| 1. |
- Fakhar-e-Alam, Muhammad, et al.
(författare)
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Photodynamic effects of zinc oxide nanowires in skin cancer and fibroblast
- 2014
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Ingår i: Lasers in Medical Science. - : Springer London. - 0268-8921 .- 1435-604X. ; 29:3, s. 1189-1194
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Tidskriftsartikel (refereegranskat)abstract
- Cytotoxic effects of zinc oxide (ZnO) nanomaterials, individual and conjugated with a photosensitizer (protoporphyrin IX), were studied in the presence and absence of ultraviolet light exposure (240 nm of light wavelength for a very short time exposure) in cell cultures of human normal and cancerous skin models. Zinc Oxide nanowires (ZnO NWs) were grown on the capillary tip and conjugated with protoporphyrin IX (PpIX). This coated tip was used as tool/pointer for intracellular drug delivery protocol in suggested normal as well as carcinogenic cellular models. After true delivery of optimal drug, the labelled biological model was irradiated with UV-A, which led to a loss of mitochondrial membrane potential, as tested by neutral red assay (NRA).
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| 2. |
- Fakhar-E-Alam, Muhammad, et al.
(författare)
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RETRACTED: Empirical Modeling of Physiochemical Immune Response of Multilayer Zinc Oxide Nanomaterials under UV Exposure to Melanoma and Foreskin Fibroblasts
- 2017
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Carcinogenesis is a complex molecular process starting with genetic and epigenetic alterations, mutation stimulation, and DNA modification, which leads to proteomic adaptation ending with an uncontrolled proliferation mechanism. The current research focused on the empirical modelling of the physiological response of human melanoma cells (FM55P) and human foreskin fibroblasts cells (AG01518) to the multilayer zinc oxide (ZnO) nanomaterials under UV-A exposure. To validate this experimental scheme, multilayer ZnO nanomaterials were grown on a femtotip silver capillary and conjugated with protoporphyrin IX (PpIX). Furthermore, PpIX-conjugated ZnO nanomaterials grown on the probe were inserted into human melanoma (FM55P) and foreskin fibroblasts cells (AG01518) under UV-A light exposure. Interestingly, significant cell necrosis was observed because of a loss in mitochondrial membrane potential just after insertion of the femtotip tool. Intense reactive oxygen species (ROS) fluorescence was observed after exposure to the ZnO NWs conjugated with PpIX femtotip model under UV exposure. Results were verified by applying several experimental techniques, e.g., ROS detection, MTT assay, and fluorescence spectroscopy. The present work reports experimental modelling of cell necrosis in normal human skin as well as a cancerous tissue. These obtained results pave the way for a more rational strategy for biomedical and clinical applications.
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| 3. |
- Kishwar, Sultana, et al.
(författare)
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Biotoxicity of nanometallic oxides and their ligands with photosensitizers in osteosarcom a cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The cytotoxic effects in osteosarcoma (U2OS) cells to different nanosized metallic oxides e.g. zinc oxide nanowires (ZnO-NWs), manganese di-oxide nanowires (MnO2 NWs), ferric oxide nanoparticles (Fe2O3 NPs) individually and their complex forms with photosensitizers photofrin®, 5-Aminolevulinic acid (5-ALA), and protoporphyrin IX (Pp IX) were studied. The cellular effects were assayed by analyzing the cellular morphology. The reactive oxygen species (ROS) were detected using 2', 7'-Dichlorofluorescein diacetate, and cell viability were assessed using MTT assay under ultraviolet (UV), visible light and laser exposed conditions. Prominent cell death with above cited nanomaterials in their complex forms with photosensitizer was observed in labeled U2OS cells. This cell death might be due to their synergetic effect via the release of singlet oxygen species in osteosarcoma cells showing their anticancer-cell effects.
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| 4. |
- Kishwar, Sultana, et al.
(författare)
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Investigation of the phototoxic effect of ZnO nanorods on fibroblasts and melanoma human cells
- 2014
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Ingår i: Laser Physics Letters. - : Institute of Physics (IOP). - 1612-2011 .- 1612-202X. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Photo-cytotoxicity of zinc oxide (ZnO) nanowires (NWs) either bare or conjugated with photosensitizers was studied in dark and after ultraviolet light exposure, in human melanoma and foreskin fibroblast cells. ZnO NWs were grown on the capillary tip and then coated with photosensitizer. This coated tip was used as pointer for intracellular insertion of ZnO NWs and photosensitizer. ZnO NWs pointer was inserted into a specific cell and then irradiated with ultraviolet (UVA), which led to loss of mitochondrial membrane potential, as estimated by loss of the Mitotracker Red staining. Dissolved ZnO NWs showed cytotoxicity as detected by MTT viability assay and morphological evaluation. UVA-irradiation enhanced the toxicity and caused the production of reactive oxygen species (ROS) resulting in cell necrosis. ZnO NWs were photo-toxic for both normal and cancer cells, questioning their bio-safety.
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| 5. |
- Sadaf, Jamal Rana, et al.
(författare)
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White Electroluminescence Using ZnO Nanotubes/GaN Heterostructure Light-Emitting Diode
- 2010
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Ingår i: NANOSCALE RESEARCH LETTERS. - : Springer Science Business Media. - 1931-7573 .- 1556-276X. ; 5:6, s. 957-960
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Tidskriftsartikel (refereegranskat)abstract
- We report the fabrication of heterostructure white light-emitting diode (LED) comprised of n-ZnO nanotubes (NTs) aqueous chemically synthesized on p-GaN substrate. Room temperature electroluminescence (EL) of the LED demonstrates strong broadband white emission spectrum consisting of predominating peak centred at 560 nm and relatively weak violet-blue emission peak at 450 nm under forward bias. The broadband EL emission covering the whole visible spectrum has been attributed to the large surface area and high surface states of ZnO NTs produced during the etching process. In addition, comparison of the EL emission colour quality shows that ZnO nanotubes have much better quality than that of the ZnO nanorods. The colour-rendering index of the white light obtained from the nanotubes was 87, while the nanorods-based LED emit yellowish colour.
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| 6. |
- Sultana, Kishwar, et al.
(författare)
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A comparative study of the electrodeposition and the aqueous chemical growth techniques for the utilization of ZnO nanorods on p-GaN for white light emitting diodes
- 2011
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Ingår i: Superlattices and Microstructures. - : Elsevier. - 0749-6036 .- 1096-3677. ; 49:1, s. 32-42
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Tidskriftsartikel (refereegranskat)abstract
- Vertically well aligned zinc oxide nanorods (ZnO NRs) were grown on p-GaN by electrodeposition (ED) and aqueous chemical growth (ACG) techniques and the structures were employed to fabricate white light emitting diodes (LEDs). Room temperature current voltage (I–V), photoluminescence (PL), and electroluminescence (EL) measurements were performed to investigate and compare both LEDs. In general, the I–V characteristics and the PL spectra of both LEDs were rather similar. Nevertheless, the EL of the ED samples showed an extra emission peak shoulder at 730 nm. Moreover, at the same injection current, the EL spectrum of the ED light emitting diode showed a small UV shift of 12 nm and its white peak was found to be broader when compared to the ACG grown LED. The broadening of the EL spectrum of the LED grown by ED is due to the introduction of more radiative deep level defects. The presented LEDs have shown excellent color rendering indexes reaching a value as high as 95. These results indicate that the ZnO nanorods grown by both techniques possess very interesting electrical and optical properties but the ED is found to be faster and more suitable for the fabrication of white LEDs.
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| 7. |
- Sultana, Kishwar
(författare)
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Device Fabrication and Photosensitizing Role of ZnO Nanostructures in Photodynamic Therapy of Cancer
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In nanoscience and nanotechnology, zinc oxide (ZnO) is gaining much research attention due to direct wide band gap (3.3 eV), large exciton binding energy (60 meV), and deep level defects emissions that cover the whole visible range. ZnO nanorods (NRs) in comparison to normal bio molecules and large surface area to volume ratio, allow them to interact within the cell thus are used as convincing intracellular carriers of photosensitizers. Vertical NRs are wave guiding cavities enhancing the light extraction efficiency from devices and are stable photosensitizing agents with their biophotonic, and biodegradation properties, therefore are appealing candidates for the photodynamic therapy of cancer. The heterojunction LEDs of ZnO NRs/p-GaN are best choice to take the advantage of GaN ideal blue-light emission and fabricated LEDs explore the potential of white LEDs with superior performance. The main objective of this thesis is not only to fabricate ZnO NRs/p-GaN, or ZnO nanotubes (ZNTs)/p-GaN heterostructures, but also to investigate their optical properties for photodynamic therapy. These LEDs have showed enhanced EL intensity covering the visible band (425–750 nm). ZnO nanorods are grown on the borosilicate glass capillaries (0.7 μm diameter) and then conjugated with photosensitizer. Such glass capillaries having ZnO nanorods complex with photosensitizer on them are used as pointer for intracellular mediated photochemistry in cells to achieve their necrosis. Mitochondrial staining of melanoma and foreskin fibroblast cells was done by Mitotracker Red with the aim of targeting the specific organelle with the prepared ZnO nanowires (NWs) Femtotip to see ROS production. Cytotoxic effects of nanometallic oxides e.g. ZnO-NRs, MnO2 NRs, and Fe2O3 NPs individually and their ligands with photosensitizers in osteosarcoma (U2OS) cells are also explored. Thus bare and ligands of nanometallic oxides, with particular focus of ZnO nanowires are having significant and convincing cytotoxic effects via the liberation of reactive oxygen species as well as Zn+2 ions in labeled cells, thus can be assigned as anticancer agents for breast cancer, melanoma cancer and osteosarcoma cells.
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| 8. |
- Sultana, Kishwar, et al.
(författare)
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Intracellular ZnO Nanorods Conjugated with Protoporphyrin for Local Mediated Photochemistry and Efficient Treatment of Single Cancer Cell
- 2010
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Ingår i: NANOSCALE RESEARCH LETTERS. - : Springer Science Business Media. - 1931-7573 .- 1556-276X. ; 5:10, s. 1669-1674
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Tidskriftsartikel (refereegranskat)abstract
- ZnO nanorods (NRs) with high surface area to volume ratio and biocompatibility is used as an efficient photosensitizer carrier system and at the same time providing intrinsic white light needed to achieve cancer cell necrosis. In this letter, ZnO nanorods used for the treatment of breast cancer cell (T47D) are presented. To adjust the sample for intracellular experiments, we have grown the ZnO nanorods on the tip of borosilicate glass capillaries (0.5 mu m diameter) by aqueous chemical growth technique. The grown ZnO nanorods were conjugated using protoporphyrin dimethyl ester (PPDME), which absorbs the light emitted by the ZnO nanorods. Mechanism of cytotoxicity appears to involve the generation of singlet oxygen inside the cell. The novel findings of cell-localized toxicity indicate a potential application of PPDME-conjugated ZnO NRs in the necrosis of breast cancer cell within few minutes.
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| 9. |
- Willander, Magnus, et al.
(författare)
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Applications of Zinc Oxide Nanowires for Bio-photonics and Bio-electronics
- 2011
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Ingår i: Proceedings of SPIE Volume 7940. - Bellingham, Washington, USA : SPIE - International Society for Optical Engineering. - 9780819484772
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Using zinc oxide (ZnO) nanostructures, nanorods (NRs) and nanoparticles (NPs) grown on different substrates (sub-micrometer glass pipettes, thin silver wire and on plastic substrate) different bio-sensors were demonstrated. The demonstrated sensors are based on potentiometric approach and are sensitive to the ionic metals and biological analyte in question. For each case a selective membrane or enzyme was used. The measurements were performed for intracellular environment as well as in some cases (cholesterol and uric acid). The selectivity in each case is tuned according to the element to be sensed. Moreover we also developed photodynamic therapy approach based on the use of ZnO NRs and NPs. Necrosis/apoptosis was possible to achieve for different types of cancerous cell. The results indicate that the ZnO with its UV and white band emissions is beneficial to photodynamic therapy technology.
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