Nanomedicine has had potential implications in bioimaging and cancer treatment in the past decade. Nanoscale covalent organic frameworks (COFs) have been developing as a significant category of biomedical nanomaterials with good application prospects on account of their high porosity, functionality, and biocompatibility. The high porosity of COFs permits the encapsulation of distinctive imaging and/or therapeutic agents with high loading efficiency. In some cases, organic building blocks can be employed to load therapeutic drugs and/or functional species through covalent bonding. The organic building blocks of COFs can also be post-modified for specific binding to biomarkers. The unique characteristics of COFs make them promising nanocarriers for bioimaging and therapeutic applications. Despite energetic research on the rational design and fabrication of COFs having been conducted for nearly a decade, the therapeutic applications of nanoscale COFs still remain less understood. This review mainly summarizes the recent research advances in the COF design and their applications in the biomedical field. In particular, the bioimaging and therapeutic applications of COFs are discussed, which include fluorescence bioimaging and different treatment approaches containing chemotherapy, photodynamic therapy, photothermal therapy, and synergistic therapy. The review also illustrates the fundamental challenges facing COF-based nanosystems in terms of size control, surface modification, biodistribution, toxicity, and biocompatibility. This review aims to promote multidisciplinary research at the interface of COFs and biomedicine.

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基于共价有机框架的纳米成像在生物成像和治疗应用中的最新进展

在过去的十年中，纳米医学已经对生物成像和癌症治疗产生了潜在的影响。纳米级共价有机骨架（COFs）由于其高孔隙率，功能性和生物相容性，已经发展成为生物医学纳米材料的重要类别，并具有良好的应用前景。COF的高孔隙率允许以高加载效率封装独特的成像和/或治疗剂。在某些情况下，可以采用有机结构单元通过共价键合负载治疗药物和/或功能性物质。COF的有机结构单元也可以进行后修饰，以与生物标记物特异性结合。COF的独特特性使其成为有前途的生物成像和治疗应用纳米载体。尽管已经进行了近十年的关于COF的合理设计和制造的积极研究，但是对纳米级COF的治疗应用仍然知之甚少。这篇综述主要总结了COF设计的最新研究进展及其在生物医学领域的应用。特别地，讨论了COF的生物成像和治疗应用，包括荧光生物成像以及包括化学疗法，光动力疗法，光热疗法和协同疗法的不同治疗方法。审查还阐明了基于COF的纳米系统在尺寸控制，表面改性，生物分布，毒性和生物相容性方面面临的基本挑战。这篇综述旨在促进COF和生物医学之间的多学科研究。