Design evolution and attachment of a melt electrowritten cardiac patch to regenerate ischemic heart disease

Abstract text (incl. figure legends and references)

Ischemic heart disease is the worldwide leading cause of death. Mechanical ventricular assist devices present the current standard treatment, although it is not a long-lasting solution. The BRAVꓱ project consists of a multidisciplinary consortium that aims for a biological ventricular assist device (BioVAD) as a regenerative alternative. The BioVAD is composed of two scaffold zones manufactured via Melt Electrowriting (MEW). An inner regenerative part and an outer support area that attaches to the heart and enables tissue integration. The present work outlines the BioVAD design evolution and characterisation.

MEW was used to manufacture 4x6cm BioVAD scaffolds filled with fibrin hydrogel. The regenerative zone with a hexagonal pore pattern, has been shown to be favourable for cardiomyocytes. [1]. The outer support zone was tailored from a variety of design elements such as sinusoidal and straight fibres. Each scaffold architecture and its interplay were morphologically and mechanically characterised. Further testing of attachment to porcine cardiac tissue was investigated by 3D printed testing set-ups.

The distinctive fibre architectures met the complex biomechanical needs of the heart. A regenerative hexagonal pore structure was successfully integrated into the surrounding support zone. Stiff areas can provide functional support to the heart by transmitting forces of the regenerative zone to the heart. The elastic zone allows stretching over the epicardium during contraction and therefore enables attachment.

Scaffold manufacturing via MEW was proven to be an outstanding method to generate a clinical-size BioVAD with characteristic zonal properties. Custom-made testing set-ups allowed advanced characterisation of the BioVAD and to investigate the attachment to porcine cardiac tissue.

Castilho M. et al., Adv. Funct. Mater., 28(40), 2018