Departamento de Física-Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, 14040-901, Brazil.
Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115, USA.
Adv Healthc Mater. 2024 Aug;13(20):e2400372. doi: 10.1002/adhm.202400372. Epub 2024 Apr 28.
Successful implementation of X-ray-activated photodynamic therapy (X-PDT) is challenging because most photosensitizers (PSs) absorb light in the blue region, but few nanoscintillators produce efficient blue scintillation. Here, efficient blue-emitting SrF:Eu scintillating nanoparticles (ScNPs) are developed. The optimized synthesis conditions result in cubic nanoparticles with ≈32 nm diameter and blue emission at 416 nm. Coating them with the meso-tetra(n-methyl-4-pyridyl) porphyrin (TMPyP) in a core-shell structure (SrF@TMPyP) results in maximum singlet oxygen (O) generation upon X-ray irradiation for nanoparticles with 6TMPyP depositions (SrF@6TMPyP). The O generation is directly proportional to the dose, does not vary in the low-energy X-ray range (48-160 kVp), but is 21% higher when irradiated with low-energy X-rays than irradiations with higher energy gamma rays. In the clonogenic assay, cancer cells treated with SrF@6TMPyP and exposed to X-rays present a significantly reduced survival fraction compared to the controls. The SrF:Eu ScNPs and their conjugates stand out as tunable nanoplatforms for X-PDT due to the efficient blue emission from the SrF:Eu cores; the ability to adjust the scintillation emission in terms of color and intensity by controlling the nanoparticle size; the efficient O production when conjugated to a PS and the efficacy of killing cancer cells.
X 射线激活光动力疗法（X-PDT）的成功实施具有挑战性，因为大多数光敏剂（PS）在蓝光区吸收光，但很少有纳米闪烁体产生有效的蓝光闪烁。在这里，开发了高效的蓝色发光 SrF:Eu 闪烁纳米粒子（ScNP）。优化的合成条件导致具有约 32nm 直径的立方纳米粒子，并在 416nm 处发出蓝色发射。用介孔四（N-甲基-4-吡啶基）卟啉（TMPyP）在核壳结构（SrF@TMPyP）中对其进行包覆，对于沉积了 6TMPyP 的纳米粒子（SrF@6TMPyP），在 X 射线照射下产生最大的单线态氧（O）生成。O 的生成与剂量成正比，在低能量 X 射线范围内（48-160kVp）不变化，但与用高能伽马射线照射相比，用低能量 X 射线照射时增加 21%。在集落形成试验中，用 SrF@6TMPyP 处理并暴露于 X 射线的癌细胞与对照组相比，存活分数显著降低。SrF:Eu ScNP 及其缀合物由于 SrF:Eu 核的高效蓝色发射，SrF:Eu ScNP 及其缀合物作为可调谐的纳米平台在 X-PDT 中脱颖而出;通过控制纳米颗粒尺寸，可以调整闪烁发射的颜色和强度;与 PS 偶联时产生的高效 O 生成和杀死癌细胞的功效。
