Tendon tears, which are common musculoskeletal injuries, heal without restoring the functional structure, leading to the injury’s progression and high incidence of re-tear after surgical repair. The possibility of scarless tendon healing, with restored native tissue properties, could improve surgical outcome or eliminate the need for surgical repair altogether, but it is not typically observed in mammals after birth. That is, until the discovery that adult Murphy Roths Large (MRL/MpJ) mouse models exhibit a regenerative capacity. According to Nelly Andarawis-Puri, Mechanical and Aerospace Engineering, the characteristics of this strain of mouse model provide an exciting opportunity to investigate mechanisms that underlie adult regenerative tendon healing.

Andarawis-Puri’s lab is investigating how the systemic environment of the MRL/MpJ mouse and the local environment of its tendon contribute to scarless tendon healing. Their hypothesis is that scarless healing in these tendons is mediated by a unique provisional extracellular matrix (ECM) that promotes improved alignment and proliferation of matrix-producing cells. However, this does not lead to excessive matrix deposition. Andarawis-Puri’s team is assessing the systemic and local factors that contribute to synthesis of MRL/MpJ’s unique provisional ECM. The team is elucidating the role of the ECM in modulating cellular response. These studies set the foundation for developing therapeutic interventions by isolating the contributions of the innate tendon and the systemic environment to the scarless tendon healing process. The potential utility of MRL/MpJ’s provisional ECM as a therapeutic intervention—that harnesses the biological and structural cues leading to scarless tendon healing—could be highly impactful for the field of tendon tissue engineering. NIH Award Number: 7R01AR068301-02