Functional ligand-mediated tailoring of size and spatial architecture in metal-organic framework/polymer hybrids for...

Diverse strategies to construct metal-organic framework (MOF)/polymer composites have been explored in recent decades due to the advanced properties benefited from their combination. However, regulating the critical parameters including size and spatial structure usually requires different strategies that interfere mutually thus complicating the systems. Herein, we reported a general approach to fabricate uniform polymer-in-MOF nanoparticles through functional ligands enabling both coordination modulation and in situ polymerization. Pyrrole ligand was first pre-coordinated with metal node Zn²⁺ and subsequently replaced by stronger 2-methylimidazole ligand to form the MOF structures. This two-step strategy allowed precise size control via regulation of MOF nucleation and growth while simultaneously facilitating the encapsulation and in situ polymerization of pyrrole within the MOF pores. As a showcase of this approach, the polypyrrole-containing MOF surface was further functionalized with cellulose to enhance biocompatibility, enabling biomedical applications for in vivo photoacoustic imaging and tumor photothermal therapy. This method provides a generalizable strategy for the synthesis of MOF/polymer composites with tunable size, architecture, and functionality for diverse biomedical applications.