scholarly journals Aspiration-assisted bioprinting for precise positioning of biologics

2020 ◽  
Vol 6 (10) ◽  
pp. eaaw5111 ◽  
Author(s):  
Bugra Ayan ◽  
Dong Nyoung Heo ◽  
Zhifeng Zhang ◽  
Madhuri Dey ◽  
Adomas Povilianskas ◽  
...  
Keyword(s):  
Self Assembly ◽  
Physical Mechanism ◽  
Single Cells ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Precise Control ◽  
3D Space ◽  
Magnitude Range ◽  
Wide Range ◽  
Order Of Magnitude

Three-dimensional (3D) bioprinting is an appealing approach for building tissues; however, bioprinting of mini-tissue blocks (i.e., spheroids) with precise control on their positioning in 3D space has been a major obstacle. Here, we unveil “aspiration-assisted bioprinting (AAB),” which enables picking and bioprinting biologics in 3D through harnessing the power of aspiration forces, and when coupled with microvalve bioprinting, it facilitated different biofabrication schemes including scaffold-based or scaffold-free bioprinting at an unprecedented placement precision, ~11% with respect to the spheroid size. We studied the underlying physical mechanism of AAB to understand interactions between aspirated viscoelastic spheroids and physical governing forces during aspiration and bioprinting. We bioprinted a wide range of biologics with dimensions in an order-of-magnitude range including tissue spheroids (80 to 600 μm), tissue strands (~800 μm), or single cells (electrocytes, ~400 μm), and as applications, we illustrated the patterning of angiogenic sprouting spheroids and self-assembly of osteogenic spheroids.

scholarly journals Polymer cyclization for the emergence of hierarchical nanostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chaojian Chen ◽  
Manjesh Kumar Singh ◽  
Katrin Wunderlich ◽  
Sean Harvey ◽  
Colette J. Whitfield ◽  
...  
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Hierarchical Structures ◽  
Structural Similarity ◽  
Vital Role ◽  
Nanomaterial Synthesis ◽  
Wide Range ◽  
Linear Poly ◽  
Polymer Folding ◽  
Dynamics Simulations

AbstractThe creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics. Inspired by the programmability and precise three-dimensional architectures of biomolecules, here we demonstrate the strategy of fabricating controlled hierarchical structures through self-assembly of folded synthetic polymers. Linear poly(2-hydroxyethyl methacrylate) of different lengths are folded into cyclic polymers and their self-assembly into hierarchical structures is elucidated by various experimental techniques and molecular dynamics simulations. Based on their structural similarity, macrocyclic brush polymers with amphiphilic block side chains are synthesized, which can self-assemble into wormlike and higher-ordered structures. Our work points out the vital role of polymer folding in macromolecular self-assembly and establishes a versatile approach for constructing biomimetic hierarchical assemblies.

Self-assembled three-dimensional hierarchical graphene hybrid hydrogels with ultrathin β-MnO2 nanobelts for high performance supercapacitors

2015 ◽  
Vol 3 (4) ◽  
pp. 1540-1548 ◽  
Author(s):  
Sheng Zhu ◽  
Hui Zhang ◽  
Ping Chen ◽  
Lin-Hui Nie ◽  
Chuan-Hao Li ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Performance ◽  
Three Dimensional ◽  
The Self ◽  
Mass Loading ◽  
Hybrid Hydrogel ◽  
Precise Control ◽  
Ultrafine Structure ◽  
Hybrid Hydrogels ◽  
Self Assembled

A facile protocol for the self-assembly of the rGO/β-MnO2 hybrid hydrogel with ultrafine structure and precise control of mass-loading for high performance supercapacitors is reported.

scholarly journals Construction of 3D Cellular Composites with Stem Cells Derived from Adipose Tissue and Endothelial Cells by Use of Optical Tweezers in a Natural Polymer Solution

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1759 ◽  
Author(s):  
Takehiro Yamazaki ◽  
Toshifumi Kishimoto ◽  
Paweł Leszczyński ◽  
Koichiro Sadakane ◽  
Takahiro Kenmotsu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Adipose Tissue ◽  
Optical Tweezers ◽  
Single Cells ◽  
Three Dimensional ◽  
Cell Types ◽  
Cellular Interactions ◽  
Research Fields ◽  
Wide Range

To better understand the regulation and function of cellular interactions, three-dimensional (3D) assemblies of single cells and subsequent functional analysis are gaining popularity in many research fields. While we have developed strategies to build stable cellular structures using optical tweezers in a minimally invasive state, methods for manipulating a wide range of cell types have yet to be established. To mimic organ-like structures, the construction of 3D cellular assemblies with variety of cell types is essential. Our recent studies have shown that the presence of nonspecific soluble polymers in aqueous solution is the key to creating stable 3D cellular assemblies efficiently. The present study further expands on the construction of 3D single cell assemblies using two different cell types. We have successfully generated 3D cellular assemblies, using GFP-labeled adipose tissue-derived stem cells and endothelial cells by using optical tweezers. Our findings will support the development of future applications to further characterize cellular interactions in tissue regeneration.

scholarly journals Aspiration-assisted Freeform Bioprinting of Tissue Spheroids in a Yield-stress Gel

2020 ◽  
Author(s):  
Bugra Ayan ◽  
Zhifeng Zhang ◽  
Nazmiye Celik ◽  
Kui Zhou ◽  
Yang Wu ◽  
...  
Keyword(s):  
Stem Cell ◽  
Yield Stress ◽  
Self Assembly ◽  
Physical Mechanism ◽  
Three Dimensional ◽  
Human Mesenchymal Stem Cell ◽  
Self Healing ◽  
New Approach ◽  
Cell Spheroids ◽  
Cellular Aggregates

AbstractBioprinting of cellular aggregates, such as tissue spheroids or organoids, in complex three-dimensional (3D) arrangements has been a major obstacle for scaffold-free fabrication of tissues and organs. In this research, we unveiled a new approach to the bioprinting of tissue spheroids in a yield stress granular gel, which exhibited unprecedented capabilities in freeform positioning of spheroids in 3D. Due to its Herschel-Bulkley and self-healing properties as well as its biological inertness, the granular gel supported both the positioning and self-assembly of tissue spheroids. We studied the underlying physical mechanism of the approach to elucidate the interactions between the aspirated spheroids and the gel’s yield-stress during the transfer of spheroids from cell media to the gel. We demonstrate the application of the proposed approach in the realization of various freeform shapes and self-assembly of human mesenchymal stem cell spheroids for the construction of cartilage and bone tissues.

scholarly journals Of balls, inks and cages: Hybrid biofabrication of 3D tissue analogs

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Nicanor Moldovan ◽  
Leni Maldovan ◽  
Michael Raghunath
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Hybrid Approach ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Support Structures ◽  
Cell Clusters ◽  
3D Space ◽  
Technical Solutions

The overarching principle of three-dimensional (3D) bioprinting is the placing of cells or cell clusters in the 3D space to generate a cohesive tissue microarchitecture that comes close to in vivo characteristics. To achieve this goal, several technical solutions are available, generating considerable combinatorial bandwidth: (i) Support structures are generated first, and cells are seeded subsequently; (ii) alternatively, cells are delivered in a printing medium, so-called “bioink,” that contains them during the printing process and ensures shape fidelity of the generated structure; and (iii) a “scaffold-free” version of bioprinting, where only cells are used and the extracellular matrix is produced by the cells themselves, also recently entered a phase of accelerated development and successful applications. However, the scaffold-free approaches may still benefit from secondary incorporation of scaffolding materials, thus expanding their versatility. Reversibly, the bioink-based bioprinting could also be improved by adopting some of the principles and practices of scaffold-free biofabrication. Collectively, we anticipate that combinations of these complementary methods in a “hybrid” approach, rather than their development in separate technological niches, will largely increase their efficiency and applicability in tissue engineering.

scholarly journals DNA-assembled superconducting 3D nanoscale architectures

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Lior Shani ◽  
Aaron N. Michelson ◽  
Brian Minevich ◽  
Yafit Fleger ◽  
Michael Stern ◽  
...  
Keyword(s):  
Self Assembly ◽  
Quantum Interference ◽  
Three Dimensional ◽  
Electrical Characterization ◽  
Field Vector ◽  
Parametric Amplifiers ◽  
Liquid Environment ◽  
Superconducting Quantum Interference ◽  
Wide Range ◽  
Physical Phenomena

Abstract Studies of nanoscale superconducting structures have revealed various physical phenomena and led to the development of a wide range of applications. Most of these studies concentrated on one- and two-dimensional structures due to the lack of approaches for creation of fully engineered three-dimensional (3D) nanostructures. Here, we present a ‘bottom-up’ method to create 3D superconducting nanostructures with prescribed multiscale organization using DNA-based self-assembly methods. We assemble 3D DNA superlattices from octahedral DNA frames with incorporated nanoparticles, through connecting frames at their vertices, which result in cubic superlattices with a 48 nm unit cell. The superconductive superlattice is formed by converting a DNA superlattice first into highly-structured 3D silica scaffold, to turn it from a soft and liquid-environment dependent macromolecular construction into a solid structure, following by its coating with superconducting niobium (Nb). Through low-temperature electrical characterization we demonstrate that this process creates 3D arrays of Josephson junctions. This approach may be utilized in development of a variety of applications such as 3D Superconducting Quantum interference Devices (SQUIDs) for measurement of the magnetic field vector, highly sensitive Superconducting Quantum Interference Filters (SQIFs), and parametric amplifiers for quantum information systems.

Force-Assembled Fe3O4 Particle Chains in Polyurethane Matrix

2016 ◽  
Vol 851 ◽  
pp. 221-225
Author(s):  
Marek Zboncak ◽  
Frantisek Ondreas ◽  
Josef Jancar
Keyword(s):  
Magnetic Field ◽  
Self Assembly ◽  
Spatial Arrangement ◽  
Precise Control ◽  
Electro Magnetic Field ◽  
Wide Range ◽  
Structural Variables ◽  
Simple Change ◽  
Electro Magnetic ◽  
Polyurethane Matrix

Despite substantial research efforts, the potential of polymer nanocomposites has still not been fully revealed, mainly due to poor control over the dispersion and alignment of nanoparticles (NPs). Since nanocomposite properties are controlled by the structural variables, it is crucial to achieve control over the NP assembly process.Self-assembly of NPs offers limited control over the NP spatial arrangement. This process results in a poorly controlled variation of simple structures such as agglomerates, clusters and dispersed NPs with the resulting structure strongly dependent a on wide range of thermodynamic parameters.On the other hand, force-assembly exploits interactions between particles induced by external force fields overcoming the thermodynamic ones. Stimulus of external electric, magnetic or electro-magnetic field is applied as the main force controlling the assembly of NPs. Understanding this process gives us the opportunity to create prescribed NP structures with controlled shape, size, and anisotropy by simple change of the force field. Precise control of structure formation on different length scales (from nanoto macro) gives us the opportunity to imitate hierarchical biological structures possessing unique balance of stiffness and toughness.Here, we report on magnetic field force assembly of Fe3O4 nanoparticles in the polyurethane matrix. Resulting NP chain structures were several NP wide and tens of micrometers long aligned along the magnetic force lines. Without the magnetic field, NP agglomerates of random size and shape were formed due to their self-assembly.

scholarly journals The impact of progenitor asymmetries on the neutrino-driven convection in core-collapse supernovae

2020 ◽  
Vol 494 (4) ◽  
pp. 5360-5373 ◽  
Author(s):  
Rémi Kazeroni ◽  
Ernazar Abdikamalov
Keyword(s):  
Buoyant Density ◽  
Three Dimensional ◽  
Core Collapse ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Post Shock ◽  
Nuclear Burning ◽  
Density Perturbations ◽  
Perturbation Parameters ◽  
The Impact

ABSTRACT The explosion of massive stars in core-collapse supernovae may be aided by the convective instabilities that develop in their innermost nuclear burning shells. The resulting fluctuations support the explosion by generating additional turbulence behind the supernova shock. It was suggested that the buoyant density perturbations arising from the interaction of the pre-collapse asymmetries with the shock may be the primary contributor to the enhancement of the neutrino-driven turbulent convection in the post-shock region. Employing three-dimensional numerical simulations of a toy model, we investigate the impact of such density perturbations on the post-shock turbulence. We consider a wide range of perturbation parameters. The spatial scale and the amplitude of the perturbations are found to be of comparable importance. The turbulence is particularly enhanced when the perturbation frequency is close to that of the convective turnovers in the gain region. Our analysis confirms that the buoyant density perturbations is indeed the main source of the additional turbulence in the gain region, validating the previous order-of-magnitude estimates.

scholarly journals Three-dimensional acoustic scattering by layered media: a novel surface formulation with operator expansions implementation

2011 ◽  
Vol 468 (2139) ◽  
pp. 731-758 ◽  
Author(s):  
David P. Nicholls
Keyword(s):  
Acoustic Waves ◽  
Three Dimensional ◽  
Acoustic Scattering ◽  
Boundary Integral ◽  
Helmholtz Equations ◽  
Irregular Structures ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Boundary Integral Operators ◽  
Operator Expansions

The scattering of acoustic waves by irregular structures plays an important role in a wide range of problems of scientific and technological interest. This contribution focuses on the rapid and highly accurate numerical approximation of solutions of Helmholtz equations coupled across irregular periodic interfaces meant to model acoustic waves incident upon a multi-layered medium. We describe not only a novel surface formulation for the problem in terms of boundary integral operators (Dirichlet–Neumann operators), but also a Boundary Perturbation methodology (the Method of Operator Expansions) for its numerical simulation. The method requires only the discretization of the layer interfaces (so that the number of unknowns is an order of magnitude smaller than volumetric approaches), while it avoids not only the need for specialized quadrature rules but also the dense linear systems characteristic of Boundary Integral/Element Methods. The approach is a generalization to multiple layers of Malcolm & Nicholls' Operator Expansions algorithm for dielectric structures with two layers. As with this precursor, this approach is efficient and spectrally accurate.

The Cave-let: A low-cost projective immersive display

2000 ◽  
Vol 6 (2_suppl) ◽  
pp. 24-26 ◽  
Author(s):  
Mark Green ◽  
Lloyd White
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Collaborative Systems ◽  
Design And Implementation ◽  
Wide Range ◽  
The World ◽  
Order Of Magnitude

This paper describes the design and implementation of a low-cost projective immersive display (PID), called the Cave-let. A PID immerses the user in a computer-generated three-dimensional environment that responds to the user's movements. Current devices of this nature are very expensive, so that fewer than 100 units have been installed around the world. A low-cost PID will enable a wide range of applications in areas such as telehealth, visualization, education and collaborative systems. To produce a low-cost PID, we identified the components of the design that represented the major costs. These were then redesigned with the aim of reducing cost as much as possible while preserving most of the functionality. The resulting device is suitable for a wide range of applications and is an order of magnitude less expensive than similar devices.

Sign in / Sign up

Export Citation Format

Share Document