The Marriage of Metal Nanoclusters With Reticular Frameworks: Synthetic Strategies and Biomedical Applications: Special Collection: Functional Metal Clusters

Metal nanoclusters (MNCs), comprising several to hundreds of metal atoms, have attracted significant research interest owing to their distinctive physicochemical properties. Reticular frameworks (RFs) with ordered porous structures, including metal–organic frameworks (MOFs), covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs), and supramolecular organic frameworks (SOFs), possess a variety of unique properties due to their high crystallinity, high porosity, large surface area, and adjustable structure. The integration of MNCs with RFs endows the resulting composites with desirable features (e.g., enhanced and tunable optical properties, improved catalytic and photophysical activities, selective molecular recognition), which facilitates a broad spectrum of biomedical applications and advancing the development of integrated theranostic nanoplatforms. This review summarizes recent advances in the synthesis and biomedical applications of various MNCs/RFs composites. We systematically categorize and evaluate key strategies for incorporating MNCs into four types of RFs (MOFs, COFs, HOFs, and SOFs) while discussing the advantages and limitations of each approach. The biomedical applications of these composites are comprehensively reviewed, encompassing biosensing, bioimaging, antitumor therapy, and antibacterial treatments. Finally, the review addresses current challenges and outlines future research directions, with the aim of guiding the rational design of novel MNCs/RFs composites, enabling precise control over their structures and functions toward advanced biomedical applications.