The Solver of Conflicting Needs: Research Advances in Janus Membranes for Tissue Engineering

Abstract Inspired by the Roman god Janus, membranes with double‐sided asymmetry (termed “Janus membranes”) have recently emerged as a promising class of multifunctional biomaterials in tissue engineering. Janus membranes uniquely address complex and often contradictory tissue engineering requirements–such as unidirectional exudate drainage versus antibacterial protection, robust tissue adhesion versus antiscarring, or mechanical integrity versus controlled biodegradability–by integrating asymmetric properties (e.g., hydrophilic–hydrophobic, adhesive/antiadhesive, porous/dense) into a single construct. This review systematically summarizes the latest advancements in Janus membrane technologies tailored specifically for tissue repair. It critically evaluates three major fabrication strategies: all‐in‐one preparation, posttreatment modification, and step‐by‐step assembly, highlighting their suitability, reproducibility, and scalability. Key optimization strategies–including asymmetric wettability, unidirectional transport, adhesion/antiadhesion properties, and interfacial stability–are thoroughly discussed to elucidate structure‐function correlations. Applications in tissue engineering, including skin, bone, abdominal wall, tendon, uterine repair, and hemostasis, are emphasized, demonstrating the multifunctional synergy inherent in Janus membranes. Finally, the review identifies current challenges–such as interfacial stability, standardized characterization, and scalable manufacturing–and offers future perspectives toward intelligentized, clinically translatable Janus membranes.