Biocircuitry and Living Programmable Materials: The Next Frontier in Synthetic Living Systems

Synthetic living materials (SLMs) integrate engineered biological systems into synthetic matrices to create materials that sense, compute, and adapt. At their core is biocircuitry: programmable gene networks that equip cells with decision-making, memory, and responsiveness. This Review examines advances in embedding biological computation within materials for biosensing, targeted drug delivery, and regenerative medicine. Recent breakthroughs─phase-separated organelles, spore-based systems, and light-responsive hydrogels─demonstrate robust, precise SLM operation under real-world conditions. Cell-free platforms enable rapid genetic circuit prototyping, while AI-driven modeling accelerates circuit optimization, bridging in silico design and deployment. We discuss key challenges, including circuit stability, metabolic burden, biocompatibility, and scalability, and outline future directions toward fully autonomous systems capable of learning and adaptation. We address biosafety, ethical considerations, and emerging policy frameworks necessary to govern the field responsibly. The convergence of synthetic biology, materials science, and computational engineering in SLMs promises sustainable, responsive materials for health, industry, and environmental applications.