The hypoxic nature of solid tumors has severely negative effects on oxygen-based photodynamic therapy. In this study, we used porous Pt nanoparticles as a catalase (CAT) nanozyme, the second near-infrared (NIR-II) region photothermal transition agents (PTAs), and carriers of photosensitizer chlorin e6 (Ce6) to synthesize a composite nanosystem Pt-Ce6. In this system, Pt-Ce6 can continuously and stably decompose H₂O₂ into oxygen, thereby alleviating tumor hypoxia and improving the effect of photodynamic therapy (PDT). With 650 nm illumination, the reactive oxygen species (ROS) produced by Ce6 will decrease the mitochondrial membrane potential (MMP, ΔΨ_m) to release cytochrome c (Cyt-c) from the mitochondria into the cytoplasm, eventually leading to mitochondrial-mediated cellular apoptosis during the PDT process. In addition, Pt-Ce6 has good photothermal stability and high photothermal conversion efficiency (52.62%) in the NIR-II region. In U14 tumor-bearing mice, Pt-Ce6 completely suppressed tumor growth and recurrence under laser irradiation. Thus the nanocomposite shows excellent PDT/photothermal therapy (PTT) synergistic performance in vitro and in vivo.

实体瘤的低氧性质对基于氧气的光动力疗法具有严重的负面影响。在这项研究中，我们使用多孔Pt纳米颗粒作为过氧化氢酶（CAT）纳米酶，第二种近红外（NIR-II）区光热过渡剂（PTA）和光敏剂二氢卟酚e6（Ce6）的载体来合成复合纳米系统Pt -CE6。在该系统中，Pt-Ce6可以将H ₂ O ₂连续稳定地分解为氧气，从而减轻了肿瘤的缺氧并提高了光动力疗法（PDT）的效果。用650nm的照明，通过的Ce6产生的活性氧物质（ROS）将降低线粒体膜电位（MMP，Δ Ψ_米）以从线粒体中释放细胞色素c（Cyt-c）进入细胞质，最终导​​致PDT过程中线粒体介导的细胞凋亡。另外，Pt-Ce6在NIR-II区域具有良好的光热稳定性和高的光热转化效率（52.62％）。在携带U14肿瘤的小鼠中，Pt-Ce6完全抑制了肿瘤生长和激光照射下的复发。因此，该纳米复合材料在体外和体内显示出优异的PDT /光热疗法（PTT）协同性能。