Journal of Biomaterials Science, Polymer Edition, 2016
Chitosan coating on magnetic nanoparticles (MNPs) was studied on biological systems as a first st... more Chitosan coating on magnetic nanoparticles (MNPs) was studied on biological systems as a first step toward the application in the biomedical field as drug-targeted nanosystems. Composition of MNPs consists of magnetite functionalized with oleic acid and coated with the biopolymer chitosan or glutaraldehyde-cross-linked chitosan. The influence of the biopolymeric coating has been evaluated by in vitro and in vivo assays on the effects of these MNPs on rat aortic endothelial cells (ECs) viability and on the random tissue distribution in mice. Results were correlated with the physicochemical properties of the nanoparticles. Nitric oxide (NO) production by ECs was determined, considering that endothelial NO represents one of the major markers of ECs function. Cell viability was studied by MTT assay. Different doses of the MNPs (1, 10 and 100 μg/mL) were assayed, revealing that MNPs coated with non-cross-linked chitosan for 6 and 24 h did not affect neither NO production nor cell viability. However, a significant decrease in cell viability was observed after 36 h treatment with the highest dose of this nanocarrier. It was also revealed that the presence and dose of glutaraldehyde in the MNPs structureimpact on the cytotoxicity. The study of the acute tissue distribution was performed acutely in mice after 24 h of an intraperitoneal injection of the MNPs and sub acutely, after 28 days of weekly administration. Both formulations greatly avoided the initial clearance by the reticuloendothelial system (RES) in liver. Biological properties found for N1 and N2 in the performed assays reveal that chitosan coating improves biocompatibility of MNPs turning these magnetic nanosystems as promising devices for targeted drug delivery.
Nanomedicine: Nanotechnology, Biology and Medicine, 2016
Superparamagnetic iron oxide nanoparticles (SPIONS) were synthesized by thermal decomposition of ... more Superparamagnetic iron oxide nanoparticles (SPIONS) were synthesized by thermal decomposition of an organometallic precursor at high temperature and coated with a bi-layer composed of oleic acid and methoxy-polyethylene glycol-phospholipid. The formulations were named SPION-PEG350 and SPION-PEG2000. Transmission electron microscopy, X-ray diffraction and magnetic measurements show that the SPIONs are near-spherical, well-crystalline, and have high saturation magnetization and susceptibility. FTIR spectroscopy identifies the presence of oleic acid and of the conjugates mPEG for each sample. In vitro biocompatibility of SPIONS was investigated using three cell lines; up to 100 μg/ml SPION-PEG350 showed non-toxicity, while SPION-PEG2000 showed no signal of toxicity even up to 200 μg/ml. The uptake of SPIONS was detected using magnetization measurement, confocal and atomic force microscopy. SPION-PEG2000 presented the highest internalization capacity, which should be correlated with the mPEG chain size. The in vivo results suggested that SPION-PEG2000 administration in mice triggered liver and kidney injury.
ABSTRACT A study of the magnetic properties of La2Cu1 − xZnxO4 + δ (0 ≤ x ≤ 0.13; δ = 0.02) by me... more ABSTRACT A study of the magnetic properties of La2Cu1 − xZnxO4 + δ (0 ≤ x ≤ 0.13; δ = 0.02) by means of magnetization measurements (M vs T, H) is reported. The Néel temperature of the 3D antiferromagnetic order (AF) is found to decrease with Zn substitution much more rapidly than in samples without excess oxygen. The effect of Zn substitution on the metamagnetic M vs. H transition is discussed, analyzing the temperature dependence of both the critical field Hc and the weak ferromagnetic moment Ms for different compositions x.
Journal of Biomaterials Science, Polymer Edition, 2016
Chitosan coating on magnetic nanoparticles (MNPs) was studied on biological systems as a first st... more Chitosan coating on magnetic nanoparticles (MNPs) was studied on biological systems as a first step toward the application in the biomedical field as drug-targeted nanosystems. Composition of MNPs consists of magnetite functionalized with oleic acid and coated with the biopolymer chitosan or glutaraldehyde-cross-linked chitosan. The influence of the biopolymeric coating has been evaluated by in vitro and in vivo assays on the effects of these MNPs on rat aortic endothelial cells (ECs) viability and on the random tissue distribution in mice. Results were correlated with the physicochemical properties of the nanoparticles. Nitric oxide (NO) production by ECs was determined, considering that endothelial NO represents one of the major markers of ECs function. Cell viability was studied by MTT assay. Different doses of the MNPs (1, 10 and 100 μg/mL) were assayed, revealing that MNPs coated with non-cross-linked chitosan for 6 and 24 h did not affect neither NO production nor cell viability. However, a significant decrease in cell viability was observed after 36 h treatment with the highest dose of this nanocarrier. It was also revealed that the presence and dose of glutaraldehyde in the MNPs structureimpact on the cytotoxicity. The study of the acute tissue distribution was performed acutely in mice after 24 h of an intraperitoneal injection of the MNPs and sub acutely, after 28 days of weekly administration. Both formulations greatly avoided the initial clearance by the reticuloendothelial system (RES) in liver. Biological properties found for N1 and N2 in the performed assays reveal that chitosan coating improves biocompatibility of MNPs turning these magnetic nanosystems as promising devices for targeted drug delivery.
Nanomedicine: Nanotechnology, Biology and Medicine, 2016
Superparamagnetic iron oxide nanoparticles (SPIONS) were synthesized by thermal decomposition of ... more Superparamagnetic iron oxide nanoparticles (SPIONS) were synthesized by thermal decomposition of an organometallic precursor at high temperature and coated with a bi-layer composed of oleic acid and methoxy-polyethylene glycol-phospholipid. The formulations were named SPION-PEG350 and SPION-PEG2000. Transmission electron microscopy, X-ray diffraction and magnetic measurements show that the SPIONs are near-spherical, well-crystalline, and have high saturation magnetization and susceptibility. FTIR spectroscopy identifies the presence of oleic acid and of the conjugates mPEG for each sample. In vitro biocompatibility of SPIONS was investigated using three cell lines; up to 100 μg/ml SPION-PEG350 showed non-toxicity, while SPION-PEG2000 showed no signal of toxicity even up to 200 μg/ml. The uptake of SPIONS was detected using magnetization measurement, confocal and atomic force microscopy. SPION-PEG2000 presented the highest internalization capacity, which should be correlated with the mPEG chain size. The in vivo results suggested that SPION-PEG2000 administration in mice triggered liver and kidney injury.
ABSTRACT A study of the magnetic properties of La2Cu1 − xZnxO4 + δ (0 ≤ x ≤ 0.13; δ = 0.02) by me... more ABSTRACT A study of the magnetic properties of La2Cu1 − xZnxO4 + δ (0 ≤ x ≤ 0.13; δ = 0.02) by means of magnetization measurements (M vs T, H) is reported. The Néel temperature of the 3D antiferromagnetic order (AF) is found to decrease with Zn substitution much more rapidly than in samples without excess oxygen. The effect of Zn substitution on the metamagnetic M vs. H transition is discussed, analyzing the temperature dependence of both the critical field Hc and the weak ferromagnetic moment Ms for different compositions x.
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Papers by Roberto Zysler