Postmortem brain tissue sections from Globus pallidus externus were routinely obtained during the autopsy to prepare tissue sections for the pathology diagnosis at Department of pathology, Comenius University, Bratislava. Tissues were taken from individuals without clinical findings of any motor abnormalities, iron metabolism, movements involving limbs, face, and tongues (Table 1). All procedures were conducted in accordance with the Declaration of Helsinki. AbstractSeveral types of iron oxides can be found in the various parts of the human brain. These can be highlighted in the light microscopy and using scanning or transmission mode of the electron microscopy. Some of them are non-magnetic, some, on the contrary, display magnetic response. It is not clear which kind of magnetic particles are accumulated in the human brain as inorganic deposits. Light microscopy, electron microscopy and sensitive Superconducting Quantum Interference Device (SQUID magnetometer) were used in order to detect iron deposits and their magnetic response in the samples extracted from the Globus pallidus of the human brain. Electron microscopy reveals a presence of the single crystals of hematite (α-Fe 2 O 3 ) of the size up to 1000 nm in the samples extracted from G. pallidus because of the diffractograms characteristic for the hexagonal unit cell; this mineral offers basically a diamagnetic response. The temperature dependence of the magnetic susceptibility allows a classification of the samples into three groups: mostly diamagnetic I, prevailing paramagnetic III, and an intermediate class II. The bulk samples exhibit a long-range magnetic ordering with magnetic hysteresis evidenced not only at low temperature but also at the room temperature. The recorded magnetic functions refer either to the presence of magnetite (Fe 3 O 4 ), or maghemite (γ-Fe 2 O 3 ). Iron oxides and oxidohydroxides found as inorganic deposits in the human brain can result from interaction between iron and microenvironment in the form of polysaccharides of glycoconjugates. They display magnetoactivity characteristic for magnetite and/or maghemite.
Osteochondral defects develop as a result of trauma, microtrauma, avascular necrosis or cancer. These are usually pre-arthrotic conditions, accompanied by chronic pain and limited joint mobility leading to decreased quality of life of the affected patients. The bone itself has self-repair potential facilitated by mesenchymal stem cells and other cells present in the bone tissue. On the other hand, mature cartilage has very low regenerative capacity due to limited mitotic potential of chondrocytes and lack of vascularization. Therefore, there is an effort to develop an alternative treatment strategy supporting and accelerating natural healing processes. We have designed nanofibrous scaffolds made of poly‑ε‑caprolactone/hyaluronic acid and enriched with specific growth factors – “osteogenic” part with BMP‑2 and “chondrogenic” part with bFGF and TGF‑β. These two parts are meant to be combined in one biphasic non‑cellular scaffold which would be possible to implant in the site of injury and serve as a mechanical support for the cells. We examined proliferation and viability of cells, depth of their penetration into scaffold, cell distribution, alkaline phosphatase activity and extracellular matrix proteins expression. We showed both “osteogenic” and “chondrogenic” scaffold was suitable for cell growth. Moreover, in comparison to the control samples, these two scaffolds exhibited positive effect on chondrogenic and osteogenic differentiation, respectively.
Samples taken from the human brain (Globus Pallidus) have been investigated by physical techniques such as light microscopy, scanning electron microscopy, transmission electron microscopy, Mössbauer spectroscopy and SQUID magnetometry. SEM-EDX/TEM investigation reveals multielemental composition of hematite and magnetite nanocrystals with sizes ranging from 40 nm to 100 nm and hematite microcrystals from 3 μm to 7 μm. Room temperature Mössbauer spectra show quadrupole doublets assigning to hematite and ferrihydrite. SQUID measurements of temperature dependence of the mass magnetic susceptibility between T = 2 – 300 K at DC field B0 = 0.1 T, the field dependence of the mass magnetization taken at the fixed temperature T0 = 2.0 and 4.6 K and the zero-field cooled and field cooled magnetization experiments (ZFCM/FCM) confirm a presence of ferrimagnetic phases such as maghemite and/or magnetite with hysteresis loops surviving until the room temperature. Differences between these measurements from the point of view of iron oxides detected can indicate important processes in human brain and interactions between ferritin as a physiological source of iron and surrounding environment.
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