In situ activated mesenchymal stem cell (MSCs) by bioactive hydrogel for myocardial infarction treatment Stem cells therapy has been proved as a promising strategy for myocardial infarction (MI) treatment. However, the therapeutic efficacy is mainly limited by cellular activity of transplanted mesenchymal stem cells (MSCs). In this study, a novel bioglass (BG)/γ-polyglutamic acid (γ-PGA)/chitosan (CS) hydrogel was obtained by in situ adding BG to stimulate the imine bonds formation.