3D Printed Tissue Engineering Scaffolds

Physiologically representative models of skeletal muscle development, regeneration and adaptation will underpin the next generation of understanding of the pathophysiological characteristics regarding health and disease in this tissue. However, investigating the cellular and molecular mechanisms that regulate muscle function in vivo is problematic, with clear experimental limitations associated with both in vivo human and animal models. As such, establishing a highly biomimetic model that accurately represents the native in vivo function is of paramount importance. Tissue engineering (TE) offers an alternative experimental platform to investigate skeletal muscle development and post-natal adaptation and function. However, many current models are not amenable to incorporation of primary human tissue, which are often limited in experimental throughput due to the complexities associated with recruiting tissue donors, donor specific variations, as well as cellular senescence associated with continued passaging. Therefore, a model that is reproducible when scaling down cell number is fundamental when generating high-powered experiments using primary human derived cells. Advances in three-dimensional (3D) printing technologies have allowed the manufacture of biocompatible scaffolds that support cell and tissue growth. 3D printing or additive manufacturing is the established terminology describing a range of manufacturing processes that can produce parts with complex and highly customisable 3D geometries. In 3D printing, parts are built layer-by-layer, using processes such as material extrusion, material jetting, vat photo-polymerisation, sheet lamination, powder bed fusion, binder jetting and direct energy deposition. Utilising digitally driven printing processes allows for the custom design and prototyping of scaffolds with attachments that are specific to particular tissue types, prior to production of a final functional scaffold. The rapid and relatively inexpensive nature of 3D printing also makes such a method suitable for laboratories to produce scaffolds ‘in-house’, rather than have to commission production from commercial manufacturing companies.