Mirror-Image Biology: Perspectives and Challenges

Mirror-image biology is an emerging frontier in synthetic biology that uses chirally inverted biomolecules—D-proteins and L-nucleic acids—to construct orthogonal biological systems. Rapid advances in biomedicine, bioengineering, environmental protection and information technology underscore the expanding potential of mirror-image biology. Owing to their inherent resistance to degradation by natural enzymes, platforms such as Spiegelmers, D-peptide therapeutics, and L-DNA nanodevices have been developed for applications including long-acting drug delivery, precise biosensing and durable information storage. However, recent progress—including attempts to assemble a D-ribosome—has pushed the field beyond molecular tools towards the possible creation of mirror-image life-like systems, raising significant biosafety and biosecurity concerns. Due to their molecular-level chiral incompatibility with natural biological systems, mirror-image organisms could theoretically evade the biological interactions and ecological controls governing natural ecosystems. If released, such organisms could pose irreversible threats to public health and ecosystem stability. This review outlines the molecular foundations, technological advances and application prospects of mirror-image biology, evaluates the associated benefits and biosafety risks, identifies gaps in current international regulatory efforts and presents a dynamic, risk-tiered framework to guide the responsible development of this transformative technology.