Thikra Mustafa

Nanotechnology is a fast-growing research technology. Nanoparticles have intensive scientific applications in many fields. Depending on the physical and chemical characteristics of a nanoparticle, it can be used either as a treatment agent to fight disease or as a delivery vehicle to transport the therapeutic drug to a specified biological organ, tissue, and cell. Cytotoxicity evaluation of nanoparticles is one of the primary concerns in clinical practices to avoid unpredicted or undesirable interactions that could worsen the case. Iron oxide nanoparticle (IONP) is the most utilized nanoparticle in medical fields for treatment, diagnostic, and imaging. This paper is designated to investigate the cytotoxicity of IONPs that decorated with Trans-Activator of Transcription (TAT) protein. WST-1 assay and flow cytometry were used to assess the cytotoxicity of TAT-IONPs, which showed no significant cytotoxic effect on mammalian breast cancer cells (MCF-7). Nanoparticles accumulation in the cell’s cytoplasm was evaluated from TEM images by measuring the size of the endosome. The results indicate that TAT-IONPs can be used as a safe and non-toxic nanoplatform for targeted delivery at 50 µg/ml or less. Also, they present an approach by which the area of intracellular endosome can be assessed from the TEM images of fixed cells. In this study, the endosome size increased in a time-dependent manner.

Nitrophenols (NPs) and their derivatives are highly toxic, mutagenic and bio-refractory pollutants commonly present in natural water resources and industrial wastewater. To remove NPs from water, N-doped graphitic carbon (NGC) and NGC adsorbent containing titanium dioxide (NGC–TiO₂) were synthesized by pyrolysis of microcrystalline cellulose and dopamine mixture, and the mixture along with TiO₂ at 500°C, respectively. NCG-TiO₂ was thoroughly characterized using various analytical techniques. NP adsorption on the NGC–TiO₂ adsorbent surface was studied by varying the pH, initial concentration of NP, and adsorbent dose. The results showed that the most efficient adsorption was achieved at pH 3. After 4 h sonication at pH 3, 80% 4-NP adsorption was achieved using NGC–TiO₂ compared to 74% with NGC adsorbent. The percentage removal of 4-NP was higher than 3-NP which was also higher than 2,4-DNP using NGC–TiO₂. 4-NP adsorption best fitted to the Langmuir isotherm plot with R² value of 0.9981 and adsorption capacity of 52.91 mg g⁻¹. The adsorption process of NP was found to follow a pseudo-second-order kinetic model. The rate constant value for the adsorption of 10⁻⁴ M 4-NP at pH 3 using 10 mg of NGC–TiO₂ adsorbent was found to be 3.76 × 10⁻⁵ g.mg⁻¹.min⁻¹

The protozoan parasite Entamoeba histolytica is a causative agent of amoebiasis, where it causes millions of cases of dysentery and liver abscess each year. Metronidazole is a drug of choice against amoebiasis. The drug is a choice because of its efficacy and low cost, but at the same time it causes several adverse side effects; therefore, it is important to find effective medications to treat amoebiasis without any complications or any side effects. The aim of this study is to evaluate the effectiveness of different concentrations (50, 75 and 100 µg/ml) of silver nanoparticle (AgNPs) against trophozoites stages of E. histolytica in vitro. The results showed a significant decrease (p ? 0.05) in numbers of trophozoites stages after treated with AgNPs and metronidazole when it was compared with the control. Likewise, a significant difference (p ? 0.05) was also observed between AgNPs groups and metronidazole drug, while it did not significantly differ between different concentrations of AgNPs. The mortality rate values of the E. histolytica trophozoites after 48h incubation with AgNPs at a concentration of 50, 75 and 100 ?g/ml, and metronidazole were 37.2%, 42.4%, 46.7% and 100%, respectively. The microscopic studies confirmed that AgNPs were effective enough to induce apoptosis. Based on our results, the anti-parasitic activity of AgNPs at different concentrations will reduce the mean number of E. histolytica trophozoites.

Due to the distinctive physical, electrical, and chemical properties of graphene nanomaterials, numerous efforts pursuing graphene‐based biomedical and industrial applications are underway. Oxidation of pristine graphene surfaces mitigates its otherwise hydrophobic characteristic thereby improving its biocompatibility and functionality. Yet, the potential widespread use of oxidized graphene derivatives raises concern about adverse impacts on human health. The p53 tumor suppressor protein maintains cellular and genetic stability after toxic exposures. Here, we show that p53 functional status correlates with oxygen functionalized graphene (f‐G) cytotoxicity and genotoxicity in vitro. The f‐G exposed p53‐competent cells, but not p53‐deficient cells, initiated G₀/G₁ phase cell cycle arrest, suppressed reactive oxygen species, and entered apoptosis. There was p53‐dependent f‐G genotoxicity evident as increased structural chromosome damage, but not increased gene mutation or chromatin loss. In conclusion, the cytotoxic and genotoxic potential for f‐G in exposed cells was dependent on the p53 functional status. These findings have broad implications for the safe and effective implementation of oxidized graphene derivatives into biomedical and industrial applications. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Advances in anticancer chemotherapy have been hindered by the lack of biocompatibility of new prospective drugs. One significant challenge concerns water insolubility, which compromises the bioavailability of the drugs leading to increased dosage and higher systemic toxicity. To overcome these problems, nanodelivery has been established as a promising approach for increasing the efficacy and lowering the required dosage of chemotherapeutics. The naturally derived compound, parthenolide (PTL), is known for its anti-inflammatory and anticancer activity, but its poor water solubility limits its clinical value. In the present study, we have used carboxyl-functionalized nanographene (fGn) delivery to overcome the extreme hydrophobicity of this drug. A water-soluble PTL analog, dimethylaminoparthenolide (DMAPT), was also examined for comparison with the anticancer efficacy of our PTL–fGn complex. Delivery by fGn was found to increase the anticancer/apoptotic effects of PTL (but not DMAPT) when delivered to the human pancreatic cancer cell line Panc-1. The IC₅₀ value for PTL decreased from 39 μM to 9.5 μM when delivered as a mixture with fGn. The IC₅₀ of DMAPT did not decrease when delivered as DMAPT–fGn and was significantly higher than that for PTL–fGn. There were significant increases in ROS formation and in mitochondrial membrane disruption in Panc-1 cells after PTL–fGn treatment as compared to PTL treatment, alone. Increases in toxicity were also seen with apoptosis detection assays using flow cytometry, ethidium bromide/acridine orange/DAPI staining, and TUNEL. Thus, fGn delivery was successfully used to overcome the poor water solubility of PTL, providing a strategy for improving the effectiveness of this anticancer agent.

Graphene and single‐walled carbon nanotubes were used to deliver the natural low‐toxicity drug gambogic acid (GA) to breast and pancreatic cancer cells in vitro, and the effectiveness of this complex in suppressing cellular integrity was assessed. Cytotoxicity was assessed by measuring lactate dehydrogenase release, mitochondria dehydrogenase activity, mitochondrial membrane depolarization, DNA fragmentation, intracellular lipid content, and membrane permeability/caspase activity. The nanomaterials showed no toxicity at the concentrations used, and the antiproliferative effects of GA were significantly enhanced by nanodelivery. The results suggest that these complexes inhibit human breast and pancreatic cancer cells grown in vitro. This analysis represents a first step toward assessing their effectiveness in more complex, targeted, nanodelivery systems. Copyright © 2014 John Wiley & Sons, Ltd.

Cancer cell chemoresistance is one of the major limitations to successful cancer treatment and one of the factors that is responsible for the possible recurrence of the disease. Here, we aimed to combine a calcium-channel blocker, verapamil, with an alternative delivery of the anti-cancer drug, doxorubicin, using nanostructural materials. This approach could reduce the cellular resistance to chemotherapeutics agents. The outcome of this complex approach on cellular viability was investigated by using various assays in both a time- and concentration-dependent manner: WST-1, flow cytometry cell viability assay, fluorescence microscopy, DNA fragmentation, and TUNEL labeling of apoptotic cells. All of these analytical assays confirmed the ability to reduce the chemoresistance of the cancer cells based on the proposed procedure.

Nanotechnology has been extensively explored for cancer diagnostics. However, the specificity of current methods to identify simultaneously several cancer biomarkers is limited due to color overlapping of bio-conjugated nanoparticles. Here, we present a technique to increase both the molecular and spectral specificity of cancer diagnosis by using tunable silver-gold nanorods with narrow surface-enhanced Raman scattering (SERS) and high photothermal contrast. The silver-gold nanorods were functionalized with four Raman-active molecules and four antibodies specific to breast cancer markers and with leukocyte-specific CD45 marker. More than two orders of magnitude of SERS signal enhancement was observed from these hybrid nanosystems compared to conventional gold nanorods. Using an antibody rainbow cocktail, we demonstrated highly specific detection of single breast cancer cells in unprocessed human blood. By integrating multiplex targeting, multicolor coding, and multimodal detection, our approach has the potential to improve multispectral imaging of individual tumor cells in complex biological environments.