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1.
The multidisciplinary research of tissue engineering utilizes biodegradable or decellularized scaffolds with autologous cell seeding. Objective of this study was to investigate the impact of different decellularization protocols on extracellular matrix integrity of xenogeneic tissue by means of multiphoton femtosecond laser scanning microscopy, biochemical and histological analysis. Pulmonary valves were dissected from porcine hearts and placed in a solution of trypsin-EDTA and incubated at 37 degrees C for either 5, 8, or 24 h, followed by a 24 h PBS washing. Native and decellularized valves were processed for histology, DNA, cell proliferation, matrix proteins and biomechanical testing. Multiphoton NIR laser microscopy has been applied for high-resolution 3D imaging of collagen and elastin. Distinct differences in several ECM components following decellularization time were observed. Total GAG contents decreased in a time-dependent manner, with o-sulfated GAGs being more susceptible to degradation than n-sulfated GAGs. Efficiency of insoluble collagen extraction increased proportionally with decellularization time, suggesting ECM-integrity may be compromised with prolonged incubation. Biomechanical testing revealed a gradual weakening of mechanical strength with increased decellularization time. The enzymatic decellularization process of heart valves revealed a time-dependent loss of cells, ECM components and biomechanical strength. In order to avoid any immune response a thorough decellularization of 24 h remains mandatory.  相似文献
2.
清除牛心包组织内细胞的方法   总被引:2,自引:1,他引:1  
置换生物心脏瓣膜的病人一般不需抗凝治疗。但由于生物心脏瓣膜的逐渐损坏,术后5年至10年需行再次换瓣手术。根据生物心脏瓣膜的病理检查发现,瓣叶的钙化变性是瓣膜原发性失功的主要形式,而瓣膜内的残存细胞和细胞碎片则起了重要的初始钙化源的作用。  相似文献
3.
利用脱细胞血管基质体外构建小口径组织工程血管   总被引:2,自引:1,他引:1  
目的探讨利用犬的间充质干细胞诱导分化种子细胞,以异种脱细胞血管基质为基础体外构建小口径血管移植物。方法采用密度梯度离心和贴壁培养的方法从犬骨髓中分离出间充质干细胞并体外培养,诱导分化成内皮样细胞和平滑肌样细胞;采用非离子型去垢剂和胰蛋白酶去除猪颈动脉血管壁结构细胞,对脱细胞基质进行组织学、力学检测及孔隙率评估。在生物反应器内采用旋转种植的方法将犬骨髓间充质干细胞诱导的内皮样细胞种植到脱细胞基质上,体外构建小口径组织工程血管。结果犬的骨髓间充质干细胞体外能够定向诱导分化为平滑肌样细胞和内皮样细胞,可以作为血管组织工程的种子细胞。经过脱细胞处理后,光镜和电镜观察证实血管壁的细胞成分完全去除。具有良好的孔径和孔隙率。支架在生物力学、孔隙率等方面符合构建组织工程血管支架的要求。在生物反应器内剪切力条件下可以初步构建出组织工程血管。结论小口径血管移植物可以将间充质干细胞诱导种子细胞,以异种脱细胞血管支架作为基质,在搏动性生物反应器内培养的方法进行构建。  相似文献
4.
Xenogeneic tissues are derived from other animal species and provide a source of material for engineering mechanically functional tissue grafts, such as heart valves, tendons, ligaments, and cartilage. Xenogeneic tissues, however, contain molecules, known as antigens, which invoke an immune reaction following implantation into a patient. Therefore, it is necessary to remove the antigens from a xenogeneic tissue to prevent immune rejection of the graft. Antigen removal can be accomplished by treating a tissue with solutions and/or physical processes that disrupt cells and solubilize, degrade, or mask antigens. However, processes used for cell and antigen removal from tissues often have deleterious effects on the extracellular matrix (ECM) of the tissue, rendering the tissue unsuitable for implantation due to poor mechanical properties. Thus, the goal of an antigen removal process should be to reduce the antigen content of a xenogeneic tissue while preserving its mechanical functionality. To expand the clinical use of antigen-removed xenogeneic tissues as biomechanically functional grafts, it is essential that researchers examine tissue antigen content, ECM composition and architecture, and mechanical properties as new antigen removal processes are developed.  相似文献
5.
Decellularized adipose tissue (DAT) has shown potential as a regenerative scaffold for plastic and reconstructive surgery to augment or replace damaged or missing adipose tissue (e.g. following lumpectomy or mastectomy). The mechanical properties of soft tissue substitutes are of paramount importance in restoring the natural shape and appearance of the affected tissues, and mechanical mismatching can lead to unpredictable scar tissue formation and poor implant integration. The goal of this work was to assess the linear elastic and hyperelastic properties of decellularized human adipose tissue and compare them to those of normal breast adipose tissue. To assess the influence of the adipose depot source on the mechanical properties of the resultant decellularized scaffolds, we performed indentation tests on DAT samples sourced from adipose tissue isolated from the breast, subcutaneous abdominal region, omentum, pericardial depot and thymic remnant, and their corresponding force–displacement data were acquired. Elastic and hyperelastic parameters were estimated using inverse finite element algorithms. Subsequently, a simulation was conducted in which the estimated hyperelastic parameters were tested in a real human breast model under gravity loading in order to assess the suitability of the scaffolds for implantation. Results of these tests showed that in the human breast, the DAT would show similar deformability to that of native normal tissue. Using the measured hyperelastic parameters, we were able to assess whether DAT derived from different depots exhibited different intrinsic nonlinearities. Results showed that DAT sourced from varying regions of the body exhibited little intrinsic nonlinearity, with no statistically significant differences between the groups.  相似文献
6.

Background

Numerous proteins and small leucine-rich proteoglycans (SLRPs) make up the composition of the extracellular matrix (ECM). Assembly of individual fibrillar components in the ECM, such as collagen, elastin, and fibronectin, is understood at the molecular level. In contrast, the incorporation of non-fibrillar components and their functions in the ECM are not fully understood.

Scope of review

This review will focus on the role of the matricellular protein thrombospondin (TSP) 2 in ECM assembly. Based on findings in TSP2-null mice and in vitro studies, we describe the participation of TSP2 in ECM assembly, cell–ECM interactions, and modulation of the levels of matrix metalloproteinases (MMPs).

Major conclusions

Evidence summarized in this review suggests that TSP2 can influence collagen fibrillogenesis without being an integral component of fibrils. Altered ECM assembly and excessive breakdown of ECM can have both positive and negative consequences including increased angiogenesis during tissue repair and compromised cardiac tissue integrity, respectively.

General significance

Proper ECM assembly is critical for maintaining cell functions and providing structural support. Lack of TSP2 is associated with increased angiogenesis, in part, due to altered endothelial cell–ECM interactions. Therefore, minor changes in ECM composition can have profound effects on cell and tissue function. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties.  相似文献
7.
The reconstruction of musculoskeletal defects is a constant challenge for orthopaedic surgeons. Musculoskeletal injuries such as fractures, chondral lesions, infections and tumor debulking can often lead to large tissue voids requiring reconstruction with tissue grafts. Autografts are currently the gold standard in orthopaedic tissue reconstruction; however, there is a limit to the amount of tissue that can be harvested before compromising the donor site. Tissue engineering strategies using allogeneic or xenogeneic decellularized bone, cartilage, skeletal muscle, tendon and ligament have emerged as promising potential alternative treatment. The extracellular matrix provides a natural scaffold for cell attachment, proliferation and differentiation. Decellularization of in vitro cell-derived matrices can also enable the generation of autologous constructs from tissue specific cells or progenitor cells. Although decellularized bone tissue is widely used clinically in orthopaedic applications, the exciting potential of decellularized cartilage, skeletal muscle, tendon and ligament cell-derived matrices has only recently begun to be explored for ultimate translation to the orthopaedic clinic.  相似文献
8.
Extracellular matrix (ECM) has been focused to understand tumor progression in addition to the genetic mutation of cancer cells. Here, we prepared “staged tumorigenesis-mimicking matrices” which mimic in vivo ECM in tumor tissue at each malignant stage to understand the roles of ECM in tumor progression. Breast tumor cells, MDA-MB-231 (invasive), MCF-7 (non-invasive), and MCF-10A (benign) cells, were cultured to form their own ECM beneath the cells and formed ECM was prepared as staged tumorigenesis-mimicking matrices by decellularization treatment. Cells showed weak attachment on the matrices derived from MDA-MB-231 cancer cells. The proliferations of MDA-MB-231 and MCF-7 was promoted on the matrices derived from MDA-MB-231 cancer cells whereas MCF-10A cell proliferation was not promoted. MCF-10A cell proliferation was promoted on the matrices derived from MCF-10A cells. Chemoresistance of MDA-MB-231 cells against 5-fluorouracil increased on only matrices derived from MDA-MB-231 cells. Our results showed that the cells showed different behaviors on staged tumorigenesis-mimicking matrices according to the malignancy of cell sources for ECM preparation. Therefore, staged tumorigenesis-mimicking matrices might be a useful in vitro ECM models to investigate the roles of ECM in tumor progression.  相似文献
9.
侯楠  朱力 《生物磁学》2011,(2):381-383
去细胞基质在组织工程及再生医学的大量应用为解决组织器官的修复和重建等难题带来了希望。去细胞方法大致可以分为三类:化学处理法、物理处理法及酶学处理法,且已经应用于组织工程及再生医学的各个方面。本文总结并分类目前常用的去细胞方法及其在组织工程各方面的应用,对目前国内外常用的去细胞方法及其在组织工程及再生医学中的应用进行回顾总结与分析。  相似文献
10.
去细胞基质在组织工程及再生医学的大量应用为解决组织器官的修复和重建等难题带来了希望。去细胞方法大致可以分为三类:化学处理法、物理处理法及酶学处理法,且已经应用于组织工程及再生医学的各个方面。本文总结并分类目前常用的去细胞方法及其在组织工程各方面的应用,对目前国内外常用的去细胞方法及其在组织工程及再生医学中的应用进行回顾总结与分析。  相似文献
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