Spatiotemporal Intracellular Deformation of Cells During Freezing-Induced Cell-Fluid-Matrix Interactions

2013 ◽  
Author(s):  
Soham Ghosh ◽  
J. Craig Dutton ◽  
Bumsoo Han
Keyword(s):  
Tissue Engineering ◽  
Cell Viability ◽  
Three Dimensional ◽  
Tissue Type ◽  
Major Constituent ◽  
Tissue Banks ◽  
Chemical Additives ◽  
Cryoprotective Agents ◽  
Cell Tissue ◽  
The Status

Freezing of biomaterials is emerging as one of the key biotechnologies in cell/tissue engineering, medicine and biology. Its applications include — 1) preservation of cell/tissue engineering products, 2) quality control of biospecimens cryopreserved in tissue banks and repositories, and 3) synthesis procedures of biomaterials such as decellularization of native tissues to create acellular (i.e., cell-free) complex three-dimensional extracellular matrices (ECMs). Traditionally, research efforts have focused on determining optimal freeze/thaw (F/T) protocols with chemical additives, so called cryoprotective agents, for a given cell/tissue-type by comparing the outcomes of F/T protocols, which are mainly gauged by cell viability. Although cell viability is the major constituent, it has recently been recognized that other features beyond viability are also critical to the functionality of biomaterials, including the microstructure of the ECM, the status of cell-matrix adhesion, and the cytoskeletal structure and organization [1, 2, 3].

Design and additive manufacturing of porous titanium scaffolds for optimum cell viability in bone tissue engineering

2020 ◽  
pp. 095440542093756
Author(s):  
Bingbing Li ◽  
Bani Davod Hesar ◽  
Yiwen Zhao ◽  
Li Ding
Keyword(s):  
Tissue Engineering ◽  
Cell Viability ◽  
Bone Tissue Engineering ◽  
Pore Size ◽  
Bone Tissue ◽  
Structural Strength ◽  
Three Dimensional ◽  
Porous Titanium ◽  
Nih3t3 Cells ◽  
Pore Sizes

Pore size, external shape, and internal complexity of additively manufactured porous titanium scaffolds are three primary determinants of cell viability and structural strength of scaffolds in bone tissue engineering. To obtain an optimal design with the combination of all three determinants, four scaffolds each with a unique topology (external geometry and internal structure) were designed and varied the pore sizes of each scaffold 3 times. For each topology, scaffolds with pore sizes of 300, 400, and 500 µm were designed. All designed scaffolds were additively manufactured in material Ti6Al4V by the direct metal laser melting machine. Compression test was conducted on the scaffolds to assure meeting minimum compressive strength of human bone. The effects of pore size and topology on the cell viability of the scaffolds were analyzed. The 12 scaffolds were ultrasonically cleaned and seeded with NIH3T3 cells. Each scaffold was seeded with 1 million cells. After 32 days of culturing, the cells were fixed for their three-dimensional architecture preservation and to obtain scanning electron microscope images.

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.

Soft-Tissue Analogue Design and Tissue Engineering of Liver

MRS Bulletin ◽  
1996 ◽  
Vol 21 (11) ◽  
pp. 52-54 ◽  
Author(s):  
Prabhas V. Moghe
Keyword(s):  
Tissue Engineering ◽  
Health Care Cost ◽  
Three Dimensional ◽  
Cell Types ◽  
The United States ◽  
Tissue Loss ◽  
Tissue Type ◽  
Design Parameters ◽  
Immune Rejection ◽  
Engineered Tissue

Tissue engineering involves the application of physical and life sciences to develop functional substitutes for dysfunctional organs or tissue structures. From an engineering standpoint, tissues contain two basic components—the cells that are organized into proper units, and the material surrounding the cells, called the extracellular matrix (ECM). A third, frequently overlooked feature essential to the maintenance of the activity of the engineered tissue is the three-dimensional architecture of the cell-matrix composite.A comprehensive review of the scope and impact of tissue engineering has previously appeared. Tissue-engineered devices have the potential to reduce the annual health-care cost related to tissue loss and end-stage organ failure to the order of $400 billion, eight million invasive surgical procedures, and 65 million hospital days. A common approach to engineer a functional tissue is to place cells derived from a healthy organ or tissue type (identical or similar to the dysfunctional tissue/organ) on or within matrices analogous to host-tissue ECM. These systems can then be enclosed in appropriate membranes that isolate cells from immune rejection following implantation or can be transplanted directly with the administration of drugs that prevent the immune rejection. Another application of these systems is for extracorporeal (outside the patient's body) device support of a dysfunctional organ. In either instance, the success of the engineered tissue depends critically on the interactions of cells with the tissue analogues. The objective of this article is to outline the simplest matrix-design parameters to control these interactions. While organs are comprised of very different tissue types, for the sake of simplicity, this article is primarily pertinent to the tissue engineering of one major organ, the liver. The choice of this tissue type is intended to serve as a comprehensive generalization of many different cell types since in the diversity and complexity of its activities, the liver has few parallels. The development of an artificial liver is also critically awaited, as in the United States alone, 35,000 people, including the many wait listed for the exorbitant liver organ transplants ($300,000), die each year of chronic liver disorders. In many other countries, liver disease is the second leading cause of death.

Functional Imaging of Matrix Structure of Cryopreserved Engineered Tissues Using Back-Directional Gated Mesoscopic Imaging

2012 ◽  
Author(s):  
Young L. Kim ◽  
Zhengbin Xu ◽  
Altug Ozcelikkale ◽  
Bumsoo Han
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Three Dimensional ◽  
Clinical Use ◽  
Matrix Structure ◽  
Non Invasive ◽  
Engineered Tissues ◽  
Cell Tissue ◽  
Matrix Interactions ◽  
Non Destructive

Successful cryopreservation of engineered tissues (ETs) can greatly advance the access and availability of cell/tissue engineering products for clinical use. One of the key challenges in cryopreserving ETs is that the functionality of ETs should be maintained throughout the preservation process. Many of the functionalities are associated with the extracellular matrix (ECM) microstructure, which in turn can be a crucial marker for the post-thaw functionality. Recent studies also reported that the ECM microstructure can be affected by freezing-induced cell-fluid-matrix interactions.1–3 Thus, it is critical to assess three-dimensional (3-D) matrix structure of cryopreserved ETs in a non-destructive, non-invasive, and rapid manner.

scholarly journals Three-dimensional printing of cell-laden bioink for blood vessel tissue engineering: Influence of process parameters and components on cell viability

2021 ◽  
Author(s):  
CONGCONG ZHAN ◽  
Yasong Hu ◽  
ANDUO ZHOU ◽  
SHANFENG ZHANG ◽  
Xia Huang
Keyword(s):  
Tissue Engineering ◽  
Blood Vessel ◽  
Cell Viability ◽  
Process Parameters ◽  
Umbilical Vein ◽  
Three Dimensional ◽  
Small Diameter ◽  
3D Bioprinting ◽  
Influence Of Process Parameters ◽  
Composite Gels

Three-dimensional (3D) bioprinting is a potential therapeutic method for tissue engineering owing to its ability to prepare cell-laden tissue constructs. The properties of bioink are crucial to accurately control the printing structure. Meanwhile, the effect of process parameters on the precise structure is not nonsignificant. We investigated the correlation between process parameters of 3D bioprinting and the structural response of κ-carrageenan-based hydrogels to explore the controllable structure, printing resolution, and cell survival rate. Small-diameter (<6 mm) gel filaments with different structures were printed by varying the shear stress of the extrusion bioprinter to simulate the natural blood vessel structure. The cell viability of the scaffold was evaluated. The in vitro culture of human umbilical vein endothelium cells (HUVECs) on the κ-carrageenan (kc) and composite gels (carrageenan/carbon nanotube and carrageenan/sodium alginate) demonstrated that the cell attachment and proliferation on composite gels were better than those on pure kc. Our results revealed that the carrageenan-based composite bioinks offer better printability, sufficient mechanical stiffness, interconnectivity, and biocompatibility. This process can facilitate precise adjustment of the pore size, porosity, and pore distribution of the hydrogel structure by optimising the printing parameters as well as realise the precise preparation of the internal structure of the 3D hydrogel-based tissue engineering scaffold. Moreover, we obtained perfused tubular filament by 3D printing at optimal process parameters.

scholarly journals Multicellular Co-Culture in Three-Dimensional Gelatin Methacryloyl Hydrogels for Liver Tissue Engineering

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1762 ◽  
Author(s):  
Juan Cui ◽  
Huaping Wang ◽  
Qing Shi ◽  
Tao Sun ◽  
Qiang Huang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Liver Function ◽  
Cell Viability ◽  
Liver Tissue ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Cell Types ◽  
Liver Tissue Engineering ◽  
Multiple Cell

Three-dimensional (3D) tissue models replicating liver architectures and functions are increasingly being needed for regenerative medicine. However, traditional studies are focused on establishing 2D environments for hepatocytes culture since it is challenging to recreate biodegradable 3D tissue-like architecture at a micro scale by using hydrogels. In this paper, we utilized a gelatin methacryloyl (GelMA) hydrogel as a matrix to construct 3D lobule-like microtissues for co-culture of hepatocytes and fibroblasts. GelMA hydrogel with high cytocompatibility and high structural fidelity was determined to fabricate hepatocytes encapsulated micromodules with central radial-type hole by photo-crosslinking through a digital micromirror device (DMD)-based microfluidic channel. The cellular micromodules were assembled through non-contact pick-up strategy relying on local fluid-based micromanipulation. Then the assembled micromodules were coated with fibroblast-laden GelMA, subsequently irradiated by ultraviolet for integration of the 3D lobule-like microtissues encapsulating multiple cell types. With long-term co-culture, the 3D lobule-like microtissues encapsulating hepatocytes and fibroblasts maintained over 90% cell viability. The liver function of albumin secretion was enhanced for the co-cultured 3D microtissues compared to the 3D microtissues encapsulating only hepatocytes. Experimental results demonstrated that 3D lobule-like microtissues fabricated by GelMA hydrogels capable of multicellular co-culture with high cell viability and liver function, which have huge potential for liver tissue engineering and regenerative medicine applications.

scholarly journals A Tailored Biomimetic Hydrogel as Potential Bioink to Print a Cell Scaffold for Tissue Engineering Applications: Printability and Cell Viability Evaluation

2021 ◽  
Vol 11 (2) ◽  
pp. 829
Author(s):  
Shyuan-Yow Chen ◽  
Yung-Chieh Cho ◽  
Tzu-Sen Yang ◽  
Keng-Liang Ou ◽  
Wen-Chien Lan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Viability ◽  
Three Dimensional ◽  
Cell Encapsulation ◽  
Pluronic F127 ◽  
Layer By Layer ◽  
Engineering Applications ◽  
Printing Quality ◽  
A Cell ◽  
Printing Parameters

The present study established a maximum standard for printing quality and developed a preliminary ideal index to print three-dimensional (3D) construct using the Gly-Arg-Gly-Asp (GRGD) peptide modified Pluronic-F127 hydrogel (hereafter defined as 3DG bioformer (3BE)) as bioink. In addition, the biocompatibility of 3BE for 3D printing applications was carefully investigated. For biocompatibility study and ideal printing parameter, we used the formulation of 3BE in three different concentrations (3BE-1: 25%, 3BE-2: 30%, and 3BE-3: 35%). The 3BE hydrogels were printed layer by layer as a cube-like construct with all diameters of the needle head under the same feed (100 mm/s). The printing parameters were determined using combinations of 3BE-1, 3BE-2, and 3BE-3 with three different standard needle sizes (Φ 0.13 mm, Φ 0.33 mm, and Φ 0.9 mm). The printed constructs were photographed and observed using optical microscopy. The cell viability and proliferation were evaluated using Live/Dead assay and immunofluorescence staining. Results showed that a stable of printed line and construct could be generated from the 3BE-3 combinations. Cytotoxicity assay indicated that the 3BE hydrogels possessed well biocompatibility. Bioprinting results also demonstrated that significant cell proliferation in the 3BE-3 combinations was found within three days of printing. Therefore, the study discovered the potential printing parameters of 3BE as bioink to print a stable construct that may also have high biocompatibility for cell encapsulation. This finding could serve as valuable information in creating a functional scaffold for tissue engineering applications.

scholarly journals Current Advances in 3D Bioprinting Technology and Its Applications for Tissue Engineering

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2958
Author(s):  
JunJie Yu ◽  
Su A Park ◽  
Wan Doo Kim ◽  
Taeho Ha ◽  
Yuan-Zhu Xin ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Viability ◽  
Cell Density ◽  
Tissue Regeneration ◽  
Three Dimensional ◽  
Living Cells ◽  
3D Bioprinting ◽  
3D Objects ◽  
Advantages And Disadvantages ◽  
Resolution Cell

Three-dimensional (3D) bioprinting technology has emerged as a powerful biofabrication platform for tissue engineering because of its ability to engineer living cells and biomaterial-based 3D objects. Over the last few decades, droplet-based, extrusion-based, and laser-assisted bioprinters have been developed to fulfill certain requirements in terms of resolution, cell viability, cell density, etc. Simultaneously, various bio-inks based on natural–synthetic biomaterials have been developed and applied for successful tissue regeneration. To engineer more realistic artificial tissues/organs, mixtures of bio-inks with various recipes have also been developed. Taken together, this review describes the fundamental characteristics of the existing bioprinters and bio-inks that have been currently developed, followed by their advantages and disadvantages. Finally, various tissue engineering applications using 3D bioprinting are briefly introduced.

Structural Studies of Fibrinolysis by Electron and Light Microscopy

1999 ◽  
Vol 82 (08) ◽  
pp. 277-282 ◽  
Author(s):  
Yuri Veklich ◽  
Jean-Philippe Collet ◽  
Charles Francis ◽  
John W. Weisel
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Plasminogen Activator ◽  
Structural Changes ◽  
Molecular Mechanisms ◽  
Degradation Products ◽  
Molecular Model ◽  
Three Dimensional ◽  
Tissue Type ◽  
Type Plasminogen Activator

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.

Sign in / Sign up

Export Citation Format

Share Document