scholarly journals Scaffolds with a High Surface Area-to-Volume Ratio and Cultured Under Fast Flow Perfusion Result in Optimal O2 Delivery to the Cells in Artificial Bone Tissues

2019 ◽  
Vol 9 (11) ◽  
pp. 2381 ◽  
Author(s):  
Thanh Danh Nguyen ◽  
Olufemi E. Kadri ◽  
Vassilios I. Sikavitsas ◽  
Roman S. Voronov
Keyword(s):  
Tissue Engineering ◽  
Surface Area ◽  
Culture Media ◽  
Financial Burden ◽  
High Surface ◽  
Molecular Transport ◽  
Computer Assisted ◽  
Maximal Surface ◽  
Tissue Engineering Scaffolds ◽  
O2 Delivery

Tissue engineering has the potential for repairing large bone defects, which impose a heavy financial burden on the public health. However, difficulties with O2 delivery to the cells residing in the interior of tissue engineering scaffolds make it challenging to grow artificial tissues of clinically-relevant sizes. This study uses image-based simulation in order to provide insight into how to better optimize the scaffold manufacturing parameters, and the culturing conditions, in order to resolve the O2 bottleneck. To do this, high resolution 3D X-ray images of two common scaffold types (salt leached foam and non-woven fiber mesh) are fed into Lattice Boltzmann Method fluid dynamics and reactive Lagrangian Scalar Tracking mass transfer solvers. The obtained findings indicate that the scaffolds should have maximal surface area-to-solid volume ratios for higher chances of the molecular collisions with the cells. Furthermore, the cell culture media should be flown through the scaffold pores as fast as practically possible (without detaching or killing the cells). Finally, we have provided a parametric sweep that maps how the molecular transport within the scaffolds is affected by variations in rates of O2 consumption by the cells. Ultimately, the results of this study are expected to benefit the computer-assisted design of tissue engineering scaffolds and culturing experiments.

scholarly journals Scaffolds with a High Surface Area-to-Volume Ratio and Cultured Under Fast Flow Perfusion Result in Optimal O2 Delivery to the Cells in Artificial Bone Tissues

2019 ◽  
Author(s):  
Thanh Danh Nguyen ◽  
Olufemi E. Kadri ◽  
Vassilios Sikavitsas ◽  
Roman S. Voronov
Keyword(s):  
Tissue Engineering ◽  
Surface Area ◽  
Culture Media ◽  
Financial Burden ◽  
High Surface ◽  
Molecular Transport ◽  
Volume Ratio ◽  
Computer Assisted ◽  
Maximal Surface ◽  
Tissue Engineering Scaffolds

Tissue engineering has the potential for repairing large bone defects, which impose a heavy financial burden on the public health. However, difficulties with O2 delivery to the cells residing in the interior of tissue engineering scaffolds make it challenging to grow artificial tissues of clinically-relevant sizes. This study uses image-based simulation in order to provide insight into how to better optimize the scaffold manufacturing parameters, and the culturing conditions, in order to resolve the O2 bottleneck. To do this, high resolution 3D X-ray images of two common scaffold types (salt leached foam and non-woven fiber mesh) are fed into a Lattice Boltzmann Method fluid dynamics and reactive Lagrangian Scalar Tracking mass transfer solvers. The obtained findings indicate that the scaffolds should have maximal surface area-to-solid volume ratios, for higher chances of the molecular collisions with the cells. Furthermore, the cell culture media should be flown through the scaffold pores as fast as practically possible (without detaching or killing the cells). Finally, we have provided a parametric sweep that maps how the molecular transport within the scaffolds is affected by variations in rates of O2 consumption by the cells. Ultimately, the results of this study are expected to benefit the computer-assisted design of tissue engineering scaffolds and culturing experiments.

scholarly journals A review on advanced nanofiber technology for membrane distillation

2019 ◽  
Vol 14 ◽  
pp. 155892501882490 ◽  
Author(s):  
Fatma Yalcinkaya
Keyword(s):  
Tissue Engineering ◽  
Surface Area ◽  
Wound Dressing ◽  
High Surface ◽  
High Surface Area ◽  
Membrane Distillation ◽  
Operating Parameters ◽  
Polymeric Nanofibers ◽  
Highly Porous ◽  
Comprehensive Study

The importance of the nanofiber webs increases rapidly due to their highly porous structure, narrow pore size, and distribution; specific surface area and compatibility with inorganics. Electrospinning has been introduced as one of the most efficient technique for the fabrication of polymeric nanofibers due to its ability to fabricate nanostructures with unique properties such as a high surface area and porosity. The process and the operating parameters affect the nanofiber fabrication and the application of nanofibers in various fields, such as sensors, tissue engineering, wound dressing, protective clothes, filtration, desalination, and distillation. In this review, a comprehensive study is presented on the parameters of electrospinning system including applications. More emphasis is given to the application of nanofibers in membrane distillation (MD). The research developments and the current situation of the nanofiber webs in MD are also discussed.

Design and 3D Printing of Hierarchical Tissue Engineering Scaffolds Based on Mechanics and Biology Perspectives

2016 ◽  
Author(s):  
Paul Egan ◽  
Stephen J. Ferguson ◽  
Kristina Shea
Keyword(s):  
Tissue Engineering ◽  
Surface Area ◽  
Structural Integrity ◽  
The Body ◽  
Cellular Growth ◽  
Design Parameters ◽  
Tissue Engineering Scaffolds ◽  
Structural Support ◽  
Trade Offs ◽  
Design Alternatives

Continued scientific research is crucial for developing new biomedical products, such as tissue engineering scaffolds, that are difficult to optimize due to the complexity of interfacing mechanical and biological systems. In this paper, mechanical and biological perspectives are used to propose and implement an approach for designing hierarchical scaffolds that provide structural support in the body as tissue regenerates. Three sequential steps are proposed for defining design needs, generating design alternatives, and fabricating design prototypes. Design needs are determined by considering mechanical and biological performance requirements, experimental procedures, and fabrication constraints. The primary mechanical requirement is a scaffold’s need to maintain structural integrity, while biologically the scaffold should promote cellular growth. Scaffold design alternatives of four topology types are generated by altering design parameters that describe a scaffold’s structure. Trade-offs are revealed for scaffold porosity and surface area properties that are known to influence mechanical and biological scaffold performance. Scaffolds of each topology type are designed with 80% porosity and fabricated, which enables their potential use in scientific experiments to measure how property trade-offs influence scaffold performance. On the basis of currently available knowledge, a to-scale spinal scaffold implant is designed and fabricated with a graphically maximized surface area to porosity ratio for a hierarchical scaffold, which represents a potentially high performing design from both mechanical and biological perspectives. These results demonstrate the importance of multidisciplinary approaches for designing complex biomedical tissue scaffolds that could significantly improve healthcare through the development of new clinical products.

High surface area biopolymeric-ceramic scaffolds for hard tissue engineering

2017 ◽  
Vol 3 (3) ◽  
pp. 035012 ◽  
Author(s):  
Lilian B Romero-Sánchez ◽  
Sara Borrego-González ◽  
Aránzazu Díaz-Cuenca
Keyword(s):  
Tissue Engineering ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Hard Tissue ◽  
Hard Tissue Engineering

Novel tissue engineering scaffolds as wound dressings loaded with Alkannins/Shikonins as active ingredients

2019 ◽  
Author(s):  
AS Arampatzis ◽  
K Theodoridis ◽  
E Aggelidou ◽  
KN Kontogiannopoulos ◽  
I Tsivintzelis ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Wound Dressings ◽  
Active Ingredients ◽  
Tissue Engineering Scaffolds

HYDROXYAPATITE, ALGINATE, AND CHITOSAN FOR BONE SCAFFOLDS: SPECTROSCOPY STUDY

2016 ◽  
Vol 19 (2) ◽  
pp. 93-100
Author(s):  
Lalita El Milla
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Functional Groups ◽  
Bone Growth ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Tissue Engineering Scaffolds ◽  
Hydroxyapatite Powder ◽  
Materials Used

Scaffolds is three dimensional structure that serves as a framework for bone growth. Natural materials are often used in synthesis of bone tissue engineering scaffolds with respect to compliance with the content of the human body. Among the materials used to make scafffold was hydroxyapatite, alginate and chitosan. Hydroxyapatite powder obtained by mixing phosphoric acid and calcium hydroxide, alginate powders extracted from brown algae and chitosan powder acetylated from crab. The purpose of this study was to examine the functional groups of hydroxyapatite, alginate and chitosan. The method used in this study was laboratory experimental using Fourier Transform Infrared (FTIR) spectroscopy for hydroxyapatite, alginate and chitosan powders. The results indicated the presence of functional groups PO43-, O-H and CO32- in hydroxyapatite. In alginate there were O-H, C=O, COOH and C-O-C functional groups, whereas in chitosan there were O-H, N-H, C=O, C-N, and C-O-C. It was concluded that the third material containing functional groups as found in humans that correspond to the scaffolds material in bone tissue engineering.

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

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