Biologisation of the Left Ventricular Assist Device

Abstract

Purpose Left ventricular assist devices (LVADs) are established implantable devices in patients with end-stage heart failure. Due to their artificial materials, anticoagulative therapy is needed, though leading to partly lethal complications and limited clinical applications. Improved LVAD hemocompatibility of all blood contacting surfaces can be achieved by their endothelialisation. Additionally, the endothelial monolayer need to resist clinically relevant flow-conditions, for which we established a new approach using magnetic forces and intracellular superparamagnetic nanoparticles (NP). Methods Endothelial cells (EC) were incubated with nanoparticles of different concentrations and coatings (sodium citrate, polyvinylpyrrolidone) for various time periods. Nanoparticulate absorption behaviour was visualized by Prussian blue staining. Batches with high intracellular nanoparticle quantities were analysed for cell viability by immunofluorescence staining and proliferation assay, possible cytotoxicity by flow cytometry. Following, cellular alignment induced by different magnetic forces was examined and transferred to LVAD impeller endothelialisation. Results Concentration-, coating- and time-dependent changes in cell viability, proliferation and cytotoxicity could be shown, indicating best results for low concentrated sodium citrate nanoparticles, which were used for subsequent cell migration experiments. Magnetic field sufficiently affected endothelialisation as significantly more NP loaded ECs adhered to the impeller surface compared to the unloaded control group. Conclusion These results are promising steps towards the effective biologisation of the LVAD, as the LVAD itself may provide the needed magnetic field for sufficient and flow-resistant endothelialisation. This hypothesis needs to be analysed within the following experiments.