Biocompatibility of Ventricular Assist Device materials

  • Gemma Radley (Discussant)

Activity: Talk or presentationOral presentationResearch


Aim: To evaluate the biocompatibility of materials used in ventricular assist devices (VADs) through their effect on cellular and protein behaviour. Results will be used to influence future designs. Methods: Highly polished discs of materials used in VAD designs – single-crystal sapphire (SAP), silicon nitride (SIN), zirconia toughened-alumina (ZTA) and titanium alloy (TI) - were suspended on polypropylene beads in petri dishes; beads only served as a negative control. Heparinised human blood was added to each dish and incubated at +37°C on a shaking plate. After 2h, the blood underwent cell count analysis and CD62L expression through flow cytometry. Similarly, sodium citrated blood was incubated for 1h with the discs; 4 mg/mL Kaolin solution serving as positive control. Blood was then analysed with flow cytometry for platelet-leukocyte aggregation, with platelet-poor plasma subjected to peptidase activity and clotting time assays. Results: Preliminary data shown as fold change from negative control. A decrease in leukocyte numbers (n = 7) was noted: 0.88±0.06 (SAP); 0.86±0.08 (SIN); 0.90±0.04 (TI); and 0.92±0.05 (ZTA). Activation detected as a decrease in CD62L expression occurred with silicon nitride (0.76-fold) but not with the other materials. Clotting time (n = 3) was reduced: 0.66±0.15 (SAP); 0.57±0.08 (SIN); and 0.54±0.10 (ZTA). Peptidase activity (n = 3) was increased: 4.43±1.95 (SAP); 4.47±1.77 (SIN); and 3.32±1.00 (ZTA). Platelet-leukocyte aggregates show SIN have the most monocyte-platelet aggregates (83.61%) and ZTA the fewest granulocyte-platelet aggregates (19.44%). Conclusions: Silicon nitride shows the highest decrease in leukocyte count, a decrease in CD62L, and the most monocyte-platelet aggregates suggesting activation and adhesion of the leukocytes to the disc. Thrombogenicity as determined through contact activation assays also indicates that SIN may be less biocompatible than the other materials. Study is ongoing to increase sample size.
PeriodSept 2015
Event title23rd Annual Meeting of the International Society for Rotary Blood Pumps
Event typeConference
LocationDubrovnik, CroatiaShow on map
Degree of RecognitionInternational