Solid State Nuclear Magnetic Resonance, Jun 1, 2013
This work presents the theoretical analysis of cross-relaxation and its applications to the study... more This work presents the theoretical analysis of cross-relaxation and its applications to the study of molecular dynamics in the solid state heteronuclear systems in the laboratory frame. The solid state NMR experiments were carried out on a homemade pulse spectrometer operating at the frequency of 30.2 MHz and 28.411 MHz for protons and fluorines, respectively. It is worth noting that this spectrometer includes a specially designed probe which simultaneously works at two slightly differing frequencies for protons and fluorine nuclei with complete absence of their interference. Contrary to a large number of previous cross-relaxation studies, in our experiments proton spins can be polarized in the magnetic field B0 or excited by rf pulses, while fluorine spins are continuously saturated for a long time. The saturation of fluorines is maintained throughout the whole duration of the experiment. It leads to a simplification of the mathematical analysis of the experimental results.
Glioblastoma (GBM) is the most common malignant neoplasm in adults among all CNS gliomas, with th... more Glioblastoma (GBM) is the most common malignant neoplasm in adults among all CNS gliomas, with the 5-year survival rate being as low as 5%. Among nanocarriers, liposomal nanoformulations are considered as a promising tool for precise drug delivery. The herein presented study demonstrates the possibility of encapsulating four selected natural compounds (curcumin, bisdemethoxycurcumin, acteoside, and orientin) and their mixtures in cationic liposomal nanoformulation composed of two lipid types (DOTAP:POPC). In order to determine the physicochemical properties of the new drug carriers, specific measurements, including particle size, Zeta Potential, and PDI index, were applied. In addition, NMR and EPR studies were carried out for a more in-depth characterization of nanoparticles. Within biological research, the prepared formulations were evaluated on T98G and U-138 MG glioblastoma cell lines in vitro, as well as on a non-cancerous human lung fibroblast cell line (MRC-5) using the MTT t...
Abstract This paper presents the comparative study of molecular dynamics and of the thermal prope... more Abstract This paper presents the comparative study of molecular dynamics and of the thermal properties of the virgin commercial monthly hydrogel contact lenses Bausch & Lomb Soflens 59 and the lenses worn for 1, 2, 3 and 4 weeks. The lenses were made from the hilafilcon B material, which was a hydrophilic copolymer of poly(2-hydroxyethyl methacrylate) pHEMA and poly(N-vinyl pyrrolidone) PVP, containing 59 wt.% of water. The 1H NMR on-resonance and off-resonance techniques have been carried out to study the molecular dynamics of the water contained in soft contact lenses. The measurements were carried out using a homemade pulse spectrometer operating at the frequency of 30.2 MHz at temperature 303 K. On the basis of the dispersion of the spin–lattice relaxation rates R1ρ = 1/T1ρ in the rotating frame the correlation times τc of the water molecules were estimated. A new method for measuring the motion parameters, based on the value of the equilibrium magnetization in the effective field Be was described. To analyze NMR off-resonance results a model-free approach with Lipari–Szabo spectral density function was used to determine the order parameter S2 and the effective correlation time τe. The thermal properties of hydrogel contact lenses have been characterized using differential scanning calorimetry DSC. It has been shown that the period of wearing contact lenses cannot be extended beyond the time specified by the manufacturer.
The work presents the study of the molecular dynamics of phenylene selenide by Nuclear Magnetic R... more The work presents the study of the molecular dynamics of phenylene selenide by Nuclear Magnetic Resonance (NMR). The spin – lattice relaxation times in the laboratory frame and the spin – lattice relaxation times off-resonance in the rotating frame (Fig.2) and the second moment of the resonance 1 H NMR lines (Fig.3) were measured as a function of temperature. The where measurements were performed using a hand – made pulse spectrometer. ] ω e [krad/s] Fig. 1. Fig. 2. Taking into account the early results for poly (p – phenylene selenide) (PPSe) it is suggested that relaxation times for poly (p – biphenylene selenide) (PPBSe) are connected with the reorientation of phenylene rings around the selenide – phenylen – selenide axis and the interaction between protons and paramagnetic centers. The correlation times of the internal motions were estimated on the basis of the dispersion of the relaxation time and the temperature dependence of the 1 H NMR line width. These results are in good a...
Solid State Nuclear Magnetic Resonance, Jun 1, 2013
This work presents the theoretical analysis of cross-relaxation and its applications to the study... more This work presents the theoretical analysis of cross-relaxation and its applications to the study of molecular dynamics in the solid state heteronuclear systems in the laboratory frame. The solid state NMR experiments were carried out on a homemade pulse spectrometer operating at the frequency of 30.2 MHz and 28.411 MHz for protons and fluorines, respectively. It is worth noting that this spectrometer includes a specially designed probe which simultaneously works at two slightly differing frequencies for protons and fluorine nuclei with complete absence of their interference. Contrary to a large number of previous cross-relaxation studies, in our experiments proton spins can be polarized in the magnetic field B0 or excited by rf pulses, while fluorine spins are continuously saturated for a long time. The saturation of fluorines is maintained throughout the whole duration of the experiment. It leads to a simplification of the mathematical analysis of the experimental results.
Glioblastoma (GBM) is the most common malignant neoplasm in adults among all CNS gliomas, with th... more Glioblastoma (GBM) is the most common malignant neoplasm in adults among all CNS gliomas, with the 5-year survival rate being as low as 5%. Among nanocarriers, liposomal nanoformulations are considered as a promising tool for precise drug delivery. The herein presented study demonstrates the possibility of encapsulating four selected natural compounds (curcumin, bisdemethoxycurcumin, acteoside, and orientin) and their mixtures in cationic liposomal nanoformulation composed of two lipid types (DOTAP:POPC). In order to determine the physicochemical properties of the new drug carriers, specific measurements, including particle size, Zeta Potential, and PDI index, were applied. In addition, NMR and EPR studies were carried out for a more in-depth characterization of nanoparticles. Within biological research, the prepared formulations were evaluated on T98G and U-138 MG glioblastoma cell lines in vitro, as well as on a non-cancerous human lung fibroblast cell line (MRC-5) using the MTT t...
Abstract This paper presents the comparative study of molecular dynamics and of the thermal prope... more Abstract This paper presents the comparative study of molecular dynamics and of the thermal properties of the virgin commercial monthly hydrogel contact lenses Bausch & Lomb Soflens 59 and the lenses worn for 1, 2, 3 and 4 weeks. The lenses were made from the hilafilcon B material, which was a hydrophilic copolymer of poly(2-hydroxyethyl methacrylate) pHEMA and poly(N-vinyl pyrrolidone) PVP, containing 59 wt.% of water. The 1H NMR on-resonance and off-resonance techniques have been carried out to study the molecular dynamics of the water contained in soft contact lenses. The measurements were carried out using a homemade pulse spectrometer operating at the frequency of 30.2 MHz at temperature 303 K. On the basis of the dispersion of the spin–lattice relaxation rates R1ρ = 1/T1ρ in the rotating frame the correlation times τc of the water molecules were estimated. A new method for measuring the motion parameters, based on the value of the equilibrium magnetization in the effective field Be was described. To analyze NMR off-resonance results a model-free approach with Lipari–Szabo spectral density function was used to determine the order parameter S2 and the effective correlation time τe. The thermal properties of hydrogel contact lenses have been characterized using differential scanning calorimetry DSC. It has been shown that the period of wearing contact lenses cannot be extended beyond the time specified by the manufacturer.
The work presents the study of the molecular dynamics of phenylene selenide by Nuclear Magnetic R... more The work presents the study of the molecular dynamics of phenylene selenide by Nuclear Magnetic Resonance (NMR). The spin – lattice relaxation times in the laboratory frame and the spin – lattice relaxation times off-resonance in the rotating frame (Fig.2) and the second moment of the resonance 1 H NMR lines (Fig.3) were measured as a function of temperature. The where measurements were performed using a hand – made pulse spectrometer. ] ω e [krad/s] Fig. 1. Fig. 2. Taking into account the early results for poly (p – phenylene selenide) (PPSe) it is suggested that relaxation times for poly (p – biphenylene selenide) (PPBSe) are connected with the reorientation of phenylene rings around the selenide – phenylen – selenide axis and the interaction between protons and paramagnetic centers. The correlation times of the internal motions were estimated on the basis of the dispersion of the relaxation time and the temperature dependence of the 1 H NMR line width. These results are in good a...
Uploads
Papers by Aneta Woźniak-Braszak