Single stem cell encapsulation by MnO2 doped hydrogel for robust bone regeneration

• MnO 2 -modified hydrogels are used to encapsulate single stem cell (SA@MSC-MnO 2 ) while maintaining biological activity . • SA@MSC-MnO 2 could accelerate the differentiation potential of MSCs and promoted 60% repair of bone defects within 8 weeks. • The doping of MnO 2 could achieve the goal of ROS clearing and improve the bone regeneration effects. Mesenchymal stem cells (MSCs) have become an important choice for regenerative medicine because of their specific differentiation ability. However, MSCs are rapidly cleared by direct injection, and living cells need to be embedded in a 3D semipermeable hydrogel matrix to prolong cell retention time to enhance therapeutic effects. Herein, MnO 2 doped alginate hydrogel was prepared for single stem cell encapsulation (SA@MSC-MnO 2 ) with maintaining biological activity . This hydrogel system could accelerate the differentiation potential of MSCs and promoted 60 % repair of bone defects within 8 weeks. Besides, the doping of MnO 2 could react with H 2 O 2 to generate H 2 O and O 2 , thus achieving the goal of reactive oxygen species (ROS) clearing and improving the bone regeneration effects. We believe that this single stem cell hydrogel encapsulation system will further promote the clinical application of stem cell therapy.