scholarly journals Recent Advances on Cell-Based Co-Culture Strategies for Prevascularization in Tissue Engineering

2021 ◽  
Vol 9 ◽  
Author(s):  
Sepehr Shafiee ◽  
Siavash Shariatzadeh ◽  
Ali Zafari ◽  
Alireza Majd ◽  
Hassan Niknejad
Keyword(s):  
Biomechanical Properties ◽  
Supporting Cell ◽  
Culture Conditions ◽  
Vascular Network ◽  
Target Tissue ◽  
Supporting Cells ◽  
Recent Advances ◽  
Endothelial Lineage ◽  
Culture Strategies

Currently, the fabrication of a functional vascular network to maintain the viability of engineered tissues is a major bottleneck in the way of developing a more advanced engineered construct. Inspired by vasculogenesis during the embryonic period, the in vitro prevascularization strategies have focused on optimizing communications and interactions of cells, biomaterial and culture conditions to develop a capillary-like network to tackle the aforementioned issue. Many of these studies employ a combination of endothelial lineage cells and supporting cells such as mesenchymal stem cells, fibroblasts, and perivascular cells to create a lumenized endothelial network. These supporting cells are necessary for the stabilization of the newly developed endothelial network. Moreover, to optimize endothelial network development without impairing biomechanical properties of scaffolds or differentiation of target tissue cells, several other factors, including target tissue, endothelial cell origins, the choice of supporting cell, culture condition, incorporated pro-angiogenic factors, and choice of biomaterial must be taken into account. The prevascularization method can also influence the endothelial lineage cell/supporting cell co-culture system to vascularize the bioengineered constructs. This review aims to investigate the recent advances on standard cells used in in vitro prevascularization methods, their co-culture systems, and conditions in which they form an organized and functional vascular network.

Effects of Bisphosphonate on Long-Term Culture of Cartilage Allografts

2013 ◽  
Author(s):  
Yilu Zhou ◽  
Lauren Resutek ◽  
Liyun Wang ◽  
X. Lucas Lu
Keyword(s):  
Medial Meniscus ◽  
Biomechanical Properties ◽  
Culture Conditions ◽  
Protective Mechanisms ◽  
Post Traumatic ◽  
Biochemical Mechanisms ◽  
Altered Metabolism

Zoledronic acid (ZA), an FDA approved bisphosphonate (BP) medicine, is widely used for the treatment of osteoclast-related bone loss diseases [1]. Our previous study has found that systemic administration of ZA could dramatically suppress the development of post-traumatic osteoarthritis (PTOA) in the DMM (destabilization of the medial meniscus) mouse model, a model recapitulating the altered joint loading associated with PTOA [2]. This finding is consistent with a few similar studies using different animal models [3]. However, little is known about the cellular and biochemical mechanisms of BP mediated chondro-protection in PTOA pathogenesis. Studies have shown that PTOA often initiates from the apoptosis and altered metabolism of cartilage chondrocytes. In this study, we will investigate the direct effects of ZA on the metabolisms of chondrocytes using long-term in vitro culture of cartilage allografts. As one of the earliest responses of chondrocytes to mechanical stimulation, intracellular calcium ([Ca 2+] i) signaling is the upstream of numerous mechanotransduction pathways [4]. We hypothesize that the chondro-protective mechanisms of ZA could be represented by the characteristics of [Ca 2+] i signaling of in situ chondrocytes. Our specific aims were to: (i) compare the in situ spontaneous [Ca 2+] i responses of chondrocytes cultured in non-ZA and ZA supplemented environments, and (ii) compare the biomechanical properties of cartilage allografts under the two culture conditions.

scholarly journals In vivo optogenetics reveals homeostatic control of cochlear sensitivity by supporting cells

2020 ◽  
Author(s):  
Victoria Lukashkina ◽  
Snezana Levic ◽  
Patricio Simões ◽  
Zhenhang Xu ◽  
Joseph DiGuiseppi ◽  
...  
Keyword(s):  
Hair Cells ◽  
Dynamic Range ◽  
Organ Of Corti ◽  
Feedback System ◽  
Supporting Cell ◽  
Outer Hair Cells ◽  
Supporting Cells ◽  
Cochlear Supporting Cells

Abstract We used optogenetics to investigate the control of auditory sensitivity by cochlear supporting cells that scaffold outer hair cells, which transduce and amplify cochlear responses to sound. In vivo and in vitro measurements of sound-induced cochlear mechanical and electrical responses were made from mice that conditionally expressed nonselective cationic channelrhodopsins in Deiters’ and outer pillar supporting cells in the organ of Corti. We demonstrated that cochlear light-stimulation and subsequent activation of channelrhodopsins depolarized the supporting cells, changed their extracellular electrical environment, and sensitized insensitive and desensitized sensitive cochlear responses to sound. We concluded that outer hair cells, Deiters’ cells and outer pillar cells interact through feedback which regulates their immediate ionic and electrical environment and controls energy flow in the mammalian cochlea to optimize its performance over its entire dynamic range. Activation of the supporting cell channelrhodopsins shunts this feedback system and restores cochlear sensitivity to a set level.

scholarly journals Extracellular Matrix Determines Biomechanical Properties of Chondrospheres during Their Maturation In Vitro

Cartilage ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 521-531 ◽  
Author(s):  
Nikolai P. Omelyanenko ◽  
Pavel A. Karalkin ◽  
Elena A. Bulanova ◽  
Elizaveta V. Koudan ◽  
Vladislav A. Parfenov ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Self Assembly ◽  
Biomechanical Properties ◽  
Culture Conditions ◽  
Secant Modulus ◽  
Structural Determinants ◽  
Maturation In Vitro

Objective Chondrospheres represent a variant of tissue spheroids biofabricated from chondrocytes. They are already being used in clinical trials for cartilage repair; however, their biomechanical properties have not been systematically investigated yet. The aim of our study was to characterize chondrospheres in long-term in vitro culture conditions for morphometric changes, biomechanical integrity, and their fusion and spreading kinetics. Results It has been demonstrated that the increase in chondrospheres secant modulus of elasticity is strongly associated with the synthesis and accumulation of extracellular matrix. Additionally, significant interplay has been found between biomechanical properties of tissue spheroids and their fusion kinetics in contrast to their spreading kinetics. Conclusions Extracellular matrix is one of the main structural determinants of chondrospheres biomechanical properties during chondrogenic maturation in vitro. The estimation of tissue spheroids’ physical behavior in vitro prior to operative treatment can be used to predict and potentially control fusogenic self-assembly process after implantation in vivo.

Amyloid Fibrils: From Disease to Design. New Biomaterial Applications for Self-Assembling Cross-β Fibrils

2007 ◽  
Vol 60 (5) ◽  
pp. 333 ◽  
Author(s):  
Sally L. Gras
Keyword(s):  
Enzyme Immobilization ◽  
Amyloid Fibrils ◽  
Protein Aggregates ◽  
Supporting Cells ◽  
Cell Behaviour ◽  
Biomimetic Materials ◽  
Self Assembling ◽  
Recent Advances ◽  
Positive Functions

Amyloid fibrils are self-assembling protein aggregates. They are essentially insoluble and resilient nanofibres that offer great potential as materials for nanotechnology and bionanotechnology. Fibrils are associated with several debilitating diseases, for example Alzheimer’s disease, but recent advances suggest they also have positive functions in nature and can be formed in vitro from generic proteins. This article explores how the unique nanotopography and advantageous properties of fibrils may be used to develop tools for probing cell behaviour, protein-based biomimetic materials for supporting cells, or platforms for biosensors and enzyme immobilization.

scholarly journals Candidate Bioinks for Extrusion 3D Bioprinting—A Systematic Review of the Literature

2021 ◽  
Vol 9 ◽  
Author(s):  
Sam P. Tarassoli ◽  
Zita M. Jessop ◽  
Thomas Jovic ◽  
Karl Hawkins ◽  
Iain S. Whitaker
Keyword(s):  
Systematic Review ◽  
Biomechanical Properties ◽  
Target Tissue ◽  
3D Bioprinting ◽  
Biomechanical Assessment ◽  
Synthetic Materials ◽  
Selection For ◽  
Specific Tissue

Purpose: Bioprinting is becoming an increasingly popular platform technology for engineering a variety of tissue types. Our aim was to identify biomaterials that have been found to be suitable for extrusion 3D bioprinting, outline their biomechanical properties and biocompatibility towards their application for bioprinting specific tissue types. This systematic review provides an in-depth overview of current biomaterials suitable for extrusion to aid bioink selection for specific research purposes and facilitate design of novel tailored bioinks.Methods: A systematic search was performed on EMBASE, PubMed, Scopus and Web of Science databases according to the PRISMA guidelines. References of relevant articles, between December 2006 to January 2018, on candidate bioinks used in extrusion 3D bioprinting were reviewed by two independent investigators against standardised inclusion and exclusion criteria. Data was extracted on bioprinter brand and model, printing technique and specifications (speed and resolution), bioink material and class of mechanical assessment, cell type, viability, and target tissue. Also noted were authors, study design (in vitro/in vivo), study duration and year of publication.Results: A total of 9,720 studies were identified, 123 of which met inclusion criteria, consisting of a total of 58 reports using natural biomaterials, 26 using synthetic biomaterials and 39 using a combination of biomaterials as bioinks. Alginate (n = 50) and PCL (n = 33) were the most commonly used bioinks, followed by gelatin (n = 18) and methacrylated gelatin (GelMA) (n = 16). Pneumatic extrusion bioprinting techniques were the most common (n = 78), followed by piston (n = 28). The majority of studies focus on the target tissue, most commonly bone and cartilage, and investigate only one bioink rather than assessing a range to identify those with the most promising printability and biocompatibility characteristics. The Bioscaffolder (GeSiM, Germany), 3D Discovery (regenHU, Switzerland), and Bioplotter (EnvisionTEC, Germany) were the most commonly used commercial bioprinters (n = 35 in total), but groups most often opted to create their own in-house devices (n = 20). Many studies also failed to specify whether the mechanical data reflected pre-, during or post-printing, pre- or post-crosslinking and with or without cells.Conclusions: Despite the continued increase in the variety of biocompatible synthetic materials available, there has been a shift change towards using natural rather than synthetic bioinks for extrusion bioprinting, dominated by alginate either alone or in combination with other biomaterials. On qualitative analysis, no link was demonstrated between the type of bioink or extrusion technique and the target tissue, indicating that bioprinting research is in its infancy with no established tissue specific bioinks or bioprinting techniques. Further research is needed on side-by-side characterisation of bioinks with standardisation of the type and timing of biomechanical assessment.

Neutrophil migration through in vitro interstitial matrix

1992 ◽  
Vol 50 (1) ◽  
pp. 894-895
Author(s):  
J. Roemer ◽  
S.R. Simon
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Cell Migration ◽  
Smooth Muscle Cells ◽  
Inflammatory Cell ◽  
Neutrophil Migration ◽  
Culture Conditions ◽  
Aortic Smooth Muscle ◽  
Specific Culture

We are developing an in vitro interstitial extracellular matrix (ECM) system for study of inflammatory cell migration. Falcon brand Cyclopore membrane inserts of various pore sizes are used as a support substrate for production of ECM by R22 rat aortic smooth muscle cells. Under specific culture conditions these cells produce a highly insoluble matrix consisting of typical interstitial ECM components, i.e.: types I and III collagen, elastin, proteoglycans and fibronectin.

In vitro assembly of 2-D crystals from partially purified EA1 protein secreted by Bacillus anthracis strain Delta Sterne-1

1994 ◽  
Vol 52 ◽  
pp. 276-277
Author(s):  
Mary Beth Downs ◽  
Wilson Ribot ◽  
Joseph W. Farchaus
Keyword(s):  
Cell Wall ◽  
Molecular Sieves ◽  
Cell Envelope ◽  
Single Species ◽  
Supporting Cell ◽  
Surface Layers ◽  
Rabbit Igg ◽  
In Vitro Assembly ◽  
Covalently Linked

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.

STEROID HORMONE METABOLISM IN RESPONSIVE TISSUES IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S279-S294 ◽  
Author(s):  
Paul Robel
Keyword(s):  
Steroid Hormone ◽  
Physiological Activity ◽  
Physiological State ◽  
Target Cells ◽  
Target Tissue ◽  
Hormone Metabolism ◽  
Metabolizing Enzymes ◽  
Relationship Of

ABSTRACT Of the information available on steroid hormone metabolism in responsive tissues, only that relating hormone metabolism to physiological activity is reviewed, i. e. metabolite activity in isolated in vitro systems, binding of metabolites to target tissue receptors, specific steroid hormone metabolizing enzymes and relationship of hormone metabolism to target organ physiological state. Further, evidence is presented in the androgen field, demonstrating 5α-reduced metabolites, formed inside the target cells, as active compounds. This has led to a consideration of testosterone as a »prehormone«. The possibility that similar events take place in tissues responding to progesterone is discussed. Finally, the role of hormone metabolism in the regulation of hormone availability and/or renewal in target cells is discussed. In this context, reference is made to the potential role of plasma binding proteins and cytosol receptors.

EVALUATION OF TISSUE STEROID BINDING IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S223-S246 ◽  
Author(s):  
C. R. Wira ◽  
H. Rochefort ◽  
E. E. Baulieu
Keyword(s):  
Protein Binding ◽  
Binding Sites ◽  
Experimental System ◽  
Specific Protein ◽  
Coupling Mechanism ◽  
Target Tissue ◽  
Protein Binding Sites ◽  
Definition Of ◽  
Hormone Specificity

ABSTRACT The definition of a RECEPTOR* in terms of a receptive site, an executive site and a coupling mechanism, is followed by a general consideration of four binding criteria, which include hormone specificity, tissue specificity, high affinity and saturation, essential for distinguishing between specific and nonspecific binding. Experimental approaches are proposed for choosing an experimental system (either organized or soluble) and detecting the presence of protein binding sites. Techniques are then presented for evaluating the specific protein binding sites (receptors) in terms of the four criteria. This is followed by a brief consideration of how receptors may be located in cells and characterized when extracted. Finally various examples of oestrogen, androgen, progestagen, glucocorticoid and mineralocorticoid binding to their respective target tissues are presented, to illustrate how researchers have identified specific corticoid and mineralocorticoid binding in their respective target tissue receptors.

Myofibrillar degeneration with diphtheria toxin

2020 ◽  
Vol 45 (4) ◽  
pp. 351-357
Author(s):  
Bilge Özerman Edis ◽  
Muhammet Bektaş ◽  
Rüstem Nurten
Keyword(s):  
Protein Synthesis ◽  
Actin Filaments ◽  
Diphtheria Toxin ◽  
Cardiac Tissue ◽  
Culture Conditions ◽  
Bacterial Toxin ◽  
Filamentous Actin ◽  
Cardiac Damage ◽  
Tissue Samples

AbstractObjectivesCardiac damage in patient with diphtheritic myocarditis is reported as the leading cause of mortality. Diphtheria toxin (DTx) is a well-known bacterial toxin inducing various cytotoxic effects. Mainly, catalytic fragment inhibits protein synthesis, induces cytotoxicity, and depolymerizes actin filaments. In this study, we aimed to demonstrate the extent of myofibrillar damage under DTx treatment to porcine cardiac tissue samples.MethodsTissue samples were incubated with DTx for 1–3 h in culture conditions. To analyze whole toxin (both fragments) distribution, conjugation of DTx with FITC was performed. Measurements were carried out with fluorescence spectrophotometer before and after dialysis. Immunofluorescence microscopy was used to show localization of DTx-FITC (15 nM) on cardiac tissue incubated for 2 h. Ultrastructural characterization of cardiac tissue samples treated with DTx (15 or 150 nM) was performed with transmission electron microscopy.ResultsDTx exerts myofibrillar disorganization. Myofilament degeneration, mitochondrial damage, vacuolization, and abundant lipid droplets were determined with 150 nM of DTx treatment.ConclusionsThis finding is an addition to depolymerization of actin filaments as a result of the DTx-actin interactions in in vitro conditions, indicating that myofilament damage can occur with DTx directly besides protein synthesis inhibition. Ultrastructural results support the importance of filamentous actin degeneration at diphtheritic myocarditis.

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