Subcutaneously engineered autologous extracellular matrix scaffolds with aligned microchannels for enhanced tendon regeneration

Improved strategies for the treatment of tendon defects are required to successfully restore mechanical function and strength to the damaged tissue. This remains a scientific and clinical challenge, given the tendon's limited innate regenerative capacity. Here, we present an engineering solution that stimulates the host cell's remodeling abilities. We combined precision-designed templates with subcutaneous implantation to generate decellularized autologous extracellular matrix (aECM) scaffolds that had highly aligned microchannels after removal of templates and cellular components. The aECM scaffolds promoted rapid cell infiltration, favorable macrophage responses, collagen-rich extracellular matrix (ECM) synthesis, and physiological tissue remodeling in rat Achilles tendon defects. At three months post-surgery, the mechanical strength of tenocyte-populated 'neo-tendons' was comparable to pre-injury state tendons. Overall, we demonstrated an in vivo bioengineering strategy for improved restoration of tendon tissue, which also offers wider implications for the regeneration of other highly organized tissues.