A novel sulfur-substituted naphthalimide (LSNI-S) was synthesized and investigated as a promising lysosome-targeting photosensitizer for photodynamic cancer therapy. The introduction of a dual-functional morpholine group to the 4-position of the naphthalimide backbone combined with the substitution of oxygen atoms by sulfur atoms could facilitate intersystem crossing from the excited singlet state to the reactive triplet state, leading to an excellent singlet oxygen generation efficiency of LSNI-S in organic solvents (Φ_Δ ≈ 0.84 in air-saturated acetonitrile). Interestingly, LSNI-S could produce reactive oxygen species via both type-I and type-II mechanisms under physiological conditions. In particular, cell studies demonstrated that LSNI-S selectively localizes in lysosomes of cancer cells and exhibits excellent photodynamic therapy efficacy.

合成了一种新型的硫取代的萘二甲酰亚胺（LSNI-S），并将其作为靶向溶酶体的光敏剂用于光动力癌症治疗。在萘二甲酰亚胺骨架的4位上引入双功能吗啉基团，并结合使用硫原子取代氧原子，可以促进从激发单重态到反应性三重态的系统间交叉，从而产生出色的单重态氧（LSNI-S在有机溶剂中的Φ效率_Δ 在空气饱和的乙腈中约为0.84）。有趣的是，LSNI-S可以在生理条件下通过I型和II型机制产生活性氧。尤其是，细胞研究表明，LSNI-S选择性定位于癌细胞的溶酶体中，并表现出出色的光动力疗法功效。