Camptothecin (CPT), an alkaloid, was first discovered from plants and has potent anti-tumor activity. Since then, CPT analogs (namely Irinotecan and Topotecan) have been approved by the FDA for cancer treatments. Curcumin, on the other hand, is a widely used photosensitizer in photodynamic therapy (PDT) treatment. In our previous work, we have reported a straightforward strategy to construct a drug self-delivery system in which two-molecular species Irinotecan and Curcumin can self-assembly into a complex of ion pairs, namely ICN, through intermolecular non-covalent interactions. We found that ICN has slightly better chemotherapy efficacy than its individual components with much fewer side effects. In this paper, we aim to combine the chemotherapy and the PDT of ICN to further improve its anti-tumor performance. The efficient cellular uptake of ICNs was observed by confocal microscopy. Dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay was used to detect the generation of singlet oxygen species. We found that the cell viability was 9% with both chemotherapy and PDT, and 31% with chemotherapy alone for the case with an ICN concentration of 10 μM, which demonstrated that the anti-tumor efficacy against the HT-29 cancer cell line was enhanced substantially with the combination therapy strategy. The study with an in vivo mouse model has further verified that the chemo-PDT dual therapy can inhibit tumor growth by 84% and 18.8% comparing with the control group and the chemotherapy group, respectively. Our results demonstrated that the new strategy using self-assembly and carrier-free nanoparticles with their chemo-PDT dual therapy may provide new opportunities to develop future combinatorial therapy methods in treating cancer.

喜树碱（CPT）是一种生物碱，最早是从植物中发现的，具有强大的抗肿瘤活性。从那时起，CPT类似物（即伊立替康和托泊替康）已被FDA批准用于癌症治疗。另一方面，姜黄素是在光动力疗法（PDT）治疗中广泛使用的光敏剂。在我们之前的工作中，我们已经报道了构建药物自我传递系统的简单策略，在该系统中，两个分子的伊立替康和姜黄素可以通过分子间非共价相互作用自组装成离子对的复合物，即ICN。我们发现，ICN的化疗功效比其单个成分略好，且副作用要少得多。本文旨在将化疗和ICN的PDT相结合，以进一步提高其抗肿瘤性能。通过共聚焦显微镜观察到ICN的有效细胞摄取。二氯二氢荧光素二乙酸酯（DCFH-DA）测定法用于检测单线态氧物种的产生。我们发现，ICN浓度为10μM的情况下，化疗和PDT的细胞活力均为9％，单独化疗的细胞活力为31％，这表明对HT-29癌细胞系的抗肿瘤功效增强基本上与联合治疗策略有关。与 这表明联合治疗策略显着增强了对HT-29癌细胞系的抗肿瘤功效。与 这表明联合治疗策略显着增强了对HT-29癌细胞系的抗肿瘤功效。与研究体内小鼠模型进一步证实，化学-PDT双重疗法与对照组和化疗组相比，可分别抑制肿瘤生长84％和18.8％。我们的结果表明，使用自组装和无载体纳米颗粒及其化学PDT双重疗法的新策略可能为开发未来的组合疗法治疗癌症提供新的机会。