scholarly journals A Novel Biodegradable Multilayered Bioengineered Vascular Construct with a Curved Structure and Multi-Branches

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 275 ◽  
Author(s):  
Yuanyuan Liu ◽  
Yi Zhang ◽  
Weijian Jiang ◽  
Yan Peng ◽  
Jun Luo ◽  
...  
Keyword(s):  
Umbilical Vein ◽  
Structural Parameters ◽  
Vascular Grafts ◽  
Cardiovascular Research ◽  
Structure Interaction ◽  
Blood Flows ◽  
3D Printed ◽  
Umbilical Vein Endothelial Cells ◽  
Inner Channel ◽  
Curved Structure

Constructing tissue engineered vascular grafts (TEVG) is of great significance for cardiovascular research. However, most of the fabrication techniques are unable to construct TEVG with a bifurcated and curved structure. This paper presents multilayered biodegradable TEVGs with a curved structure and multi-branches. The technique combined 3D printed molds and casting hydrogel and sacrificial material to create vessel-mimicking constructs with customizable structural parameters. Compared with other fabrication methods, the proposed technique can create more native-like 3D geometries. The diameter and wall thickness of the fabricated constructs can be independently controlled, providing a feasible approach for TEVG construction. Enzymatically-crosslinked gelatin was used as the material of the constructs. The mechanical properties and thermostability of the constructs were evaluated. Fluid-structure interaction simulations were conducted to examine the displacement of the construct’s wall when blood flows through it. Human umbilical vein endothelial cells (HUVECs) were seeded on the inner channel of the constructs and cultured for 72 h. The cell morphology was assessed. The results showed that the proposed technique had good application potentials, and will hopefully provide a novel technological approach for constructing integrated vasculature for tissue engineering.

scholarly journals Bioprinting small-diameter vascular vessel with endothelium and smooth muscle by the approach of two-step crosslinking process

2021 ◽  
Author(s):  
Qianheng Jin ◽  
Guangzhe Jin ◽  
Jihui Ju ◽  
Lei Xu ◽  
Linfeng Tang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Uv Light ◽  
Umbilical Vein ◽  
Vascular Grafts ◽  
Three Dimensional ◽  
Small Diameter ◽  
Tubular Structure ◽  
Flat Structure ◽  
Crosslinking Process ◽  
Umbilical Vein Endothelial Cells

Three-dimensional (3D) bioprinting shows great potential for autologous vascular grafts due to its simplicity, accuracy, and flexibility. 6mm diameter vascular grafts are used in clinic. However, producing small-diameter vascular grafts are still an enormous challenge. Normally, sacrificial hydrogels are used as temporary lumen support to mold tubular structure which will affect the structure’s stability. In this study, we develop a new bioprinting approach to fabricating small-diameter vessel using two-step crosslinking process. ¼ lumen wall of bioprinted gelatin mechacrylate (GelMA) flat structure is exposed to ultraviolet (UV) light briefly for having certain strength, while ¾ lumen wall shows as concave structure remained uncrosslinked. Pre-crosslinked flat structure is merged towards the uncrosslinked concave structure. Two individual structures will be combined tightly into an intact tubular structure by receiving more UV exposure time. Complicated tubular structures are constructed by these method. Notably, the GelMA-based bioink loaded with smooth muscle cells (SMCs) are bioprinted as the outer layer and human umbilical vein endothelial cells (HUVECs) are seeded onto the inner surface. A bionic vascular vessel with dual layers is fabricated successfully and keeps good viability, and functionality. This study may provide a novel idea for fabricating biomimetic vascular network or other more complicated organs.

Abstract 9487: Implantation of Scaffold-Free Tubular Tissue Using a Bio-3D Printer Augments Vascular Remodeling and Endothelialization

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Manabu Itoh ◽  
Koichi Nakayama ◽  
Ryo Noguchi ◽  
Keiji Kamohara ◽  
Kojirou Furukawa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Vascular Grafts ◽  
Three Dimensional ◽  
Dermal Fibroblasts ◽  
3D Printer ◽  
Multicellular Spheroids ◽  
Biological Features ◽  
Normal Human ◽  
Umbilical Vein Endothelial Cells

Introduction: Small caliber synthetic vascular grafts are not clinically available. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a “Bio-3D printer”-based system, which enables the creation of various three-dimensional structures pre-designed using a computer system. With this system, we created a tubular structure (Fig. 1), and studied its biological features. Methods: We made 1.5 mm in diameter scaffold-free tubular tissues from MCS (1.25 x 10[[Unable to Display Character: ⁷]] cells) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%) and normal human dermal fibroblasts (50%) using a Bio-3D printer. The vessels were cultured in a perfusion system. We implanted grafts into the abdominal aortas of F344 nude rats, and assessed the flow by ultrasonography and performed histological examinations on the second (N=5) and fifth (N=5) days after implantation. Results: All grafts were patent. Remodeling of the vessel (enlargement of the lumen area and thinning of the wall) was observed (Fig. 2). A layer of endothelial cells was developed after implantation of the graft (Fig. 3). Conclusions: The scaffold-free vascular grafts made of MCS using a Bio-3D printer showed biological features comparable to native vessels. Further studies are warranted toward the clinical application of this novel technology.

Designing Biomimetic Triple-Layered Nanofibrous Vascular Grafts via Combinatorial Electrospinning Approach

2020 ◽  
Vol 20 (10) ◽  
pp. 6396-6405 ◽  
Author(s):  
Chuang Wu ◽  
Haiguang Zhang ◽  
Qingxi Hu ◽  
Murugan Ramalingam
Keyword(s):  
Glycolic Acid ◽  
Umbilical Vein ◽  
Vascular Grafts ◽  
Structure And Function ◽  
Vascular Structure ◽  
Cardiovascular Tissue ◽  
Tubular Scaffold ◽  
Layered Nanostructures ◽  
Umbilical Vein Endothelial Cells ◽  
And Function

Biomimetic vascular grafts with multi-layered nanostructures can mimic structure and function of native blood vessels, but it is often challenging. This study demonstrates the feasibility of using combinatorial electrospinning approach for designing triple-layered nanofibrous tubular scaffold with inner and outer layer made up of co-axial poly(lactic-co-glycolic acid) (PLGA)/gelatin nanofibers (PLGA-core/gelatin-shell) and the intermediate layer with PLGA nanofibers that mimics native vascular structure. The assessment of biomechanical and biological analysis showed enhanced mechanical strength, suture strength and biocompatibility when cultured with human umbilical vein endothelial cells (HUVECs). Altogether, the results suggest that the combinatorial electrospinning approach is potentially useful for the fabrication of biomimetic vascular grafts suitable for cardiovascular tissue engineering applications.

Endothelialization of Crosslinked Albumin-heparin Gels

1999 ◽  
Vol 82 (12) ◽  
pp. 1757-1763 ◽  
Author(s):  
Gert Bos ◽  
Nicole Scharenborg ◽  
André Poot ◽  
Gerard Engbers ◽  
Tom Beugeling ◽  
...  
Keyword(s):  
Culture Medium ◽  
Umbilical Vein ◽  
Vascular Grafts ◽  
Cellular Interactions ◽  
Gel Growth ◽  
Endothelial Cell Seeding ◽  
Stationary Conditions ◽  
Umbilical Vein Endothelial Cells ◽  
In Vitro Stability

SummaryCrosslinked gels of albumin as well as heparinized albumin gels, potential sealants of prosthetic vascular grafts, were studied with regard to in vitro stability, binding of basic fibroblast growth factor (bFGF) and cellular interactions. A small percentage of the heparin present in these gels, was released during storage in SDS solution. During storage in cell culture medium at 37° C, heparin release was 21-25 percent. Release of albumin did not occur.Human umbilical vein endothelial cells (HUVECs) rapidly adhered and subsequently spread on (heparinized) albumin gels, but proliferation was only observed if heparin was present in the gel.Binding of 125I-bFGF to heparinized albumin gel was 35 percent higher than to non-heparinized albumin gel. Growth of HUVECs occurred only on heparinized albumin gel loaded with bFGF and not on bFGF-loaded albumin gel.The number of platelets deposited under stationary conditions onto heparinized albumin gel was about twice the number found on nonheparinized albumin gel. Seeding of HUVECs on heparinized albumin gel, significantly reduced the number of platelets adhering to this surface. Moreover, no spreading of platelets was observed on substrates seeded with HUVECs.It can be concluded that crosslinked gels of albumin to which heparin is immobilized, are candidate sealants for prosthetic vascular grafts and suitable substrates for endothelial cell seeding.

Evaluation of human umbilical vein endothelial cells growth onto heparin-modified electrospun vascular grafts

2021 ◽  
Author(s):  
Pablo C. Caracciolo ◽  
Patricia Diaz-Rodriguez ◽  
Inés Ardao ◽  
David Moreira ◽  
Florencia Montini-Ballarin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Vascular Grafts ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

scholarly journals Porous Bilayer Vascular Grafts Fabricated from Electrospinning of the Recombinant Human Collagen (RHC) Peptide-Based Blend

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4042
Author(s):  
Thi My Do ◽  
Yang Yang ◽  
Aipeng Deng
Keyword(s):  
Outer Layer ◽  
Mechanical Test ◽  
Umbilical Vein ◽  
Vascular Grafts ◽  
Water Soluble ◽  
Causes Of Mortality ◽  
Human Collagen ◽  
Nanoscale Fibers ◽  
Umbilical Vein Endothelial Cells

Cardiovascular diseases, including coronary artery and peripheral vascular pathologies, are leading causes of mortality. As an alternative to autografts, prosthetic grafts have been developed to reduce the death rate. This study presents the development and characterization of bilayer vascular grafts with appropriate structural and biocompatibility properties. A polymer blend of recombinant human collagen (RHC) peptides and polycaprolactone (PCL) was used to build the inner layer of the graft by electrospinning and co-electrospinning the water-soluble polyethylene oxide (PEO) as sacrificial material together with PCL to generate the porous outer layer. The mechanical test demonstrated the bilayer scaffold’s appropriate mechanical properties as compared with the native vascular structure. Human umbilical vein endothelial cells (HUVEC) showed enhanced adhesion to the lumen after seeding on nanoscale fibers. Meanwhile, by enhancing the porosity of the microfibrous outer layer through the removal of PEO fibers, rat smooth muscle cells (A7r5) could proliferate and infiltrate the porous layer easily.

Ultrastructural observations on the in vitro cytoadherence of Plasmodium falciparum infected red blood cells

1990 ◽  
Vol 48 (3) ◽  
pp. 914-915
Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Umbilical Vein ◽  
Cell Types ◽  
Amelanotic Melanoma ◽  
Cytoplasmic Process ◽  
Umbilical Vein Endothelial Cells

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).

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