Biofabrication. 2019 Sep 27. doi: 10.1088/1758-5090/ab48ca. [Epub ahead of print]

<i>In situ</i> tissue engineering of tendon-to-bone interface by endogenous stem/progenitor cells.

Tarafder S¹, Brito JA², Minhas S², Effiong L³, Thomopoulos S³, Lee CH⁴.

Abstract

The long-term success of surgically repaired of rotator cuff tears is largely dependent on restoration of a functional tendon-to-bone interface. We implemented micro-precise spatiotemporal delivery of growth factors in 3D-printed scaffolds for integrative regeneration of a fibrocartilaginous tendon-to-bone interface. Sustained and spatially controlled release of tenogenic, chondrogenic, and osteogenic growth factors was achieved using microsphere-based delivery carriers embedded in thin membrane-like scaffolds. In vitro, the scaffolds embedded with spatiotemporal delivery of growth factors successfully guided regional differentiation of mesenchymal progenitor cells, forming multiphase tissues with tendon-like, cartilage-like, and bone-like regions. In vivo, when implanted at the interface between the supraspinatus tendon and the humeral head in a rat rotator cuff repair model, these scaffolds promoted recruitment of endogenous tendon progenitor cells followed by integrative healing of tendon and bone via reformation of strong fibrocartilaginous interfaces. Our findings demonstrate the potential of in situ tissue engineering of tendon-to-bone interfaces by endogenous progenitor cells. The in situ tissue engineering approach shows translational potential for improving outcomes after rotator cuff repair.