scholarly journals Engineering the Composition of Microfibers to Enhance the Remodeling of a Cell-Free Vascular Graft

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1613
Author(s):  
Fang Huang ◽  
Yu-Fang Hsieh ◽  
Xuefeng Qiu ◽  
Shyam Patel ◽  
Song Li
Keyword(s):  
Vascular Graft ◽  
Animal Studies ◽  
Vascular Grafts ◽  
Cell Infiltration ◽  
Tubular Scaffold ◽  
Base Polymer ◽  
A Cell ◽  
Scaffold Materials ◽  
Stromal Cell Derived Factor ◽  
Technology Blending

The remodeling of vascular grafts is critical for blood vessel regeneration. However, most scaffold materials have limited cell infiltration. In this study, we designed and fabricated a scaffold that incorporates a fast-degrading polymer polydioxanone (PDO) into the microfibrous structure by means of electrospinning technology. Blending PDO with base polymer decreases the density of electrospun microfibers yet did not compromise the mechanical and structural properties of the scaffold, and effectively enhanced cell infiltration. We then used this technique to fabricate a tubular scaffold with heparin conjugated to the surface to suppress thrombosis, and the construct was implanted into the carotid artery as a vascular graft in animal studies. This graft significantly promoted cell infiltration, and the biochemical cues such as immobilized stromal cell-derived factor-1α further enhanced cell recruitment and the long-term patency of the grafts. This work provides an approach to optimize the microfeatures of vascular grafts, and will have broad applications in scaffold design and fabrication for regenerative engineering.

Development of a Compliant Electrospun Polyurethane Vascular Graft

2010 ◽  
Author(s):  
Andrew Whitton ◽  
David J. Flint ◽  
Richard A. Black
Keyword(s):  
Vascular Graft ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Immunofluorescence Analysis ◽  
Aortic Smooth Muscle ◽  
Contractile Phenotype ◽  
A Cell ◽  
Substitute Material ◽  
Cells Cultured

Synthetic vascular grafts are an integral tool in vascular surgery. However, the consistent failure of small diameter grafts is one of the main limitations of these devices. For this reason electrospun polyurethane has been investigated for its suitability as a vascular substitute material in this present study. Aligned and random mesh electrospun polyurethane materials were produced and analysed in vitro by investigating the effect of using both materials as a substrate for the culture of human aortic smooth muscle cells. Immunofluorescence analysis showed that cells cultured on electrospun polyurethane maintained a contractile phenotype to a much greater extent than those cultured on cast polyurethane membranes. This contractile phenotype is associated with the state in which a cell would normally reside in a healthy vessel, suggesting that electrospun polyurethane may provide a suitable vascular substitute material.

scholarly journals Achieving Informed Consent for Cellular Therapies: A Preclinical Translational Research Perspective on Regulations versus a Dose of Reality

2016 ◽  
Vol 44 (3) ◽  
pp. 394-401 ◽  
Author(s):  
Aileen J. Anderson ◽  
Brian J. Cummings
Keyword(s):  
Informed Consent ◽  
Animal Studies ◽  
Research Participant ◽  
Research Subject ◽  
Cellular Therapies ◽  
Research Perspective ◽  
Pharmaceutical Agent ◽  
A Cell ◽  
The Subject ◽  
Novel Therapeutic Strategies

A central principle of bioethics is “subject autonomy,” the acknowledgement of the primacy of the informed consent of the subject of research. Autonomy requires informed consent — the assurance that the research participant is informed about the possible risks and benefits of the research. In fact, informed consent is difficult when a single drug is being tested, although subjects have a baseline understanding of the testing of a pharmacological agent and the understanding that they can stop taking the drug if there were an adverse event. However, informed consent is even less easily achieved in the modern arena of complex new molecular and cellular therapies. In this article, we argue that as science confronts new issues such as transplantation of stem cell products, which may live within the participant for the rest of their lives, researchers must carefully consider and constantly re-examine how they properly inform subjects considering participation trials of these novel therapeutic strategies.For example, the manufacture of a vial of a cell product that consists of a collection of growing cells is very different than the production of a vial of identical pills, which can be presumed to be identical. The scientific concepts on which these cellular approaches are based may seem alien and incomprehensible to a research subject, who thinks of a clinical trial as simply the selection and testing of the most efficacious pharmaceutical agent already proven to work in preclinical animal studies. The research subject would be wrong.

Preparation of Electrospun Poly(ε-caprolactone)/Poly(trimethylene carbonate) Blend Scaffold for In Situ Vascular Tissue Engineering

2012 ◽  
Vol 629 ◽  
pp. 60-63
Author(s):  
Tao Jiang ◽  
Guo Quan Zhang ◽  
Hui Li ◽  
Ji Na Xun
Keyword(s):  
Tissue Engineering ◽  
Vascular Graft ◽  
Vascular Tissue ◽  
Electrospinning Process ◽  
Vascular Tissue Engineering ◽  
Trimethylene Carbonate ◽  
Scaffold Materials ◽  
Degradation Time

In the active field of vascular graft research, in situ vascular tissue engineering is a novel concept. This approach aims to use biodegradable synthetic materials. After implantation, the synthetic material progressively degrades and should be replaced by autologous cells. Poly (ε-caprolactone) (PCL) is often used for vascular graft because of its good mechanical strength and its biocompatibility. It is easily processed into micro and nano-fibers by electrospinning to form a porous, cell-friendly scaffold. However, the degradation time of polycaprolactone is too long to match the tissue regeneration time. In this study, poly (ε-caprolactone) /poly (trimethylene carbonate) (PTMC) blend scaffold materials have been prepared for biodegradable vascular graft using an electrospinning process. Because the degradation time of PTMC is shorter than PCL in vivo. The morphological characters of PCL/PTMC blend scaffold materials were investigated by scanning electron microscope (SEM). The molecular components and some physical characteristics of the blend scaffold materials were tested by FT-IR and DSC analysis.

Electrospun poly(l-lactide-co-caprolactone)–collagen–chitosan vascular graft in a canine femoral artery model

2015 ◽  
Vol 3 (28) ◽  
pp. 5760-5768 ◽  
Author(s):  
Tong Wu ◽  
Bojie Jiang ◽  
Yuanfei Wang ◽  
Anlin Yin ◽  
Chen Huang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tissue Regeneration ◽  
Femoral Artery ◽  
Vascular Graft ◽  
Patency Rate ◽  
Vascular Grafts ◽  
Enhance Gene Expression

(P(LLA-CL)–COL–CS) composite vascular grafts could effectively improve patency rate, promote tissue regeneration, and enhance gene expression.

BIOSPUN VASCULAR GRAFTS: IN VIVO EVALUATION OF A NOVEL SMALL‐DIAMETER BIOACTIVE NANOFIBROUS VASCULAR GRAFT FOR ARTERIAL RECONSTRUCTION

2008 ◽  
Vol 22 (S2) ◽  
pp. 605-605
Author(s):  
Mauricio Antonio Contreras ◽  
Mathew Douglas Phaneuf ◽  
Shengqian Wu ◽  
Martin J. Bide ◽  
Frank W. LoGerfo
Keyword(s):  
Vascular Graft ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Arterial Reconstruction ◽  
In Vivo Evaluation

The post-morphological analysis of electrospun vascular grafts following mechanical testing

2018 ◽  
Vol 38 (6) ◽  
pp. 525-535 ◽  
Author(s):  
Ipek Yalcin Enis ◽  
Telem Gok Sadikoglu ◽  
Jana Horakova ◽  
David Lukas
Keyword(s):  
Mechanical Properties ◽  
Cardiovascular Diseases ◽  
Production Technology ◽  
Vascular Graft ◽  
Morphological Analysis ◽  
Vascular Grafts ◽  
Single Layer ◽  
Composite Effect ◽  
Polymer Type ◽  
Morphology And Mechanical Properties

AbstractVascular grafts provide promising scaffolds for patients recuperating from cardiovascular diseases. Since it is necessary to mimic the native vessel in order to overcome the limitations of currently employed synthetic prostheses, researchers are tending to focus on the design of electrospun biodegradable multi-layer scaffolds which involves varying either the polymer type or constructional properties in each layer which, in turn, reveals the importance of layer interactions and their composite effect on the final multi-layer graft. This study describes the fabrication of biodegradable single-layer tubular scaffolds from polycaprolactone and poly(L-lactide)caprolactone polymers composed of either randomly distributed or, preferably, radially oriented fibers. Subsequently, bi-layer scaffolds were fabricated with a randomly distributed inner layer and a radially oriented outer layer from various polymer couple variations. The study focuses on vascular graft production technology including its morphology and mechanical properties. The post-morphologies of single-layer and bi-layer tubular scaffolds designed for vascular grafts were investigated as a continuation of a previously performed analysis of their mechanical properties. The results indicate that the mechanical properties of the final bi-layer grafts were principally influenced by the radially oriented outer layers acting as thetunica mediaof the native vessels when the appropriate polymer couples were chosen for the sub-layers.

scholarly journals Current Advance and Future Prospects of Tissue Engineering Approach to Dentin/Pulp Regenerative Therapy

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Ting Gong ◽  
Boon Chin Heng ◽  
Edward Chin Man Lo ◽  
Chengfei Zhang
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Animal Studies ◽  
Banking System ◽  
Engineering Technology ◽  
Potential Health ◽  
Regenerative Endodontics ◽  
Immunological Rejection ◽  
Canal Systems ◽  
Scaffold Materials

Recent advances in biomaterial science and tissue engineering technology have greatly spurred the development of regenerative endodontics. This has led to a paradigm shift in endodontic treatment from simply filling the root canal systems with biologically inert materials to restoring the infected dental pulp with functional replacement tissues. Currently, cell transplantation has gained increasing attention as a scientifically valid method for dentin-pulp complex regeneration. This multidisciplinary approach which involves the interplay of three key elements of tissue engineering—stem cells, scaffolds, and signaling molecules—has produced an impressive number of favorable outcomes in preclinical animal studies. Nevertheless, many practical hurdles need to be overcome prior to its application in clinical settings. Apart from the potential health risks of immunological rejection and pathogenic transmission, the lack of a well-established banking system for the isolation and storage of dental-derived stem cells is the most pressing issue that awaits resolution and the properties of supportive scaffold materials vary across different studies and remain inconsistent. This review critically examines the classic triad of tissue engineering utilized in current regenerative endodontics and summarizes the possible techniques developed for dentin/pulp regeneration.

scholarly journals The Usefulness of Biosynthetic Vascular Graft Omniflow II and Autologous Veins for the Treatment of Massive Infection of Dacron Vascular Graft with Enterococcus faecalis HLAR

2016 ◽  
Vol 65 (4) ◽  
pp. 471-474 ◽  
Author(s):  
Witold Woźniak ◽  
Robert Bajno ◽  
Michał Świder ◽  
Piotr Ciostek
Keyword(s):  
Vascular Surgery ◽  
Enterococcus Faecalis ◽  
Vascular Graft ◽  
Vascular Grafts ◽  
Risk Of Infection ◽  
Omniflow Ii ◽  
Observation Period

Infections of vascular grafts are the most severe complications in vascular surgery. We present the case of a 73-year-old male with infection of a dacron prosthesis with a strain of Enterococcus faecalis. The patient was treated with replacement of a full prosthesis with a combined graft constructed from Biosynthetic Vascular graft Omniflow and autologous veins. This graft is recommended for implantation in patients with a higher risk of infection. Our case is one of the first reported usage of this kind of graft in the aortic region and in a 2 years observation period no recurrence of infection was observed.

The Effect of Antithrombin III-Independent Thrombin Inhibitors and Heparin on Fibrin Accretion onto Fibrin-Coated Polyethylene

1993 ◽  
Vol 69 (02) ◽  
pp. 130-134 ◽  
Author(s):  
F D Rubens ◽  
J I Weitz ◽  
J L Brash ◽  
R L Kinlough-Rathbone
Keyword(s):  
Vascular Graft ◽  
Antithrombin Iii ◽  
Vascular Grafts ◽  
Barium Chloride ◽  
Thrombin Inhibitors ◽  
Thrombin Inhibitor ◽  
Recombinant Hirudin ◽  
Graft Thrombosis ◽  
Polyethylene Tubing

SummaryProsthetic vascular grafts become coated with a layer of fibrin that contributes to graft thrombosis and occlusion. We compared the effect of antithrombin III-independent inhibitors of thrombin with heparin for their ability to prevent fibrin accretion onto a model of a vascular graft formed in vitro by coating polyethylene tubing with thrombin bound to a layer of polymerized fibrin. Equivalent antithrombin concentrations of heparin, D-Phe-Pro-Arg CH2Cl (PPACK), recombinant hirudin (r-hirudin), and Hirulog-1 were added to barium chloride-adsorbed plasma containing radiolabelled fibrinogen. Whereas, PPACK and r-hirudin persistently inhibited fibrin accretion, the inhibition by heparin was transient. Hirulog-1 had no effect on early fibrin accretion and was actually associated with enhanced accretion at 30 min (control 11.7 ± 2.0 μg fibrin/cm2; Hirulog-1, 18.4 ± 3.5 μg fibrin/cm2, p <0.001). Both Hirulog-1 and r-hirudin displaced radiolabelled thrombin from the fibrin surface. Whereas hirudin-thrombin complexes are stable, Hirulog-1 produces only transient inhibition of the displaced thrombin thereby accounting for the enhanced fibrin accretion with this anticoagulant. These studies show that the antithrombin III-independent inhibitors, r-hirudin and PPACK, are more effective inhibitors of fibrin accretion onto fibrin-coated polyethylene than heparin or Hirulog-1. In addition, they emphasize the importance of determining the ability of anticoagulants to displace thrombin from fibrin and to form stable thrombin-inhibitor complexes; lack of stability of thrombin-inhibitor complexes must be countered by levels of anticoagulant that are adequate to maintain its effectiveness.

Sign in / Sign up

Export Citation Format

Share Document