Photophysics of dopamine-modified quantum dots and effects on biological systems

Clarke, Samuel; Hollmann, Christiane; Zhang, Zhijun; Suffern, Diana; Bradforth, Stephen E.; Dimitrijević, Nada M.; Minarik, W. G.; Nadeau, Jay L.

doi:10.1038/nmat1631

Cited by 291 publications

(273 citation statements)

References 28 publications

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“…Free radical generation by lipodots Clarke et al for QD560-dopamine in A9 cells, 28 and in our previous studies for non-targeted QD655 in Du145 cells. 31,36 Silver and Ou 40 postulated that fluorescence quenching could be attributed to the interaction of QDs with cellular molecules, particularly lysosomal enzymes.…”

supporting

confidence: 59%

“…21,22 Besides imaging, QDs are now emerging as therapeutic agents alone 23 or in combination with external radiation. [24][25][26] It has been recently shown that QDs irradiated with UV radiation, [27][28][29] blue light, photodynamic application. The most likely mechanism of photosensitized action of QDs is photogeneration of excitons and electron-hole pairs (e − and h + ) 32 and subsequent electron transfer to oxygen adsorbed on the QD surface forming a superoxide (O 2 − ) free radical.…”

Section: Introductionmentioning

confidence: 99%

“…The most likely mechanism of photosensitized action of QDs is photogeneration of excitons and electron-hole pairs (e − and h + ) 32 and subsequent electron transfer to oxygen adsorbed on the QD surface forming a superoxide (O 2 − ) free radical. 33 So far, the photodynamic effect of QDs has been demonstrated for UV radiation by Clarke et al on epithelial cells 28 and Chang et al on pancreatic cells. 34 Derfus et al have demonstrated cytotoxic effects of CdSe QDs with photocatalytically impaired capping shell during UV radiation on hepatocytes.…”

Section: Introductionmentioning

confidence: 99%

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Entrapment in phospholipid vesicles quenches photoactivity of quantum dots

Generalov

Kavaliauskiene²,

Westrøm³

et al. 2011

IJN

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Quantum dots have emerged with great promise for biological applications as fluorescent markers for immunostaining, labels for intracellular trafficking, and photosensitizers for photodynamic therapy. However, upon entry into a cell, quantum dots are trapped and their fluorescence is quenched in endocytic vesicles such as endosomes and lysosomes. In this study, the photophysical properties of quantum dots were investigated in liposomes as an in vitro vesicle model. Entrapment of quantum dots in liposomes decreases their fluorescence lifetime and intensity. Generation of free radicals by liposomal quantum dots is inhibited compared to that of free quantum dots. Nevertheless, quantum dot fluorescence lifetime and intensity increases due to photolysis of liposomes during irradiation. In addition, protein adsorption on the quantum dot surface and the acidic environment of vesicles also lead to quenching of quantum dot fluorescence, which reappears during irradiation. In conclusion, the in vitro model of phospholipid vesicles has demonstrated that those quantum dots that are fated to be entrapped in endocytic vesicles lose their fluorescence and ability to act as photosensitizers.

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supporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Entrapment in phospholipid vesicles quenches photoactivity of quantum dots

Generalov

Kavaliauskiene²,

Westrøm³

et al. 2011

IJN

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“…Small biomolecules include quantum dots modified with dopamine via EDC chemistry (Clarke et al 2006(Clarke et al , 2008, with serotonin via a PEG spacer (Rosenthal et al 2002) or gold nanoparticles decorated with sugar molecules (de la .…”

Section: (Iii) Peptides Proteins Enzymes and Antibodiesmentioning

confidence: 99%

Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles

Sperling

Parak

2010

Phil. Trans. R. Soc. A.

1,409

1,092

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Inorganic colloidal nanoparticles are very small, nanoscale objects with inorganic cores that are dispersed in a solvent. Depending on the material they consist of, nanoparticles can possess a number of different properties such as high electron density and strong optical absorption (e.g. metal particles, in particular Au), photoluminescence in the form of fluorescence (semiconductor quantum dots, e.g. CdSe or CdTe) or phosphorescence (doped oxide materials, e.g. Y 2 O 3 ), or magnetic moment (e.g. iron oxide or cobalt nanoparticles). Prerequisite for every possible application is the proper surface functionalization of such nanoparticles, which determines their interaction with the environment. These interactions ultimately affect the colloidal stability of the particles, and may yield to a controlled assembly or to the delivery of nanoparticles to a target, e.g. by appropriate functional molecules on the particle surface. This work aims to review different strategies of surface modification and functionalization of inorganic colloidal nanoparticles with a special focus on the material systems gold and semiconductor nanoparticles, such as CdSe/ZnS. However, the discussed strategies are often of general nature and apply in the same way to nanoparticles of other materials.

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“…26,27 However, this ligand conjugation can produce some disadvantages such as a quenching of fluorescence, induction of toxicity, and distribution to other recognized organs. 27,28 We developed theranostic liposomes for brain delivery without the need for ligand association.…”

Section: 15mentioning

confidence: 99%

Theranostic liposomes loaded with quantum dots and apomorphine for brain targeting and bioimaging

Wen¹,

Zhang²,

Al‐Suwayeh³

et al. 2012

IJN

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Quantum dots (QDs) and apomorphine were incorporated into liposomes to eliminate uptake by the liver and enhance brain targeting. We describe the preparation, physicochemical characterization, in vivo bioimaging, and brain endothelial cell uptake of the theranostic liposomes. QDs and the drug were mainly located in the bilayer membrane and inner core of the liposomes, respectively. Spherical vesicles with a mean diameter of ∼140 nm were formed. QDs were completely encapsulated by the vesicles. Nearly 80% encapsulation percentage was achieved for apomorphine. A greater fluorescence intensity was observed in mouse brains treated with liposomes compared to free QDs. This result was further confirmed by ex vivo imaging of the organs. QD uptake by the heart and liver was reduced by liposomal incorporation. Apomorphine accumulation in the brain increased by 2.4-fold after this incorporation. According to a hyperspectral imaging analysis, multifunctional liposomes but not the aqueous solution carried QDs into the brain. Liposomes were observed to have been efficiently endocytosed into bEND3 cells. The mechanisms involved in the cellular uptake were clathrin-and caveolamediated endocytosis, which were energy-dependent. To the best of our knowledge, our group is the first to develop liposomes with a QD-drug hybrid for the aim of imaging and treating brain disorders.

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Photophysics of dopamine-modified quantum dots and effects on biological systems

Cited by 291 publications

References 28 publications

Entrapment in phospholipid vesicles quenches photoactivity of quantum dots

Entrapment in phospholipid vesicles quenches photoactivity of quantum dots

Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles

Theranostic liposomes loaded with quantum dots and apomorphine for brain targeting and bioimaging

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