Department of Medical Biochemistry, National Research Center, Cairo, Egypt.
Photodiagnosis Photodyn Ther. 2013 May;10(2):173-85. doi: 10.1016/j.pdpdt.2012.08.003. Epub 2012 Sep 25.
Photodynamic therapy (PDT) is a therapeutic modality involving the use of a photosensitizer agent activated by light of appropriate wavelength to selectively destroy tumor cells. Indocyanine green (ICG) is a promising photosensitive agent for PDT of tumor cells. The main disadvantage of using ICG in PDT is the instability of ICG in aqueous solutions. Encapsulating ICG dye in a biocompatible matrix based on PEBBLE technology showed an improvement of aqueous stability comparing with free ICG dye. The main objective of this study is to investigate the photodynamic effect of ICG-ormosil PEBBLEs on two different cell lines: human breast adenocarcinoma cells (MCF-7) and hepatocellular carcinoma cells (HepG2).
ICG-embedded ormosil PEBBLEs were synthesized based on a sol-gel process, and characterized by transmission electron microscopy and other fluorescence tests. The cell viability was evaluated by MTT and trypan blue assays. Apoptosis, necrosis, and DNA damage (comet assay), were evaluated by fluorescence microscopic tests.
The results declared that ICG-ormosil PEBBLEs and free ICG both have the same cytotoxic and phototoxic effect on MCF-7 and HepG2 cell lines, where the apoptotic mode of cell death is preferentially occurred in case of PDT using ICG-ormosil PEBBLEs. Both ICG and ICG-ormosil PEBBLEs induced DNA damage after laser exposure. These results would suggest that entrapping ICG in Polymeric nanoparticles forming ICG-ormosil PEBBLEs improve the aqueous stability of the photosensitizer and in the same time retain its photodynamic activity, suggesting that it is preferred to use ICG-ormosil PEBBLEs instead of free ICG dye.
光动力疗法（PDT）是一种治疗方法，涉及使用光敏剂，通过适当波长的光激活，以选择性地破坏肿瘤细胞。吲哚菁绿（ICG）是一种有前途的用于肿瘤细胞 PDT 的光敏剂。在 PDT 中使用 ICG 的主要缺点是 ICG 在水溶液中的不稳定性。基于 PEBBLE 技术将 ICG 染料封装在生物相容性基质中，与游离 ICG 染料相比，显示出对水稳定性的提高。本研究的主要目的是研究 ICG-ORMOSIL PEBBLES 对两种不同细胞系的光动力作用：人乳腺癌腺癌细胞（MCF-7）和肝癌细胞（HepG2）。
基于溶胶-凝胶工艺合成了 ICG 嵌入的 ORMOSIL PEBBLES，并通过透射电子显微镜和其他荧光测试进行了表征。通过 MTT 和台盼蓝测定法评估细胞活力。通过荧光显微镜测试评估凋亡、坏死和 DNA 损伤（彗星试验）。
结果表明，ICG-ORMOSIL PEBBLES 和游离 ICG 对 MCF-7 和 HepG2 细胞系均具有相同的细胞毒性和光毒性作用，其中 PDT 使用 ICG-ORMOSIL PEBBLES 时优先发生细胞凋亡模式。ICG 和 ICG-ORMOSIL PEBBLES 在激光照射后均诱导 DNA 损伤。这些结果表明，将 ICG 包埋在形成 ICG-ORMOSIL PEBBLES 的聚合物纳米粒子中可以提高光敏剂的水稳定性，同时保持其光动力活性，表明使用 ICG-ORMOSIL PEBBLES 而不是游离 ICG 染料更为可取。
