Polycatecholamine and gentamicin as modifiers for antibacterial and blood-biocompatible polyester vascular prostheses

Endothelial cell (EC) seeding is postulated as a mechanism of improving patency in small caliber vascular grafts. However the majority of seeded EC are lost within 24 hours of restoration of blood flow in previous canine studies . We postulate that the cells have insufficient time to fully develop their attachment to the graft surface prior to exposure to hemodynamic stress. We allowed EC to incubate on fibronectin-coated ePTFE grafts for four different time periods after seeding and measured EC retention after perfusion in a canine ex vivo shunt circuit.Autologous canine EC, were enzymatically harvested, grown to confluence, and labeled with 30 μCi 111 Indium-oxine/80 cm 2 flask. Four groups of 5 cm x 4 mm ID ePTFE vascular prostheses were coated with 1.5 μg/cm.2 human fibronectin, and seeded with 1.5 x 105 EC/ cm.2. After seeding grafts in Group 1 were incubated in complete growth medium for 90 minutes, Group 2 were incubated for 24 hours, Group 3 for 72 hours and Group 4 for 6 days. Grafts were then placed in the canine ex vivo circuit, constructed between femoral artery and vein, and subjected to blood flow of 75 ml per minute for 6 hours. Continuous counting of γ-activity was made possible by placing the seeded graft inside the γ-counter detection crystal for the duration of perfusion. EC retention data after 30 minutes, 2 hours and 6 hours of flow are shown in the table.

Download Full-text

In vivo assessment of anti-CD34 coated ePTFE vascular prostheses

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0029-1246678 ◽

2010 ◽

Vol 58 (S 01) ◽

Cited By ~ 1

Author(s):

W Mrowczynski ◽

A Rungatscher ◽

F Buchegger ◽

JC Tille ◽

D Mugnai ◽

...

Keyword(s):

Vascular Prostheses ◽

In Vivo Assessment

Download Full-text

An in vitro rotation model composed of disposables for investigation of endothelialization of artificial vascular prostheses

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0031-1297843 ◽

2012 ◽

Vol 60 (S 01) ◽

Author(s):

M Lescan ◽

J Kobba ◽

M Avci-Adali ◽

B Neumann ◽

N Perle ◽

...

Keyword(s):

Vascular Prostheses ◽

Rotation Model

Download Full-text

Binding of Tissue Plasminogen Activator to Vascular Grafts

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646541 ◽

1989 ◽

Vol 61 (01) ◽

pp. 131-136 ◽

Cited By ~ 8

Author(s):

Richard A Harvey ◽

Hugh C Kim ◽

Jonathan Pincus ◽

Stanley Z Trooskin ◽

Josiah N Wilcox ◽

...

Keyword(s):

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Fibrinolytic Activity ◽

Polymer Surface ◽

Enzymic Activity ◽

Vascular Prostheses ◽

Chemically Modified ◽

Insoluble Surfactant ◽

Tissue Plasminogen

SummaryTissue plasminogen activator labeled with radioactive iodine (125I-tPA) was immobilized on vascular prostheses chemically modified with a thin coating of water-insoluble surfactant, tridodecylmethylammonium chloride (TDM AC). Surfactant- treated Dacron, polytetrafluoroethylene (PTFE), silastic, polyethylene and polyurethane bound appreciable amounts of 125I- tPA (5-30 μg 125I-tPA/cm2). Upon exposure to human plasma, the amount of 125I-tPA bound to the surface shows an initial drop during the first hour of incubation, followed by a slower, roughly exponential release with a t½ of appoximately 75 hours. Prostheses containing bound tPA show fibrinolytic activity as measured both by lysis of clots formed in vitro, and by hydrolysis of a synthetic polypeptide substrate. Prior to incubation in plasma, tPA bound to a polymer surface has an enzymic activity similar, if not identical to that of the native enzyme in buffered solution. However, exposure to plasma causes a decrease in the fibrinolytic activity of both bound tPA and enzyme released from the surface of the polymer. These data demonstrate that surfactant-treated prostheses can bind tPA, and that these chemically modified devices can act as a slow-release drug delivery system with the potential for reducing prosthesis-induced thromboembolism.

Download Full-text

Naturally Produced Extracellular Matrix Is an Excellent Substrate for Canine Endothelial Cell Proliferation and Resistance to Shear Stress on PTFE Vascular Grafts

Thrombosis and Haemostasis ◽

10.1055/s-0038-1665417 ◽

1997 ◽

Vol 78 (05) ◽

pp. 1392-1398 ◽

Cited By ~ 16

Author(s):

A Schneider ◽

M Chandra ◽

G Lazarovici ◽

I Vlodavsky ◽

G Merin ◽

...

Keyword(s):

Extracellular Matrix ◽

Endothelial Cells ◽

Shear Stress ◽

Endothelial Cell ◽

Cell Attachment ◽

Thrombus Formation ◽

Endothelial Cell Proliferation ◽

Ptfe Graft ◽

Vascular Prostheses ◽

Endothelial Cell Attachment

SummaryPurpose: Successful development of a vascular prosthesis lined with endothelial cells (EC) may depend on the ability of the attached cells to resist shear forces after implantation. The present study was designed to investigate EC detachment from extracellular matrix (ECM) precoated vascular prostheses, caused by shear stress in vitro and to test the performance of these grafts in vivo. Methods: Bovine aortic endothelial cells were seeded inside untreated polytetrafluoro-ethylene (PTFE) vascular graft (10 X 0.6 cm), PTFE graft precoated with fibronectin (FN), or PTFE precoated with FN and a naturally produced ECM (106 cells/graft). Sixteen hours after seeding the medium was replaced and unattached cells counted. The strength of endothelial cell attachment was evaluated by subjecting the grafts to a physiologic shear stress of 15 dynes/cm2 for 1 h. The detached cells were collected and quantitated. PTFE or EC preseeded ECM coated grafts were implanted in the common carotid arteries of dogs. Results: While little or no differences were found in the extent of endothelial cell attachment to the various grafts (79%, 87% and 94% of the cells attached to PTFE, FN precoated PTFE, or FN+ECM precoated PTFE, respectively), the number of cells retained after a shear stress was significanly increased on ECM coated PTFE (20%, 54% and 85% on PTFE, FN coated PTFE, and FN+ECM coated PTFE, respectively, p <0.01). Implantation experiments in dogs revealed a significant increase in EC coverage and a reduced incidence of thrombus formation on ECM coated grafts that were seeded with autologous saphenous vein endothelial cells prior to implantation. Conclusion: ECM coating significantly increased the strength of endothelial cell attachment to vascular prostheses subjected to shear stress. The presence of adhesive macromolecules and potent endothelial cell growth promoting factors may render the ECM a promising substrate for vascular prostheses.

Download Full-text

Development of a 3-step model to evaluate the intrinsic thrombogenicity of vascular prostheses

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-2008-1038081 ◽

2008 ◽

Vol 56 (S 1) ◽

Author(s):

M Wilhelmi ◽

KF Gratz ◽

R Mischke ◽

AM Pichlmaier ◽

O Teebken ◽

...

Keyword(s):

Vascular Prostheses ◽

Step Model

Download Full-text

Biodegradable small calibre polydioxanone-based vascular prostheses: Potential as coronary bypass grafts

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-2008-1037921 ◽

2008 ◽

Vol 56 (S 1) ◽

Author(s):

B Walpoth ◽

M Cikirikcioglu ◽

D Mugnai ◽

JC Tille ◽

E Pektok ◽

...

Keyword(s):

Coronary Bypass ◽

Bypass Grafts ◽

Vascular Prostheses ◽

Coronary Bypass Grafts

Download Full-text

Dilatation of Vascular Prostheses in Ascending Aortic Position: A Long-Term Follow-Up Computed Tomography Study with Comparison of Different Measurement Methods

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0036-1597116 ◽

2016 ◽

Vol 66 (03) ◽

pp. 206-214

Author(s):

Matthias Endlich ◽

Christian Krämer ◽

Chris Probst ◽

Armin Welz ◽

Kai Wilhelm ◽

...

Keyword(s):

Computed Tomography ◽

Measurement Methods ◽

Point Of View ◽

Cross Sectional ◽

Vascular Prostheses ◽

Aortic Replacement ◽

Ascending Aortic Replacement ◽

Long Term Follow Up ◽

Methods Of Measurement

Background The aim of this study was to evaluate long-term dilatation of Hemashield Gold and Hemashield Platinum vascular prostheses in ascending aortic position using different measurement methods to obtain precise results. Methods Between 1999 and 2007, 73 patients with Stanford type A dissection received ascending aortic replacement with Hemashield Gold and Hemashield Platinum prostheses. Measurements were performed using multiplanar reconstruction mode of electrocardiogram (ECG)-gated, multislice spiral computed tomography (MSCT) in strictly orthogonal cross-sectional planes. Different methods of measurement were compared and maximum dilatation was estimated for different time spans. Results Diameters calculated from the measured circumference showed a significant (p = 0.037) but clinically not relevant difference (0.1 mm) to the mean between the largest and the shortest cross-sectional diameter of the prosthesis. Dilatation after 24.2 ± 10.2 months was 8.5 ± 4.5%. Long-term dilatation after 91.8 ± 34 months amounted to 11.8 ± 4.2%. Conclusion Based on ECG-gated MSCT images, the presented methods of measurement provided reliable results. Long-term analysis shows low dilatation rates for Hemashield prostheses, which therefore can be considered as safe from this point of view. Nevertheless, a maximal dilatation of 20% could be relevant in valve sparing root replacement. It remains unclear if a dilatation like this contributes to the formation of suture aneurysms.

Download Full-text

The Influence of a Knitted Hydrophilic Prosthesis of Blood Vessels on the Activation of Coagulation System—In Vitro Study

Nanomaterials ◽

10.3390/nano11061600 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1600

Author(s):

Maria Szymonowicz ◽

Maciej Dobrzynski ◽

Sara Targonska ◽

Agnieszka Rusak ◽

Zbigniew Rybak ◽

...

Keyword(s):

Blood Vessels ◽

Initial Period ◽

In Vitro Study ◽

Vascular Prosthesis ◽

Coagulation System ◽

Factor Xii ◽

Scanning Calorimetry ◽

Vascular Prostheses ◽

Control Value

The replacement of affected blood vessels of the polymer material can cause imbalances in the blood haemostatic system. Changes in blood after the implantation of vascular grafts depend not only on the chemical composition but also on the degree of surface wettability. The Dallon® H unsealed hydrophilic knitted vascular prosthesis double velour was assessed at work and compare with hydrophobic vascular prosthesis Dallon®. Spectrophotometric studies were performed in the infrared and differential scanning calorimetry, which confirmed the effectiveness of the process of modifying vascular prostheses. Determination of the parameters of coagulation time of blood after contact in vitro with Dallon® H vascular prosthesis was also carried out. Prolongation of activated thromboplastin time, decreased activity of factor XII, IX and VIII, were observed. The prolonged thrombin and fibrinogen were reduced in the initial period of the experiment. The activity of plasminogen and antithrombin III and protein C were at the level of control value. The observed changes in the values of determined parameters blood coagulation do not exceed the range of referential values for those indexes. The observed changes are the result of considerable blood absorptiveness by the prosthesis of blood vessels and their sealing.

Download Full-text