Photothermal therapy (PTT) makes it difficult to achieve good performance on tumor treatments due to insufficient photothermal conversion efficiency, etc. Combining PTT with photodynamic therapy (PDT) and other therapeutic tools can significantly enhance the tumor-killing ability and has been widely used in the development of therapeutic platforms. Copper sulfide nanoparticle (CuS NP) photothermal reagents have the advantages of low toxicity and simple synthesis; therefore, combining CuS NPs with PDT photosensitizers is an effective strategy to construct a PTT/PDT combination therapeutic platform. However, PDT photosensitizers and photothermal agents generally assembled through hydrophobic interaction, suffer from low coating efficiency or the risk of drug leakage, thus seriously restricting their applications. To address these challenges, CuS NPs with excellent photothermal conversion performance were selected as the core material to prepare CuS@COF nanosheets through a dual-ligand assistant strategy with 4,7-bis(4-aminophenyl)-2,1,3-benzothiadiazole (BTD) and 2,4,6-trihydroxybenzene-1,3,5-tricarbaldehyde (TP). As a PTT/PDT combination therapeutic platform, CuS@COF nanosheets possess a porous TP–BDT-based COF shell, and it can sufficiently contact oxygen to provide high singlet oxygen (¹O₂) yield under 505 nm laser irradiation. Upon illumination with a 1064 nm laser, CuS@COF nanosheets can effectively convert the photon energy into thermal energy with a photothermal conversion efficiency of 63.4%. The results of the CCK8 experiment showed that the phototoxicity of the PTT/PDT combination treatment reached 85.1%, which was much higher than the effect of a single treatment. It was also confirmed in vivo that the tumor inhibition effect of the PDT/PTT combination treatment group was much greater than that of the single treatment group.

中文翻译：

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双波长响应 CuS@COF 纳米片用于高性能光热/光动力组合治疗

光热疗法（PTT）由于光热转换效率不足等原因，在肿瘤治疗上很难取得良好的效果。将PTT与光动力疗法（PDT）等治疗工具相结合，可以显着增强肿瘤杀伤能力，已被广泛应用于治疗平台的开发。硫化铜纳米颗粒（CuS NP）光热试剂具有毒性低、合成简单等优点；因此，将CuS NPs与PDT光敏剂结合是构建PTT/PDT联合治疗平台的有效策略。然而，PDT光敏剂和光热剂通常通过疏水相互作用组装，涂层效率低或存在药物泄漏的风险，从而严重限制了其应用。为了应对这些挑战，选择具有优异光热转换性能的CuS NPs作为核心材料，通过4,7-双(4-氨基苯基)-2,1,3-苯并噻二唑的双配体辅助策略制备CuS@COF纳米片(BTD) 和 2,4,6-三羟基苯-1,3,5-三甲醛 (TP)。作为PTT/PDT组合治疗平台，CuS@COF纳米片具有基于TP-BDT的多孔COF壳，在505 nm激光照射下可以充分接触氧气以提供高单线态氧（¹ O ₂）产率。在1064 nm激光照射下，CuS@COF纳米片可以有效地将光子能转化为热能，光热转换效率为63.4%。CCK8实验结果表明，PTT/PDT联合治疗的光毒性达到85.1%，远高于单一治疗的效果。体内实验也证实，PDT/PTT联合治疗组的肿瘤抑制效果远大于单一治疗组。