Date Time In a Supramolecular Realm: Advances in Intracellular Spaces with De Novo Designed Peptide Scientists at Tokyo Institute of Technology (Tokyo Tech) have set out to harness the potential of self-assembling peptides (SAPs) in intracellular spaces. They present a de novo designed peptide, Y15, which displays a strong tendency to assemble in cellular environments. The addition of Y15-tagged bioactive proteins can functionalize these assemblies, enhancing their utility and relevance by leaps and bounds. Over the last two decades, biomaterials research has made significant progress, transitioning from traditional biomaterials to biomaterials with controlled structure and dynamic functionality. A number of building blocks have been explored for developing biomaterials by self-assembly, but SAPs have garnered special attention due to their tunability and potential use in various applications such as tissue engineering, wound healing, and vaccinations. Despite these benefits, the SAP-based approach is less explored in the intracellular context.