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1.
皮肤成纤维细胞复合纤维修复前交叉韧带的初步研究   总被引:2,自引:0,他引:2  
目的:本实验采用皮肤成纤维细胞修复原位冻融的前交叉韧带,以探索皮肤成纤维细胞作为构建组织工程前交叉韧带种子细胞的可行性.方法:体外分离培养兔皮肤成纤维细胞(SF),传代培养之后将细胞复合纤维生物蛋白胶,将细胞.纤维蛋白胶复合物植入原位冻融的前交叉韧带处.12周取材切片行HE染色及天狼猩红染色,使用偏振光显微镜观察.并使用图象分析软件对Ⅰ、Ⅲ型胶原含量进行半定量分析.结果:采用皮肤成纤维细胞复合纤维生物蛋白胶修复原位冻融的前交叉韧带的Ⅲ型胶原含量较单纯冻融的前交叉韧带明显减少,而较正常前交叉韧带则无明显统计学差异(P>0.05).结论:皮肤成纤维细胞可作为构建组织工程前交又韧带的较为理想的种子细胞选择.  相似文献   

2.
目的:通过对聚对苯二甲酸乙二醇酯(Polyethylene terephthalate,PET)材料的编织和力学性能的分析,初步探讨使用该材料构建组织工程韧带支架的可行性。方法:将不同强度的PET单纤维通过经编法编织成支架材料;然后使用电子拉力机对编织好的支架材料以及消毒处理后的支架材料进行力学性能测试并进行分析。结果:PET编织构建的支架材料结构稳定,其极限抗张强度已达到了前交叉韧带的力学要求。辐照消毒对支架材料的力学性能无短期影响。结论:该支架材料编织结构设计合理,具有优良的力学性能,消毒后对其力学性能无短期影响,有望通过改进生物学性能后成为一种较理想的组织工程前交叉韧带支架材料。  相似文献   

3.
研究探索自组装短肽R2I4R2在人皮肤成纤维细胞体外三维培养的应用效果与对创伤修复过程的作用。通过圆二色谱仪分析不同时间、温度和离子条件对其二级结构的影响;刚果红染色宏观检测短肽自组装情况;体外培养人皮肤成纤维细胞探索细胞在R2I4R2形成的纳米纤维网络中的生长状态及凋亡情况;建立SD大鼠皮肤创伤模型,HE染色与免疫组织化学检测其对皮肤创伤修复的病理变化。结果表明,R2I4R2在不同条件下均可形成较为稳定的二级结构;自组装24h后可形成均一稳定的膜片状结构,为细胞三维培养提供支架;人皮肤成纤维细胞可在R2I4R2形成的纳米纤维网络三维环境中生长且状态良好;动物实验表明,短肽R2I4R2可减少炎症、促进新生血管生成、加速皮肤创伤修复过程。自组装短肽R2I4R2作为新的纳米支架材料,可用于细胞三维培养与皮肤创伤修复。  相似文献   

4.
目的:研究担载碱性成纤维细胞生长因子(b-FGF)微球复合明胶支架的外形特征、孔径、孔隙率及体外释放动力学,以期构建具有缓释功能、高孔隙率的担载细胞因子的新型复合明胶支架。方法:本文利用冷冻相分离法和S/O/W法先将b-FGF水溶液包裹于PLGA微球中,然后埋置于明胶溶液中制备为多孔复合明胶支架。分别对微球的形态和复合明胶支架的基本形态、孔径、孔隙率进行表征,通过Elisa法测定b-FGF在复合明胶支架中的体外释放行为。结果:制备成形态良好的三维复合明胶支架,其孔隙率为82.90%±1.45%,孔径范围为150~300μm,复合明胶支架中b-FGF在体外缓慢释放20余天。结论:担载蛋白微球复合明胶支架不仅满足组织工程支架的要求,还能有效缓释细胞因子,为细胞和组织生长提供良好的微环境,为进一步应用于组织工程领域提供了可能。  相似文献   

5.
研究经乙基-(3-二甲基氨基丙基)碳化二亚胺盐酸盐(EDC)处理的Ⅱ型胶原-硫酸软骨素支架材料的性能特点,并在体外构建组织工程软骨。从鸡软骨中提取Ⅱ型胶原,以不同浓度的EDC为交联剂通过冷冻干燥的方法制备Ⅱ型胶原与硫酸软骨素复合支架并测定其理化性质。将体外培养的新生兔关节软骨细胞接种在Ⅱ型胶原与硫酸软骨素复合支架上,观察软骨细胞在支架上的生长形态并检测支架上软骨细胞分泌的糖胺聚糖含量及Ⅱ型胶原含量。结果表明:采用EDC与硫酸软骨素交联增加了支架的稳定性,最适的交联剂质量浓度为7 mg/mL。软骨细胞在复合支架上增殖分化良好,并保持软骨细胞特异分化的表型,分泌Ⅱ型胶原与蛋白多糖(GAG)。培养14 d后已有软骨样组织形成。  相似文献   

6.
目的:探讨雪旺细胞(Schwann’s cells,SCs)在同种异体骨支架上的生物相容性,体外构建组织工程骨神经化模型。方法:利用新鲜人体骨骼制备同种异体骨支架材料,检测其物理性能;采用优化方法提取新生SD大鼠坐骨、臂丛神经培养SCs,实验分为三维培养实验组(SCs+同种异体骨)、二维培养对照组(SCs+胶原玻片),S-100抗体免疫荧光染色鉴定SCs纯度;细胞计数法检测两组细胞增殖特点;细胞接种后第3、7天取样,扫描电镜观察。结果:同种异体骨支架具有良好的三维孔隙结构,适宜细胞贴附生长;S-100免疫荧光染色证实SCs纯度95%;扫描电镜检测显示两组SCs均可正常粘附增殖,细胞间排布规律相似,培养早期实验组SCs胞体更加细长,伪足更加明显,随着培养时间的延长表现出较强的迁移能力;细胞增殖检测:两组SCs生长曲线特征基本一致,支架材料对SCs无毒性作用。结论:同种异体骨支架SCs具有良好的生物相容性,其三维立体多孔结构有利于SCs的粘附与迁移,初步构建了体外组织工程骨神经化模型。  相似文献   

7.
目的:研究低氧(2%氧)对成年Wistar大鼠心脏成纤维细胞DNA合成及Ⅰ、Ⅲ型胶原前a肽链表达的影响.方法:分离培养成年Wistar大鼠心脏成纤维细胞,采用液体闪烁计数方法检测心脏成纤维细胞的DNA合成速率,采用原位杂交技术检测Ⅰ、Ⅲ型胶原前α肽链mRNA的表达.结果:成年Wistar大鼠心脏成纤维细胞在低氧第6h、12 h时3H-TdR掺入量较常氧组显著增加,分别增加34%(P<0.05)和36%(P<0.01);低氧第4 h、8 h、12 h Ⅰ型胶原前α肽链mRNA表达显著高于常氧培养的细胞;低氧第2 h,Ⅲ型胶原前α肽链mRNA表达显著高于常氧培养的细胞.结论:低氧能够直接促进体外培养的成年Wistar大鼠心脏成纤维细胞DNA合成和Ⅰ、Ⅲ型胶原前α肽链表达,提示低氧对心脏成纤维细胞生长和胶原表达的直接调节可能是低氧性心肌纤维化的重要机制.  相似文献   

8.
目的:探讨经聚乳酸-聚羟基乙酸共聚物(PLGA)改性的水溶性胶原在体外对牛血清白蛋白(BSA)的缓释性能.方法:将PLGA、胶原和BSA制备成复合物,用ELISA法检测本复合物对BSA的缓释性质.结果:本复合物约以6.61 ng/d的速率稳定地缓释BSA,在30天的考察期内,BSA累积释放率达到43%,本复合物形态保持完好.结论:本PLGA-胶原复合物有望发展成为一种体内植入型,具有对生物活性物质长效缓释性质的组织工程支架.  相似文献   

9.
目的:研究新型聚羟丁酸酯作为组织工程软骨支架材料的可行性.方法:取幼兔软骨组织中软骨细胞体外培养扩增.实验组接种软骨细胞于支架材料上,体外培养两周后埋植于新西兰大白兔背部皮下;对照组埋入未接种细胞的支架材料.扫描电镜观察材料表面形态及细胞生长情况.分别于第4、8、12周取出标本,大体观察后进行HE和Masson染色,观察组织工程软骨形成情况.结果:扫描电镜观察可见裸材料孔隙分布均匀,形状不规则;细胞材料复合体体外培养两周后材料表面爬满细胞且生长状态良好.埋植材料取出后可见不同时间点实验组标本大小无明显变化,对照组标本逐渐变小.HE和Masson染色显示各组支架材料至12周时已被完全吸收;实验组12周时可见较成熟软骨组织;对照组支架材料被吸收后最终被纤维结缔组织取代.结论:此新型聚羟丁酸酯材料可作为组织工程软骨支架材料.  相似文献   

10.
PLGA的不同组成对支架材料性能的影响研究   总被引:5,自引:0,他引:5  
研究PLGA的不同组成对支架材料的力学性能、降解性能和生物学性能的影响。采用溶液浇注/颗粒沥取法制备出不同组成的PLGA多孔支架,对支架的力学性能和降解速率进行考察,同时将人真皮成纤维细胞接种于不同组成的PLGA支架材料上,培养不同时间后,检测细胞的粘附率和增殖率,以及细胞产生的总胶原含量,并通过扫描电镜观察支架上的细胞形态。结果显示,随PLA比例的增加,支架的力学强度增加,降解速率降低,但都不是线性变化。70:30比例的支架,拉伸强度最高,而70:30和80:20两种比例的支架,其降解速率没有显著性差异。PLGA不同组成的支架,均具有良好的细胞相容性,成纤维细胞粘附率和增殖率在三种比例的支架上没有显著性差异,细胞在支架表面生长良好,分泌大量的细胞外基质,细胞基本铺满整个支架。本文研究发现,PLGA的组成对支架力学性能、降解性能和生物学性能有细小但显著的影响,这将对组织构建选用PLGA支架材料提供有益的帮助。  相似文献   

11.
The in vitro responses of Schwann cells (RT4-D6P2T, a schwannoma cell line derived from a chemically induced rat peripheral neurotumor) on various types of electrospun fibrous scaffolds of some commercially available biocompatible and biodegradable polymers, i.e., poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polycaprolactone (PCL), poly(l-lactic acid) (PLLA), and chitosan (CS), were reported in comparison with those of the cells on corresponding solution-cast film scaffolds as well as on a tissue-culture polystyrene plate (TCPS), used as the positive control. At 24 h after cell seeding, the viability of the attached cells on the various substrates could be ranked as follows: PCL film > TCPS > PCL fibrous > PLLA fibrous > PHBV film > CS fibrous approximately CS film approximately PLLA film > PHB film > PHBV fibrous > PHB fibrous. At day 3 of cell culture, the viability of the proliferated cells on the various substrates could be ranked as follows: TCPS > PHBV film > PLLA film > PCL film > PLLA fibrous > PHB film approximately PCL fibrous > CS fibrous > CS film > PHB fibrous > PHBV fibrous. At approximately 8 h after cell seeding, the cells on the flat surfaces of all of the film scaffolds and that of the PCL nanofibrous scaffold appeared in their characteristic spindle shape, while those on the surfaces of the PHB, PHBV, and PLLA macrofibrous scaffolds also appeared in their characteristic spindle shape, but with the cells being able to penetrate to the inner side of the scaffolds.  相似文献   

12.
A comparative study on the in vitro osteogenic potential of electrospun poly-L-lactide/hydroxyapatite/collagen (PLLA/HA/Col, PLLA/HA, and PLLA/Col) scaffolds was conducted. The morphology, chemical composition, and surface roughness of the fibrous scaffolds were examined. Furthermore, cell attachment, distribution, morphology, mineralization, extracellular matrix protein localization, and gene expression of human mesenchymal stromal cells (hMSCs) differentiated on the fibrous scaffolds PLLA/Col/HA, PLLA/Col, and PLLA/HA were also analyzed. The electrospun scaffolds with a diameter of 200–950 nm demonstrated well-formed interconnected fibrous network structure, which supported the growth of hMSCs. When compared with PLLA/H%A and PLLA/Col scaffolds, PLLA/Col/HA scaffolds presented a higher density of viable cells and significant upregulation of genes associated with osteogenic lineage, which were achieved without the use of specific medium or growth factors. These results were supported by the elevated levels of calcium, osteocalcin, and mineralization (P<0.05) observed at different time points (0, 7, 14, and 21 days). Furthermore, electron microscopic observations and fibronectin localization revealed that PLLA/Col/HA scaffolds exhibited superior osteoinductivity, when compared with PLLA/Col or PLLA/HA scaffolds. These findings indicated that the fibrous structure and synergistic action of Col and nano-HA with high-molecular-weight PLLA played a vital role in inducing osteogenic differentiation of hMSCs. The data obtained in this study demonstrated that the developed fibrous PLLA/Col/HA biocomposite scaffold may be supportive for stem cell based therapies for bone repair, when compared with the other two scaffolds.  相似文献   

13.
Evaluation of a hydrogel-fiber composite for ACL tissue engineering   总被引:1,自引:0,他引:1  
The anterior cruciate ligament (ACL) is necessary for normal knee stability and movement. Unfortunately the ACL is also the most frequently injured ligament of the knee with severe disruptions requiring surgical intervention. In response to this, tissue engineering has emerged as an option for ACL replacement and repair. In this study we present a novel hydrogel-fibrous scaffold as a potential option for ACL replacement. The scaffold was composed of PLLA fibers, in a previously evaluated braid-twist structure, combined with a polyethylene glycol diacrylate (PEGDA) hydrogel to improve viscoelastic properties. Both hydrogel concentration (10%, 15%, and 20%) and amount of hydrogel (soaking the fibrous scaffold in hydrogel solution or encasing the scaffold in a block of hydrogel) were evaluated. It was found that the braid-twist scaffold had a greater porosity and larger number of pores above 100 μm than braided scaffolds with the same braiding angle. After testing for their effects on swelling, fiber degradation, and protein release, as well as viscoelastic and tensile testing (when combined with fibrous scaffolds), it was found that the composite scaffold soaked in 10% hydrogel had the best chemical release and mechanical properties. The optimized structure behaved similarly to natural ligament in tension with the addition of the hydrogel decreasing the ultimate tensile stress (UTS), but the UTS was still comparable to natural ACL. In addition, cellular studies showed that the hydrogel-PLLA fiber composite supported fibroblast growth.  相似文献   

14.
Time-dependent adsorption behavior of poly(3-hydroxybutyrate) (PHB) depolymerase from Ralstonia pickettiiT1 on a polyester surface was studied by complementary techniques of quarts crystal microbalance (QCM) and atomic force microscopy (AFM). Amorphous poly(l-lactide) (PLLA) thin films were used as adsorption substrates. Effects of enzyme concentration on adsorption onto the PLLA surface were determined time-dependently by QCM. Adsorption of PHB depolymerase took place immediately after replacement of the buffer solutions with the enzyme solutions in the cell, followed by a gradual increase in the amount over 30 min. The amount of PHB depolymerase molecules adsorbed on the surface of amorphous PLLA thin films increased with an increase in the enzyme concentration. Time-dependent AFM observation of enzyme molecules was performed during the adsorption of PHB depolymerase. The phase response of the AFM signal revealed that the nature of the PLLA surface around the PHB depolymerase molecule was changed due to the adsorption function of the enzyme and that PHB depolymerase adsorbed onto the PLLA surface as a monolayer at a lower enzyme concentration. The number of PHB depolymerase molecules on the PLLA surface depended on the enzyme concentration and adsorption time. In addition, the height of the adsorbed enzyme was found to increase with time when the PLLA surface was crowded with the enzymes. In the case of higher enzyme concentrations, multilayered PHB depolymerases were observed on the PLLA thin film. These QCM and AFM results indicate that two-step adsorption of PHB depolymerase occurs on the amorphous PLLA thin film. First, adsorption of PHB depolymerase molecules takes place through the characteristic interaction between the binding domain of PHB depolymerase and the free surface of an amorphous PLLA thin film. As the adsorption proceeded, the surface region of the thin film was almost covered with the enzyme, which was accompanied by morphological changes. Second, the hydrophobic interactions among the enzymes in the adlayer and the solution become more dominant to stack as a second layer.  相似文献   

15.
Phase structures and enzymatic degradation of poly(l-lactide) (PLLA)/atactic poly(3-hydroxybutyrate) (ata-PHB) blends with different compositions were characterized by using atomic force microscopy (AFM). Differential scanning calorimetry (DSC) thermograms of PLLA/ata-PHB blends with different compositions showed two glass transition temperatures, indicating that the PLLA/ata-PHB blends are immiscible in the melt. Surface morphologies of the thin films for PLLA/ata-PHB blends were determined by AFM. Phase separated morphology was recognized from the AFM topography and phase images. The domain size of the components was dependent on the blend ratio. Enzymatic degradation of the PLLA/ata-PHB blends was performed by using both PHB depolymerase and proteinase K. Either PLLA or ata-PHB domains were eroded depending on the kinds of enzyme. Surface morphologies after enzymatic degradation have revealed the phase structure along the depth direction. Enzymatic adsorption of PHB depolymerase was examined on the surface of PLLA/ata-PHB blends. The enzyme molecules were found on both domains of the binary blends. The larger number of enzyme molecules was found on the PLLA domains relative to those on the ata-PHB domains, suggesting the higher affinity of the enzyme against PLLA domain.  相似文献   

16.
Poly[(R)-3-hydroxybutyrate] (PHB) depolymerases adsorbed on poly(L-lactide) (PLLA) thin film were directly observed by atomic force microscopy (AFM). A PLLA thin film of 100 nm thickness was prepared on a silicon wafer by spin-cast method. The PLLA thin film was treated at 220 degrees C and quenched to room temperature, resulting in the formation of a completely amorphous film with a smooth surface. Then, the PHB depolymerases from Pseudomonas stutzeri YM1006 and Ralstonia pickettii T1 were dispersed on the amorphous PLLA thin film. Direct AFM observation has revealed that the PHB depolymerases bind in an elliptic shape on the surface of the PLLA thin film and that a small ridge is created around each enzyme molecule. After removal of the enzymes with 40% ethanol aqueous solution, small hollows were found on the PLLA thin film. These results suggest that a PHB depolymerase interacts with polyester molecules during their adsorption to make a hollow on the substrate surface.  相似文献   

17.
Abstract Background aims. Mesenchymal stromal cells (MSC) are pluripotent adult stem cells capable of osteogenesis and chondrogenesis to form bone and cartilage. This characteristic gives them the potential for bone and cartilage regeneration. Synthetic polymers have been studied to examine whether they could be used as a scaffold for tissue engineering. In the current study a two-dimensional (2-D) poly(l-lactic acid) (PLLA) scaffold was treated with chemokine, adhesion and extracellular matrix molecules with the aim of using biologic molecules to improve the attachment of human MSC. Methods. MSC were isolated from human bone marrow and applied to a 2-D PLLA scaffold. Chemokines ligand (CXCL12 and CXCL13), adhesion molecules [P-selectin, vascular cell adhesion molecule (VCAM)-1 and heparin] and extracellular matrix molecules (fibronectin and type IV collagen) were coated on the scaffold and their effects on the number of MSC that adhered were recorded. Results. When used alone CXCL12 and CXCL13 enhanced MSC adhesion, as did VCAM-1, P-selectin, fibronectin and collagen, but not heparin. The effects of VCAM-1, P-selectin and heparin were enhanced by the addition of CXCL12. Incubation of MSC with antibodies to integrins α4 and α5β1 inhibited their adhesion to VCAM-1 and fibronectin-treated PLLA respectively, suggesting that these integrins were involved in the MSC interactions. Conclusions. The use of certain chemokines and adhesion and extracellular matrix molecules, alone or in combination, is beneficial for the attachment of MSC to PLLA, and may be helpful as natural molecules in scaffolds for regenerative medicine.  相似文献   

18.
The anterior cruciate ligament (ACL) is the most commonly injured intra-articular ligament of the knee. The insufficient vascularization of this tissue prevents it from healing completely after extreme tearing or rupture, creating a need for ACL grafts for reconstruction. The limitations of existing grafts have motivated the investigation of tissue-engineered ACL grafts. A successful tissue-engineered graft must possess mechanical properties similar to the ACL; to date no commercially available synthetic graft has achieved this. To accomplish this goal we have combined the techniques of polymer fiber braiding and twisting to design a novel poly L-lactic acid (PLLA) braid-twist scaffold for ACL tissue engineering. The scaffold is designed to accurately mimic the biomechanical profile and mechanical properties of the ACL. In this study, braid-twist scaffolds were constructed and compared to braided scaffolds and twisted fiber scaffolds. The addition of fiber twisting to the braided scaffold resulted in a significant increase in the ultimate tensile strength, an increase in ultimate strain, and an increase in the length of the toe region in these constructs over scaffolds that were braided. Based on the findings of this study, the braid-twist scaffold studied was found to be a promising construct for tissue engineering of the ACL.  相似文献   

19.
The development of methods to predict the strength and stiffness of biomaterials used in tissue engineering is critical for load-bearing applications in which the essential functional requirements are primarily mechanical. We previously quantified changes in the effective stiffness (E) of needled nonwoven polyglycolic acid (PGA) and poly-L-lactic acid (PLLA) scaffolds due to tissue formation and scaffold degradation under three-point bending. Toward predicting these changes, we present a structural model for E of a needled nonwoven scaffold in flexure. The model accounted for the number and orientation of fibers within a representative volume element of the scaffold demarcated by the needling process. The spring-like effective stiffness of the curved fibers was calculated using the sinusoidal fiber shapes. Structural and mechanical properties of PGA and PLLA fibers and PGA, PLLA, and 50:50 PGA/PLLA scaffolds were measured and compared with model predictions. To verify the general predictive capability, the predicted dependence of E on fiber diameter was compared with experimental measurements. Needled nonwoven scaffolds were found to exhibit distinct preferred (PD) and cross-preferred (XD) fiber directions, with an E ratio (PD/XD) of approximately 3:1. The good agreement between the predicted and experimental dependence of E on fiber diameter (R2 = 0.987) suggests that the structural model can be used to design scaffolds with E values more similar to native soft tissues. A comparison with previous results for cell-seeded scaffolds (Engelmayr, G. C., Jr., et al., 2005, Biomaterials, 26(2), pp. 175-187) suggests, for the first time, that the primary mechanical effect of collagen deposition is an increase in the number of fiber-fiber bond points yielding effectively stiffer scaffold fibers. This finding indicated that the effects of tissue deposition on needled nonwoven scaffold mechanics do not follow a rule-of-mixtures behavior. These important results underscore the need for structural approaches in modeling the effects of engineered tissue formation on nonwoven scaffolds, and their potential utility in scaffold design.  相似文献   

20.
Human mesenchymal stem cells (MSCs) were cultured in vitro in a cobweb-like biodegradable polymer scaffold: a poly(dl-lactic-co-glycolic acid)-collagen hybrid mesh in serum-free DMEM containing TGF-beta3 for 1-10 weeks. The cells adhered to the hybrid mesh, distributed evenly, and proliferated to fill the spaces in the scaffold. The ability of the cells to express gene encoding type I collagen decreased, whereas its ability to express type II collagen and aggrecan increased. Histological examination by HE staining indicated that the cells showed fibroblast morphology at the early stage and became round after culture for 4 weeks. The cartilaginous matrices were positively stained by safranin O and toluidine blue. Immunostaining with anti-type II collagen and anti-cartilage proteoglycan showed that type II collagen and cartilage proteoglycan were detected around the cells. In addition, a homogeneous distribution of cartilaginous extracellular matrices was detected around the cells. These results suggest the chondrogenic differentiation of the mesenchymal stem cells in the hybrid mesh. The PLGA-collagen hybrid mesh enabled the aggregation of mesenchymal stem cells and provided a promotive microenvironment for the chondrogenic differentiation of the MSCs.  相似文献   

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