Yang Ju-Il, Lee Hye-Lim, Choi Seon-Hee, Kim Jungsoo, Yu Young-Bob, Jeong Young-Il, Kang Dae-Hwan
Department of Medical Science, Pusan National University School of Medicine, Yangsan 50612, Korea.
Department of Internal Medicine, Pusan National University Yangsan Hospital, Yangsan 50612, Korea.
Materials (Basel). 2021 Dec 25;15(1):138. doi: 10.3390/ma15010138.
The aim of this study is to fabricate nanophotosensitizers composed of methoxy poly(ethylene glycol) (mPEG), chlorin e6 (Ce6), and phenylboronic acid pinacol ester (PBAP) with diselenide linkages for reactive oxygen species (ROS)-sensitive photodynamic therapy (PDT) of cervical cancer cells. To fabricate nanophotosensitizers, Ce6 was conjugated with mPEG via selenocystamine linkage and then remaining carboxylic acid groups of Ce6 was attached to PBAP (mPEGseseCe6PBAP conjugates). Nanophotosensitizers of mPEGseseCe6PBAP conjugates were prepared by dialysis method. In transmission electron microscope (TEM) observation, nanophotosensitizers of mPEGseseCe6PBAP conjugates have spherical shapes and their diameters were less than 150 nm. The average diameter of mPEGseseCe6PBAP nanophotosensitizers was 92.7 ± 9.6 nm in particle size analysis. When HO was added to the nanophotosensitizer solution, nanophotosensitizers were sensitively disintegrated according to the HO concentration and then changed from monomodal distribution to multimodal distribution in particle size distribution. Furthermore, Ce6 release from nanophotosensitizers also increased according to the HO concentration. When HO was added to cell culture of HeLa human cervical cancer cells, intracellular Ce6 uptake of nanophotosensitizers were gradually increased according to the HO concentration, indicating that nanophotosensitizers showed ROS-sensitive delivery of Ce6 against cancer cells.As well as free Ce6, nanophotosensitizers in the absence of light irradiation have low intrinsic cytotoxicity against RAW264.7 cells and HeLa cells. However, nanophotosensitizers induced cell death dose-dependently under light irradiation. Especially, nanophotosensitizers showed significantly higher ROS generation and phototoxicity against HeLa cells in vitro. When nanophotosensitizers were intravenously administered to animal tumor xenograft model of HeLa cells, tumor tissues revealed stronger fluorescence intensity than other tissues by light irradiation while absence of light irradiation induced relatively lower fluorescence intensity in tumor tissues, indicating that nanophotosensitizers have sensitivity against oxidative stress in tumor tissues. We suggest that nanophotosensitizers of mPEGseseCe6PBAP conjugates are promising vehicle for PDT of cervical cancer cells.
本研究的目的是制备由甲氧基聚（乙二醇）（mPEG）、二氢卟吩e6（Ce6）和苯硼酸频哪醇酯（PBAP）组成的具有二硒键的纳米光敏剂，用于对宫颈癌细胞进行活性氧（ROS）敏感的光动力疗法（PDT）。为了制备纳米光敏剂，Ce6通过硒代胱胺键与mPEG共轭，然后将Ce6剩余的羧酸基团连接到PBAP上（mPEGseseCe6PBAP共轭物）。mPEGseseCe6PBAP共轭物的纳米光敏剂通过透析法制备。在透射电子显微镜（TEM）观察中，mPEGseseCe6PBAP共轭物的纳米光敏剂呈球形，其直径小于150nm。在粒度分析中，mPEGseseCe6PBAP纳米光敏剂的平均直径为92.7±9.6nm。当向纳米光敏剂溶液中加入HO时，纳米光敏剂根据HO浓度敏感地分解，然后在粒度分布上从单峰分布变为多峰分布。此外，纳米光敏剂中Ce6的释放也根据HO浓度而增加。当向HeLa人宫颈癌细胞的细胞培养物中加入HO时，纳米光敏剂的细胞内Ce6摄取量根据HO浓度逐渐增加，表明纳米光敏剂对癌细胞显示出ROS敏感的Ce6递送。与游离Ce6一样，在无光照射的情况下，纳米光敏剂对RAW264.7细胞和HeLa细胞的内在细胞毒性较低。然而，纳米光敏剂在光照射下剂量依赖性地诱导细胞死亡。特别是，纳米光敏剂在体外对HeLa细胞显示出明显更高的ROS生成和光毒性。当将纳米光敏剂静脉注射到HeLa细胞的动物肿瘤异种移植模型中时，光照射下肿瘤组织显示出比其他组织更强的荧光强度，而无光照射时肿瘤组织中的荧光强度相对较低，表明纳米光敏剂对肿瘤组织中的氧化应激具有敏感性。我们认为mPEGseseCe6PBAP共轭物的纳米光敏剂是用于宫颈癌细胞PDT的有前景的载体。
