光动力疗法（PDT）作为最有前途的癌症治疗方法之一，仍受到组织缺氧、蓝紫光（200-450 nm）和红光（750 nm）光穿透浅等缺点的限制。比蓝紫光对组织的穿透力更强，但仍低于近红光（750-1350 nm）。因此，我们提出了一种将近红外光触发PDT与一氧化氮（NO）气体疗法相结合的协同治疗系统，以增强抗肿瘤效果。将上转换纳米颗粒（UCNPs）负载ZnPc光敏剂和L-精氨酸（L-Arg）NO供体，得到UCN@mSiO2@ZnPc@L-Arg纳米复合材料。在980 nm激光照射下，可产生用于PDT的活性氧（ROS）并与l-Arg反应生成NO，此前报道NO对肿瘤细胞具有比ROS更强的杀伤作用，并且在促进我们研究中的 PDT。体外和体内试验均表明，与单独应用PDT相比，PDT与NO疗法联合治疗可显着增强肿瘤杀伤效果。基于 UCNPs 的纳米复合材料有望广泛应用于生物医学中的肿瘤抑制。版权所有 © 2024 作者。由 Elsevier B.V. 出版。保留所有权利。

Photodynamic therapy (PDT), as one of the most promising cancer therapy methods, is still limited by several drawbacks, such as tissue hypoxia and shallow light penetration of blue-violet light (200-450 nm), and red light (750 nm) is more penetrating to tissues than blue-violet light, but still lower than near-red light (750-1350 nm). Therefore, we proposed a synergistic therapy system by combining the near-infrared light-triggered PDT with nitric oxide (NO)-based gas therapy to enhance the anti-tumor effects. Upconversion nanoparticles (UCNPs) were loaded with the photosensitizers of ZnPc and the NO donors of l-arginine (L-Arg) to obtain the nanocomposites of UCN@mSiO2@ZnPc@L-Arg. Under 980 nm laser irradiation, reactive oxygen species (ROS) could be produced for PDT and react with l-Arg to produce NO, which is previously reported to have a greater killing effect on tumor cells than ROS and also plays an important role in promoting PDT in our study. Both the in vitro and in vivo tests demonstrated that the combined therapy of PDT with NO therapy could enhance the tumor killing effect significantly compared with the unique application of PDT. The UCNPs-based nanocomposites are expected to be widely used in biomedicine for tumor inhibition.Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.