Supramolecular biomaterials and hydrogels have gained great interest in biomedical engineering for applications such as drug delivery, tissue engineering, regenerative medicine and immunology. Supramolecular hydrogels are assembled by interlinking small molecules in a noncovalent fashion, for example through metal coordination. One such example is the coordination between metals and phenolic compounds, which has previously been used to engineer conformal coatings and thin films, as well as to stabilize hydrogels prepared using pre-synthesized macromolecular building blocks. Recently, metal-phenolic supramolecular gelation was demonstrated through the direct gelation between naturally occurring, unmodified polyphenols and group IV metal ions (Ti IV or Zr IV ). This coordination-driven supramolecular assembly can be initiated by simple mixing at ambient conditions in various solvents over large concentration ranges and metal-ligand stoichiometries. The result is robust and adaptive gels, which can be used for controlling concurrent assembly processes (e.g., crystallization of metal-organic frameworks or pharmaceuticals), or for in situ co-gelation of diverse dopants. While the in vitro cytotoxicity of this new class of materials based on metal-phenolic supramolecular gelation has been studied and observed to be negligible, in vivo studies are yet to be reported.