Research Progress in Functional Metal-Organic Frameworks for Tumor Therapy

Malignant tumor is considered to be one of the most threatening diseases to human health because it is easy to metastasis and relapse, hard to cure with high mortality. Construction of anti-tumor drug delivery systems would effectively improve the therapeutic efficiency of traditional tumor therapy agents. However, the complicated tumor micro-environment as well as the individual diversity of tumor would lead to low efficiency or treatment failure. The conventional tumor treatments. such as chemotherapy, radiotherapy and surgery, have been unable to satisfy the demand for tumor therapy owing to the severe side effect and low therapeutic efficiency. In recent years, researchers have designed a lot of multifunctional nano-drug carriers for efficient tumor therapy with reduced side effects. Metal-organic frameworks (MOFs), a class of ordered porous crystal materials, have received significant research attention for their applications in gas adsorption and separation, catalysis, drug delivery, immobilized bio-macromolecules and tumor therapy. Due to tunable inorganic building blocks and organic linkers, MOFs can not only integrate drugs or photosensitizers into periodic arrays, but also possess large pore sizes and high surface areas for drug encapsulation. Currently, the biomedical research of MOFs mainly includes the preparation of multifunctional biocompatible nanomaterials through controllable synthesis and reasonable surface modification. MOFs based nanomaterials with desired physiological functions have been widely used for targeting tumor imaging and therapy by utilizing their unique physical and chemical properties. The recent progress on the bio-functionalization of MOFs, including new design strategies and application in tumor therapy is summarized. Particularly, the construction of MOF-based nanoplatforms for tumor therapy on the basis of biomedical polymer modified MOFs is also described in detail. The development trends of MOFs for biomedical application are also prospected. We believe that this work will offer a preliminary understanding to design MOF-based drug delivery systems and acquire the therapeutic strategies of MOF-based nano-medicine for future clinical biomedical applications.