title: Size Effects on the Interaction of QDs with the Mitochondrial Membrane In Vitro.
abstract: The mitochondrial toxicity induced by GSH-CdTe Quantum dots (QDs) of different sizes was investigated. The decreases in absorbance and transmission electron microscopy images show that QDs induce the swelling of mitochondria. Results of flow cytometry indicate that QDs cause a reduction of mitochondrial membrane potential (MMP). A remarkable increase in fluidity of protein regions of mitochondrial membrane is observed, whereas the lipid regions are not obviously affected. Cyclosporin A (CsA) effectively prevents the QD-induced mitochondrial swelling. On the basis of these results, it is proposed that QDs induce mitochondrial permeability transition (MPT). Moreover, with increasing QDs size, a pronounced MPT is observed. The difference between the membrane fluidity induced by QDs and Cadmium ion and the ineffective protective effects of EDTA suggests that the mitochondrial toxicity of QDs cannot be only attributed to the release of metal ion. The protective effects of HSA indicate that the interaction of QDs with pore-forming protein gives rise to the increase in membrane fluidity. This hypothesis is demonstrated by the interaction of QDs with model membranes and proteins using differential scanning calorimetry and isothermal titration microcalorimetry. In conclusion, as the size of QDs increases, the binding affinity of QDs with membrane protein increases, and therefore causes a pronounced mitochondrial damage.
authors: College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, People's Republic of China. lailu@aliyun.com.
authors: Lu
authors: L
authors: Lai
authors: College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, People's Republic of China.
authors: Ya-Ping
authors: YP
authors: Li
authors: College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, People's Republic of China.
authors: Ping
authors: P
authors: Mei
authors: College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, People's Republic of China.
authors: Wu
authors: W
authors: Chen
authors: State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecule Sciences, Wuhan University, Wuhan, 430072, People's Republic of China.
authors: Feng-Lei
authors: FL
authors: Jiang
authors: State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecule Sciences, Wuhan University, Wuhan, 430072, People's Republic of China. yiliuchem@whu.edu.cn.
authors: Yi
authors: Y
authors: Liu
mesh_terms: D001692:Biological Transport; D002463:Cell Membrane Permeability / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D008560:Membrane Fluidity / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D051336:Mitochondrial Membranes / Q000378:metabolism*; D008933:Mitochondrial Swelling / Q000187:drug effects; D010316:Particle Size; D011188:Potassium / Q000378:metabolism; D011522:Protons; D045663:Quantum Dots / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity
chemical_list: D011522:Protons; D011188:Potassium
keywords: CdTe Quantum dots; Mitochondria; Model membranes