Creating Scaffolds for Muscle Tissue

In this project, WFIRM scientists developed a scaffold that can guide the formation of muscle tissue – suggesting the possibility of providing implantable functional muscle tissue for patients with large muscle defects.

A challenge in engineering any organ or tissue is selecting the right biomaterial to support the cells and provide a three-dimensional space, or scaffold, for cells to form into new tissues. In the case of muscle tissue, the ideal biomaterial should be biocompatible to permit cell adhesion and growth, degradable over time as muscle cells mature into tissue, and elastic to accommodate contractile function.

It is well known that the structure and organization of muscle fibers dictates tissue function. With that in mind, scientists sought to develop a scaffold that guides the formation of muscle tissue to mimic native tissue. They used a combination of collagen and a polymer known as PLC, which had previously been shown to be biocompatible and improve cellular adhesion and growth characteristics.

Scaffolds were created through a process known as electrospinning – in which the liquid biomaterial is “sprayed” onto a spinning mandrel, creating a highly porous material. To test the best orientation of fibers, they fabricated scaffolds with different orientations – some with the fibers oriented randomly and others with a unidirectional orientation.

When the scaffolds were seeded with muscle cells, they found that human muscle cells were able to adhere, grown and fuse into muscle fibers along the longitudinal axis of scaffolds with the unidirectional orientation. The scaffolds with aligned fibers greatly influenced the muscle cell organization and enhanced the formation of muscle tissue.

(The influence of electrospun aligned poly(epsilon-caprolactone)/collagen nanofiber meshes on the formation of self-aligned skeletal muscle myotubes. Choi JS, Lee SJ, Christ GJ, Atala A, Yoo JJ. Biomaterials. 2008 Jul;29(19):2899-906. Epub 2008 Apr 9.)