Micro-engineered architected metamaterials for cell and tissue engineering

Architected metamaterials are built upon the assembly of repeating cellular structures, exhibiting unprecedented mechanical properties attributed to the tunability of cellular geometries. They have demonstrated a wide range of applications in the optical and electromagnetic fields, and recently they are employed as advanced tissue engineering scaffolds. The microgeometry-driven strategy enlarges the design domain of scaffold features and enables more accurate manipulation of cell-material interactions. In this review, we introduce the most popular metamaterial designs in biomedical engineering and summarize their representative applications to fabricate in vitro models and in vivo implants. These studies validate the unique advantages of metamaterials in supporting mechanobiological studies and improving the functionality of tissue replacements. Nevertheless, the evolution of meta-biomaterials requires more detailed investigations of the relationship between structural designs and cell phenotypes as well as accurate theoretical models.