Supramolecular metal-organic frameworks as host-guest nanoplatforms for versatile and customizable biomedical applications

Molecular imaging of disease with multifunctional nanoparticles has improved specificity and sensitiv-ity but also raises the complexity, potential toxicity, and cost. Here, we show a facile and degradable self-assembly ss-cyclodextrin metal-organic framework (ss-CD-MOF) nanoplatform for customizable mul-tifunctional imaging. These ss-CD-MOF nanoparticles were obtained with favorable morphology and size by controlling the degradation time. The ss-CD-MOF were used as nanoplatforms for facile functionaliza-tion with adamantane (Ad)-modified probes through host-guest interactions between the surface ss-CD units and Ad molecules. We demonstrated the method's feasibility and capability by developing vari-ous contrast agents for multiple biomedical imaging, including fluorescence imaging, magnetic resonance imaging (MRI), and computed tomography (CT) imaging. The nanoprobes showed superior performance compared to the corresponding small molecular probes, including better physio-chemical properties (e.g., about 5 times of T 1 relaxivity for MRI, 1.2 times of Hounsfield units for CT), improved pharmacokinet-ics, effective tissue imaging capability, and low safety concerns. These ss-CD-MOF-based nanoparticles are promising host-guest nanoplatforms for developing multifunctional and safe imaging probes.Statement of Significance Molecular imaging of disease with multifunctional nanoparticles has improved specificity and sensitiv-ity but also raises the complexity, potential toxicity, and cost. Here, we introduce facile and degradable self-assembly ss-cyclodextrin metal-organic framework (ss-CD-MOF) nanoplatforms for customizable mul-tifunctional imaging. The significance of this work includes: 1) This work reports the tailoring of MOFs nanoparticles with suitable sizes and shapes for biomedical applications through controllable morpho-logical transition and degradation; 2) The ss-CD-MOF-based host-guest nanoplatforms are facile and fea-sible for developing multifunctional nanoparticular contrast agents for effective tissue imaging; 3) The nanoparticular contrast agents show low safety concerns with a long-term tissue deposition similar to the small molecular probes.& COPY; 2023 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.