Janus hydrogel microrobots with bioactive ions for the regeneration of tendon-bone interface.

Regenerating natural gradients of the tendon‒bone interface (TBI) is a major challenge in the reconstruction of rotator cuff tear (RCT). In this study, magnetic Janus hydrogel microrobots to match the TBI orientation during RCT reconstruction surgery are developed via a biofriendly gas-shearing microfluidic platform. Through separate loading of Mg and Zn, the microrobots facilitate the immediate restoration and long-term maintenance of the natural mineral gradient in the TBI after implantation and alignment through magnetic manipulation.