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Wurm EMT, Lin LL, Ferguson B, Lambie D, Prow TW, Walker GJ, Soyer HP. A blueprint for staging of murine melanocytic lesions based on the Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) model. Exp Dermatol 2012; 21:676-81. [PMID: 22742762 DOI: 10.1111/j.1600-0625.2012.01543.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2012] [Indexed: 12/22/2022]
Abstract
It has been shown that gene mutations which drive the development of malignant melanoma (MM) in humans also lead to emergence of MM when engineered mice. However, little attention has been paid to the clinical and histopathological features of melanocytic lesions and their natural history in a given mouse model. This knowledge is crucial to enable us to understand how engineered mutations influence the initiation and evolution of melanocytic lesions, and/or for the use of mice as a preclinical model to test specific treatments. We recently reported the development of melanocytic proliferations along the spectrum of naevi to MM in a Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) mouse model. In this study, we followed the development of lesions over time using digital photography and dermoscopy with the aim to correlate the clinical and histopathological features of lesions developing in this model. We identified two types of lesions. The first are slow-growing dermal MMs that emanate from dermal naevi. The second did not emanate from naevi, grew rapidly, and appeared to be solely confined to the subcutaneous fat. We present a simple staging system for the MMs that progress from naevi, based on depth of extension into the dermis and subcutis. This represents a blueprint for documentation and follow-up of MMs in the live animal, which is critical for the proper use of murine melanoma models.
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Krishnan G, Grice JE, Roberts MS, Benson HAE, Prow TW. Enhanced sonophoretic delivery of 5-aminolevulinic acid: preliminary humanex vivopermeation data. Skin Res Technol 2012; 19:e283-9. [DOI: 10.1111/j.1600-0846.2012.00640.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2012] [Indexed: 11/30/2022]
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Butler MK, Prow TW, Guo YN, Lin LL, Webb RI, Martin DJ. High-pressure freezing/freeze substitution and transmission electron microscopy for characterization of metal oxide nanoparticles within sunscreens. Nanomedicine (Lond) 2012; 7:541-51. [DOI: 10.2217/nnm.11.149] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Aims: To date, the description of a single, suitable method to observe in detail metal oxide nanoparticles in situ within sunscreens is currently lacking, despite growing concern as to how they interact with humans. This study explores the usefulness of transmission electron microscopy to characterize the nanoparticles in sunscreens. Materials & methods: High-pressure freezing then freeze substitution was used to prepare resin-embedded commercial sunscreen samples, and ultrathin sections of these were observed with transmission electron microscopy. Conventional room temperature processing for resin embedding was also trialed. Results: High-pressure frozen/freeze substituted samples provided clear visualization of the size and shape of the nanoparticles and agglomerates and allowed further characterization of the composition and crystal form of the metal oxides, while conventionally processed chemically fixed samples were subject to distribution/agglomeration artifacts. Conclusion: Transmission electron microscopy of high-pressure frozen/freeze substituted samples is an ideal method to completely observe metal oxide nanoparticles in situ in sunscreens.
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Lin LL, Grice JE, Butler MK, Zvyagin AV, Becker W, Robertson TA, Soyer HP, Roberts MS, Prow TW. Time-correlated single photon counting for simultaneous monitoring of zinc oxide nanoparticles and NAD(P)H in intact and barrier-disrupted volunteer skin. Pharm Res 2011; 28:2920-30. [PMID: 21717255 DOI: 10.1007/s11095-011-0515-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 06/15/2011] [Indexed: 01/09/2023]
Abstract
PURPOSE There is a lack of relevant, non-animal alternatives for assessing exposure and toxicity of nanoparticle-containing cosmetics, e.g. sunscreens. Our goal was to evaluate timecorrelated single photon counting (TCSPC) for simultaneous monitoring of zinc oxide nanoparticles (ZnO-NP) and the metabolic state of volunteer skin. METHODS We separated the fluorescence lifetime signatures of endogenous fluorophore signals (i.e. nicotinamide adenine dinucleotide phosphate, NAD(P)H and keratin) and the ZnO-NP signal using advanced TCSPC to simultaneously determine ZnO-NP penetration profiles and NAD(P)H changes in subjects with altered barrier function, including tape-stripped skin and in psoriasis or atopic dermatitis lesions. RESULTS We detected no ZnO-NP penetration into viable human skin in any group. ZnO-NP signal was significantly increased (p < 0.01) on the surface of tape-stripped and lesional skin after 4 and 2 h of treatment, respectively. Free NAD(P)H signal significantly increased in tape-stripped viable epidermis treated for 4 h of ZnO-NP compared to vehicle control. No significant NAD(P)H changes were noted in the lesional study. CONCLUSION TCSPC techniques enabled simultaneous, real-time quantification of ZnO-NP concentration and NAD(P)H via non-invasive imaging in the stratum corneum and viable epidermis of volunteers.
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Prow TW, Monteiro-Riviere NA, Inman AO, Grice JE, Chen X, Zhao X, Sanchez WH, Gierden A, Kendall MAF, Zvyagin AV, Erdmann D, Riviere JE, Roberts MS. Quantum dot penetration into viable human skin. Nanotoxicology 2011; 6:173-85. [DOI: 10.3109/17435390.2011.569092] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Raphael AP, Prow TW, Crichton ML, Chen X, Fernando GJP, Kendall MAF. Targeted, needle-free vaccinations in skin using multilayered, densely-packed dissolving microprojection arrays. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:1785-1793. [PMID: 20665628 DOI: 10.1002/smll.201000326] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Targeting of vaccines to abundant immune cell populations within our outer thin skin layers using miniaturized devices-much thinner than a needle and syringe, could improve the efficacy of vaccines (and other immunotherapies). To meet this goal, a densely packed dissolving microprojection array (dissolving Nanopatch) is designed, achieving functional miniaturization by 1) formulating small microneedles (two orders of magnitude smaller than a standard needle and syringe) and 2) multiple layering of the payload within microprojections with tight tolerances (of the order of a micrometer). The formulation method is suitable to many vaccines because it is without harsh or complex chemical processes, and it is performed at low temperatures and at a neutral pH. When the formulated dNPs are applied to skin, consistent and robust penetration is achieved, rapidly targeting the skin strata of interest (<5 min; significantly faster than larger dissolving microneedles that have been previously reported). Resultant diffusion is significantly enhanced within the dermis compared with the epidermis. Using two different antigens (ovalbumin and a commercial trivalent influenza vaccine [Fluvax2008]), the administration of these dissolving patches generate robust systemic immune responses in a mouse model. To the authors' knowledge, this is the first report of successful vaccination with any form of dissolving microneedles. The patches made by this method therefore have the potential for pain-free, needle-free, and effective vaccination in humans.
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Prow TW, Chen X, Prow NA, Fernando GJP, Tan CSE, Raphael AP, Chang D, Ruutu MP, Jenkins DWK, Pyke A, Crichton ML, Raphaelli K, Goh LYH, Frazer IH, Roberts MS, Gardner J, Khromykh AA, Suhrbier A, Hall RA, Kendall MAF. Nanopatch-targeted skin vaccination against West Nile Virus and Chikungunya virus in mice. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:1776-1784. [PMID: 20665754 DOI: 10.1002/smll.201000331] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The 'Nanopatch' (NP) comprises arrays of densely packed projections with a defined geometry and distribution designed to physically target vaccines directly to thousands of epidermal and dermal antigen presenting cells (APCs). These miniaturized arrays are two orders of magnitude smaller than standard needles-which deliver most vaccines-and are also much smaller than current microneedle arrays. The NP is dry-coated with antigen, adjuvant, and/or DNA payloads. After the NP was pressed onto mouse skin, a protein payload co-localized with 91.4 + or - 4.1 APC mm(-2) (or 2925 in total) representing 52% of the delivery sites within the NP contact area, agreeing well with a probability-based model used to guide the device design; it then substantially increases as the antigen diffuses in the skin to many more cells. APC co-localizing with protein payloads rapidly disappears from the application area, suggesting APC migration. The NP also delivers DNA payloads leading to cutaneous expression of encoded proteins within 24 h. The efficiency of NP immunization is demonstrated using an inactivated whole chikungunya virus vaccine and a DNA-delivered attenuated West Nile virus vaccine. The NP thus offers a needle-free, versatile, highly effective vaccine delivery system that is potentially inexpensive and simple to use.
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Sanchez WY, Prow TW, Sanchez WH, Grice JE, Roberts MS. Analysis of the metabolic deterioration of ex vivo skin from ischemic necrosis through the imaging of intracellular NAD(P)H by multiphoton tomography and fluorescence lifetime imaging microscopy. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:046008. [PMID: 20799810 DOI: 10.1117/1.3466580] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Ex vivo human skin has been used extensively for cosmeceutical and drug delivery studies, transplantable skin allografts, or skin flaps. However, it has a half-life of a few days due to ischemic necrosis. Traditional methods of assessing viability can be time-consuming and provide limited metabolic information. Using multiphoton tomography and fluorescence lifetime imaging (MPT-FLIM) we assess ischemic necrosis of ex vivo skin by NAD(P)H autofluorescence intensity and fluorescence lifetime. Ex vivo skin is stored in the presence and absence of nutrient media (Dulbecco Modified Eagle Medium) at -20, 4, and 37 degrees C and room temperature over a 7-day time course to establish different rates of metabolic deterioration. At higher temperatures we observe a decrease in NAD(P)H autofluorescence, higher image noise, and a significant increase in the average fluorescence lifetime (tau(m)) from approximately 1000 to 2000 ps. Additionally, significant distortions in NAD(P)H fluorescence lifetime histograms correspond to the reduction in autofluorescence. Skin kept at 4 degrees C, with or without media, showed the least change. Our findings suggest that MPT-FLIM enables useful noninvasive optical biopsies to monitor the metabolic state and deterioration of human skin for research and clinical purposes.
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Crichton ML, Ansaldo A, Chen X, Prow TW, Fernando GJ, Kendall MA. The effect of strain rate on the precision of penetration of short densely-packed microprojection array patches coated with vaccine. Biomaterials 2010; 31:4562-72. [DOI: 10.1016/j.biomaterials.2010.02.022] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 02/08/2010] [Indexed: 10/19/2022]
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Prow TW. Toxicity of nanomaterials to the eye. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2009; 2:317-33. [DOI: 10.1002/wnan.65] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Chen X, Prow TW, Crichton ML, Jenkins DW, Roberts MS, Frazer IH, Fernando GJ, Kendall MA. Dry-coated microprojection array patches for targeted delivery of immunotherapeutics to the skin. J Control Release 2009; 139:212-20. [DOI: 10.1016/j.jconrel.2009.06.029] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 05/25/2009] [Accepted: 06/25/2009] [Indexed: 10/20/2022]
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Prow TW, Bhutto I, Grebe R, Uno K, Merges C, McLeod DS, Lutty GA. Nanoparticle-delivered biosensor for reactive oxygen species in diabetes. Vision Res 2008; 48:478-85. [PMID: 18252237 DOI: 10.1016/j.visres.2007.09.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Accepted: 09/28/2007] [Indexed: 11/18/2022]
Abstract
The cell's own antioxidant response element (ARE) can be used to evaluate the complications of diabetes mellitus. The hypothesis that a synthetic ARE could be used as a genetic switch, or biosensor, to turn on and off therapeutic genes is tested herein. Mitochondrial oxidative stress (MOS) has been hypothesized as one of the earliest insults in diabetes. Fluorescent probes used to monitor MOS revealed that the addition of glucose at physiological levels to cultures of endothelial cells was able to induce MOS above normal levels and in a dose-dependant manner. Additional data showed that increased glucose levels activated the ARE-GFP in a dose-dependant manner. These data support the hypothesis that the induction of MOS is more sensitive to hyperglycemia than the induction of the ARE. Delivery of an ARE-GFP construct with nanoparticles to the eye was successful using sub-retinal injection. This ARE-GFP/nanoparticle construct was functional and reported the activation of the ARE in diabetic rat retinal pigment epithelium (RPE). These data support the use of nanoparticle-delivered biosensors for monitoring the oxidative status of tissues in vivo.
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Uno K, Merges CA, Grebe R, Lutty GA, Prow TW. Hyperoxia inhibits several critical aspects of vascular development. Dev Dyn 2007; 236:981-90. [PMID: 17366630 PMCID: PMC4942183 DOI: 10.1002/dvdy.21122] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Normal human retinal vascular development uses angiogenesis and vasculogenesis, both of which are interrupted in the vaso-obliteration phase of retinopathy of prematurity (ROP). Canine oxygen-induced retinopathy (OIR) closely resembles human ROP. Canine retinal endothelial cells (ECs) and angioblasts were used to model OIR and characterize the effects of hyperoxia on angiogenesis and vasculogenesis. Cell cycle analysis showed that hyperoxia reduced the number of G1 phase cells and showed increased arrest in S phase for both cell types. Migration of ECs was significantly inhibited in hyperoxia (P < 0.01). Hyperoxia disrupted the cytoskeleton of angioblasts but not ECs after 2 days. Differentiation of angioblasts into ECs (determined by acetylated low-density lipoprotein uptake) was evaluated after basic fibroblast growth factor treatment. Differentiation of angioblasts into pericytes was determined by smooth muscle actin expression after treatment with platelet-derived growth factor. Differentiation into ECs was significantly inhibited by hyperoxia (P < 0.0001). The percentage of CXCR4(+) cells (a marker for retinal vascular precursors) increased in both treatment groups after hyperoxia. These data show novel mechanisms of hyperoxia-induced disruption of vascular development.
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Lutty GA, Kim S, Bhutto I, McLeod D, Grebe R, Prow TW. In vivo toxicity of nanoparticles for gene therapy in the eye. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2006. [DOI: 10.1016/j.nano.2006.10.110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Prow TW, Kotov NA, Lvov YM, Rijnbrand R, Leary JF. Nanoparticles, molecular biosensors, and multispectral confocal microscopy. J Mol Histol 2004; 35:555-64. [PMID: 15614609 DOI: 10.1007/s10735-004-2196-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2004] [Revised: 05/27/2004] [Indexed: 10/26/2022]
Abstract
Complex, multilayered nanoparticles hold great promise for more sophisticated drug/gene delivery systems to single cells. Outermost layers can include cell targeting and cell-entry facilitating molecules. The next layer can include intracellular targeting molecules for precise delivery of the nanoparticle complex inside the cell of interest. Molecular biosensors can be used to confirm the presence of expected molecules (for example, reactive oxygen species (ROS) as a surrogate molecule for signs of infection, or for activation in radiation damage, etc.) prior to delivery of counter-measure molecules such as drugs or gene therapy. They can also be used as a feedback control mechanism to control the proper amount of drug/gene delivery for each cell. Importantly, the full nanoparticle system can be used to prevent any cells from encountering the drug unless that cell is specifically targeted. Thus, if a cell is initially non-specifically targeted, a secondary check for other molecular targets which must also be present inside the target cell of interest can be used to catch initial targeting mistakes and prevent subsequent delivery of treatment molecules to the wrong cells. The precise intracellular location of nanoparticles within specific regions of a cell can be confirmed by 3D multispectral confocal microscopy. These single cell molecular morphology measurements can be extended from individual cells, to other cells in a tissue in tissue monolayers or tissue sections.
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Yang X, Li X, Prow TW, Reece LM, Bassett SE, Luxon BA, Herzog NK, Aronson J, Shope RE, Leary JF, Gorenstein DG. Immunofluorescence assay and flow-cytometry selection of bead-bound aptamers. Nucleic Acids Res 2003; 31:e54. [PMID: 12736320 PMCID: PMC156057 DOI: 10.1093/nar/gng054] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
An immunofluorescence assay was developed to identify proteins specifically binding to oligonucleoside phosphorodithioate (ODN) aptamers from a bead-bound ODN library. Accordingly, NF-kappaB p50 protein was incubated with either bead-bound NF-kappaB consensus sequence or a bead-bound ODN combinatorial library and adsorption was then assessed using a specific primary antibody and a secondary antibody conjugated with Alexa 488 fluorescent dye. This assay avoids any problems related to fluorescently labeling target proteins. The method is straightforward and readily applicable to other transcription factors and proteins, and the feasibility of its application for high-throughput screening of large aptamer bead-based libraries by flow cytometry is demonstrated.
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Yang X, Bassett SE, Li X, Luxon BA, Herzog NK, Shope RE, Aronson J, Prow TW, Leary JF, Kirby R, Ellington AD, Gorenstein DG. Construction and selection of bead-bound combinatorial oligonucleoside phosphorothioate and phosphorodithioate aptamer libraries designed for rapid PCR-based sequencing. Nucleic Acids Res 2002; 30:e132. [PMID: 12466564 PMCID: PMC137987 DOI: 10.1093/nar/gnf132] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2002] [Revised: 09/23/2002] [Accepted: 10/03/2002] [Indexed: 11/13/2022] Open
Abstract
Chemically synthesized combinatorial libraries of unmodified or modified nucleic acids have not previously been used in methods to rapidly select oligonucleotides binding to target biomolecules such as proteins. Phosphorothioate oligonucleotides (S-ODNs) or phosphorodithioate oligonucleotides (S2-ODNs) with sulfurs replacing one or both of the non-bridging phosphate oxygens bind to proteins more tightly than unmodified oligonucleotides and have the potential to be used as diagnostic reagents and therapeutics. We have applied a split synthesis methodology to create one-bead one-S-ODN and one-bead one-S2-ODN libraries. Binding and selection of specific beads to the transcription factor NF-kappaB p50/p50 protein were demonstrated. Sequencing both the nucleic acid bases and the positions of any 3'-O-thioate/dithioate linkages was carried out by using a novel PCR-based identification tag of the selected beads. This approach allows us to rapidly and conveniently identify S-ODNs or S2-ODNs that bind to proteins.
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