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od 2020-09-20

Dr inż. Agnieszka Boś-Liedke  | 2018-01 - obecnie

Adiunkt

   WF UAM pokój: 134      +48 61-829-5239       agnieszka.bos-liedke@amu.edu.pl

  0000-0002-4009-0501     4224381 / AAE-1122-2021     24366052300     
Publikacje                Magistrowie      Licencjusze      Seminaria


6.

Czechowski T., Samolej A., Baranowski M., Boś-Liedke A., Chlewicki W., Jurga J., Tadyszak K.

Adaptive Modulation Amplitude in 2D Spectral-Spatial EPR Imagine A study concerning the image quality in Electron Paramagnetic Resonance Imaging (EPRI) in 2D spectralspatial (2D SSI) experiments is presented. The aim of the measurements is to improve the signal to noise ratio (SNR) of the projections by applying a more consciously selected modulation amplitude parameter. Data is gathered by applying three constant and one adaptive modulation amplitude. The three fixed modulation amplitudes values are leading to undermodulated (0.01 G), partially overmodulated (0.15 G) and fully overmodulated (0.65 G) projections. The study demonstrates the advantages of the adaptive method, which involves selecting different and dependent on cosine function modulation amplitudes for each projection. The study is performed on a phantom containing four tubes of LiPc and TCNQ, characterized by a different peak to peak linewidth and spin concentration

Acta Physica Polonica A, 133(3), 710-712 (2018)

DOI: 10.12693/APhysPolA.133.710   (Pobrane:  2018-04-12)

5.

Boś-Liedke A. Walawender M., Woźniak A., Flak D., Gapiński J., Jurga S., Kucińska M., Plewiński A., Murias M., Elewa M., Lampp L., Imming P., Tadyszak K.

EPR oximetry sensor-developing a TAM derivative for in vivo studies Oxygenation is one of the most important physiological parameters of biological systems. Low oxygen concentration (hypoxia) is associated with various pathophysiological processes in different organs. Hypoxia is of special importance in tumor therapy, causing poor response to treatment. Triaryl methyl (TAM) derivative radicals are commonly used in electron paramagnetic resonance (EPR) as sensors for quantitative spatial tissue oxygen mapping. They are also known as magnetic resonance imaging (MRI) contrast agents and fluorescence imaging compounds. We report the properties of the TAM radical tris(2,3,5,6-tetrachloro-4-carboxy-phenyl)methyl, (PTMTC), a potential multimodal (EPR/fluorescence) marker. PTMTC was spectrally analyzed using EPR and characterized by estimation of its sensitivity to the oxygen in liquid environment suitable for intravenous injection (1mM PBS, pH=7.4). Further, fluorescent emission of the radical was measured using the same solvent and its quantum yield was estimated. An in vitro cytotoxicity examination was conducted in two cancer cell lines, HT-29 (colorectal adenocarcinoma) and FaDu (squamous cell carcinoma) and followed by uptake studies. The stability of the radical in different solutions (PBS pH=7.4, cell media used for HT-29 and FaDu cells culturing and cytotoxicity procedure, full rat blood and blood plasma) was determined. Finally, a primary toxicity test of PTMTC was carried out in mice. Results of spectral studies confirmed the multimodal properties of PTMTC. PTMTC was demonstrated to be not absorbed by cancer cells and did not interfere with luciferin-luciferase based assays. Also in vitro and in vivo tests showed that it was non-toxic and can be freely administrated till doses of 250 mg/kg BW via both i.v. and i.p. injections. This work illustrated that PTMTC is a perfect candidate for multimodal (EPR/fluorescence) contrast agent in preclinical studies.

Cell Biochemistry and Biophysics, , 1-10 (2017)

DOI: 10.1007/s12013-017-0824-3   (Pobrane:  2020-10-23)

4.

Tadyszak K., Boś-Liedke A., Jurga J., Baranowski M., Mrówczynski R., Chlewicki W., Jurga S., Czechowski T.

Overmodulation of projections as signal-to-noise enhancement method in EPR imaging A study concerning the image quality in electron paramagnetic resonance imaging in two-dimensional spatial experiments is presented. The aim of the measurements was to improve the signal-to-noise ratio (SNR) of the projections and the reconstructed image by applying modulation amplitude higher than the radical electron paramagnetic resonance linewidth. Data were gathered by applying four constant modulation amplitudes, where one was below 1/3 (Amod=0.04 mT) of the radical linewidth (ΔBpp=0.14 mT). Three other modulation amplitude values were used in this experiment, leading to undermodulated (Amod < 1/3 ΔBpp), partially overmodulated (Amod ∼ 1/3 ΔBpp) and fully overmodulated (Amod ≥ 1/3 ΔBpp) projections. The advantages of an applied overmodulation condition were demonstrated in the study performed on a phantom containing four shapes of 1.25 mM water solution of 2, 2, 6, 6-tetramethyl-1-piperidinyloxyl. It was shown that even when the overmodulated reference spectrum was used in the deconvolution procedure, as well as the projection itself, the phantom shapes reconstructed as images directly correspond to those obtained in undermodulation conditions. It was shown that the best SNR of the reconstructed images is expected for the modulation amplitude close to 1/3 of the projection linewidth, which is defined as the distance from the first maximum to the last minimum of the gradient-broadened spectrum. For higher modulation amplitude, the SNR of the reconstructed image is decreased, even if the SNR of the measured projection is increased.
(C) 2015 John Wiley & Sons, Ltd.

Magnetic Resonance in Chemistry, 54(2), 136-142 (2016)

DOI: 10.1002/mrc.4330   (Pobrane:  2020-10-25)

3.

Woźniak A., Noculak A., Gapiński J., Kociołek D., Boś-Liedke A., Zalewski T., Grześkowiak B.F., Kołodziejczak A., Jurga S., Bański M., Misiewicz J., Podhorodecki A.

Cytotoxicity and imaging studies of beta-NaGdF4:Yb3+Er3+@PEG-Mo nanorods Multimodal imaging based on nanostructures has become a subject of interest for numerous biomedical laboratories. The main focus was placed on applying nanocrystals for the purpose of two types of clinical imaging (contrast and fluorescent agents) due to their excellent luminescence and/or paramagnetic properties. Such systems should also be characterized by low toxicity and high cellular uptake efficiency. Since bare rare earth fluoride nanocrystals influence the cell membrane integrity, it is expected that their coatings will improve biocompatibility profile, as well as increase hydrophilicity, dispersion and chemical stability. Hence, by synthesis of beta-NaGdF4:Yb3+Er3+ nanorods (NRs) coated with noncovalently bounded polyethylene glycol monooleate (PEG-Mo), it should be possible to obtain multimodal imaging biomarkers meeting established criteria. Synthesis of beta-NaGdF4:Yb3+Er3+@PEG-Mo NRs was performed by the co-precipitation method. These nanostructures were characterized in terms of their size, morphology, zeta potential, magnetic and optical properties as well as their cytotoxicity profile and cellular internalization was evaluated. It was shown that the shape and size of nanocrystals, namely 20 nm nanorods, present generally accepted parameters for biomedical purpose. Ligand attraction of PEG-Mo 860 resulted in the encapsulation of oleic acid coated NRs and formation of hydrophilic bilayer. Superparamagnetic and luminescence properties were highly efficient. Cytotoxic profiles of normal and cancer cell lines were low and determined by dose and time. Cellular uptake was confirmed by the presence of upconversion luminescence in cell interior. These findings are showing multimodal imaging properties of rod shaped beta-NaGdF4:Yb3+Er3+@PEG-Mo NRs which may be useful in some biomedical applications.

RSC Advances, 6(98), 95633-95643 (2016)

DOI: 10.1039/c6ra20415e   (Pobrane:  2018-04-04)

2.

Boś A., Bergmann R., Strobel K., Hofheinz F., Steinbach J., den Hoff Jv.

Cerebral blood flow quantification in the rat: a direct comparison of arterial spin labeling MRI with radioactive microsphere PET Arterial spin labeling magnetic resonance imaging (ASL-MRI) has been recognised as a valuable method for non-invasive assessment of cerebral blood flow but validation studies regarding quantification accuracy by comparison against an accepted gold standard are scarce, especially in small animals. We have conducted the present study with the aim of comparing ASL flow-sensitive alternating inversion recovery (FAIR)-derived unidirectional water uptake (K1) and 68Ga/64Cu microsphere (MS)-derived blood flow (f) in the rat brain.

EJNMMI Research, 2(1), 47 (2012)

DOI: 10.1186/2191-219X-2-47   (Pobrane:  2018-01-28)

1.

Cegiel M., Bazarnik M., Biskupski P., Winiarz S., Gutek J., Boś A., Suto S., Mielcarek S., Wawro A., Czajka R.

STM study of titanium silicide nanostructure growth on Si(111)-(root 19 x root 19) substrate We have performed an STM/STS study of titanium silicide nanostructures grown on Si(1 1 1)-(root 19 x root 19) substrate by Ti evaporation and post-deposition annealing. The (root 19 x root 19) reconstruction was induced by Ni doping. The reaction between the deposited material and the substrate at 220 K was radically different from that observed in the case of the standard Si(1 1 1)-(7 x 7) substrate, as evidenced by the different evaporation time necessary to obtain a comparable coverage of the surface. The annealing was accomplished by direct heating of a crystal sample (up to 520 K, 670 K and 970 K). Measurements showed that coalescence of Ti nanoislands began between 520 K and 670 K. Annealing above 900 K led to alloying of Ti, Ni and Si. As a consequence, Si(1 1 1)-(7 x 7) reconstruction occurred at the cost of Si(1 1 1)-(root 19 x root 19). (C) 2008 Elsevier B. V. All rights reserved.

Applied Surface Science, 254(21), 6948-6951 (2008)

DOI: 10.1016/j.apsusc.2008.05.001   (Pobrane:  2018-01-28)

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