scholarly journals Innovative Human Three-Dimensional Tissue-Engineered Models as an Alternative to Animal Testing

2020 ◽  
Vol 7 (3) ◽  
pp. 115
Author(s):  
Patrick Bédard ◽  
Sara Gauvin ◽  
Karel Ferland ◽  
Christophe Caneparo ◽  
Ève Pellerin ◽  
...  

Animal testing has long been used in science to study complex biological phenomena that cannot be investigated using two-dimensional cell cultures in plastic dishes. With time, it appeared that more differences could exist between animal models and even more when translated to human patients. Innovative models became essential to develop more accurate knowledge. Tissue engineering provides some of those models, but it mostly relies on the use of prefabricated scaffolds on which cells are seeded. The self-assembly protocol has recently produced organ-specific human-derived three-dimensional models without the need for exogenous material. This strategy will help to achieve the 3R principles.

NANO ◽  
2009 ◽  
Vol 04 (01) ◽  
pp. 1-5 ◽  
Author(s):  
JAIHAI WANG ◽  
MIRA PATEL ◽  
DAVID H. GRACIAS

We describe a strategy to construct three-dimensional (3D) containers with nanoporous walls by the self-assembly of lithographically patterned two-dimensional cruciforms with solder hinges. The first step involves fabricating two-dimensional (2D) cruciforms composed of six unlinked patterns: each pattern has an open window. The second step entails photolithographic patterning of solder hinges that connect the cruciform. The third step involves the deposition of polystyrene particles within the windows and the subsequent electrodeposition of metal in the voids between the polystyrene particles. Following the dissolution of the particles, the cruciforms are released from the substrate and heated above the melting point of the solder causing the cruciforms to spontaneously fold up into 3D cubic containers with nanoporous walls. We believe these 3D containers with nanoporous side walls are promising for molecular separations and cell-based therapies.


2014 ◽  
Vol 2 (20) ◽  
pp. 3123-3132 ◽  
Author(s):  
Ming-Hao Yao ◽  
Jie Yang ◽  
Ming-Shuo Du ◽  
Ji-Tao Song ◽  
Yong Yu ◽  
...  

A class of physical hydrogels photo-cross-linked from multi-branched photopolymeriized monomers based on the self-assembly of coiled-coil polypeptide P is developed.


2017 ◽  
Vol 73 (7) ◽  
pp. 541-545
Author(s):  
Hua Xie ◽  
Wang-Jian Fang ◽  
Xiao-Qiang Yao

One of the most interesting phenomena in coordination polymers (CPs) is the co-existence of different interlaced motifs. However, CPs having two different interlaced motifs at the same time are still rare. Colourless block-shaped crystals of the two-dimensional polymer poly[[aqua(μ2-naphthalene-2,6-dicarboxylato){μ2-4,4′-[oxybis(4,1-phenylene)]dipyridine}cadmium(II)] monohydrate], {[Cd(C12H6O4)(C22H16N2O)(H2O)]·H2O} n , (I), was synthesized under hydrothermal conditions by the self-assembly of 4,4′-[oxybis(4,1-phenylene)]dipyridine (OPY) with CdII in the presence of naphthalene-2,6-dicarboxylic acid (H2ndc). Each CdII ion is six-coordinated by two N atoms from the pyridine rings of two OPY ligands and by four O atoms, three of which are from two ndc2− ligands and one of which is from a water molecule. In (I), every two identical two-dimensional (2D) 63 layers are interpenetrated in a parallel fashion, resulting in an interesting 2D→2D framework with both polyrotaxane and polycatenane characteristics. The extension of these sheets into a three-dimensional supramolecular net is via O—H...O hydrogen bonds. The solid-state photoluminescence properties of (I) are also discussed.


2007 ◽  
Vol 35 (3) ◽  
pp. 535-537 ◽  
Author(s):  
V. Jayawarna ◽  
A. Smith ◽  
J.E. Gough ◽  
R.V. Ulijn

The design of self-assembled peptide-based structures for three-dimensional cell culture and tissue repair has been a key objective in biomaterials science for decades. In search of the simplest possible peptide system that can self-assemble, we discovered that combinations of di-peptides that are modified with aromatic stacking ligands could form nanometre-sized fibres when exposed to physiological conditions. For example, we demonstrated that a number of Fmoc (fluoren-9-ylmethyloxycarbonyl) modified di- and tri-peptides form highly ordered hydrogels via hydrogen-bonding and π–π interactions from the fluorenyl rings. These highly hydrated gels allowed for cell proliferation of chondrocytes in three dimensions [Jayawarna, Ali, Jowitt, Miller, Saiani, Gough and Ulijn (2006) Adv. Mater. 18, 611–614]. We demonstrated that fibrous architecture and physical properties of the resulting materials were dictated by the nature of the amino acid building blocks. Here, we report the self-assembly process of three di-phenylalanine analogues, Fmoc-Phe-Phe-OH, Nap (naphthalene)-Phe-Phe-OH and Cbz (benzyloxycarbonyl)-Phe-Phe-OH, to compare and contrast the self-assembly properties and cell culture conditions attributable to their protecting group difference. Fibre morphology analysis of the three structures using cryo-SEM (scanning electron microscopy) and TEM (transmission electron microscopy) suggested fibrous structures with dramatically varying fibril dimensions, depending on the aromatic ligand used. CD and FTIR (Fourier-transform IR) data confirmed β-sheet arrangements in all three samples in the gel state. The ability of these three new hydrogels to support cell proliferation of chondrocytes was confirmed for all three materials.


MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.


1998 ◽  
Vol 25 (4) ◽  
pp. 621-630 ◽  
Author(s):  
Yasser Hassan ◽  
Said M Easa

Coordination of highway horizontal and vertical alignments is based on subjective guidelines in current standards. This paper presents a quantitative analysis of coordinating horizontal and sag vertical curves that are designed using two-dimensional standards. The locations where a horizontal curve should not be positioned relative to a sag vertical curve (called red zones) are identified. In the red zone, the available sight distance (computed using three-dimensional models) is less than the required sight distance. Two types of red zones, based on stopping sight distance (SSD) and preview sight distance (PVSD), are examined. The SSD red zone corresponds to the locations where an overlap between a horizontal curve and a sag vertical curve should be avoided because the three-dimensional sight distance will be less than the required SSD. The PVSD red zone corresponds to the locations where a horizontal curve should not start because drivers will not be able to perceive it and safely react to it. The SSD red zones exist for practical highway alignment parameters, and therefore designers should check the alignments for potential SSD red zones. The range of SSD red zones was found to depend on the different alignment parameters, especially the superelevation rate. On the other hand, the results showed that the PVSD red zones exist only for large values of the required PVSD, and therefore this type of red zones is not critical. This paper should be of particular interest to the highway designers and professionals concerned with highway safety.Key words: sight distance, red zone, combined alignment.


2015 ◽  
Vol 3 (4) ◽  
pp. 1540-1548 ◽  
Author(s):  
Sheng Zhu ◽  
Hui Zhang ◽  
Ping Chen ◽  
Lin-Hui Nie ◽  
Chuan-Hao Li ◽  
...  

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.


2009 ◽  
Vol 65 (3) ◽  
pp. m139-m142 ◽  
Author(s):  
Rajesh Koner ◽  
Israel Goldberg

The title compound, (5,10,15,20-tetra-4-pyridylporphyrinato)zinc(II) 1,2-dichlorobenzene disolvate, [Zn(C40H24N8)]·2C6H4Cl2, contains a clathrate-type structure. It is composed of two-dimensional square-grid coordination networks of the self-assembled porphyrin moiety, which are stacked one on top of the other in a parallel manner. The interporphyrin cavities of the overlapping networks combine into channel voids accommodated by the dichlorobenzene solvent. Molecules of the porphyrin complex are located on crystallographic inversion centres. The observed two-dimensional assembly mode of the porphyrin units represents a supramolecular isomer of the unique three-dimensional coordination frameworks of the same porphyrin building block observed earlier. The significance of this study lies in the discovery of an additional supramolecular isomer of the rarely observed structures of metalloporphyrins self-assembled directly into extended coordination polymers without the use of external ligand or metal ion auxiliaries.


Nano Letters ◽  
2011 ◽  
Vol 11 (6) ◽  
pp. 2533-2537 ◽  
Author(s):  
C.-H. Chang ◽  
L. Tian ◽  
W. R. Hesse ◽  
H. Gao ◽  
H. J. Choi ◽  
...  

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