Upconverting Gd₂O₃:Yb, Tm nanoparticles that can provide photodynamic therapy (PDT) for cancer cells upon 980 nm near-infrared (NIR) laser irradiation are prepared. The nanoparticles emit bright blue upconversion fluorescence (470∼520 nm) when excited by a 980 nm laser. A well-selected PDT drug, merocyanine 540 (MC540), which shows an absorption maximum within the 495∼540 nm band, is loaded onto the surface of the nanoparticles to obtain Gd₂O₃:Yb, TmMC540. A prominent PDT-induced killing effect on both human cervical cancer cells (HeLa cells) and human hepatocellular liver carcinoma cells (HepG2 cells) is achieved under 980 nm laser irradiation at a very low power density of 0.65 W cm^-2, which is lower than The American National Standard for the safe use of 980 nm lasers (0.72 W cm^-2. The cell death modes are further studied in detail via a uranyl acetate section-staining method to analyze the morphological cell changes before and after PDT. With clear evidence of mitochondrial damage, chromatin condensation and the formation of apoptotic bodies, an apoptosis mechanism is confirmed to be responsible for both HeLa and HepG2 cell death in Gd₂O₃:Yb, Tm-MC540-mediated PDT. Due to excessive damage, the cancer cells are efficiently killed, and autophagy is found to be initiated immediately after PDT.

中文翻译：

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Gd 2 O 3：Yb，Tm纳米粒子在超低功率980 nm激光触发的光动力疗法中的抗癌作用和细胞死亡途径。

制备了可在980 nm近红外（NIR）激光照射下为癌细胞提供光动力疗法（PDT）的上转换Gd 2 O 3：Yb，Tm纳米粒子。当被980 nm激光激发时，纳米颗粒会发出明亮的蓝色上转换荧光（470-520 nm）。将精选的PDT药物花菁540（MC540）表现在495-540 nm波段内的最大吸收，将其负载在纳米粒子的表面上，以获得Gd 2 O 3：Yb TmMC540。一个突出的PDT诱导的在两个人宫颈癌细胞（HeLa细胞）和人肝细胞肝癌细胞（HepG2细胞）的杀伤作用的980nm的激光照射下，在0.65的非常低的功率密度钨厘米实现^-2，这是较低的安全使用980 nm激光（0.72 W cm ^-2。通过乙酸铀酰切片染色法进一步研究细胞死亡模式，以分析PDT之前和之后的形态细胞变化。有明显的线粒体损伤，染色质浓缩和凋亡小体形成的证据，证实了凋亡机制是引起Gd 2 O 3：Yb，Tm-MC540介导的PDT中HeLa和HepG2细胞死亡的原因。由于过度损伤，癌细胞被有效杀死，并且发现自噬在PDT之后立即开始。