Browsing by Subject "Iron oxide nanoparticles"

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Open Access
Engineered bacteria with genetic circuits accumulating nanomagnets as MRI contrast agents
(Wiley, 2022-01-25) Yavuz, Merve; Ütkür, Mustafa; Kehribar, Ebru Şahin; Yağız, Ecrin; Sarıtaş, Emine Ülkü; Şeker, Urartu Özgür Şafak
The demand for highly efficient cancer diagnostic tools increases alongside the high cancer incidence nowadays. Moreover, there is an imperative need for novel cancer treatment therapies that lack the side effects of conventional treatment options. Developments in this aspect employ magnetic nanoparticles (MNPs) for biomedical applications due to their stability, biocompatibility, and magnetic properties. Certain organisms, including many bacteria, can synthesize magnetic nanocrystals, which help their spatial orientation and survival by sensing the earth's geomagnetic field. This work aims to convert Escherichia coli to accumulate magnetite, which can further be coupled with drug delivery modules. The authors design magnetite accumulating bacterial machines using genetic circuitries hiring Mms6 with iron-binding activity and essential in magnetite crystal formation. The work demonstrates that the combinatorial effect of Mms6 with ferroxidase, iron transporter protein, and material binding peptide enhances the paramagnetic behavior of the cells in magnetic resonance imaging (MRI) measurements. Cellular machines are also engineered to display Mms6 peptide on the cell surface via an autotransporter protein that shows augmented MRI performance. The findings are promising for endowing a probiotic bacterium, able to accumulate magnetite intracellularly or extracellularly, serving as a theranostics agent for cancer diagnostics via MRI scanning and hyperthermia treatment. © 2022 Wiley-VCH GmbH.
Open Access
Synthesis of iron oxide core chitosan nanoparticles in a 3D printed microfluidic device
(Springer, 2021-03-02) Aşık, M.D.; Kaplan, M.; Çetin, Barbaros; Sağlam, N.
Nanostructures are capable of major changes in our life. However, the game changing properties of experimental nanostructures mostly are not repeatable for the industry and it is not easy to produce the amount of nanoparticles necessary for the industrial world. Repeatable methods, which do not require highly trained personnel, for industrial-scale production should be developed to transfer the academic research to the use of people. Although there are various successful microfluidics devices that have been designed for microstructures synthesis, the synthesis of the nanostructures is not an enlightened area and there is a need for research to reach a better state. Especially, the development and design of microfluidics devices for biopolymeric nanoparticles are very important. The biopolymeric nanoparticles have uses in both nanotechnology and nanomedicine especially as theragnostic tools. In this study, a microfluidic device has been modeled, designed, and manufactured for especially iron oxide core chitosan nanoparticles. The microfluidics channels were manufactured by 3D printing. After nanoparticles synthesized by manufactured device, these particles were characterized, and their properties were examined. In addition to the flow rate, chemical concentrations, and pH, the structure of the microfluidics channel and hurdles have effects on the particle size and particle size distribution. Best results were obtained with 120-120ml/h flow rates and 0.06-0.03% concentrations at pH 4.5 for chitosan-tripolyphosphate couple. The nanoparticles that were produced in microchannels with hurdles under these conditions have a DLS measurement of 190±15 nm in diameter with 69% intensity. In conclusion, the 3D printed microfluidic channels are able to synthesize nanoparticles in a reproducible way with or without iron oxide core.
Open Access
Zeta potential: A surface electrical characteristic to probe the interaction of nanoparticles with normal and cancer human breast epithelial cells
(Springer New York LLC, 2008) Zhang, Y.; Yang, M.; Portney, N. G.; Cui, D.; Budak, G.; Özbay, Ekmel; Ozkan, M.; Ozkan, C. S.
We demonstrate the use of surface Zeta potential measurements as a new tool to investigate the interactions of iron oxide nanoparticles and cowpea mosaic virus (CPMV) nanoparticles with human normal breast epithelial cells (MCF10A) and cancer breast epithelial cells (MCF7) respectively. A substantial understanding in the interaction of nanoparticles with normal and cancer cells in vitro will enable the capabilities of improving diagnostic and treatment methods in cancer research, such as imaging and targeted drug delivery. A theoretical Zeta potential model is first established to show the effects of binding process and internalization process during the nanoparticle uptake by cells and the possible trends of Zeta potential change is predicted for different cell endocytosis capacities. The corresponding changes of total surface charge of cells in the form of Zeta potential measurements were then reported after incubated respectively with iron oxide nanoparticles and CPMV nanoparticles. As observed, after MCF7 and MCF10A cells were incubated respectively with two types of nanoparticles, the significant differences in their surface charge change indicate the potential role of Zeta potential as a valuable biological signature in studying the cellular interaction of nanoparticles, as well as specific cell functionality.