Metamorphic green nanomaterials: bio-responsive architectures for adaptive theranostics

Adaptive nanomaterials are emerging as a cornerstone of sustainable theranostics, offering intelligent, responsive, and environmentally responsible solutions to complex biomedical challenges. This perspective introduces metamorphic green nanomaterials as a paradigm shift from static constructs to dynamic bio-responsive systems. Traditionally, green nanomaterials have been valued for eco-friendly synthesis and passive biocompatibility. In this work, we explore how they can be re-engineered to undergo pre-programmed architectural and functional transformations in situ upon encountering specific biological cues. Such metamorphosis, through controlled disassembly, reassembly, or shape-shifting, unlocks emergent functionalities at target sites, enabling adaptive theranostic capabilities. We discuss how converging innovations in the biosynthesis of complex precursors, dynamic DNA/RNA nanotechnology, biocatalytic triggers, and AI-driven computational co-design are pivotal to realizing these multi-state systems. Potential applications include sequential drug delivery cascades that overcome biological barriers and resistance, sense-and-remediate platforms for pathogenic niches or environmental pollutants, and dynamic scaffolds for regenerative medicine that adapt to evolving tissue needs. While challenges remain in fidelity and scalable manufacturing, the inherent biocompatibility and sustainability of green components provide unique advantages. Metamorphic green nanomaterials may represent a step toward autonomous living nanomachines and may advance theranostic technologies through enhanced intelligence, adaptability, and ecological responsibility, paving the way for personalized nanomedicine.