| 1. |
- Drab, Mitja, et al.
(författare)
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Chapter Six - The role of membrane vesiculation and encapsulation in cancer diagnosis and therapy
- 2019
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Ingår i: Advances in Biomembranes and Lipid Self-Assembly. - : Elsevier. - 2451-9634. ; 29, s. 159-199
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Tidskriftsartikel (refereegranskat)abstract
- We summarize recent findings and advances in cancer diagnostics in relation to extracellular vesicles (EVs) and emerging therapeutic options of nanomaterials. We revise the common mechanism for EV inception, vesiculation, through a physical model of the liquid mosaic membrane with laterally mobile membrane rafts that determine local spontaneous curvature. If such in-plane orientational ordering is present, we show that spatial non-homogeneities may trigger energetically favourable membrane vesiculation. In addition, we revise a novel technique of cancer therapy using multifunctional titanium nanobeads (NBs) that form a fully biocompatible system used for optical imaging, magnetic resonance imaging and selective reactive oxygen species photo-generation. We study the encapsulation of these functional NBs theoretically with Monte Carlo (MC) simulations and find that the wrapping transition depends on the strength of mobile charges, giving insight into future functional optimization for maximum therapeutic benefit.
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| 2. |
- Imani, Roghayeh, et al.
(författare)
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Band edge engineering of TiO2@DNA nanohybrids and implications for capacitive energy storage devices.
- 2015
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Ingår i: Nanoscale. - : RSC Publishing. - 2040-3364 .- 2040-3372. ; 7:23, s. 10438-10448
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Tidskriftsartikel (refereegranskat)abstract
- Novel mesoporous TiO2@DNA nanohybrid electrodes, combining covalently encoded DNA with mesoporous TiO2 microbeads using dopamine as linker, were prepared and characterised for application in supercapacitors. Detailed information about donor density, charge transfer resistance and chemical capacitance, which have important role in the performance of an electrochemical device, were studied by electrochemical methods. The results indicated the improvement of electrochemical performance of TiO2 nanohybrid electrode by DNA surface functionalisation. A supercapacitor was constructed from TiO2@DNA nanohybrids with PBS as electrolyte. From the supercapacitor experiment, it was found that the addition of DNA played an important role in improving the specific capacitance (Cs) of the TiO2 supercapacitor. The highest Cs value of 8 F/g was observed for TiO2@DNA nanohybrids. The nanohybrid electrodes were shown to be stable over long-term cycling, retaining 95% of their initial specific capacitance after 1500 cycles.
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| 3. |
- Imani, Roghayeh, et al.
(författare)
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Band edge engineering of TiO2@DNA nanohybrids and implications for capacitive energy storage devices
- 2015
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 7:23, s. 10438-10448
-
Tidskriftsartikel (refereegranskat)abstract
- Novel mesoporous TiO2@DNA nanohybrid electrodes, combining covalently encoded DNA with mesoporous TiO2 microbeads using dopamine as a linker, were prepared and characterised for application in supercapacitors. Detailed information about donor density, charge transfer resistance and chemical capacitance, which have an important role in the performance of an electrochemical device, were studied by electrochemical methods. The results indicated the improvement of electrochemical performance of the TiO2 nanohybrid electrode by DNA surface functionalisation. A supercapacitor was constructed from TiO2@DNA nanohybrids with PBS as the electrolyte. From the supercapacitor experiment, it was found that the addition of DNA played an important role in improving the specific capacitance (C-s) of the TiO2 supercapacitor. The highest Cs value of 8 F g(-1) was observed for TiO2@DNA nanohybrids. The nanohybrid electrodes were shown to be stable over long-term cycling, retaining 95% of their initial specific capacitance after 1500 cycles.
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| 4. |
- Imani, Roghayeh, et al.
(författare)
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Biocompatibility of different nanostructured TiO2 scaffolds and their potential for urologic applications
- 2016
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Ingår i: Protoplasma. - : Springer Science and Business Media LLC. - 0033-183X .- 1615-6102. ; 253:6, s. 1439-1447
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Tidskriftsartikel (refereegranskat)abstract
- Despite great efforts in tissue engineering of the ureter, urinary bladder, and urethra, further research is needed in order to improve the patient's quality of life and minimize the economic burden of different lower urinary tract disorders. The nanostructured titanium dioxide (TiO2) scaffolds have a wide range of clinical applications and are already widely used in orthopedic or dental medicine. The current study was conducted to synthesize TiO2 nanotubes by the anodization method and TiO2 nanowires and nanospheres by the chemical vapor deposition method. These scaffolds were characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods. In order to test the urologic applicability of generated TiO2 scaffolds, we seeded the normal porcine urothelial (NPU) cells on TiO2 nanotubes, TiO2 nanowires, TiO2 nanospheres, and on the standard porous membrane. The viability and growth of the cells were monitored everyday, and after 3 weeks of culturing, the analysis with scanning electron microscope (SEM) was performed. Our results showed that the NPU cells were attached on all scaffolds; they were viable and formed a multilayered epithelium, i.e., urothelium. The apical plasma membrane of the majority of superficial NPU cells, grown on all three different TiO2 scaffolds and on the porous membrane, exhibited microvilli; thus, indicating that they were at a similar differentiation stage. The maximal caliper diameter measurements of superficial NPU cells revealed significant alterations, with the largest cells being observed on nanowires and the smallest ones on the porous membrane. Our findings indicate that different nanostructured TiO2 scaffolds, especially nanowires, have a great potential for tissue engineering and should be further investigated for various urologic applications.
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| 5. |
- Imani, Roghayeh, et al.
(författare)
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Multifunctional Gadolinium-Doped Mesoporous TiO2 Nanobeads : Photoluminescence, Enhanced Spin Relaxation, and Reactive Oxygen Species Photogeneration, Beneficial for Cancer Diagnosis and Treatment
- 2017
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 13:20
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Tidskriftsartikel (refereegranskat)abstract
- Materials with controllable multifunctional abilities for optical imaging (OI) and magnetic resonant imaging (MRI) that also can be used in photodynamic therapy are very interesting for future applications. Mesoporous TiO2 sub-micrometer particles are doped with gadolinium to improve photoluminescence functionality and spin relaxation for MRI, with the added benefit of enhanced generation of reactive oxygen species (ROS). The Gd-doped TiO2 exhibits red emission at 637 nm that is beneficial for OI and significantly improves MRI relaxation times, with a beneficial decrease in spin-lattice and spin-spin relaxation times. Density functional theory calculations show that Gd3+ ions introduce impurity energy levels inside the bandgap of anatase TiO2, and also create dipoles that are beneficial for charge separation and decreased electron-hole recombination in the doped lattice. The Gd-doped TiO2 nanobeads (NBs) show enhanced ability for ROS monitored via center dot OH radical photogeneration, in comparison with undoped TiO2 nanobeads and TiO2 P25, for Gd-doping up to 10%. Cellular internalization and biocompatibility of TiO2@xGd NBs are tested in vitro on MG-63 human osteosarcoma cells, showing full biocompatibility. After photoactivation of the particles, anticancer trace by means of ROS photogeneration is observed just after 3 min irradiation.
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| 6. |
- Imani, Roghayeh, et al.
(författare)
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Combined cytotoxic effect of UV-irradiation and TiO2 microbeads in normal urothelial cells, low-grade and high-grade urothelial cancer cells
- 2015
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Ingår i: Photochemical and Photobiological Sciences. - : Springer Science and Business Media LLC. - 1474-905X .- 1474-9092. ; 14:3, s. 583-590
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Tidskriftsartikel (refereegranskat)abstract
- The differentiation of urothelial cells results in normal terminally differentiated cells or by alternative pathways in low-grade or high-grade urothelial carcinomas. Treatments with traditional surgical and chemotherapeutical approaches are still inadequate and expensive, as bladder tumours are generally highly recurrent. In such situations, alternative approaches, using irradiation of the cells and nanoparticles, are promising. The ways in which urothelial cells, at different differentiation levels, respond to UV-irradiation (photolytic treatment) or to the combination of UV-irradiation and nanoparticles (photocatalytic treatment), are unknown. Here we tested cytotoxicity of UV-irradiation on (i) normal porcine urothelial cells (NPU), (ii) human low-grade urothelial cancer cells (RT4), and (iii) human high-grade urothelial cancer cells (T24). The results have shown that 1 minute of UV-irradiation is enough to kill 90% of the cells in NPU and RT4 cultures, as determined by the live/dead viability assay. On the other hand, the majority of T24 cells survived 1 minute of UV-irradiation. Moreover, even a prolonged UV-irradiation for 30 minutes killed <50% of T24 cells. When T24 cells were pre-supplemented with mesoporous TiO2 microbeads and then UV-irradiated, the viability of these high-grade urothelial cancer cells was reduced to < 10%, which points to the highly efficient cytotoxic effects of TiO2 photocatalysis. Using electron microscopy, we confirmed that the mesoporous TiO2 microbeads were internalized into T24 cells, and that the cell's ultrastructure was heavily compromised after UV-irradiation. In conclusion, our results show major differences in the sensitivity to UV-irradiation among the urothelial cells with respect to cell differentiation. To achieve an increased cytotoxicity of urothelial cancer cells, the photocatalytic approach is recommended.
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| 7. |
- Imani, Roghayeh, et al.
(författare)
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Electrochemical detection of DNA damage through visible-light-induced ROS using mesoporous TiO2 microbeads
- 2014
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Ingår i: Electrochemistry communications. - Philadelphia, PA, United States : Elsevier. - 1388-2481 .- 1873-1902. ; 40, s. 84-87
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Tidskriftsartikel (refereegranskat)abstract
- Rapid detection of DNA damage could serve as a basis for genotoxicity studies of new bio-nanoconjugations. A novel TiO2 bio-nanoconjugation, consisting of mesoporous TiO2 microbeads, dopamine (DA) and ss-DNA, was constructed on fluorine-doped tin oxide-coated glass (FTO) and used for the detection of DNA damage in the photocatalytic reaction of TiO2 under visible light. Stable mesoporous TiO2 microbeads films were coated on FTO by the doctor-blade method; dopamine with oxygen containing ligands, was tightly coupled to the titanium surface prepaired under phase coordination. Specific single-strands of DNA were electronically linked to TiO2 by using a dopamine bridge. DNA damage, caused by reactive oxygen species (ROS) that were photogenerated through the photocatalytic reaction, was detected with square wave voltammetry (SWV) by recording the catalytic oxidation current of [Ru(NH3)6]3 +, an intercalated electroactive probe. The ability of antioxidant to protect DNA against damage in the photocatalytic reaction was also tested.
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| 8. |
- Imani, Roghayeh, et al.
(författare)
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Fabrication of Microfibre-nanowire Junction Arrays of ZnO/SnO2 Composite by the Carbothermal Evaporation Method
- 2014
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Ingår i: Nanomaterials and Nanotechnology. - : SAGE Publications. - 1847-9804. ; 4, s. 21-
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Tidskriftsartikel (refereegranskat)abstract
- A cotton-like ZnO/SnO2 nanocomposite was grown by the carbothermal evaporation of a mixture of ZnO and SnO2 powders at 1100 degrees C by the vapour-liquid-solid process, in which the Sn particles produced by the reduction of SnO2 act as the catalyst. Field-emission scanning electron microscope images suggest that the composites are made of microfibre-nanowire junction arrays. The structure is formed due to the fast growth of the ZnO microfibre and the subsequent epitaxial radial growth of the ZnO nanowires with Sn particles at the tips. The photovoltaic performance of the ZnO/SnO2 nanocomposite sensitized with a D35-cpdt dye was investigated. A dye-sensitized solar cell (DSSC) with a ZnO/SnO2 nanocomposite photoanode based on a cobalt electrolyte achieved a solar-to-electricity conversion efficiency of similar to 0.34% with a short circuit current (JSC) of 0.66 mA/cm(2), an open circuit voltage (VOC) of 870 mV, and a fill factor (FF) of 59. The results show the potential of this one dimensional structure in cobalt electrolyte-based DSSCs; the further optimization which is needed to achieve higher efficiencies is also discussed.
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| 9. |
- Patra, Hirak Kumar, et al.
(författare)
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On/off-switchable anti-neoplastic nanoarchitecture
- 2015
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 5:14571, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Throughout the world, there are increasing demands for alternate approaches to advanced cancer therapeutics. Numerous potentially chemotherapeutic compounds are developed every year for clinical trial and some of them are considered as potential drug candidates. Nanotechnology-based approaches have accelerated the discovery process, but the key challenge still remains to develop therapeutically viable and physiologically safe materials suitable for cancer therapy. Here, we report a high turnover, on/off-switchable functionally popping reactive oxygen species (ROS) generator using a smart mesoporous titanium dioxide popcorn (TiO2 Pops) nanoarchitecture. The resulting TiO2 Pops, unlike TiO2 nanoparticles (TiO2 NPs), are exceptionally biocompatible with normal cells. Under identical conditions, TiO2 Pops show very high photocatalytic activity compared to TiO2 NPs. Upon on/off-switchable photo activation, the TiO2 Pops can trigger the generation of high-turnover flash ROS and can deliver their potential anticancer effect by enhancing the intracellular ROS level until it crosses the threshold to open the death gate, thus reducing the survival of cancer cells by at least six times in comparison with TiO2 NPs without affecting the normal cells.
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| 10. |
- Patra, Hirak, et al.
(författare)
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Novel anti-neoplastic approach for photodynamic theranostics by biocompatible TiO2 popcorn nanostructure for a high-throughput flash ROS generator
- 2014
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Ingår i: 24<sup>th </sup>Anniversary World Congress on Biosensors – Biosensors 2014. - : Elsevier.
-
Konferensbidrag (refereegranskat)abstract
- Reactive oxygen species (ROS) are important secondary messengers in the intracellular signaling system for regulating redox homeostasis in normal cells. Compared to normal cells, cancer cells have increased ROS levels due to a faster metabolic rate. We have used this discriminating overproduction of ROS levels in cancer cells as a target for a photodynamic anti-neoplastic theranostic approach using mesoporous TiO2 microbeads with a popcorn nanostructure. We have created a novel flash ROS generator using a two-step procedure consisting of sol-gel and solvothermal processes to obtain mesoporous TiO2 microbeads with high photocatalytic efficiency. A photon-induced comparative study has been carried out for the ROS generation ability using TiO2 nanoparticles and mesoporous TiO2 microbeads. We have shown that in under otherwise identical conditions the extent of photocatalytical ROS generated by mesoporous TiO2 microbeads is more than twice that produced by TiO2 nanoparticles. In vitro in the absence of irradiation, the mesoporous TiO2 microbeads are exceptionally biocompatible, allowing almost ~100% cellular survival rate even at a dose of 100 µg/mL. In contrast, commercial nanoparticles showed concentration dependent cytotoxicity of nearly 15% within 24h in the absence of any irradiation. Upon photo activation, the mesoporous TiO2 microbead structures delivered their potential anticancer effect by interfering with the mitochondrial activity by producing ROS in the intracellular environment and thus reducing the survival rate of cells by more than 30% in comparison with commercial nanoparticles, where only an increase of 5% in cell death was observed. Thus we have developed a smart on/off switchable photodynamic anti-neoplastic theranostic approach that can be combined with specific cell recognition elements for future cancer management.
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