Integration of single-layer skin hollow fibers and scaffolds develops a three-dimensional hybrid bioreactor for bioartificial livers

2013 ◽  
Vol 25 (1) ◽  
pp. 207-216 ◽  
Author(s):  
Shichang Zhang ◽  
Li Chen ◽  
Tao Liu ◽  
Zhengguo Wang ◽  
Yingjie Wang
Author(s):  
X. Lin ◽  
X. K. Wang ◽  
V. P. Dravid ◽  
J. B. Ketterson ◽  
R. P. H. Chang

For small curvatures of a graphitic sheet, carbon atoms can maintain their preferred sp2 bonding while allowing the sheet to have various three-dimensional geometries, which may have exotic structural and electronic properties. In addition the fivefold rings will lead to a positive Gaussian curvature in the hexagonal network, and the sevenfold rings cause a negative one. By combining these sevenfold and fivefold rings with sixfold rings, it is possible to construct complicated carbon sp2 networks. Because it is much easier to introduce pentagons and heptagons into the single-layer hexagonal network than into the multilayer network, the complicated morphologies would be more common in the single-layer graphite structures. In this contribution, we report the observation and characterization of a new material of monolayer graphitic structure by electron diffraction, HREM, EELS.The synthesis process used in this study is reported early. We utilized a composite anode of graphite and copper for arc evaporation in helium.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 956
Author(s):  
Philipp Taus ◽  
Adrian Prinz ◽  
Heinz D. Wanzenboeck ◽  
Patrick Schuller ◽  
Anton Tsenov ◽  
...  

Biomimetic structures such as structural colors demand a fabrication technology of complex three-dimensional nanostructures on large areas. Nanoimprint lithography (NIL) is capable of large area replication of three-dimensional structures, but the master stamp fabrication is often a bottleneck. We have demonstrated different approaches allowing for the generation of sophisticated undercut T-shaped masters for NIL replication. With a layer-stack of phase transition material (PTM) on poly-Si, we have demonstrated the successful fabrication of a single layer undercut T-shaped structure. With a multilayer-stack of silicon oxide on silicon, we have shown the successful fabrication of a multilayer undercut T-shaped structures. For patterning optical lithography, electron beam lithography and nanoimprint lithography have been compared and have yielded structures from 10 µm down to 300 nm. The multilayer undercut T-shaped structures closely resemble the geometry of the surface of a Morpho butterfly, and may be used in future to replicate structural colors on artificial surfaces.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kiyoshi Masuyama ◽  
Tomoaki Higo ◽  
Jong-Kook Lee ◽  
Ryohei Matsuura ◽  
Ian Jones ◽  
...  

AbstractIn contrast to hypertrophic cardiomyopathy, there has been reported no specific pattern of cardiomyocyte array in dilated cardiomyopathy (DCM), partially because lack of alignment assessment in a three-dimensional (3D) manner. Here we have established a novel method to evaluate cardiomyocyte alignment in 3D using intravital heart imaging and demonstrated homogeneous alignment in DCM mice. Whilst cardiomyocytes of control mice changed their alignment by every layer in 3D and position twistedly even in a single layer, termed myocyte twist, cardiomyocytes of DCM mice aligned homogeneously both in two-dimensional (2D) and in 3D and lost myocyte twist. Manipulation of cultured cardiomyocyte toward homogeneously aligned increased their contractility, suggesting that homogeneous alignment in DCM mice is due to a sort of alignment remodelling as a way to compensate cardiac dysfunction. Our findings provide the first intravital evidence of cardiomyocyte alignment and will bring new insights into understanding the mechanism of heart failure.


2021 ◽  
Vol 28 ◽  
Author(s):  
Xiaohong Li ◽  
Liang Wen ◽  
Jiao Liu ◽  
Xiaohong Wang

: End-stage liver diseases have long been a threat to human health, and so far, the treatment of these diseases lacks of effective means. Allogenic organ transplantation has become the last straw for most of the patients with end-stage liver diseases. However, this technique has been greatly limited by the serious shortage of donors and other factors, such as immune rejection, drug syndrome, and high cost. Recently, the emergence of three-dimensional (3D) bioprinting technologies, together with the magnetic resonance imaging (MRI) and computed tomography (CT) techniques, has driven the rapid growth of this field toward liver therapies. There are several basic requirements for liver 3D bioprinting. From information collection of diseased livers, to 3D printing of liver substitutes (containing the major structural, material and functional characters), and to clinical applications, suitable ‘bioinks’ and ‘bioprinters’ have played essential roles. In this review, we highlight the advanced ‘bioinks’ and ‘bioprinters’ that have been used for vascularized and innervated liver tissue 3D bioprinting. Further studies for the incorporation of biliary networks in the bioartificial livers have been emphasized. It is expected that when all the bottle-neck problems for liver 3D bioprinting are solved, batch (i.e. mass) and personalized production of bioartificial livers will make it very easy to treat end-stage liver diseases.


Author(s):  
Akira Yamada ◽  
Fuminori Niikura ◽  
Koji Ikuta

Biodegradable polymers are employed in medicine and its further application is expected with eagerness. But the lack of an appropriate processing method retards the progress. To overcome this problem, we have developped a novel three-dimensional microfabrication system. The system design allows us the processing of the free three-dimensional micro-level forms by stacking up melted polymers from the nozzle. Different from the conventional method, we adopted a batch process to supply materials in order to eliminate the prior process that required toxic solvents. In addition, it is possible to handle almost all biodegradable thermoplastic resins by adopting this system. A single layer from the piled-up layers of extruded lines was observed to evaluate the resolution. The lateral and depth resolutions attained are 40 μm and 45 μm, respectively. Biodegradable polymers enable three-dimensional microstructures such as micro-pipes, micro-bends, and micro-coil springs to be manufactured in less than 15 min. The biocompatibility of the newly fabricated structure was evaluated using a cell line (PC12). For this purpose, a small vessel, with a transparent base, was fabricated using PLA and cells were cultivated in it. The results were then compared with the results obtained using the standard method. The mechanical strength of our microstructures was evaluated using a tensile strength test. The tensile strength of the microstructure was lower than the one obtained from the conventional method, but has enough strength for fabrication of medical devices. Our system renders it possible to produce toxic-free, as well as transparent and leakage-free devices. Our system is expected to have potential applications in optimum design and fabrication of implantable devices, especially in tissue engineering.


Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 349 ◽  
Author(s):  
Erik S. Hamilton ◽  
Vahid Ganjalizadeh ◽  
Joel G. Wright ◽  
Holger Schmidt ◽  
Aaron R. Hawkins

Optofluidic devices are capable of detecting single molecules, but greater sensitivity and specificity is desired through hydrodynamic focusing (HDF). Three-dimensional (3D) hydrodynamic focusing was implemented in 10-μm scale microchannel cross-sections made with a single sacrificial layer. HDF is achieved using buffer fluid to sheath the sample fluid, requiring four fluid ports to operate by pressure driven flow. A low-pressure chamber, or pit, formed by etching into a substrate, enables volumetric flow ratio-induced focusing at a low flow velocity. The single layer design simplifies surface micromachining and improves device yield by 1.56 times over previous work. The focusing design was integrated with optical waveguides and used in order to analyze fluorescent signals from beads in fluid flow. The implementation of the focusing scheme was found to narrow the distribution of bead velocity and fluorescent signal, giving rise to 33% more consistent signal. Reservoir effects were observed at low operational vacuum pressures and a balance between optofluidic signal variance and intensity was achieved. The implementation of the design in optofluidic sensors will enable higher detection sensitivity and sample specificity.


Author(s):  
Sandeep S. Pendhari ◽  
Sameer S. Sawarkar ◽  
Yogesh M. Desai ◽  
Nilesh Patil

2020 ◽  
Vol 21 (17) ◽  
pp. 6215
Author(s):  
Cristina Olgasi ◽  
Alessia Cucci ◽  
Antonia Follenzi

Liver transplantation is the most common treatment for patients suffering from liver failure that is caused by congenital diseases, infectious agents, and environmental factors. Despite a high rate of patient survival following transplantation, organ availability remains the key limiting factor. As such, research has focused on the transplantation of different cell types that are capable of repopulating and restoring liver function. The best cellular mix capable of engrafting and proliferating over the long-term, as well as the optimal immunosuppression regimens, remain to be clearly well-defined. Hence, alternative strategies in the field of regenerative medicine have been explored. Since the discovery of induced pluripotent stem cells (iPSC) that have the potential of differentiating into a broad spectrum of cell types, many studies have reported the achievement of iPSCs differentiation into liver cells, such as hepatocytes, cholangiocytes, endothelial cells, and Kupffer cells. In parallel, an increasing interest in the study of self-assemble or matrix-guided three-dimensional (3D) organoids have paved the way for functional bioartificial livers. In this review, we will focus on the recent breakthroughs in the development of iPSCs-based liver organoids and the major drawbacks and challenges that need to be overcome for the development of future applications.


2020 ◽  
Vol 984 ◽  
pp. 177-182
Author(s):  
Meng Lei Zhou ◽  
Li Na Zhang ◽  
Yang Liu ◽  
Feng Qiang Nan

In order to obtain better quality and mechanical performances, the coating process of super-porous propellants was optimized. The mechanical performances of super-porous propellants were tested, under some conditions with different temperatures, different numbers of cladding layers, different thicknesses of the cladding layer and different ratios of inner and outer layers, through many different analytical methods including impact test, interrupted-burning test and three-dimensional video observation test. The results show that the mechanical performances of super-porous propellants are positively correlated with the temperature, the coating thickness and the ratio of the outer layer. The double-layer coating also can obtain better coating effect than the single-layer coating.


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