Optical tracking of organically modified silica nanoparticles as DNA carriers: A nonviral, nanomedicine approach for gene delivery

Roy, Indrajit; Ohulchanskyy, Tymish Y.; Bharali, Dhruba J.; Pudavar, Haridas E.; Mistretta, Ruth A.; Kaur, Navjot; Prasad, Paras N.

doi:10.1073/pnas.0408039101

Cited by 433 publications

(290 citation statements)

References 28 publications

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“…Ultrafine silica nanoparticles, functionalized with amino groups, have been shown to bind and protect plasmid DNA from enzymatic digestion and to effect cell transfection in vitro (7)(8)(9). Recent work by our group has established the feasibility of using amino-functionalized organically modified silica (ORMOSIL) nanoparticles as a nonviral vector for in vitro gene transfection (10). This formulation of nanoparticles overcomes many of the limitations of ''unmodified'' silica nanoparticles.…”

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confidence: 99%

Organically modified silica nanoparticles: A nonviral vector for in vivo gene delivery and expression in the brain

Bharali

Klejbor

Stachowiak

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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mentioning

confidence: 99%

Organically modified silica nanoparticles: A nonviral vector for in vivo gene delivery and expression in the brain

Bharali

Klejbor

Stachowiak

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

571

383

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“…Imaging cells exposed to fluorescently labelled nanoparticles using confocal fluorescence microscopy is one of the most common ways in which to ensure nanoparticles can be tracked and monitored as they enter and localise within cells. [6][7][8] However, not all nanoparticles can be easily fluorescently labelled.…”

Section: Introductionmentioning

confidence: 99%

Identifying and localizing intracellular nanoparticles using Raman spectroscopy

Dorney¹,

Bonnier²,

Garcia³

et al. 2012

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106

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Raman microscopy is employed to spectroscopically image biological cells previously exposed to fluorescently labelled polystyrene nanoparticles and, in combination with Kmeans clustering and Principal Component Analysis (PCA), is demonstrated to be capable of localising the nanoparticles and identifying the subcellular environment based on the molecular spectroscopic signatures. The neutral nanoparticles of 50 nm or 100 nm, as characterised by dynamic light scattering, are shown to be non-toxic to a human lung adenocarcinoma cell-line (A549), according to a range of cytotoxicity assays including Neutral Red, Alamar Blue, Coomassie Blue and (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Confocal fluorescence microscopy identifies intracellular fluorescence due to the nanoparticle exposure, but the fluorescence distribution is spatially diffuse, potentially due to detachment of the dye from the nanoparticles, and the technique fails to unambiguously identify the distribution of the nanoparticles within the cells. Raman spectroscopic mapping of the cells in combination with K-means cluster analysis is used to clearly identify and localise the polystyrene nanoparticles in exposed cells, based on their characteristic spectroscopic signatures. PCA identifies the local environment as rich in lipidic signatures which are associated with localisation of the nanoparticles in the endoplasmic reticulum. The importance of optimised cell growth conditions and fixation processes is highlighted. The preliminary study demonstrates the potential of the technique to unambiguously identify and locate nonfluorescent nanoparticles in cells and to probe not only the local environment but also changes to the cell metabolism which may be associated with cytotoxic responses.

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“…tissues, blood and single cells). [1][2][3][4][5][6][7][8][9][10][11] In microarray and microspot techniques, spatial resolution of individual reactive sites on a chip is extremely important. At the same time, improved labeling and detection technologies are required to analyze smaller sample volumes and to measure samples on a limited solid-phase area.…”

Section: Introductionmentioning

confidence: 99%

Surface Modification of Silica Nanoparticles to Reduce Aggregation and Nonspecific Binding

2006

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In this paper, a systematic study of the design and development of surface modification schemes for silica nanoparticles is presented. The nanoparticle surface design involves an optimum balance of the use of inert and active surface functional groups to achieve minimal nanoparticle aggregation and reduce nanoparticle non-specific binding. Silica nanoparticles were prepared in a water-in-oil microemulsion and subsequently surface modified via co-hydrolysis with tetraethylorthosilicate (TEOS) and various organosilane reagents. Nanoparticles with different functional groups, including carboxylate, amine, amine/phosphonate, polyethylene glycol, octadecyl, and carboxylate/octadecyl groups were produced. Aggregation studies, using SEM, dynamic light scattering, and zeta potential analysis, indicate that severe aggregation among amine-modified silica nanoparticles can be reduced by adding inert functional groups, such as methyl phosphonate, to the surface. To determine the effect of various surface modification schemes on nanoparticle non-specific binding, the interaction between functionalized silica nanoparticles and a DNA chip was also studied using confocal imaging/ fluorescence microscopy. Dye-doped silica nanoparticles functionalized with octadecyl and carboxylate groups showed minimal non-specific binding. Using these surface modification schemes, fluorescent dye-doped silica nanoparticles can be more readily conjugated with biomolecules and used as highly fluorescent, sensitive, and reproducible labels in bioanalytical applications.

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Optical tracking of organically modified silica nanoparticles as DNA carriers: A nonviral, nanomedicine approach for gene delivery

Cited by 433 publications

References 28 publications

Organically modified silica nanoparticles: A nonviral vector for in vivo gene delivery and expression in the brain

Organically modified silica nanoparticles: A nonviral vector for in vivo gene delivery and expression in the brain

Identifying and localizing intracellular nanoparticles using Raman spectroscopy

Surface Modification of Silica Nanoparticles to Reduce Aggregation and Nonspecific Binding

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