Multidimensional interactions of living materials with biological entities.

Living materials, defined by dynamic biological activity and responsive capabilities, are emerging as pivotal therapeutic agents in biomedicine. Their therapeutic effects are driven by active interactions with biological entities at multiple levels. However, most existing reviews focus narrowly on fabrication methods or specific applications, lacking a comprehensive, integrated analysis of the complex, multidimensional interactions between living materials and host cells, tissues, disease microenvironments, and the organism as a whole. This gap impedes the full understanding of the regulatory mechanisms that govern the relationship between these interactions and therapeutic outcomes. This work aims to bridge this gap by systematically analyzing the core interaction mechanisms of living materials-ranging from bacteria, bacteriophages, and viruses to cells and microalgae-with their host environments. We explore four-dimensional interactions: living material-cell, living material-tissue, living material-disease microenvironment, and living material-host. By synthesizing insights across these dimensions, we propose a unified framework linking living-material properties to host interactions and disease intervention. This study provides foundational principles and identifies key technical challenges for optimizing living materials, facilitating their rational design and clinical translation. Ultimately, this research seeks to accelerate the innovative application of living materials in the treatment of major diseases.