scholarly journals Magnetic levitational bioassembly of 3D tissue construct in space

2020 ◽  
Vol 6 (29) ◽  
pp. eaba4174 ◽  
Author(s):  
Vladislav A. Parfenov ◽  
Yusef D. Khesuani ◽  
Stanislav V. Petrov ◽  
Pavel A. Karalkin ◽  
Elizaveta V. Koudan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Three Dimensional ◽  
Label Free ◽  
Tissue Constructs ◽  
Advanced Stages ◽  
Feasible Alternative ◽  
New Perspective ◽  
First Time ◽  
Conceptual Advance ◽  
Good Agreement

Magnetic levitational bioassembly of three-dimensional (3D) tissue constructs represents a rapidly emerging scaffold- and label-free approach and alternative conceptual advance in tissue engineering. The magnetic bioassembler has been designed, developed, and certified for life space research. To the best of our knowledge, 3D tissue constructs have been biofabricated for the first time in space under microgravity from tissue spheroids consisting of human chondrocytes. Bioassembly and sequential tissue spheroid fusion presented a good agreement with developed predictive mathematical models and computer simulations. Tissue constructs demonstrated good viability and advanced stages of tissue spheroid fusion process. Thus, our data strongly suggest that scaffold-free formative biofabrication using magnetic fields is a feasible alternative to traditional scaffold-based approaches, hinting a new perspective avenue of research that could significantly advance tissue engineering. Magnetic levitational bioassembly in space can also advance space life science and space regenerative medicine.

scholarly journals Microvascular fragment spheroids: Three-dimensional vascularization units for tissue engineering and regeneration

2021 ◽  
Vol 12 ◽  
pp. 204173142110355
Author(s):  
Lisa Nalbach ◽  
Danièle Müller ◽  
Selina Wrublewsky ◽  
Wolfgang Metzger ◽  
Michael D Menger ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Function ◽  
Smooth Muscle Actin ◽  
Three Dimensional ◽  
Stromal Vascular Fraction ◽  
Muscle Actin ◽  
Tissue Constructs ◽  
First Time ◽  
Tissue Defects

Adipose tissue-derived microvascular fragments (MVF) serve as vascularization units in tissue engineering and regenerative medicine. Because a three-dimensional cellular arrangement has been shown to improve cell function, we herein generated for the first time MVF spheroids to investigate whether this further increases their vascularization potential. These spheroids exhibited a morphology, size, and viability comparable to that of previously introduced stromal vascular fraction (SVF) spheroids. However, MVF spheroids contained a significantly higher number of CD31-positive endothelial cells and α-smooth muscle actin (SMA)-positive perivascular cells, resulting in an enhanced angiogenic sprouting activity. Accordingly, they also exhibited an improved in vivo vascularization and engraftment after transplantation into mouse dorsal skinfold chambers. These findings indicate that MVF spheroids are superior to SVF spheroids and, thus, may be highly suitable to improve the vascularization of tissue defects and implanted tissue constructs.

scholarly journals Computer modelling and simulation of a novel printing head for complex tissue engineering constructs

2020 ◽  
Vol 318 ◽  
pp. 01045
Author(s):  
Gokhan Ates
Keyword(s):  
Tissue Engineering ◽  
Computer Modelling ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Biological Properties ◽  
Functionally Graded ◽  
Mixing Efficiency ◽  
Tissue Constructs ◽  
Multiple Materials ◽  
Graded Structures

In tissue engineering, three-dimensional functional scaffolds with tailored biological properties are needed to be able to mimic the hierarchical structure of biological tissues. Recent developments in additive biomanufacturing allow to extrude multiple materials enabling the fabrication of more sophisticated tissue constructs. These multi-material biomanufacturing systems comprise multiple printing heads through which individual materials are sequentially printed. Nevertheless, as more printing heads are added the fabrication process significantly decreases, since it requires mechanical switching among the physically separated printheads to enable printing multiple materials. In addition, this approach is not able to create biomimetic tissue constructs with property gradients. To address these limitations, this paper presents a novel static mixing extrusion printing head to enable the fabrication of multi-material, functionally graded structures using a single nozzle. Computational fluid dynamics (CFD) was used to numerically analyze the influence of Reynolds number on the flow pattern of biomaterials and mixing efficiency considering different miscible materials.

scholarly journals Naturally Prefabricated Marine Biomaterials: Isolation and Applications of Flat Chitinous 3D Scaffolds from Ianthella labyrinthus (Demospongiae: Verongiida)

2019 ◽  
Vol 20 (20) ◽  
pp. 5105 ◽  
Author(s):  
Mario Schubert ◽  
Björn Binnewerg ◽  
Alona Voronkina ◽  
Lyubov Muzychka ◽  
Marcin Wysokowski ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Three Dimensional ◽  
Marine Sponges ◽  
Biologically Active ◽  
3D Scaffolds ◽  
Chemical Treatments ◽  
The Family ◽  
Unique Source ◽  
Induced Pluripotent ◽  
First Time

Marine sponges remain representative of a unique source of renewable biological materials. The demosponges of the family Ianthellidae possess chitin-based skeletons with high biomimetic potential. These three-dimensional (3D) constructs can potentially be used in tissue engineering and regenerative medicine. In this study, we focus our attention, for the first time, on the marine sponge Ianthella labyrinthus Bergquist & Kelly-Borges, 1995 (Demospongiae: Verongida: Ianthellidae) as a novel potential source of naturally prestructured bandage-like 3D scaffolds which can be isolated simultaneously with biologically active bromotyrosines. Specifically, translucent and elastic flat chitinous scaffolds have been obtained after bromotyrosine extraction and chemical treatments of the sponge skeleton with alternate alkaline and acidic solutions. For the first time, cardiomyocytes differentiated from human induced pluripotent stem cells (iPSC-CMs) have been used to test the suitability of I. labyrinthus chitinous skeleton as ready-to-use scaffold for their cell culture. Results reveal a comparable attachment and growth on isolated chitin-skeleton, compared to scaffolds coated with extracellular matrix mimetic Geltrex®. Thus, the natural, unmodified I. labyrinthus cleaned sponge skeleton can be used to culture iPSC-CMs and 3D tissue engineering. In addition, I. labyrinthus chitin-based scaffolds demonstrate strong and efficient capability to absorb blood deep into the microtubes due to their excellent capillary effect. These findings are suggestive of the future development of new sponge chitin-based absorbable hemostats as alternatives to already well recognized cellulose-based fabrics.

scholarly journals A Customizable, Low-Cost Perfusion System for Sustaining Tissue Constructs

2018 ◽  
Vol 23 (6) ◽  
pp. 592-598
Author(s):  
Brian J. O’Grady ◽  
Jason X. Wang ◽  
Shannon L. Faley ◽  
Daniel A. Balikov ◽  
Ethan S. Lippmann ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Viability ◽  
Large Scale ◽  
Low Cost ◽  
Three Dimensional ◽  
Tissue Scaffolds ◽  
Perfusion System ◽  
Pump System ◽  
Tissue Constructs ◽  
Engineered Tissue

The fabrication of engineered vascularized tissues and organs requiring sustained, controlled perfusion has been facilitated by the development of several pump systems. Currently, researchers in the field of tissue engineering require the use of pump systems that are in general large, expensive, and generically designed. Overall, these pumps often fail to meet the unique demands of perfusing clinically useful tissue constructs. Here, we describe a pumping platform that overcomes these limitations and enables scalable perfusion of large, three-dimensional hydrogels. We demonstrate the ability to perfuse multiple separate channels inside hydrogel slabs using a preprogrammed schedule that dictates pumping speed and time. The use of this pump system to perfuse channels in large-scale engineered tissue scaffolds sustained cell viability over several weeks.

Ratchet mechanism of drops climbing a vibrated oblique plate

2017 ◽  
Vol 835 ◽  
Author(s):  
Hang Ding ◽  
Xi Zhu ◽  
Peng Gao ◽  
Xi-Yun Lu
Keyword(s):  
Contact Angle ◽  
Theoretical Analysis ◽  
Numerical Simulations ◽  
Contact Angle Hysteresis ◽  
Three Dimensional ◽  
Direct Numerical Simulations ◽  
Ratchet Mechanism ◽  
Wetted Area ◽  
First Time ◽  
Good Agreement

In this paper, we investigate the ratchet mechanism of drops climbing a vibrated oblique plate based on three-dimensional direct numerical simulations, which for the first time reproduce the existing experiment (Brunet et al., Phys. Rev. Lett., vol. 99, 2007, 144501). With the help of numerical simulations, we identify an interesting and important wetting behaviour of the climbing drop; that is, the breaking of symmetry due to the inclination of the plate with respect to the acceleration leads to a hysteresis of the wetted area in one period of harmonic vibration. In particular, the average wetted area in the downhill stage is larger than that in the uphill stage, which is found to be responsible for the uphill net motion of the drop. A new hydrodynamic model is proposed to interpret the ratchet mechanism, taking account of the effects of the acceleration and contact angle hysteresis. The predictions of the theoretical analysis are in good agreement with the numerical results.

Transient Radiation Element Method for Three-Dimensional Scattering, Absorbing, and Emitting Media

2001 ◽  
Author(s):  
Zhixiong Guo ◽  
Sunil Kumar ◽  
Shigenao Maruyama
Keyword(s):  
Radiative Transfer ◽  
Transient Analysis ◽  
Radiative Heat ◽  
Three Dimensional ◽  
The Media ◽  
Emitting Media ◽  
Inhomogeneous Properties ◽  
First Time ◽  
Good Agreement ◽  
Element Method

Abstract In this study transient radiative heat transfer is investigated in scattering, absorbing, and emitting media. The radiation element method is formulated for the first time to solve the transient radiative transfer equation in 3-D geometries. The sensitivity and accuracy of the method are examined. A good agreement of temporal transmittance predicted by the present method and Monte Carlo method is found. The characteristics of transient analysis are investigated via various problems of radiative transfer in inhomogeneous cubes. It is found that the transmitted signals are strongly affected by the inhomogeneous properties of the media through which the radiation has passed. In the position where the radiation travels a larger optical thickness, the broadening of the transmitted pulse width is more obvious and the magnitude of the transmittance is smaller.

scholarly journals Three-Dimensional Bioprinting of Functional Skeletal Muscle Tissue Using GelatinMethacryloyl-Alginate Bioinks

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 679 ◽  
Author(s):  
Seyedmahmoud ◽  
Çelebi-Saltik ◽  
Barros ◽  
Nasiri ◽  
Banton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Tissue Engineering ◽  
Muscle Tissue ◽  
Three Dimensional ◽  
Skeletal Muscle Tissue ◽  
3D Bioprinting ◽  
Uv Crosslinking ◽  
Tissue Constructs ◽  
Muscle Tissues ◽  
Alginate Concentration

Skeletal muscle tissue engineering aims to fabricate tissue constructs to replace or restore diseased or injured skeletal muscle tissues in the body. Several biomaterials and microscale technologies have been used in muscle tissue engineering. However, it is still challenging to mimic the function and structure of the native muscle tissues. Three-dimensional (3D) bioprinting is a powerful tool to mimic the hierarchical structure of native tissues. Here, 3D bioprinting was used to fabricate tissue constructs using gelatin methacryloyl (GelMA)-alginate bioinks. Mechanical and rheological properties of GelMA-alginate hydrogels were characterized. C2C12 myoblasts at the density 8 × 106 cells/mL were used as the cell model. The effects of alginate concentration (0, 6, and 8% (w/v)) and crosslinking mechanism (UV crosslinking or ionic crosslinking with UV crosslinking) on printability, cell viability, proliferation, and differentiation of bioinks were studied. The results showed that 10% (w/v) GelMA-8% (w/v) alginate crosslinked using UV light and 0.1 M CaCl2 provided the optimum niche to induce muscle tissue formation compared to other hydrogel compositions. Furthermore, metabolic activity of cells in GelMA bioinks was improved by addition of oxygen-generating particles to the bioinks. It is hoped that such bioprinted muscle tissues may find wide applications in drug screening and tissue regeneration.

scholarly journals Polarization-insensitive 3D conformal-skin metasurface cloak

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
He-Xiu Xu ◽  
Guangwei Hu ◽  
Yanzhao Wang ◽  
Chaohui Wang ◽  
Mingzhao Wang ◽  
...  
Keyword(s):  
3D Printing ◽  
Incident Light ◽  
Three Dimensional ◽  
Free Form ◽  
Polarization Insensitive ◽  
Wavelength Scale ◽  
First Time ◽  
Printing Techniques ◽  
Flat Ground ◽  
Good Agreement

AbstractElectromagnetic metasurface cloaks provide an alternative paradigm toward rendering arbitrarily shaped scatterers invisible. Most transformation-optics (TO) cloaks intrinsically need wavelength-scale volume/thickness, such that the incoming waves could have enough long paths to interact with structured meta-atoms in the cloak region and consequently restore the wavefront. Other challenges of TO cloaks include the polarization-dependent operation to avoid singular parameters of composite cloaking materials and limitations of canonical geometries, e.g., circular, elliptical, trapezoidal, and triangular shapes. Here, we report for the first time a conformal-skin metasurface carpet cloak, enabling to work under arbitrary states of polarization (SOP) at Poincaré sphere for the incident light and arbitrary conformal platform of the object to be cloaked. By exploiting the foundry three-dimensional (3D) printing techniques to fabricate judiciously designed meta-atoms on the external surface of a conformal object, the spatial distributions of intensity and polarization of its scattered lights can be reconstructed exactly the same as if the scattering wavefront were deflected from a flat ground at any SOP, concealing targets under polarization-scanning detections. Two conformal-skin carpet cloaks working for partial- and full-azimuth plane operation are respectively fabricated on trapezoid and pyramid platforms via 3D printing. Experimental results are in good agreement with numerical simulations and both demonstrate the polarization-insensitive cloaking within a desirable bandwidth. Our approach paves a deterministic and robust step forward to the realization of interfacial, free-form, and full-polarization cloaking for a realistic arbitrary-shape target in real-world applications.

scholarly journals Coaxial Electrohydrodynamic Bioprinting of Pre-vascularized Cell-laden Constructs for Tissue Engineering

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Mao Mao ◽  
Hongtao Liang ◽  
Jiankang He ◽  
Ayiguli Kasimu ◽  
Yanning Zhang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Feeding Rate ◽  
Three Dimensional ◽  
Vascular Networks ◽  
The Core ◽  
Collagen Hydrogel ◽  
Tissue Constructs ◽  
Vascular Structures ◽  
Living Tissues ◽  
Moving Speed

Recapitulating the vascular networks that maintain the delivery of nutrition, oxygen, and byproducts for the living cells within the three-dimensional (3D) tissue constructs is a challenging issue in the tissue-engineering area. Here, a novel coaxial electrohydrodynamic (EHD) bioprinting strategy is presented to fabricate thick pre-vascularized cell-laden constructs. The alginate and collagen/calcium chloride solution were utilized as the outer-layer and inner-layer bioink, respectively, in the coaxial printing nozzle to produce the core-sheath hydrogel filaments. The effect of process parameters (the feeding rate of alginate and collagen and the moving speed of the printing stage) on the size of core and sheath lines within the printed filaments was investigated. The core-sheath filaments were printed in the predefined pattern to fabricate lattice hydrogel with perfusable lumen structures. Endothelialized lumen structures were fabricated by culturing the core-sheath filaments with endothelial cells laden in the core collagen hydrogel. Multilayer core-sheath filaments were successfully printed into 3D porous hydrogel constructs with a thickness of more than 3 mm. Finally, 3D pre-vascularized cardiac constructs were successfully generated, indicating the efficacy of our strategy to engineer living tissues with complex vascular structures.

scholarly journals 3D DEM simulations of monotonic interface behaviour between cohesionless sand and rigid wall of different roughness

2020 ◽  
Author(s):  
A. Grabowski ◽  
M. Nitka ◽  
J. Tejchman
Keyword(s):  
Normal Stress ◽  
Three Dimensional ◽  
Rigid Wall ◽  
Interface Roughness ◽  
Wall Friction ◽  
Dem Simulations ◽  
New Perspective ◽  
Interface Behaviour ◽  
Good Agreement ◽  
Three Dimensional Simulations

Abstract The paper deals with three-dimensional simulations of a monotonic quasi-static interface behaviour between cohesionless sand and a rigid wall of different roughness during wall friction tests in a parallelly guided direct shear test under constant normal stress. Numerical modelling was carried out by the discrete element method (DEM) using spheres with contact moments to approximately capture a non-uniform particle shape. The varying wall surface topography was simulated by a regular mesh of triangular grooves (asperities) along the wall with a different height, distance and inclination. The calculations were carried out with different initial void ratios of sand and vertical normal stress. The focus was to quantify the effect of wall roughness on the evolution of mobilized wall friction and shear localization, also to specify the ratios between slip and rotation and between shear stress/force and couple stress/moment in the sand at the wall. DEM simulations were generally in good agreement with reported experimental results for similar interface roughness. The findings presented in this paper offer a new perspective on the understanding of the wall friction phenomenon in granular bodies.

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