The conformational characteristics of Congo red, Evans blue and Trypan blue

Skowronek, Marek; Roterman, Irena; Konieczny, Leszek; Stopa, Barbara; Rybarska, Janina; Piekarska, Barbara; Górecki, Andrzej; Król, Marek

doi:10.1016/s0097-8485(99)00089-3

Cited by 39 publications

(32 citation statements)

References 33 publications

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“…To further explore the potential of using PBCA NPs to deliver targeted molecular imaging dyes that are noncovalently adsorbed onto nanoparticles for imaging AD neuropathological changes in vivo, we synthesized NPs loaded with Trypan blue (M r 872.9 Da), a plaque-binding red fluorescing diazo dye that is well documented not to cross the BBB (21,22). We first confirmed through confocal imaging of postmortem brain slices that i.v.…”

Section: Resultsmentioning

confidence: 98%

Nanoparticles enhance brain delivery of blood–brain barrier-impermeable probes for in vivo optical and magnetic resonance imaging

Koffie

Farrar

Saidi

et al. 2011

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

225

142

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Several imaging modalities are suitable for in vivo molecular neuroimaging, but the blood-brain barrier (BBB) limits their utility by preventing brain delivery of most targeted molecular probes. We prepared biodegradable nanocarrier systems made up of poly(n-butyl cyanoacrylate) dextran polymers coated with polysorbate 80 (PBCA nanoparticles) to deliver BBB-impermeable molecular imaging probes into the brain for targeted molecular neuroimaging. We demonstrate that PBCA nanoparticles allow in vivo targeting of BBBimpermeable contrast agents and staining reagents for electron microscopy, optical imaging (multiphoton), and whole brain magnetic resonance imaging (MRI), facilitating molecular studies ranging from individual synapses to the entire brain. PBCA nanoparticles can deliver BBB-impermeable targeted fluorophores of a wide range of sizes: from 500-Da targeted polar molecules to 150,000-Da tagged immunoglobulins into the brain of living mice. The utility of this approach is demonstrated by (i) development of a "Nissl stain" contrast agent for cellular imaging, (ii) visualization of amyloid plaques in vivo in a mouse model of Alzheimer's disease using (traditionally) non-BBB-permeable reagents that detect plaques, and (iii) delivery of gadolinium-based contrast agents into the brain of mice for in vivo whole brain MRI. Four-dimensional real-time two-photon and MR imaging reveal that brain penetration of PBCA nanoparticles occurs rapidly with a time constant of ∼18 min. PBCA nanoparticles do not induce nonspecific BBB disruption, but collaborate with plasma apolipoprotein E to facilitate BBB crossing. Collectively, these findings highlight the potential of using biodegradable nanocarrier systems to deliver BBB-impermeable targeted molecular probes into the brain for diagnostic neuroimaging.in vivo multiphoton imaging | transgenic mice T he ability to image structure and function in the brain using tools as diverse as multiphoton fluorescence imaging and magnetic resonance imaging (MRI) hold the promise of providing insight into physiology and pathophysiological conditions, but are greatly limited by the ability to deliver contrast agents with molecular specificity across the blood-brain barrier (BBB). Although several molecular imaging contrast agents targeted to structures of interest have been developed for research and clinical applications, only a small fraction of them cross the BBB, including amyloid binding dyes that required many years to develop (1-4). This leads to surprising gaps in the ability to monitor cells and cellular processes in the central nervous system (CNS), requiring skull burr holes and topical application to visualize agents ranging from simple molecular Nissl stains to highly specific antibodies (5-7). Multiple approaches have been developed to nonspecifically disrupt the BBB to allow BBB-impermeable targeted molecular imaging probes entrance into brain parenchyma, but these approaches induce uncontrolled neuronal injuries as well as allow circulating toxins and neuroactive agents to g...

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Section: Resultsmentioning

confidence: 98%

Nanoparticles enhance brain delivery of blood–brain barrier-impermeable probes for in vivo optical and magnetic resonance imaging

Koffie

Farrar

Saidi

et al. 2011

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

225

142

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“…Cells were incubated in suspension for 24 h in medium supplemented with 0%, 2.5%, 5%, 7.5%, or 10% FBS with or without 50 ng/ml PMA. Cell viability was quantified by trypan blue exclusion test [14]. Cell viability significantly decreased in the absence of FBS, but the cell viability in the medium with 5% FBS reached 90% of that with 10% FBS in the absence of PMA (Fig.…”

Section: Determination Of the Culture Condition And Adhesion Assaymentioning

confidence: 96%

Intracellular protein phosphorylation in adherent U937 monocytes mediated by various culture conditions and fibronectin-derived surface ligands

2005

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Macrophages play a central role in the normal healing process after tissue injury and the host response to foreign objects such as biomaterials. The process leading to macrophage adhesion and activation on protein-adsorbed substrates is complex and unresolved. While the use of primary cells offers clinical relevancy, macrophage cell lines offer unique advantages such as availability and relatively homogeneous phenotype as models to probe the molecular mechanism of cellsurface interaction. Our goal was to better characterize the effect of the culture condition and surface-associated ligands on the extent of U937 adhesion. Tyrosine phosphorylation of intracellular proteins was surveyed as a basis to seek a greater understanding of the molecular mechanism involved in mediating U937 adhesion on various ligand-adsorbed surfaces. U937 viability and adhesion on tissue culture polystyrene (TCPS) increased with (i) increasing serum level, (ii) decreasing tyrosine phosphorylation inhibitor AG18 concentration, or (iii) increasing culture time. The adsorption of various adhesion proteins such as fibronectin and peptide ligands (i.e., RGD, PHSRN) on TCPS did not significantly increase the adherent density of U937 when compared with albumin and PBS ligand controls. However, ligand identity and the presence of phorbol myristate acetate dramatically affected the extent (i.e., increase or decrease) and the identity (i.e., molecular weight) of phosphotyrosine proteins in adherent U937 in a time-dependent manner. The extent and identity of phosphotyrosine proteins did not exhibit a clear AG18 dose dependency, rather the level of tyrosine phosphorylation for a distinct group of proteins was either increased or decreased for a given AG18 concentration. r

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“…12,13 Trypan blue is a blue bis-azo dye. It is a symmetrical molecule consisting of three main parts connected by two azo bonds 14,15,16 (see Figure 3).…”

Section: Discussionmentioning

confidence: 99%

A histological analysis of lens capsules stained with trypan blue for capsulorrhexis in phacoemulsification cataract surgery

Singh

Sarodia

Brown

et al. 2003

Eye

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Purpose Staining of anterior lens capsules with dye to facilitate completion of continuous curvilinear capsulorrhexis is now being used more frequently in phacoemulsification of white and mature cataracts with poor red reflexes. This study examined the histological characteristics of anterior lens capsules stained with trypan blue. The layer(s) of the lens capsule that stained with dye and the extent of accumulation of dye in these layers of the lens capsule were determined. To the best of our knowledge this has not been described before. Methods A series of 10 stained lens capsules were analysed histologically. The dye used in this study consisted of a standard sterile, noninflammatory, nonpyrogenic, 2 ml solution containing 0.6 mg/ml of trypan blue. Following capsulorrhexis, samples were sent to the laboratory for histological analysis. Frozen sections (8 lm) were prepared and examined with the light microscope. All 10 capsules were cut by frozen section to preserve trypan blue staining (which would be leached by processing) and then subjected to immunohistochemistry for collagen IV. Immunohistochemical analysis using markers for type IV collagen were done on formalinfixed specimens for morphological comparison with the frozen sections. A counterstain highlighted the epithelium. Results Continuous curvilinear capsulorrhexis was successfully and easily completed in all cases without any complications. Frozen section analysis using light microscopy demonstrated accumulation of trypan blue dye in the basement membrane of the lens capsule. Staining was concentrated in the portion of the membrane adjacent to the lens epithelium. The lens epithelium could not be clearly identified on the frozen sections. Consequently, immunohistochemical analysis with markers for type IV collagen was performed. A counterstain highlighted the epithelium. This confirmed that the layer staining with trypan blue was the basement membrane, a consistent feature on all the specimens. Conclusions Trypan blue selectively stains the basement membrane of the anterior lens capsule. There is a concentration of dye in the basement membrane adjacent to the lens epithelial cell layer. The lens cortex does not appear clinically to stain with trypan blue. This enables surgeons to distinguish the lens capsule from the cortex and provides sufficient contrast for successful completion of continuous curvilinear capsulorrhexis during cataract surgery.

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The conformational characteristics of Congo red, Evans blue and Trypan blue

Cited by 39 publications

References 33 publications

Nanoparticles enhance brain delivery of blood–brain barrier-impermeable probes for in vivo optical and magnetic resonance imaging

Nanoparticles enhance brain delivery of blood–brain barrier-impermeable probes for in vivo optical and magnetic resonance imaging

Intracellular protein phosphorylation in adherent U937 monocytes mediated by various culture conditions and fibronectin-derived surface ligands

A histological analysis of lens capsules stained with trypan blue for capsulorrhexis in phacoemulsification cataract surgery

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