Mimicking Transmural Helical Cardiomyofibre Orientation Using Bouligand-like Pore Structures in Ice-Templated Collagen Scaffolds

Abstract

The helical arrangement of cardiac muscle fibres underpins the contractile properties of the heart chamber. Across the heart wall, the helical angle of the aligned fibres changes gradually across the range of 90–180°. It is essential to recreate this structural hierarchy in vitro for developing functional artificial tissue. Ice templating can achieve single-oriented pore alignment via unidirectional ice solidification with a flat base mould design. We hypothesise that the orientation of aligned pores can be controlled simply via base topography, and we propose a scalable base design to recapitulate the transmural fibre orientation. We have utilised finite element simulations for rapid testing of base designs, followed by experimental confirmation of the Bouligand-like orientation. X-ray microtomography of experimental samples showed a gradual shift of 106 ± 10°, with the flexibility to tailor pore size and spatial helical angle distribution for personalised medicine.

Keywords

• freeze drying
• cardiac tissue engineering
• polymer processing
• anisotropic porosity