scholarly journals Capillary-Like Formations of Endothelial Cells in Defined Patterns Generated by Laser Bioprinting

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1538
Author(s):  
Lothar Koch ◽  
Andrea Deiwick ◽  
Boris Chichkov
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
High Cell Density ◽  
Cell Types ◽  
High Cell ◽  
Tubular Structures ◽  
Promising Technique ◽  
External Stimulation ◽  
Random Patterns ◽  
Printed Patterns

Bioprinting is seen as a promising technique for tissue engineering, with hopes of one day being able to produce whole organs. However, thick tissue requires a functional vascular network, which naturally contains vessels of various sizes, down to capillaries of ~10 µm in diameter, often spaced less than 200 µm apart. If such thick tissues are to be printed, the vasculature would likely need to be printed at the same time, including the capillaries. While there are many approaches in tissue engineering to produce larger vessels in a defined manner, the small capillaries usually arise only in random patterns by sprouting from the larger vessels or from randomly distributed endothelial cells. Here, we investigated whether the small capillaries could also be printed in predefined patterns. For this purpose, we used a laser-based bioprinting technique that allows for the combination of high resolution and high cell density. Our aim was to achieve the formation of closed tubular structures with lumina by laser-printed endothelial cells along the printed patterns on a surface and in bioprinted tissue. This study shows that such capillaries are directly printable; however, persistence of the printed tubular structures was achieved only in tissue with external stimulation by other cell types.

scholarly journals Moderate Hypothermia Has the Potential to Reveal the Dominant/Submissive Relationship in a Co-Culture System Consisting of Osteoblasts and Endothelial Cells

Micro ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 181-193
Author(s):  
Kouki Inomata ◽  
Michiyo Honda
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Culture System ◽  
Spatial Organization ◽  
Cellular Proliferation ◽  
Cell Types ◽  
Culture Conditions ◽  
Moderate Hypothermia ◽  
Bone Homeostasis ◽  
And Migration

Microvessels in bone are indispensable for maintaining bone homeostasis based on a dynamic remodeling system. In cell-based tissue engineering, vascularization into the regenerative bone is a key strategy to avoid hypoxia and necrosis around re-implanted tissues. Previous studies have shown that direct contact between osteoblasts and endothelial cells stimulates differentiation of both cell types. However, no studies have revealed the dominant/submissive relationship. In the present study, we examined the effect of hypothermia on monoculture and co-culture to assess which cells tightly coordinated osteogenesis and angiogenesis in the co-culture system. As for osteoblasts, exposure to hypothermia suppressed cellular proliferation, migration, and differentiation. Evaluation of the behavior of endothelial cells showed that hypothermia should not affect basic functions such as proliferation and migration. Under co-culture conditions, both osteogenic differentiation and the formation of vessel-like angiogenic structures were suppressed by hypothermia, but the spatial organization of alkaline phosphatase-positive cell clusters, which tend to localize around microvascular lumens, was not altered. These data suggest that hypothermia attenuates heterotypic intercellular crosstalk which robustly depends on osteoblasts to inhibit both osteogenesis and angiogenesis in the co-culture system. Taken together, this approach will provide new insights into the relationship between osteoblasts and endothelial cells in tissue engineering.

scholarly journals Ectopic transient overexpression of OCT-4 facilitates BMP4-induced osteogenic transdifferentiation of human umbilical vein endothelial cells

2020 ◽  
Vol 11 ◽  
pp. 204173142090920
Author(s):  
Seung Hyun L Kim ◽  
Seunghun S Lee ◽  
Inseon Kim ◽  
Janet Kwon ◽  
Song Kwon ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Cell Therapy ◽  
Bone Morphogenetic Protein ◽  
Umbilical Vein ◽  
Cell Types ◽  
Bone Morphogenetic Protein 4 ◽  
Morphogenetic Protein ◽  
Umbilical Vein Endothelial Cells

Limitation in cell sources for autologous cell therapy has been a recent focus in stem cell therapy and tissue engineering. Among various research advances, direct conversion, or transdifferentiation, is a notable and feasible strategy for the generation and acquirement of wanted cell source. So far, utilizing cell transdifferentiation technology in tissue engineering was mainly restricted at achieving single wanted cell type from diverse cell types with high efficiency. However, regeneration of a complete tissue always requires multiple cell types which poses an intrinsic complexity. In this study, enhanced osteogenic differentiation was achieved by transient ectopic expression of octamer-binding transcription factor 4 ( OCT-4) gene followed by bone morphogenetic protein 4 treatment on human umbilical vein endothelial cells. OCT-4 transfection and bone morphogenetic protein 4 treatment resulted in enhanced expression of osteogenic markers such as core-binding factor alpha 1, alkaline phosphatase, and collagen 1 compared with bone morphogenetic protein 4 treatment alone. Furthermore, we employed gelatin-heparin cryogel in cranial defect model for in vivo bone formation. Micro-computed tomography and histological analysis of in vivo samples showed that OCT-4 transfection followed by bone morphogenetic protein 4 treatment resulted in efficient transdifferentiation of endothelial cells to osteogenic cells. These results suggest that the combination of OCT-4 and bone morphogenetic protein 4 on endothelial cells would be a reliable multicellular transdifferentiation model which could be applied for bone tissue engineering.

scholarly journals Bioprinting of high cell‐density constructs leads to controlled lumen formation with self‐assembly of endothelial cells

2019 ◽  
Vol 13 (10) ◽  
pp. 1883-1895 ◽  
Author(s):  
Kevin Tröndle ◽  
Fritz Koch ◽  
Günter Finkenzeller ◽  
G. Björn Stark ◽  
Roland Zengerle ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Density ◽  
Self Assembly ◽  
High Cell Density ◽  
High Cell ◽  
Lumen Formation

Investigating the Effect of Mechanical Stimuli on Omental Mesothelium Differentiation

2013 ◽  
Author(s):  
Lucas Hofmeister ◽  
Todd Lagus ◽  
Elaine Shelton ◽  
Jon Edd ◽  
David Bader ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Wound Healing ◽  
Endothelial Cells ◽  
Terminal Differentiation ◽  
Cell Types ◽  
Mechanical Stimuli ◽  
Vascular Repair ◽  
Cardiovascular Tissue ◽  
Autologous Cell ◽  
Cell Source

Cell sourcing for tissue engineered approaches to vascular repair is a serious issue confronting the field of cardiovascular tissue engineering. Omental mesothelium is a promising autologous cell source for vascular repair and has been used for numerous other therapies [1]. Until recently, omental mesothelium was only thought to play a paracrine role in wound healing but there is increasing evidence that omental mesothelium can undergo divergent terminal differentiation to reparative vasculogenic cell types including: endothelial cells, fibroblasts, or vascular smooth muscle cells.

scholarly journals Vascularisation of pluripotent stem cell–derived myocardium: biomechanical insights for physiological relevance in cardiac tissue engineering

2021 ◽  
Author(s):  
Oisín King ◽  
Ilona Sunyovszki ◽  
Cesare M. Terracciano
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Stem Cell ◽  
Cardiac Tissue ◽  
Cell Types ◽  
In Vitro Techniques ◽  
Physiological Relevance ◽  
Diverse Field ◽  
Biomechanical Stimuli

AbstractThe myocardium is a diverse environment, requiring coordination between a variety of specialised cell types. Biochemical crosstalk between cardiomyocytes (CM) and microvascular endothelial cells (MVEC) is essential to maintain contractility and healthy tissue homeostasis. Yet, as myocytes beat, heterocellular communication occurs also through constantly fluctuating biomechanical stimuli, namely (1) compressive and tensile forces generated directly by the beating myocardium, and (2) pulsatile shear stress caused by intra-microvascular flow. Despite endothelial cells (EC) being highly mechanosensitive, the role of biomechanical stimuli from beating CM as a regulatory mode of myocardial-microvascular crosstalk is relatively unexplored. Given that cardiac biomechanics are dramatically altered during disease, and disruption of myocardial-microvascular communication is a known driver of pathological remodelling, understanding the biomechanical context necessary for healthy myocardial-microvascular interaction is of high importance. The current gap in understanding can largely be attributed to technical limitations associated with reproducing dynamic physiological biomechanics in multicellular in vitro platforms, coupled with limited in vitro viability of primary cardiac tissue. However, differentiation of CM from human pluripotent stem cells (hPSC) has provided an unlimited source of human myocytes suitable for designing in vitro models. This technology is now converging with the diverse field of tissue engineering, which utilises in vitro techniques designed to enhance physiological relevance, such as biomimetic extracellular matrix (ECM) as 3D scaffolds, microfluidic perfusion of vascularised networks, and complex multicellular architectures generated via 3D bioprinting. These strategies are now allowing researchers to design in vitro platforms which emulate the cell composition, architectures, and biomechanics specific to the myocardial-microvascular microenvironment. Inclusion of physiological multicellularity and biomechanics may also induce a more mature phenotype in stem cell–derived CM, further enhancing their value. This review aims to highlight the importance of biomechanical stimuli as determinants of CM-EC crosstalk in cardiac health and disease, and to explore emerging tissue engineering and hPSC technologies which can recapitulate physiological dynamics to enhance the value of in vitro cardiac experimentation.

Complex Vesicles, Microtubules, and Cytoplasmic Filaments in the Endothelial Cells of Normal Dog Aorta

1968 ◽  
Vol 26 ◽  
pp. 172-173
Author(s):  
C. N. Sun ◽  
J. J. Ghidoni
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Cross Sections ◽  
Functional Significance ◽  
Tubular Structures ◽  
Aldehyde Fixation ◽  
Cytoplasmic Filaments

Endothelial cells in longitudinal and cross sections of aortas from 3 randomly selected “normal” mongrel dogs were studied by electron microscopy. Segments of aorta were distended with cold cacodylate buffered 5% glutaraldehyde for 10 minutes prior to being cut into small, well oriented tissue blocks. After an additional 1-1/2 hour period in glutaraldehyde, the tissue blocks were well rinsed in buffer and post-fixed in OsO4. After dehydration they were embedded in a mixture of Maraglas, D.E.R. 732, and DDSA.Aldehyde fixation preserves the filamentous and tubular structures (300 Å and less) for adequate demonstration and study. The functional significance of filaments and microtubules has been recently discussed by Buckley and Porter; the precise roles of these cytoplasmic components remains problematic. Endothelial cells in canine aortas contained an abundance of both types of structures.

In vitro Three Dimensional Scaffold-free Construct of Human Adipose-derived Stem Cells in Coculture with Endothelial Cells and Fibroblasts

2017 ◽  
Vol 68 (6) ◽  
pp. 1341-1344
Author(s):  
Grigore Berea ◽  
Gheorghe Gh. Balan ◽  
Vasile Sandru ◽  
Paul Dan Sirbu
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Endothelial Cells ◽  
Single Cell ◽  
Cell Line ◽  
Bone Repair ◽  
Umbilical Vein ◽  
Human Fibroblasts ◽  
Three Dimensional ◽  
Adipose Derived Stem Cells

Complex interactions between stem cells, vascular cells and fibroblasts represent the substrate of building microenvironment-embedded 3D structures that can be grafted or added to bone substitute scaffolds in tissue engineering or clinical bone repair. Human Adipose-derived Stem Cells (hASCs), human umbilical vein endothelial cells (HUVECs) and normal dermal human fibroblasts (NDHF) can be mixed together in three dimensional scaffold free constructs and their behaviour will emphasize their potential use as seeding points in bone tissue engineering. Various combinations of the aforementioned cell lines were compared to single cell line culture in terms of size, viability and cell proliferation. At 5 weeks, viability dropped for single cell line spheroids while addition of NDHF to hASC maintained the viability at the same level at 5 weeks Fibroblasts addition to the 3D construct of stem cells and endothelial cells improves viability and reduces proliferation as a marker of cell differentiation toward osteogenic line.

Role of Growth Factors and Endothelial Cells in Therapeutic Angiogenesis and Tissue Engineering

2006 ◽  
Vol 1 (3) ◽  
pp. 333-343 ◽  
Author(s):  
Masashi Nomi ◽  
Hideaki Miyake ◽  
Yoshifumi Sugita ◽  
Masato Fujisawa ◽  
Shay Soker
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Growth Factors ◽  
Therapeutic Angiogenesis

Uncovering the Diversification of Tissue Engineering on the Emergent Areas of Stem Cells, Nanotechnology and Biomaterials

2020 ◽  
Vol 15 (3) ◽  
pp. 187-201 ◽  
Author(s):  
Sunil K. Dubey ◽  
Amit Alexander ◽  
Munnangi Sivaram ◽  
Mukta Agrawal ◽  
Gautam Singhvi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Immune System ◽  
Clinical Application ◽  
Cell Types ◽  
Patient Specific ◽  
Potential Strategy ◽  
Induced Pluripotent ◽  
Treat All ◽  
The Impact

Damaged or disabled tissue is life-threatening due to the lack of proper treatment. Many conventional transplantation methods like autograft, iso-graft and allograft are in existence for ages, but they are not sufficient to treat all types of tissue or organ damages. Stem cells, with their unique capabilities like self-renewal and differentiate into various cell types, can be a potential strategy for tissue regeneration. However, the challenges like reproducibility, uncontrolled propagation and differentiation, isolation of specific kinds of cell and tumorigenic nature made these stem cells away from clinical application. Today, various types of stem cells like embryonic, fetal or gestational tissue, mesenchymal and induced-pluripotent stem cells are under investigation for their clinical application. Tissue engineering helps in configuring the stem cells to develop into a desired viable tissue, to use them clinically as a substitute for the conventional method. The use of stem cell-derived Extracellular Vesicles (EVs) is being studied to replace the stem cells, which decreases the immunological complications associated with the direct administration of stem cells. Tissue engineering also investigates various biomaterials to use clinically, either to replace the bones or as a scaffold to support the growth of stemcells/ tissue. Depending upon the need, there are various biomaterials like bio-ceramics, natural and synthetic biodegradable polymers to support replacement or regeneration of tissue. Like the other fields of science, tissue engineering is also incorporating the nanotechnology to develop nano-scaffolds to provide and support the growth of stem cells with an environment mimicking the Extracellular matrix (ECM) of the desired tissue. Tissue engineering is also used in the modulation of the immune system by using patient-specific Mesenchymal Stem Cells (MSCs) and by modifying the physical features of scaffolds that may provoke the immune system. This review describes the use of various stem cells, biomaterials and the impact of nanotechnology in regenerative medicine.

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