Synthesis and biomedical application of nanocomposites integrating metal-organic frameworks with upconversion nanoparticles

Nanocomposite, being an exciting concept for combining distinct types of nanoparticles together, has opened up novel opportunities in controlling more demanding characteristics for biomedical applications. Thanks to the synergistic and complementary effects, MOFs-UCNPs nanocomposites generated by integrating metal–organic frameworks (MOFs) with upconversion nanoparticles (UCNPs), have exhibited better performances in diagnosis and treatment in contrast to either MOFs or UCNPs single component. However, researches on this issue are still at initial stage owing to the presence of lattice mismatching between these two distinct kinds of materials. Review on MOFs-UCNPs nanocomposites applied in biomedicine is urgently required for promoting the development of this field. Here, this review provides a comprehensive overview of MOFs-UCNPs nanocomposites on fabricating strategies and biomedical applications in therapy, drug delivery, bioimaging, and biosensor. The light-related applications of nanocomposites in these four parts are highlighted, and moreover, multi-role played by single MOFs-UCNPs nanocomposite is stressed in both diagnosing and treating tumors. Finally, the present technical challenges and opportunities arising in precise diagnosis and efficient treatment as well as theranostic application based on MOFs-UCNPs nanocomposites have also been presented.