Tissue damaged as a result of ligament, tendon or muscle tissue injury often is treated by replacement with artificial material, cadaver tissue or donated tissue. However, artificial material is unable to sustain the mechanical properties required for ligament and tendon functions, and the material strength often degrades and results in failure after implantation. In addition, there is a shortage of natural sources such as cadaver and donated tissue that are safe and functional for use as biological grafts.

Tissue engineering provides a promising alternative for replacement of defective tissue with natural tissue generated from a subject’s own cells. For quality ligament, tendon and muscle tissue regeneration, cultured cells and newly formed tissues require mechanical stimulation to encourage cell growth and facilitate extracellular matrix deposition. The cultured cells and new tissues also must be protected from extreme mechanical stress during regeneration (both ex vivo and in vivo) and transplantation. However, engineered scaffold structures having favorable biological structure, mechanical properties and effective mechanical stimulation are not readily available. A need exists for the development of mechanically sound and biologically favorable scaffold structures to meet the demand for tissue engineered ligament, tendon and muscle grafts.

UW–Madison researchers have developed a method for creating a braided, nanofibrous scaffold consisting of multiple braided strands of electrospun nanofiber bundles (see image below). The nanofibers used in the structure have high porosity, variable pore-size distribution, high surface-to-volume ratio and morphological similarity to natural extracellular matrix, resulting in a highly favorable microenvironment for cell growth. The secondary bundled structure provides aligned nanofibers with anisotropic (directional) mechanical properties, which can substitute for ligament collagen fibers, while providing tensile strength and flexibility as in a natural ligament. The tertiary braided structure affords additional control with respect to the biological microenvironment and mechanical properties.

File Number: P100002US01