Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
J Mater Chem B. 2023 Sep 20;11(36):8649-8656. doi: 10.1039/d3tb01475d.
Charge-transfer (CT) cocrystals consisting of an electron donor and acceptor have gained attention for designing photothermal (PT) conversion materials with potential for biomedical and therapeutic use. However, the applicability of CT cocrystals is limited by their low stability and aqueous dispersity in biological settings. In this study, we present the self-assembly of CT cocrystals within hydrogen-bonded organic frameworks (HOFs), which not only allows for the dispersion and stabilization of cocrystals in aqueous solution but also promotes the CT interaction within the confined space of HOFs for photothermal conversion. We demonstrate that the CT interaction-driven self-assembly of tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) with PFC-1 HOFs results in the formation of cocrystal-encapsulated TQC@PFC-1 while retaining the crystalline structure of the cocrystal and PFC-1. TQC@PFC-1, in particular, exhibits significant absorption in the second near-infrared region (NIR-II) and excellent photothermal conversion efficiency, as high as 32%. Cellular delivery studies show that TQC@PFC-1 can be internalized in different types of cancer cells, leading to an effective NIR-II photothermal therapy effect both in cultured cells and . We anticipate that the strategy of self-assembly and stabilization of CT cocrystals in nanoscale HOFs opens the path for tuning their photophysical properties and interfacing cocrystals with biological settings for photothermal therapeutic applications.
电荷转移（CT）共晶由电子供体和受体组成，由于其在生物医学和治疗应用方面具有潜在的光热（PT）转换材料设计的潜力而备受关注。然而，CT 共晶的适用性受到其在生物环境中的低稳定性和水分散性的限制。在这项研究中，我们提出了在氢键有机框架（HOFs）内自组装 CT 共晶，这不仅允许共晶在水溶液中分散和稳定，而且还促进了 HOF 受限空间内 CT 相互作用的光热转换。我们证明，四硫富瓦烯（TTF）和四氰基对醌二甲烷（TCNQ）与 PFC-1 HOF 之间的 CT 相互作用驱动的自组装导致共晶包封的 TQC@PFC-1 的形成，同时保留共晶和 PFC-1 的晶体结构。特别是，TQC@PFC-1 在第二近红外区（NIR-II）表现出显著的吸收，光热转换效率高达 32%。细胞递送研究表明，TQC@PFC-1 可以被不同类型的癌细胞内化，导致在培养细胞和体内都能有效发挥 NIR-II 光热治疗作用。我们预计，在纳米尺度 HOF 中自组装和稳定 CT 共晶的策略为调节它们的光物理性质以及将共晶与生物环境接口用于光热治疗应用开辟了道路。
