Surface anticoagulation of mechanical heart valves using electrically induced biomimetic glycocalyx: An in-vitro study to assess hemocompatibility and optimal voltage

Figures

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  Fig 1. The experimental setup for testing the antithrombotic effect and hemocompatibility of electrically activated prosthetic valve. A-Electrical connectivity of the prosthetic valve to the pacemaker with a lead electrode. B-Expanded view of prosthetic valve-lead junction. C-Prosthetic valve with lead was placed in a 50 ml polystyrene test tube for exposure to blood/PRP, while the pacemaker was placed outside the test tube, in a plastic container (shown in D). D-Experimental session with blood/PRP exposure to the valve in an environ shaker and an incubator at 35 ± 2 °C for 30 min.**.

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  Fig 2. The effect of prosthetic valve voltage on in vitro testing with PRP. % change from initial to 30-minutes of immersion of the prosthetic valve is shown in the plot. PTT: Partial thromboplastin time, C3a: Activated complement C3. The height of the bar (numerical value displayed above the bar) for control (0 V) corresponds to the average of the two control valve measurements (Tables 2–3), while it depicts the individual valve values for 0.25 and 0.5 V.**.

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  Fig 3. The effect of prosthetic valve voltage on in vitro testing with Whole blood. % change from initial to 30 minutes of immersion of the prosthetic valve is shown in the plot. The height of the bars (numerical value displayed above the bar) for control (0 V) and 0.25 V corresponds to the average of two replicate measurements (Tables 4–5), while it depicts the individual values for valve at 0.5 V. PTT: Partial thromboplastin time, C3a: Activated complement C3, Hb: Hemoglobin, PF4: Platelet factor 4. **.

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  Fig 4. SEM images of the test valve at 0.25 V and immersed in PRP. The scanning parameters of the images A, B, C are – A: Mag = 2700 × , WD = 13.1 mm; B: Mag = 5000 × , WD = 13.1 mm; C: Mag = 3000 × , WD = 13.4 mm. Mag = Magnification, WD = working distance.**.

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  Fig 5. SEM images of the test valve at 0.5 V and immersed in PRP. The scanning parameters of the images A, B, C are – A: Mag = 1800 × , WD = 12.4 mm; B: Mag = 2500 × , WD = 12.4 mm; C: Mag = 5000 × , WD = 13.7 mm. Mag = Magnification, WD = working distance.**.

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  Fig 6. SEM images of the control valve (0 V) and immersed in PRP. A, B, C images were taken at multiple sites on the valve with different scanning parameters described as follows – A: Mag = 700 × , WD = 12.5 mm; B: Mag = 2500 × , WD = 12.9 mm; C: Mag = 5000 × , WD = 12.5 mm. Mag = Magnification, WD = working distance**.

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  Fig 7. SEM images of the reference valve that is not exposed to blood/PRP. A, B, C images were taken at multiple sites on the valve with different scanning parameters described as follows – A: Mag = 500 × , WD = 10.7 mm, aV = 10 kV; B: Mag = 2500 × , WD = 10.7 mm, aV = 10 kV; C: Mag = 10000 × , WD = 9.9 mm, aV = 5 kV. Mag = Magnification, WD = working distance, aV = acceleration voltage, kV = kilovolts. Except for sputter coating artifacts, the valve is free from cellular or proteinaceous deposits, as it is not exposed to blood or PRP**.

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  Fig 8. A schematic representation of the intended clinical deployment of the electrically activated prosthetic valve, including the pacemaker-electrical connectivity. A- Prosthetic mechanical heart valve. B- Valve-lead junction. C-Lead electrode. D-Pacemaker.