scholarly journals Embossed Membranes with Vascular Patterns Guide Vascularization in a 3D Tissue Model

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 792 ◽  
Author(s):  
Soyoung Hong ◽  
Eun Young Kang ◽  
Jaehee Byeon ◽  
Sung-ho Jung ◽  
Changmo Hwang
Keyword(s):  
Blood Vessel ◽  
Three Dimensional ◽  
Vascular Endothelial ◽  
Electrospun Membrane ◽  
Tissue Constructs ◽  
Vacuum Forming ◽  
Electrospun Membranes ◽  
Vascular Structures ◽  
Endothelial Growth Factor ◽  
Flat Membranes

The vascularization of three-dimensional (3D) tissue constructs is necessary for transporting nutrients and oxygen to the component cells. In this study, a vacuum forming method was applied to emboss a vascular pattern on an electrospun membrane so that guided vascular structures could develop within the construct. Two- or six-layer constructs of electrospun membranes seeded with endothelial cells and pericytes were stacked and subcutaneously implanted into mice. Blood vessel formation in the implanted constructs with six alternating layers of flat membranes and membranes embossed with a blood vessel pattern was observed after two weeks of implantation. The formation of blood vessels was observed along the embossed blood vessel pattern in the structure of the embossed membrane laminated at four weeks and eight weeks. Vascular endothelial growth factor (VEGF) and angiopoietin 1 (Ang-1) were highly expressed in the vascularized structures. Therefore, we demonstrated that a structure capable of producing a desired blood vessel shape with electrospun membranes embossed with a blood vessel pattern can be manufactured, and that a variety of structures can be manufactured using electrospun membranes in the tissue engineering era.

Early changes in coronary artery wall structure detected by microcomputed tomography in experimental hypercholesterolemia

2007 ◽  
Vol 293 (3) ◽  
pp. H1997-H2003 ◽  
Author(s):  
Xiang-Yang Zhu ◽  
Michael D. Bentley ◽  
Alejandro R. Chade ◽  
Erik L. Ritman ◽  
Amir Lerman ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Coronary Artery ◽  
Growth Factor ◽  
Three Dimensional ◽  
Wall Structure ◽  
Vascular Endothelial ◽  
Micro Ct ◽  
Artery Wall ◽  
Coronary Artery Wall ◽  
Endothelial Growth Factor

Changes in the structure of the artery wall commence shortly after exposure to cardiovascular risk factors, such as hypercholesterolemia (HC), but may be difficult to detect. The ability to study vascular wall structure could be helpful in evaluation of the factors that instigate atherosclerosis and its pathomechanisms. The present study tested the hypothesis that early morphological changes in coronary arteries of hypercholesterolemic (HC) pigs can be detected using the novel X-ray contrast agent OsO4 and three-dimensional micro-computed tomography (CT). Two groups of pigs were studied after they were fed a normal or an HC (2% cholesterol) diet for 12 wk. Hearts were harvested, coronary arteries were injected with 1% OsO4 solution, and cardiac samples (6-μm-thick) were scanned by micro-CT. Layers of the epicardial coronary artery wall, early lesions, and perivascular OsO4 accumulation were determined. Leakage of OsO4 from myocardial microvessels was used to assess vascular permeability, which was correlated with immunoreactivity of vascular endothelial growth factor in corresponding histological cross sections. OsO4 enhanced the visualization of coronary artery wall layers and facilitated detection of early lesions in HC in longitudinal tomographic sections of vascular segments. Increased density of perivascular OsO4 in HC was correlated with increased vascular endothelial growth factor expression and suggested increased microvascular permeability. The use of OsO4 as a contrast agent in micro-CT allows three-dimensional visualization of coronary artery wall structure, early lesion formation, and changes in vascular permeability. Therefore, this technique can be a useful tool in atherosclerosis research.

390 Characterisation of a Platelet Rich Fibrin Membrane and Formation of an Autologous Fibrin Mesh

2021 ◽  
Vol 108 (Supplement_6) ◽  
Author(s):  
Joshua Burke ◽  
Jack Helliwell ◽  
Mikolaj Kowal ◽  
David Jayne
Keyword(s):  
Three Dimensional ◽  
Clinical Results ◽  
Vascular Endothelial ◽  
Blood Draw ◽  
Platelet Rich Fibrin ◽  
Fibrin Scaffold ◽  
Surgical Sutures ◽  
Endothelial Growth Factor ◽  
Range Of Values ◽  
Fibrin Membrane

Abstract Aim Platelet-rich fibrin (PRF) is a three-dimensional fibrin scaffold with associated platelets and leukocytes which releases high quantities of growth factors over a sustained period of time. PRF has shown promising clinical results in promoting wound healing and tissue regeneration. The aims of this feasibility study were to establish optimal spinning methods for production of PRF, to quantify the production of vascular endothelial growth factor (VEGF) by PRF and to explore new vehicles of clinical PRF delivery. Method Assessment of optimal production involved comparisons between Protocol 1 (EDTA bottle) and Protocol 2 (no additive) at three different centrifugation forces: 400g, 1000g and 1700g. VEGF production was analysed using ELISA with varied incubation periods and PRF plug segments. Novel methods for PRF delivery were explored using surgical sutures and a Zimmer® Skin Graft Mesher. Results Protocol 2 demonstrated shorter average time to blood draw (9.8s compared to 13.6s) and to centrifuge (25.5s compared to 33.1s) with a decreased range of values. All PRF segments exhibited a positive correlation between incubation time and amount of VEGF produced with the bottom segments producing on average more VEGF. A segment of the fibrin plug was successfully secured on a suture and meshed in a 1:1.5 ratio. Conclusions PRF production can be optimised using blood bottles with no additive and high centrifugation forces. VEGF production by PRF peaks at 120 hours with the bottom PRF segment exhibiting the highest rate of production. The first description of a PRF mesh enables new clinical applications.

Taming of the wild vessel: promoting vessel stabilization for safe therapeutic angiogenesis

2011 ◽  
Vol 39 (6) ◽  
pp. 1654-1658 ◽  
Author(s):  
Silvia Reginato ◽  
Roberto Gianni-Barrera ◽  
Andrea Banfi
Keyword(s):  
Current Knowledge ◽  
Single Gene ◽  
Therapeutic Angiogenesis ◽  
Maturation Stage ◽  
Vascular Endothelial ◽  
Cellular Regulation ◽  
Vessel Growth ◽  
Vascular Structures ◽  
Endothelial Growth Factor ◽  
Vascular Maturation

VEGF (vascular endothelial growth factor) is the master regulator of blood vessel growth. However, it displayed substantial limitations when delivered as a single gene to restore blood flow in ischaemic conditions. Indeed, uncontrolled VEGF expression can easily induce aberrant vascular structures, and short-term expression leads to unstable vessels. Targeting the second stage of the angiogenic process, i.e. vascular maturation, is an attractive strategy to induce stable and functional vessels for therapeutic angiogenesis. The present review discusses the limitations of VEGF-based gene therapy, briefly summarizes the current knowledge of the molecular and cellular regulation of vascular maturation, and describes recent pre-clinical evidence on how the maturation stage could be targeted to achieve therapeutic angiogenesis.

Interaction between vascular endothelial cells and vascular intimal spindle-shaped cells in vitro

1983 ◽  
Vol 60 (1) ◽  
pp. 89-102
Author(s):  
D de Bono ◽  
C. Green
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Three Dimensional ◽  
Vascular Endothelial ◽  
Pure Cultures ◽  
Species Specific ◽  
Endothelial Growth Factor

The interactions between human or bovine vascular endothelial cells and fibroblast-like vascular intimal spindle-shaped cells have been studied in vitro, using species-specific antibodies to identify the different components in mixed cultures. Pure cultures of endothelial cells grow as uniform, nonoverlapping monolayers, but this growth pattern is lost after the addition of spindle cells, probably because the extracellular matrix secreted by the latter causes the endothelial cells to modify the way they are attached to the substrate. The result is a network of tubular aggregates of endothelial cells in a three-dimensional ‘polylayer’ of spindle-shaped cells. On the other hand, endothelial cells added to growth-inhibited cultures of spindle-shaped cells will grow in sheets over the surface of the culture. Human endothelial cells grown in contact with spindle-shaped cells have a reduced requirement for a brain-derived endothelial growth factor. The interactions of endothelial cells and other connective tissue cells in vitro may be relevant to the mechanisms of endothelial growth and blood vessel formation in vivo, and emphasize the potential importance of extracellular matrix in controlling endothelial cell behaviour.

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