Metal–Organic Frameworks as Intelligent Drug Nanocarriers for Cancer Therapy

Metal–organic frameworks (MOFs) are crystalline porous materials with periodic network structures formed by self–assembly of metal ions and organic ligands. Attributed to their tunable composition and pore size, ultrahigh surface area (1000–7000 m2/g) and pore volume (1.04–4.40 cm3/g), easy surface modification, appropriate physiological stability, etc., MOFs have been widely used in biomedical applications in the last two decades, especially for the delivery of bioactive agents. In the initial stage, MOFs were widely used to load small molecule drugs with ultra–high doses. Whereafter, more recent work has focused on the load of biomacromolecules, such as nucleic acids and proteins. Over the past years, we have devoted extensive effort to investigate the function of MOF materials for bioactive agent delivery. MOFs can be used not only as an intelligent nanocarrier to deliver or protect bioactive agents but also as an activator for their release or activation in response to the different microenvironments. Altogether, this review details the current progress of MOF materials for bioactive agent delivery and looks into their future development.