title: Photoreactivity of Metal-Organic Frameworks in Aqueous Solutions: Metal Dependence of Reactive Oxygen Species Production.
abstract: Promising applications of metal-organic frameworks (MOFs) in various fields have raised concern over their environmental fate and safety upon inevitable discharge into aqueous environments. Currently, no information regarding the transformation processes of MOFs is available. Due to the presence of repetitive π-bond structure and semiconductive property, photochemical transformations are an important fate process that affects the performance of MOFs in practical applications. In the current study, the generation of reactive oxygen species (ROS) in isoreticular MIL-53s was studied. Scavengers were employed to probe the production of (1)O2, O2(•-), and •OH, respectively. In general, MIL-53(Cr) and MIL-53(Fe) are dominated by type I and II photosensitization reactions, respectively, and MIL-53(Al) appears to be less photoreactive. The generation of ROS in MIL-53(Fe) may be underestimated due to dismutation. Further investigation of MIL-53(Fe) encapsulated diclofenac transformation revealed that diclofenac can be easily transformed by MIL-53(Fe) generated ROS. However, the cytotoxicity results implied that the ROS generated from MIL-53s have little effect on the viability of the human hepatocyte (HepG2) cell line. These results suggest that the photogeneration of ROS by MOFs may be metal-node dependent, and the application of MIL-53s as drug carriers needs to be carefully considered due to their high photoreactivity.
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University , Beijing 100084, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University , Beijing 100084, China.
authors.forename: Yanxin
authors.initials: Y
authors.lastname: Gao
authors.affiliation: MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University , Hangzhou 310058, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University , Beijing 100084, China.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Lyles School of Civil Engineering and Division of Environmental and Ecological Engineering, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Yingcan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University , Beijing 100084, China.
authors.forename: Kunyang
authors.initials: K
authors.lastname: Zhang
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University , Beijing 100084, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
mesh_terms: D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D002851:Chromatography, High Pressure Liquid; D004008:Diclofenac / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D017665:Hydroxyl Radical / Q000737:chemistry; D008027:Light; D008670:Metals / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D026082:Singlet Oxygen / Q000737:chemistry; D012996:Solutions; D013481:Superoxides / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D008670:Metals; D009930:Organic Chemicals; D017382:Reactive Oxygen Species; D012996:Solutions; D014867:Water; D013481:Superoxides; D004008:Diclofenac; D026082:Singlet Oxygen; D017665:Hydroxyl Radical