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1.
Bioreactor cultivation of osteochondral grafts 总被引:4,自引:0,他引:4
Vunjak-Novakovic G Meinel L Altman G Kaplan D 《Orthodontics & craniofacial research》2005,8(3):209-218
The clinical utility of tissue engineering depends upon our ability to direct cells to form tissues with characteristic structural and mechanical properties across different hierarchical scales. Ideally, an engineered graft should be tailored to (re)establish the structure and function of the native tissue being replaced. Engineered grafts of such high fidelity would also foster fundamental research by serving as physiologically relevant models for quantitative in vitro studies. The approach discussed here involves the use of human mesenchymal stem cells (hMSC) cultured on custom-designed scaffolds (providing a structural and logistic template for tissue development) in bioreactors (providing environmental control, biochemical and mechanical cues). Cartilage, bone and ligaments have been engineered by using hMSC, highly porous protein scaffolds (collagen; silk) and bioreactors (perfused cartridges with or without mechanical loading). In each case, the scaffold and bioreactor were designed to recapitulate some aspects of the environment present in native tissues. Medium flow facilitated mass transport to the cells and thereby enhanced the formation of all three tissues. In the case of cartilage, dynamic laminar flow patterns were advantageous as compared to either turbulent steady flow or static (no flow) cultures. In the case of bone, medium flow affected the geometry, distribution and orientation of the forming bone-like trabeculae. In the case of ligament, applied mechanical loading (a combination of dynamic stretch and torsion) markedly enhanced cell differentiation, alignment and functional assembly. Taken together, these studies provide a basis for the ongoing work on engineering osreochondral grafts for a variety of potential applications, including those in the craniofacial complex. 相似文献
2.
气管替代物利用体内天然环境对细胞贴覆生长及支架性能改善,促进移植物血管化,诱导免疫耐受和提高术后生存率有指导意义。内外层壁覆有干细胞和气道上皮细胞的脱细胞气管,利用天然生物反应器于体内预培养促组织工程气管成熟的方法,以实现黏膜的再上皮化、软骨细胞形成和血管化,在此基础上进行原位移植,对于长段气管病损有良好的临床应用前景。现就组织工程气管体内构建的意义及研究现状予以综述。 相似文献
3.
Minimal mechanical load and tissue culture conditions preserve native cell phenotype and morphology in tendon—a novel ex vivo mouse explant model 下载免费PDF全文
Stefania L. Wunderli Jonas Widmer Niklaus Amrein Jasper Foolen Unai Silvan Olivier Leupin Jess G. Snedeker 《Journal of orthopaedic research》2018,36(5):1383-1390
4.
Cyclic mechanical stimulation rescues achilles tendon from degeneration in a bioreactor system 下载免费PDF全文
Tao Wang Zhen Lin Ming Ni Christine Thien Robert E. Day Bruce Gardiner Jonas Rubenson Thomas B. Kirk David W. Smith Allan Wang David G. Lloyd Yan Wang Qiujian Zheng Ming H. Zheng 《Journal of orthopaedic research》2015,33(12):1888-1896
Physiotherapy is one of the effective treatments for tendinopathy, whereby symptoms are relieved by changing the biomechanical environment of the pathological tendon. However, the underlying mechanism remains unclear. In this study, we first established a model of progressive tendinopathy‐like degeneration in the rabbit Achilles. Following ex vivo loading deprivation culture in a bioreactor system for 6 and 12 days, tendons exhibited progressive degenerative changes, abnormal collagen type III production, increased cell apoptosis, and weakened mechanical properties. When intervention was applied at day 7 for another 6 days by using cyclic tensile mechanical stimulation (6% strain, 0.25 Hz, 8 h/day) in a bioreactor, the pathological changes and mechanical properties were almost restored to levels seen in healthy tendon. Our results indicated that a proper biomechanical environment was able to rescue early‐stage pathological changes by increased collagen type I production, decreased collagen degradation and cell apoptosis. The ex vivo model developed in this study allows systematic study on the effect of mechanical stimulation on tendon biology. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1888–1896, 2015. 相似文献
5.
《Expert opinion on biological therapy》2013,13(5):677-682
Due to its accessibility, size and contact with the blood circulation, the skin is an attractive target for somatic gene therapy. Permanent cutaneous expression can be achieved by genetic manipulation of epidermal keratinocytes ex vivo followed by transplantation or by local injection of viral vectors. Furthermore, progress is being made to develop topical gene transfer methods leading to permanent gene expression. There is experimental evidence showing that genetically engineered skin can produce and secrete medically relevant proteins to the circulation and also produce enzymes that can clear metabolites accumulating in various diseases. Thus, cutaneous gene transfer approaches may be relevant not only for local skin diseases, but also for certain systemic disorders. 相似文献
6.
Alexandra J. E. Farran Sean S. Teller Fang Jia Rodney J. Clifton Randall L. Duncan Xinqiao Jia 《Journal of tissue engineering and regenerative medicine》2013,7(3):213-225
To engineer a functional vocal fold tissue, the mechanical environment of the native tissue needs to be emulated in vitro. We have created a dynamic culture system capable of generating vibratory stimulations at human phonation frequencies. The novel device is composed of a function generator, a power amplifier, an enclosed loudspeaker and a circumferentially‐anchored silicone membrane. The vibration signals are translated to the membrane aerodynamically by the oscillating air pressure underneath. The vibration profiles detected on the membrane were symmetrical relative to the centre of the membrane as well as the resting position over the range of frequencies (60–300 Hz) and amplitudes tested (1–30 µm). The oscillatory motion of the membrane gave rise to two orthogonal, in‐plane strain components that are similar in magnitude (0.47%) and are strong functions of membrane thickness. Neonatal foreskin fibroblasts (NFFs) attached to the membrane were subjected to a 1 h vibration at 60, 110 and 300 Hz, with the displacement at the centre of the membrane varying in the range 1–30 µm, followed by a 6 h rest. These regimens did not cause morphological changes to the cells. An increase in cell proliferation was detected when NFFs were driven into oscillation at 110 Hz with a normal displacement of 30 µm. qPCR results showed that the expression of genes encoding some extracellular matrix proteins was altered in response to changes in vibratory frequency and amplitude. The dynamic culture device provides a potentially useful in vitro platform for evaluating cellular responses to vibration. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
7.
Sheehy EJ Buckley CT Kelly DJ 《Journal of tissue engineering and regenerative medicine》2011,5(9):747-758
The objective of this study was to investigate how a combination of different scaffold architectures and rotational culture would influence the functional properties of thick cartilaginous tissues engineered using either chondrocytes or bone marrow-derived mesenchymal stem cells (BM-MSCs). Expanded porcine chondrocytes and BM-MSCs were suspended in 2% agarose and cast in custom-designed moulds to produce either regular solid or channelled construct cylinders. The study consisted of three seperate experimental arms. First, chondrocyte and BM-MSC constructs were cultured in free swelling conditions for 9 weeks. Second, constructs were subjected to rotational culture for a period of 3 weeks. Finally, BM-MSC-seeded constructs were subjected to delayed rotational culture, in which constructs were first cultured for 3 weeks in free swelling conditions, followed by an additional 3 weeks in rotating culture conditions. Constructs were supplemented with TGFβ3 during the first 3 weeks of all experiments. The introduction of channels alone had little effect on the spatial patterns of tissue accumulation in either chondrocyte- or BM-MSC-seeded constructs. The two cell types responded differentially to rotational culture, resulting in the formation of a more homogeneous tissue in chondrocyte-seeded constructs, but significantly inhibiting chondrogenesis of BM-MSCs. This inhibition of chondrogenesis in response to dynamic culture conditions was not observed if BM-MSC-seeded constructs were first maintained in free swelling conditions for 3 weeks prior to rotation. The results of this study demonstrate that bioreactor culture conditions that are beneficial for chondrocyte-based cartilage tissue engineering may be suboptimal for BM-MSCs. 相似文献
8.
Yanru Wu Yun Gyeong Kang In Gul Kim Ji Eun Kim Eun Jin Lee Eun‐Jae Chung Jung‐Woog Shin 《Journal of tissue engineering and regenerative medicine》2019,13(8):1394-1405
The tissue‐engineered oesophagus serves as an alternative and promising therapeutic approach for long‐gap oesophageal replacement. This study proposes an advanced in vitro culture platform focused on construction of the oesophagus by combining an electrospun double‐layered tubular scaffold, stem cells, biochemical reagents, and biomechanical factors. Human mesenchymal stem cells were seeded onto the inner and outer surfaces of the scaffold. Mechanical stimuli were applied with a hollow organ bioreactor along with different biochemical reagents inside and outside of the scaffold. Electrospun fibres in a tubular scaffold were found to be randomly and circumferentially oriented for the inner and outer surfaces, respectively. Amongst the two types of mechanical stimuli, the intermittent shear flow that can simultaneously cause circumferential stretching due to hydrostatic pressure, and shear stress caused by flow on the inner surface, was found to be more effective for simultaneous differentiation into epithelial and muscle lineage than steady shear flow. Under these conditions, the expression of epithelial markers on the inner surface was significantly observed, although it was minimal on the outer surface. Muscle differentiation showed the opposite expression pattern. Meanwhile, the mechanical tests showed that the strength of the scaffold was improved after incubation for 14 days. We have developed a potential platform for tissue‐engineered oesophagus construction. Specifically, simultaneous differentiation into epithelial and muscle lineages can be achieved by utilizing the double‐layered scaffold and appropriate mechanical stimulation. 相似文献
9.
Poh Soo Lee Ricarda Hess Jens Friedrichs Vanessa Haenchen Hagen Eckert Gianaurelio Cuniberti Derrick Rancourt Roman Krawetz Vera Hintze Michael Gelinsky Dieter Scharnweber 《Journal of tissue engineering and regenerative medicine》2019,13(9):1672-1684
Bone development and homeostasis are intricate processes that require co‐existence and dynamic interactions among multiple cell types. However, controlled dynamic niches that derive and support stable propagation of these cells from single stem cell source is not sustainable in conventional culturing vessels. In bioreactor cultures that support dynamic niches, the limited source and stability of growth factors are often a major limiting factor for long‐term in vitro cultures. Hence, alternative growth factor‐free differentiation approaches are designed and their efficacy to achieve different osteochondral cell types is investigated. Briefly, a dynamic niche is achieved by varying medium pH, oxygen tension (pO2) distribution in bioreactor, initiating chondrogenic differentiation with chondroitin sulphate A (CSA), and implementing systematic differentiation regimes. In this study, we demonstrated that CSA is a potent chondrogenic inducer, specifically in combination with acidic medium and low pO2. Further, endochondral ossification is recapitulated through a systematic chondrogenic–osteogenic (ch‐os) differentiation regime, and multiple osteochondral cell types are derived. Chondrogenic hypertrophy was also enhanced specifically in high pO2 regions. Consequently, mineralised constructs with higher structural integrity, volume, and tailored dimensions are achieved. In contrast, a continuous osteogenic differentiation regime (os‐os) has derived compact and dense constructs, whereas a continuous chondrogenic differentiation regime (ch‐ch) has attenuated construct mineralisation and impaired development. In conclusion, a growth factor‐free differentiation approach is achieved through interplay of pO2, medium pH, and systematic differentiation regimes. The controlled dynamic niches have recapitulated endochondral ossification and can potentially be exploited to derive larger bone constructs with near physiological properties. 相似文献
10.
Design and validation of a dynamic cell‐culture system for bone biology research and exogenous tissue‐engineering applications 下载免费PDF全文
Alexander C. Allori Edward H. Davidson Derek D. Reformat Alexander M. Sailon James Freeman Adam Vaughan David Wootton Elizabeth Clark John L. Ricci Stephen M. Warren 《Journal of tissue engineering and regenerative medicine》2016,10(10):E327-E336
Bone lacunocanalicular fluid flow ensures chemotransportation and provides a mechanical stimulus to cells. Traditional static cell‐culture methods are ill‐suited to study the intricacies of bone biology because they ignore the three‐dimensionality of meaningful cellular networks and the lacunocanalicular system; furthermore, reliance on diffusion alone for nutrient supply and waste product removal effectively limits scaffolds to 2–3 mm thickness. In this project, a flow‐perfusion system was custom‐designed to overcome these limitations: eight adaptable chambers housed cylindrical cell‐seeded scaffolds measuring 12 or 24 mm in diameter and 1–10 mm in thickness. The porous scaffolds were manufactured using a three‐dimensional (3D) periodic microprinting process and were composed of hydroxyapatite/tricalcium phosphate with variable thicknesses, strut sizes, pore sizes and structural configurations. A multi‐channel peristaltic pump drew medium from parallel reservoirs and perfused it through each scaffold at a programmable rate. Hermetically sealed valves permitted sampling or replacement of medium. A gas‐permeable membrane allowed for gas exchange. Tubing was selected to withstand continuous perfusion for > 2 months without leakage. Computational modelling was performed to assess the adequacy of oxygen supply and the range of fluid shear stress in the bioreactor–scaffold system, using 12 × 6 mm scaffolds, and these models suggested scaffold design modifications that improved oxygen delivery while enhancing physiological shear stress. This system may prove useful in studying complex 3D bone biology and in developing strategies for engineering thick 3D bone constructs. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献