Artificial nanocage-based 3D framework platforms: From construction design to biomedical applications

Three-dimensional (3D) discrete nanocages possess the characteristics of definite structure, ultra-high specific surface area and porosity, adjustable cavities and windows, and easy chemical functionalization. As a new class of functionalized nanomaterials, nanocages have attracted widespread attention in biological applications and clinical translation. However, there are many unmet challenges to make nanocages more bioavailable and therapeutically effective. In this review, we summarize the unique properties and common topological types of nanocages with great potential in biomedical applications. Focus is kept on reviewing recent progress and emerging multi-functional bioengineering for effective drug delivery, imaging, diagnosis, and treatment. The remaining challenges and suggestions for the rational design of next-generation nanocages are also discussed. We aim to guide some key trends in reporting the biological activity and potential applications of 3D nanocage structures for precision biomedicine.