高方形孔的力学性能,两种改进的孔隙丰富了组织工程支架的结构,研究结果为两种支架的临床应用提供力学依据。     

明胶/氧化纳米纤维素高弹性模量高孔隙皮肤支架的3D打印工艺

背景：在采用主动修复治疗手段应对皮肤创伤时，需要使用组织工程技术生成新的组织来代替坏死组织，皮肤支架在创伤修复领域具有良好的应用前景。皮肤支架需要呈现具有一定力学强度的三维多孔结构，以满足细胞增殖分裂的需求，而目前使用的明胶基生物材料力学强度弱，无法达到皮肤支架的使用要求。目的：针对明胶/氧化纳米纤维素复合材料制备组织工程皮肤支架时使用的3D打印工艺进行研究，重点研究不同工艺参数下制备皮肤支架的孔隙率与其力学强度之间的关系。方法：从葎草中提取10%浓度的氧化纳米纤维素晶须，再与5%的明胶复合得到明胶/氧化纳米纤维素复合材料，检测明胶与明胶/氧化纳米纤维素复合材料的弹性模量。以明胶/氧化纳米纤维素复合材料为基材，采用3D打印挤压成型方法制备皮肤支架，通过对材料进行力学性能测试和流变特性测试确定挤压成型工艺参数(填充间隙1.5-2.5 mm,0.1 mm均布；气压160-200 kPa)，并以此制备具有三维多孔结构的皮肤支架。对皮肤支架进行了抗压性能的测试并与有限元分析结果相对比，论证了支架打印时的填充间隙与支架孔隙率及力学强度之间的关系。结果与结论：(1)通过实验得出，加入10%浓度的氧...     

纳米羟基磷灰石/胶原蛋白/丝素蛋白复合骨组织工程支架材料的生物相容性

背景:通过将两种及两种以上材料共混制备复合支架材料可以弥补各自的不足,利用各种材料的互补特性来满足组织工程对支架的要求。目的:制备纳米羟基磷灰石/胶原蛋白/丝素蛋白复合三维支架材料,并研究其细胞相容性。方法:将纳米羟基磷灰石、胶原蛋白与丝素蛋白分别按质量比为1∶1∶5、1∶2∶5、1∶3∶5的比例混合,制备纳米羟基磷灰石/胶原蛋白/丝素蛋白复合材料,测试其孔隙率、孔径大小、吸水膨胀率及压缩力学性能。将表征结果良好的质量比为1∶2∶5的纳米羟基磷灰石/胶原蛋白/丝素蛋白复合材料与MC3T3-E1细胞体外复合培养,MTT法检测复合培养2,4,6,8,12 d后的细胞活性。结果与结论:羟基磷灰石/胶原蛋白/丝素蛋白按质量1∶2∶5的比例混合更符合要求:孔径98-260μm,孔隙率为(96.72±2.78)%,吸水膨胀率为(549.37±35.29)%,生物力学试验机测定其力学性能稳定、压缩应变及弹性模量等指标适宜骨组织工程研究应用。MC3T3-E1细胞在纳米羟基磷灰石/胶原蛋白/丝素蛋白复合三维支架上生长增殖良好,表明纳米羟基磷灰石/胶原/丝素复合三维支架具有良好的细胞相容性。     

Polymer scaffolds with interconnected spherical pores and controlled architecture for tissue engineering: fabrication, mechanical properties, and finite element modeling

A method is proposed in which the geometric properties of 3D scaffolds with application in tissue engineering can be tailored: porosity, pore size, and interconnection throat size. The architecture of the fabricated scaffolds is analyzed by scanning electron microscopy. The mechanical properties of these structures are discussed on the basis of compression stress-strain measurements. Moreover, the mechanical properties of the scaffolds are estimated by means of finite element modeling (FEM) in which the compression stress-strain test is simulated on an ideal structure based on the crystalline face centered cubic system. The elastic properties of the constructs are explained on the basis of the FEM model that supports the main mechanical conclusion of the experimental results: the compressive modulus in the first linear region does not depend on the geometric characteristics of the pore (pore size, interconnection throat size) but only on the total porosity of the scaffold.     

Crosslinked poly(epsilon-caprolactone/D,L-lactide)/bioactive glass composite scaffolds for bone tissue engineering

A series of elastic polymer and composite scaffolds for bone tissue engineering applications were designed. Two crosslinked copolymer matrices with 90/10 and 30/70 mol % of epsilon-caprolactone (CL) and D,L-lactide (DLLA) were prepared with porosities from 45 to 85 vol % and their mechanical and degradation properties were tested. Corresponding composite scaffolds with 20-50 wt % of particulate bioactive glass (BAG) were also characterized. Compressive modulus of polymer scaffolds ranged from 190+/-10 to 900+/-90 kPa. Lactide rich scaffolds absorbed up to 290 wt % of water in 4 weeks and mainly lost their mechanical properties. Caprolactone rich scaffolds absorbed no more than 110 wt % of water in 12 weeks and kept their mechanical integrity. Polymer and composite scaffolds prepared with P(CL/DLLA 90/10) matrix and 60 vol % porosity were further analyzed in simulated body fluid and in osteoblast culture. Cell growth was compromised inside the 2 mm thick three-dimensional scaffold specimens as a static culture model was used. However, composite scaffolds with BAG showed increased osteoblast adhesion and mineralization when compared to neat polymer scaffolds.     

Fabrication of three-dimensional porous scaffolds of complicated shape for tissue engineering. I. Compression molding based on flexible-rigid combined mold

A novel method for the fabrication of complexly shaped three-dimensional porous scaffolds has been developed by combining modified compression molding and conventional particulate leaching. The resultant scaffolds of various shapes, including some shaped like auricles, were made of hydrophobic biodegradable and bioresorbable poly(D,L-lactic acid) (PDLLA) and poly(D,L-lactic-co-glycolic acid) (PLGA). A polymer-particulate mixture was first prepared by the conventional solvent casting method and then compressively molded in a specially designed flexible-rigid combined mold which facilitates shaping and mold release during the fabrication process. The molding was carried out at a moderate temperature, above the glass transition temperature and below the flow temperature of these amorphous polymers. A porous scaffold was then obtained after particulate leaching. The pores are highly interconnected and uniformly distributed both in the bulk and on the external surface of the scaffolds, and the porosity can exceed 90%. The mechanical properties of the resultant porous scaffolds are satisfactory as determined by measurements of compressive modulus and compressive stress at 10% strain. Good viability of cells seeded in the porous scaffolds was confirmed. This novel fabrication method is promising in tissue engineering because of its ability to produce precise and complexly (anatomically) shaped porous scaffolds.     

In vitro chondrocyte behavior on porous biodegradable poly (e-caprolactone)/polyglycolic acid scaffolds for articular chondrocyte adhesion and proliferation

In this study, poly(e-caprolactone)/polyglycolic acid (PCL/PGA) scaffolds for repairing articular cartilage were fabricated via solid-state cryomilling along with compression molding and porogen leaching. Four distinct scaffolds were fabricated using this approach by four independent cryomilling times. These scaffolds were assessed for their suitability to promote articular cartilage regeneration with in vitro chondrocyte cell culture studies. The scaffolds were characterized for pore size, porosity, swelling ratio, compressive, and thermal properties. Cryomilling time proved to significantly affect the physical, mechanical, and morphological properties of the scaffolds. In vitro bovine chondrocyte culture was performed dynamically for 1, 7, 14, 28, and 35 days. Chondrocyte viability and adhesion were tested using MTT assay and scanning electron microscopy micrographs. Glycosaminoglycan (GAG) and DNA assays were performed to investigate the extracellular matrix (ECM) formation and cell proliferation, respectively. PCL/PGA scaffolds demonstrated high porosity for all scaffold types. Morphological analysis and poly(ethylene oxide) continuity demonstrated the existence of a co-continuous network of interconnected pores with pore sizes appropriate for tissue engineering and chondrocyte ingrowth. While mean pore size decreased, water uptake and compressive properties increased with increasing cryomilling times. Compressive modulus of 12, 30, and 60 min scaffolds matched the compressive modulus of human articular cartilage. Viable cells increased besides increase in cell proliferation and ECM formation with progress in culture period. Chondrocytes exhibited spherical morphology on all scaffold types. The pore size of the scaffold affected chondrocyte adhesion, proliferation, and GAG secretion. The results indicated that the 12 min scaffolds delivered promising results for applications in articular cartilage repair.     

Fabrication and characterization of gelatin-based biocompatible porous composite scaffold for bone tissue engineering

In this study, composite scaffolds were prepared with polyethylene oxide (PEO)-linked gelatin and tricalcium phosphate (TCP). Chitosan, a positively charged polysaccharide, was introduced into the scaffolds to improve the properties of the artificial bone matrix. The chemical and thermal properties of composite scaffolds were investigated by Fourier transform infrared spectroscopy, thermogravimetric analyzer, differential thermal analyzer. In vitro cytotoxicity of the composite scaffold was also evaluated and the sample showed no cytotoxic effect. The morphology was studied by SEM and light microscopy. It was observed that the prepared scaffold had an open interconnected porous structure with pore size of 230-354 μm, which is suitable for osteoblast cell proliferation. The mechanical properties were assessed and it was found that the composite had compressive modulus of 1200 MPa with a strength of 5.2 MPa and bending modulus of 250 MPa having strength of 12.3 MPa. The porosity and apparent density were calculated and it was found that the incorporation of TCP can reduce the porosity and water absorption. It was revealed from the study that the composite had a 3D porous microstructure and TCP particles were dispersed evenly among the crosslinked gelatin/chitosan scaffold. ? 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3020-3028, 2012.     

Fabrication of porous ultra-short single-walled carbon nanotube nanocomposite scaffolds for bone tissue engineering

We investigated the fabrication of highly porous scaffolds made of three different materials [poly(propylene fumarate) (PPF) polymer, an ultra-short single-walled carbon nanotube (US-tube) nanocomposite, and a dodecylated US-tube (F-US-tube) nanocomposite] in order to evaluate the effects of material composition and porosity on scaffold pore structure, mechanical properties, and marrow stromal cell culture. All scaffolds were produced by a thermal-crosslinking particulate-leaching technique at specific porogen contents of 75, 80, 85, and 90 vol%. Scanning electron microcopy, microcomputed tomography, and mercury intrusion porosimetry were used to analyze the pore structures of scaffolds. The porogen content was found to dictate the porosity of scaffolds. There was no significant difference in porosity, pore size, and interconnectivity among the different materials for the same porogen fraction. Nearly 100% of the pore volume was interconnected through 20microm or larger connections for all scaffolds. While interconnectivity through larger connections improved with higher porosity, compressive mechanical properties of scaffolds declined at the same time. However, the compressive modulus, offset yield strength, and compressive strength of F-US-tube nanocomposites were higher than or similar to the corresponding properties for the PPF polymer and US-tube nanocomposites for all the porosities examined. As for in vitro osteoconductivity, marrow stromal cells demonstrated equally good cell attachment and proliferation on all scaffolds made of different materials at each porosity. These results indicate that functionalized ultra-short single-walled carbon nanotube nanocomposite scaffolds with tunable porosity and mechanical properties hold great promise for bone tissue engineering applications.     

Fabrication and material properties of fibrous PHBV scaffolds depending on the cross-ply angle for tissue engineering

Fibrous PHBV cross-ply scaffolds were fabricated using the electrospinning technique. The electrospun fibers were arranged depending on angles of alignment, which were 180°, 90°, 60°, and 45°. The stress and strain values of the fibrous PHBV cross-ply scaffolds increased as the cross-ply angle increased. At 180°, the strength and strain values of the fibers depended on tensile loading directions. At an alignment of 90°, the PHBV scaffolds had a stress value of 3.5?MPa, which was more than two times higher than the random structure. The cell morphology and proliferation of L-929 cells was strongly dependant on the fiber alignment and the best results were observed when the angle alignment was high. The results of this study showed that the cross-ply structure of the PHBV scaffold affected not only the cell adhesion and spreading properties but also dictated the mechanical properties, which were dependent on the angles of alignment.     

Gelatin/chitosan/hyaluronan scaffold integrated with PLGA microspheres for cartilage tissue engineering

Poly(lactide-co-glycotide) (PLGA) microspheres integrated into gelatin/chitosan/hyaluronan scaffolds were fabricated by freeze-drying and crosslinking with 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide. The effects of the microspheres on porosity, density, compressive modulus, phosphate-buffered saline uptake ratio and weight loss of the scaffolds were evaluated. Generally, a scaffold with a higher PLGA content had a lower porosity and weight loss, and a medium uptake ratio, but a larger apparent density and compressive modulus. When the PLGA content was lower than 50%, the PLGA-integrated scaffolds had a similar pore size (approximately 200microm) as that of the control, and as much as 90% of their porosity could be preserved. In vitro chondrocyte culture in the 50% PLGA-integrated scaffold demonstrated that the cells could proliferate and secrete extracellular matrix at the same level as in the control gelatin/chitosan/hyaluronan scaffold.     

碳纤维-聚乳酸-聚乙二醇复合支架的制备及性能检测

背景：长期实验发现聚乳酸-聚乙二醇支架的力学性能及细胞相容性能较差,因此多数研究向支架中加入其他材料,以提高其生物活性及力学性能。 目的：制备改性碳纤维-聚乳酸-聚乙二醇支架,并检测其性能。 方法：采用溶液潘注/粒子沥滤法制备改性碳纤维-聚乳酸-聚乙二醇复合支架。对比改性碳纤维-聚乳酸-聚乙二醇复合支架与聚乳酸-聚乙二醇支架的超微结构、孔隙率、吸水性、降解率及力学性能。将改性碳纤维-聚乳酸-聚乙二醇复合支架与聚乳酸-聚乙二醇支架分别与SD大鼠成骨细胞共培养,12 h后采用沉淀法检测细胞黏附率;培养1,3,5,7,9 d后,采用 MTT 法检测细胞增殖。 结果与结论：聚乳酸-聚乙二醇支架材料表面孔结构分布均匀,孔径为(404.0±10.5) µm;改性碳纤维-聚乳酸-聚乙二醇支架碳纤维表面见大量纵向沟槽,表面孔结构分布均匀,孔径为(433.0±3.0) µm,两组支架孔径比较差异有显著性意义(P < 0.05)。改性碳纤维-聚乳酸-聚乙二醇支架的孔隙率、吸水性、弹性模量和抗压强度、降解率、细胞黏附率与增殖率均高于聚乳酸-聚乙二醇支架(P < 0.05)。表明改性碳纤维的加入改善了聚乳酸-聚乙二醇复合支架的力学性能及细胞相容性。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程