Two-photon excited fluorescence microscopy and nanoparticle-assisted photodynamic therapy (PDT) are two important areas in biomedical research, and their combination can be more beneficial. A type of red emissive photosensitizer (PS) with aggregation-induced emission (AIE) features, which is called tetraphenylethylene (TPE-red), was synthesized and further encapsulated with poly(styrene-co-maleic anhydride) (PSMA) to form nanoparticles. Two-photon fluorescence, as well as two-photon excited reactive oxygen species (ROS) generation by TPE-red–PSMA nanoparticles, was characterized. A large two-photon absorption cross-section was observed at 1040 nm with a femtosecond (fs) laser. PDT via two-photon excitation was well realized on tumor cells, using TPE-red–PSMA nanoparticles as PSs under 1040 nm fs laser excitation. Based on our study, we believe that two-photon excited PDT with AIE-active PSs has great potential applications in deep tissue imaging-guided therapy.

中文翻译：

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聚集诱导的发射纳米粒子作为用于双光子光动力疗法的光敏剂

双光子激发荧光显微镜和纳米粒子辅助光动力疗法（PDT）是生物医学研究中的两个重要领域，它们的结合会更有益。A型的红色发光光敏剂（PS）与聚集诱导发光（AIE）特征，这被称为四苯基（TPE-红色），合成并进一步用聚（苯乙烯-包封的共-马来酸酐）（PSMA），以形成纳米粒子。表征了由TPE-red-PSMA纳米粒子产生的双光子荧光以及双光子激发的活性氧（ROS）。用飞秒（fs）激光在1040 nm处观察到较大的两光子吸收截面。PDT通过在1040 nm fs激光激发下，使用TPE-red-PSMA纳米粒子作为PS，在肿瘤细胞上很好地实现了双光子激发。根据我们的研究，我们相信具有AIE活性PS的双光子激发PDT在深层组织成像引导疗法中具有巨大的潜在应用。