Department of Chemistry, Institute of Interdisciplinary Convergence Research, Research Institute of Halal Industrialization Technology, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, 06974, Republic of Korea.
Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), 123 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea.
Sci Rep. 2018 Nov 20;8(1):17101. doi: 10.1038/s41598-018-35513-1.
Advancements in the fabrication of upconversion nanoparticles (UCNPs) for synthetic control can enable a broad range of applications in biomedical systems. Herein, we experimentally verified the role of the hydrothermal reaction (HR) time in the synthesis of NaYF:20%Yb/3%Er UCNPs on their morphological evolution and phase transformation at different temperatures. Characterizations of the as-prepared UCNPs were conducted using X-ray diffraction (XRD), electron microscopy and spectroscopy, and thermogravimetric and upconversion (UC) luminescence analysis. We demonstrated that determining the optimal HR time, also referred to here as the threshold time, can produce particles with good homogeneity, hexagonal phase, and UC luminescence efficiency. Subsequently, the polymer coated UCNPs maintained their original particle size distribution and luminescence properties, and showed improved dispersibility in a variety of solvents, cellular nontoxicity, in vitro bioimaging, and biocompatibility as compared to the bare UCNP. Besides this, polyacrylic acid conjugated UCNPs (UCNP@PAA) also revealed the strong anticancer effect by conjugating with doxorubicin (DOX) as compared to the free DOX. Based on these findings, we suggest that these particles will be useful in drug-delivery systems and as in vivo bioimaging agents synchronously.
上转换纳米粒子（UCNPs）的制造技术的进步可以为生物医学系统中的各种应用提供广泛的可能性。在此，我们通过实验验证了水热反应（HR）时间在不同温度下对 NaYF:20%Yb/3%Er UCNPs 合成过程中的形态演变和相变的影响。通过 X 射线衍射（XRD）、电子显微镜和光谱学、热重分析和上转换（UC）发光分析对所制备的 UCNPs 进行了表征。我们证明，确定最佳 HR 时间（也称为阈值时间）可以产生具有良好均一性、六方相和 UC 发光效率的颗粒。随后，聚合物涂覆的 UCNPs 保持了其原始的颗粒尺寸分布和发光性能，与裸 UCNP 相比，在各种溶剂中具有更好的分散性、细胞毒性低、体外生物成像和生物相容性。此外，与游离 DOX 相比，与多柔比星（DOX）结合的聚丙烯酸接枝 UCNPs（UCNP@PAA）也显示出较强的抗癌作用。基于这些发现，我们建议这些颗粒将在药物传递系统和体内生物成像剂中同时得到应用。
