Implantable living materials autonomously deliver therapeutics using contained engineered bacteria.

Microbes are increasingly used as living therapeutics, yet their uncontrolled dissemination in the body has remained a clinical roadblock. Physical containment remains largely unattainable owing to eventual bacteria escape. In this work, we present an implantable material that encapsulates and confines bacteria, wherein synthetically engineered microbes produce therapeutic payloads from within. We developed a hydrogel scaffold with dual mechanical features: high stiffness to regulate bacterial proliferation and high toughness to resist material fracture under physiological stress. This design achieved complete bacterial containment for 6 months and withstood multiple forms of mechanical loading that otherwise caused catastrophic material failure. By genetically engineering embedded bacteria, we endowed the material with environmental sensing and on-demand therapeutic release capabilities and demonstrated autonomous treatment in a murine prosthetic joint infection model.