"HONEYCOMB FILMS": BIOINTERFACE FOR TISSUE ENGINEERING

2002 ◽  
Vol 01 (05n06) ◽  
pp. 415-418 ◽  
Author(s):  
TAKEHIRO NISHIKAWA ◽  
KEIKO ARAI ◽  
JUNKO HAYASHI ◽  
MASAHIKO HARA ◽  
MASATSUGU SHIMOMURA
Keyword(s):  
Tissue Engineering ◽  
Three Dimensional ◽  
Single Layer ◽  
Amphiphilic Polymer ◽  
The Self ◽  
Double Layers ◽  
Tissue Formation ◽  
Moist Air ◽  
Microporous Polymer ◽  
Flat Film

We report that tissue-like structure can be formed when cells are cultured on a microporous polymer film (honeycomb film). The honeycomb films were fabricated by applying a moist air to a spread polymer solution containing biodegradable polymers (poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL)) and an amphiphilic polymer. Hepatocytes were cultured on a self-supporting honeycomb film of PLLA. The hepatocytes formed a single layer of columnar shape cells with a thickness of 20 μm. The tissue formation of hepatocytes was specifically occurred on the honeycomb film of PLLA and not on a flat film of PLLA. Three-dimensional tissue structures were formed, when cells were cultured on both sides of the self-supporting honeycomb film. Double layers of hepatocytes were obtained by the method. Striated tissues such as heart and blood vessel could be reconstructed by utilizing a stretched honeycomb film of PCL.

Honeycomb Films of Biodegradable Polymers for Tissue Engineering

2002 ◽  
Vol 724 ◽  
Author(s):  
Takehiro Nishikawa ◽  
Keiko Arai ◽  
Junko Hayashi ◽  
Masahiko Hara ◽  
Masatsugu Shimomura
Keyword(s):  
Biodegradable Polymers ◽  
Three Dimensional ◽  
Single Layer ◽  
Amphiphilic Polymer ◽  
The Self ◽  
Double Layers ◽  
Tissue Formation ◽  
Moist Air ◽  
Flat Film ◽  
Microporous Films

AbstractWe report that microporous films (honeycomb films) can lead various types of cells to tissue formation. The honeycomb films were fabricated by applying a moist air to a spread polymer solution containing biodegradable polymers (poly(L-lactic acid) (PLLA) and poly (ε-caprolactone) (PCL)) and an amphiphilic polymer. Hepatocytes were cultured on a self-supporting honeycomb film of PLLA. The hepatocytes formed a single layer of columnar shape cells with a thickness of 20 μm. The tissue formation of hepatocytes specifically occurred on the honeycomb film of PLLA, not on a flat film of PLLA. Three dimensional tissue structures were formed, when cells were cultured on both sides of the self-supporting honeycomb film. Double layers of hepatocytes were obtained by the method. Striated tissues such as heart and blood vessel could be reconstructed by utilizing a stretched honeycomb film of PCL.

scholarly journals 3D Nanoprinting Technologies for Tissue Engineering Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Jin Woo Lee
Keyword(s):  
Tissue Engineering ◽  
Tissue Regeneration ◽  
Three Dimensional ◽  
Photon Absorption ◽  
Tissue Formation ◽  
Original Function ◽  
Cell Dynamics ◽  
Scaffold Fabrication ◽  
Two Photon Absorption ◽  
Two Photon

Tissue engineering recovers an original function of tissue by replacing the damaged part with a new tissue or organ regenerated using various engineering technologies. This technology uses a scaffold to support three-dimensional (3D) tissue formation. Conventional scaffold fabrication methods do not control the architecture, pore shape, porosity, or interconnectivity of the scaffold, so it has limited ability to stimulate cell growth and to generate new tissue. 3D printing technologies may overcome these disadvantages of traditional fabrication methods. These technologies use computers to assist in design and fabrication, so the 3D scaffolds can be fabricated as designed and standardized. Particularly, because nanofabrication technology based on two-photon absorption (2PA) and on controlled electrospinning can generate structures with submicron resolution, these methods have been evaluated in various areas of tissue engineering. Recent combinations of 3D nanoprinting technologies with methods from molecular biology and cell dynamics have suggested new possibilities for improved tissue regeneration. If the interaction between cells and scaffold system with biomolecules can be understood and controlled and if an optimal 3D environment for tissue regeneration can be realized, 3D nanoprinting will become an important tool in tissue engineering.

scholarly journals Biodegradable Microfluidic Scaffolds for Vascular Tissue Engineering

2004 ◽  
Vol 845 ◽  
Author(s):  
C. J. Bettinger ◽  
J. T. Borenstein ◽  
R. S. Langer
Keyword(s):  
Tissue Engineering ◽  
Vascular Tissue ◽  
Time Lag ◽  
Three Dimensional ◽  
Single Layer ◽  
Vascular Tissue Engineering ◽  
Engineering Applications ◽  
Organ Regeneration ◽  
Superior Mechanical Properties ◽  
Microfabrication Techniques

ABSTRACTThis work describes the integration of novel microfabrication techniques for vascular tissue engineering applications in the context of a novel biodegradable elastomer. The field of tissue engineering and organ regeneration has been borne out of the high demand for organ transplants. However, one of the critical limitations in regeneration of vital organs is the lack of an intrinsic blood supply. This work expands on the development of scaffolds for vascular tissue engineering applications by employing microfabrication techniques. Unlike previous efforts, this work focuses on fabricating single layer and three-dimensional scaffolds from poly(glycerol-sebacate) (PGS), a novel biodegradable elastomer with superior mechanical properties. The transport properties of oxygen and carbon dioxide in PGS were measured through a series of time-lag diffusion experiments. The results of these measurements were used to calculate a characteristic length scale for oxygen diffusion limits in solid PGS scaffolds. Single layer and three-dimensional microfluidic scaffolds were then produced using fabrication techniques specific for PGS. This work has resulted in the fabrication of solid PGS-based scaffolds with biomimetic fluid flow and capillary channels on the order of 10 microns in width. Fabrication of complex, three-dimensional microfluidic PGS scaffolds was also demonstrated by stacking and bonding multiple microfluidic layers.

Cs3NdSi8O19 und Cs6Nd2Si21O48: Zwei cäsiumhaltige Oxosilicate des Neodyms im Vergleich / Cs3NdSi8O19 and Cs6Nd2Si21O48: Two Caesium-containing Oxosilicates of Neodymium in Comparison

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1329-1338 ◽  
Author(s):  
Marion C. Schäfer ◽  
Thomas Schleid
Keyword(s):  
Solid State ◽  
Coordination Sphere ◽  
Quaternary System ◽  
Three Dimensional ◽  
Single Layer ◽  
Solid State Reactions ◽  
Double Layers ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
First Case

In the quaternary system Cs / Nd / Si / O, two new representatives, the phyllo-oxosilicate Cs3NdSi8O19 and the tecto-oxosilicate Cs6Nd2Si21O48, were synthesized by CsF-flux-supported solid-state reactions between Nd2O3 and SiO2. The first one, Cs3NdSi8O19 (orthorhombic, Cmcm (no. 63), a = 705.74(5), b = 2712.85(19), c = 1163.72(8) pm, Z = 4), is not isotypic to the related scandium compound Cs3ScSi8O19. The [SiO4]4− tetrahedra (d(Si4+ -O2−) = 156 -163 pm) in the structure of Cs3NdSi8O19 are connected via common corners to form corrugated, loop-branched double layers containing four- and eight-membered rings in the (010) plane and eight-membered rings along [001]. Each of the eight-membered ellipses emerging along [100] is additionally loopbranched by two four-membered chains. The oxosilicate double layers are cross-linked by vertexsharing via otherwise isolated [NdO6]9− octahedra (d(Nd3+-O2-)= 232 - 234 pm) to build up a three-dimensional framework. Also in between the oxosilicate double layers, the (Cs1)+ cations are located on the 8 f site. Each of the octagonal channels along [001] hosts one (Cs3)+ and two (Cs2)+ cations, which both reside at only partially occupied sites (8g and 8 f , respectively) and disorder, because otherwise too short Cs+ ・ ・ ・ Cs+ distances would occur. The second compound, Cs6Nd2Si21O48, crystallizes also in an orthorhombic space group (Pmmn (no. 59), a = 2189.24(15), b = 731.92(5), c = 1593.61(11) pm, Z = 2). Starting from a loop-branched single layer containing five- and eight-membered rings, a three-dimensional framework of vertex-shared [SiO4]4− tetrahedra (d(Si4+-O2−) = 149 - 164 pm) built up, in which the Si-O distances range from 149 to 164 pm within a broad range. In certain cavities, one kind of Nd3+, but four kinds of Cs+ cations (here, all sites with full occupation) are embedded. Also surrounded by only six O2− anions just like in the first case, the Nd3+ cations (d(Nd3+-O2−) = 233 - 237 pm) exhibit an unusually small, but not unknown coordination sphere for this relatively large lanthanoid(III) cation

scholarly journals Pectin-Based Scaffolds for Tissue Engineering Applications

2021 ◽  
Author(s):  
Anna Lapomarda ◽  
Aurora De Acutis ◽  
Carmelo De Maria ◽  
Giovanni Vozzi
Keyword(s):  
Tissue Engineering ◽  
Wound Healing ◽  
Tissue Regeneration ◽  
Three Dimensional ◽  
Tissue Formation ◽  
Fabrication Technology ◽  
Engineering Applications ◽  
Structural Support ◽  
Interdisciplinary Field ◽  
Alternative Approaches

Tissue engineering (TE) is an interdisciplinary field that was introduced from the necessity of finding alternative approaches to transplantation for the treatment of damaged and diseased organs or tissues. Unlike the conventional procedures, TE aims at inducing the regeneration of injured tissues through the implantation of customized and functional engineered tissues, built on the so-called ‘scaffolds’. These provide structural support to cells and regulate the process of new tissue formation. The properties of the scaffold are essentials, and they can be controlled by varying the biomaterial formulation and the fabrication technology used to its production. Pectin is emerging as an alternative biomaterial to non-degradable and high-cost petroleum-based biopolymers commonly used in this field. It shows several promising properties including biocompatibility, biodegradability, non-toxicity and gelling capability. Pectin-based formulations can be processed through different fabrication approaches into bidimensional and three-dimensional scaffolds. This chapter aims at highlighting the potentiality in using pectin as biomaterial in the field of tissue engineering. The most representative applications of pectin in preparing scaffolds for wound healing and tissue regeneration are discussed.

Processing Windows for Forming Silk Fibroin Biomaterials into a 3D Porous Matrix

2005 ◽  
Vol 58 (10) ◽  
pp. 716 ◽  
Author(s):  
Hyeon Joo Kim ◽  
Hyun Suk Kim ◽  
Akira Matsumoto ◽  
In-Joo Chin ◽  
Hyoung-Joon Jin ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Organic Solvent ◽  
Silk Fibroin ◽  
Three Dimensional ◽  
Solution Concentration ◽  
Porous Matrix ◽  
Tissue Formation ◽  
Porous Structures ◽  
Protein Polymer ◽  
Modes Of Processing

In the present study we clarify phase diagrams related to silk fibroin processing into three-dimensional porous structures useful for biomaterials and for scaffolds in tissue engineering. All-aqueous and organic solvent (hexafluoroisopropanol) modes of processing are compared relative to solution concentration of silk protein polymer and size of porogen (NaCl particles). The results clarify the range of conditions under which these biomaterial matrices can be formed, with a broader range of pore sizes and smoother surface morphology generated from the organic solvent process. These structures are directly applicable to fundamental studies of protein-based biomaterial assembly as well as cell interactions and tissue formation with these systems.

Alginate Microspheroid Encapsulation and Delivery of MG-63 Cells Into Polycaprolactone Scaffolds: A New Biofabrication Approach for Tissue Engineering Constructs

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Lokesh K. Narayanan ◽  
Arun Kumar ◽  
Zhuo (George) Tan ◽  
Susan Bernacki ◽  
Binil Starly ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Cells ◽  
Three Dimensional ◽  
Cell Delivery ◽  
Tissue Formation ◽  
New Approach ◽  
Encapsulated Cells ◽  
Structural Framework ◽  
3D Matrix ◽  
Seeding Efficiency

Scaffolds play an important role in tissue engineering by providing structural framework and a surface for cells to attach, proliferate, and secrete extracellular matrix (ECM). In order to enable efficient tissue formation, delivering sufficient cells into the scaffold three-dimensional (3D) matrix using traditional static and dynamic seeding methods continues to be a critical challenge. In this study, we investigate a new cell delivery approach utilizing deposition of hydrogel-cell encapsulated microspheroids into polycaprolactone (PCL) scaffolds to improve the seeding efficiency. Three-dimensional-bioplotted PCL constructs (0 deg/90 deg lay down, 284 ± 6 μm strand width, and 555 ± 8 μm strand separation) inoculated with MG-63 model bone cells encapsulated within electrostatically generated calcium-alginate microspheroids (Ø 405 ± 13 μm) were evaluated over seven days in static culture. The microspheroids were observed to be uniformly distributed throughout the PCL scaffold cross section. Encapsulated cells remained viable within the constructs over the test interval with the highest proliferation noted at day 4. This study demonstrates the feasibility of the new approach and highlights the role and critical challenges to be addressed to successfully utilize 3D-bioprinting for microencapsulated cell delivery.

scholarly journals The crystal structure of naujakasite, a double sheet silicate

1975 ◽  
Vol 116 ◽  
pp. 11-24
Author(s):  
R Basso ◽  
A Dal Negro ◽  
A Della Giusta ◽  
L Ungaretti
Keyword(s):  
Crystal Structure ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Single Layer ◽  
Structural Formula ◽  
Double Layers ◽  
Cell Dimensions ◽  
Sheet Silicate ◽  
Computer Controlled ◽  
Oxygen Atoms

The crystal structure of naujakasite from Tuperssuatsiait has been determined by X-ray data from four-circle computer controlled Philips PW 1100 diffractometer (Mo Kα radiation). Naujakasite crystallizes in the space group C2/m with cell dimensions a = 15.025(1), b = 7.991(2), c = 10.486(1) Å, β = 113°40'(5'); the structural formula is Na6FeAl4Si8O26, Z = 2. The structure has been solved by Patterson methods and refined by full matrix least-squares method to Rw = 0.027. Naujakasite is a sheet silicate with double layers of tetrahedra perpendicular to the c direction. All the oxygen atoms of the structure are shared between two tetrahedra except one that interrupts the three-dimensional linking. Each single layer is formed by rings of six tetrahedra and the linkage between two single layers gives rise to rings of four and six tetrahedra. Out of the three independent tetrahedral sites present in the structure one is occupied by silicon and the other two by (0.5 Si + 0.5 AI). The Na-O polyhedra (quite irregular) and the Fe-O polyhedron (a tetragonal bipyramid) are all linked together forming a three-dimensional framework in which all the oxygen atoms of the structure are involved.

Preparation of three-dimensional multilayer ECM-simulated woven/knitted fabric composite scaffolds for potential tissue engineering applications

2019 ◽  
Vol 90 (7-8) ◽  
pp. 925-936 ◽  
Author(s):  
Dandan Guo ◽  
Shuai Wang ◽  
Yuxiang Yin ◽  
Jun Luo ◽  
Chenjie Meng ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Pore Diameter ◽  
Fiber Diameter ◽  
Three Dimensional ◽  
Single Layer ◽  
Woven Fabrics ◽  
Collagen Solution ◽  
Tendon Tissue Engineering ◽  
Bonding Properties ◽  
Composite Fabrics

The extracellular matrix (ECM), with its multilayer fiber structure, regulates diverse functions including cell proliferation, migration, differentiation and tissue regeneration effects. To mimic and replace the native ECM, the structures and properties of three single-layer fabric substrates including warp/weft-knitted and woven fabrics were analyzed, then two-layer warp/weft-knitted composite fabrics prepared by polyurethane (PU) bonding, and woven composite fabrics prepared by polycaprolactone (PCL)/collagen solution bonding or PU bonding, were studied. After PCL/collagen solution bonding or PU bonding, properties such as pore diameter, air permeability, stress and the contact angle of composite fabrics decreased by some degree, while fiber diameter, thickness and the thermal conductivity of composite fabrics increased. In combination with fiber diameter, pore diameter and physical properties, we know that warp- or weft-knitted composite fabrics are ideal scaffolda for potential applications in nerve, myocardium and tendon tissue engineering.

Characterization of a monolayer graphitic structure

1994 ◽  
Vol 52 ◽  
pp. 760-761
Author(s):  
X. Lin ◽  
X. K. Wang ◽  
V. P. Dravid ◽  
J. B. Ketterson ◽  
R. P. H. Chang
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Synthesis Process ◽  
Graphitic Structure ◽  
Positive Gaussian Curvature ◽  
Graphitic Sheet ◽  
Structural And Electronic Properties ◽  
New Material ◽  
Hexagonal Network

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.

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