Medical Aspects of Nanomaterial Toxicity

Nanosilver is the most popular and most studied nanomaterial, however, a family of nanomaterials is rapidly enlarging. They are used in various branches of industry and everyday life. In medicine new nanomaterials can be used either alone or in combination with other “classical” drugs, e.g. cytostatic drugs or antibiotics. They can be also used as diagnostic agents. A development of nanoparticles has led to a new combination of diagnostic and therapy - theranostic. Size of a particle makes a difference not only between bulk material and nanomaterial, but also in their properties and toxicity. Nanomaterials can have beneficial properties, but can also be toxic. New issues concerning nanomaterials arise - an industrial exposure and environmental pollution. They can enter human body in various ways. Cellular mechanisms of nanomaterial toxicity comprise mainly a generation of reactive oxygen species and genotoxicity. The differences between toxicity of fine particles and nanoparticles have led to an origin of a new branch of science, nanotoxicology

Would you donate your body? Attitudes of students of nursing and physiotherapy towards body donation for educational and scientific purposes

Background: Human body is the most perfect atlas of human anatomy. Body donation after death is, next to donation of organs for the purpose of transplantation, another most altruistic act, which significantly influences the future of medicine, as regards teaching of anatomy and clinical disciplines. Because students are mainly the beneficiaries of corpse donations, it appears important to learn about their attitudes to this altruistic act. The purpose was to assess the awareness and attitudes of students of nursing and physiotherapy towards body donation for educational and scientific purposes. Materials and methods: A total of 128 Polish students (110 women and 18 men) from the faculties of nursing and physiotherapy of the Medical University of Silesia in Katowice, Poland took part in the questionnaire study. The average age in respective groups was 19.94±0.34 years of age in case of nursing and 19.93±0.25 years of age in case of physiotherapy. The first part of the proprietary questionnaire concerned classes in body dissection conducted in prosectorium and their significance for teaching anatomy. The second part applied to the program of Conscious Body Donation, attitudes towards the body in prosectorium and the approach to body donation for educational and scientific purposes. Results: The results of the study indicate that students from both faculties are in favor of body donation after death for educational and scientific purposes. Unfortunately, only a small percentage of them expressed the willingness to become body donators. The main reasons for the reluctance to do so included psychological barrier and concern for the family. Conclusions: Most of students who responded to the questionnaire support the idea of body donation for educational and scientific purposes after death, yet they appear to be more willing to donate their organs for transplantation than their bodies for educational or scientific purposes after death. There are numerous factors which influence students’ attitude to body donation. More emphasis should be put on educating students, which could contribute to changing their attitude toward that altruistic act, and in consequence may increase the number of donors in the future

Evaluation of subarachnoid space and subarachnoid cisterns in children and teenagers based on computed tomography studies

Purpose: The aim of the study was to develop the normative values of linear indices to the diagnosis of changes in size of the subarachnoid space. Material and methods: Retrospective studies were conducted based on 507 head computed tomography (CT) examinations in children from 0-18 years of age. In total 381 tests were selected for correct reference values. Patients were divided into age groups. For each group, linear indices were calculated, taking into account the size of the fluid spaces in relation to the size of the skull and then the mean with standard deviation, median, as well as 10th and 90th percentile were calculated. The range between the 10th and the 90th percentiles was defined as the reference value. Results: Obtained normative values, minimum and maximum for all groups: index of basal cistern size to the size of the skull - 0.129-0.197; index of basal cistern transverse dimension to the size of the skull - 0.173-0.255; index of basal cistern sagittal dimension to the size of the skull - 0.086-0.150; index of prepontine cistern - 0.034-0.067; index of interhemispheric fissure width - 0.044-0.127; index of Sylvian fissure - 0.036-0.085; index of insular cistern width - 0.020-0.074; index of subarachnoid space - 0.017-0.081. Conclusions: The linear indices can be calculated based on images achieved during routine CT examination. The reference values allow us to determine if the size of the subarachnoid space is within the normal range for a given age group. The results from the oldest age group can also be referred to the adults. Key words: external hydrocephalus, subarachnoid space, computed tomography (CT), linear indices, infants and children

Structure and properties of slow-resorbing nanofibers obtained by (co-axial) electrospinning as tissue scaffolds in regenerative medicine

With the rapid advancement of regenerative medicine technologies, there is an urgent need for the development of new, cell-friendly techniques for obtaining nanofibers—the raw material for an artificial extracellular matrix production. We investigated the structure and properties of PCL10 nanofibers, PCL5/PCL10 core-shell type nanofibers, as well as PCL5/PCLAg nanofibres prepared by electrospinning. For the production of the fiber variants, a 5–10% solution of polycaprolactone (PCL) (Mw = 70,000–90,000), dissolved in a mixture of formic acid and acetic acid at a ratio of 70:30 m/m was used. In order to obtain fibers containing PCLAg 1% of silver nanoparticles was added. The electrospin was conducted using the above-described solutions at the electrostatic field. The subsequent bio-analysis shows that synthesis of core-shell nanofibers PCL5/PCL10, and the silver-doped variant nanofiber core shell PCL5/PCLAg, by using organic acids as solvents, is a robust technique. Furthermore, the incorporation of silver nanoparticles into PCL5/PCLAg makes such nanofibers toxic to model microbes without compromising its biocompatibility. Nanofibers obtained such way may then be used in regenerative medicine, for the preparation of extracellular scaffolds: (i) for controlled bone regeneration due to the long decay time of the PCL, (ii) as bioscaffolds for generation of other types of artificial tissues, (iii) and as carriers of nanocapsules for local drug delivery. Furthermore, the used solvents are significantly less toxic than the solvents for polycaprolactone currently commonly used in electrospin, like for example chloroform (CHCl3), methanol (CH3OH), dimethylformamide (C3H7NO) or tetrahydrofuran (C4H8O), hence the presented here electrospin technique may allow for the production of multilayer nanofibres more suitable for the use in medical field

The comparison of multipotential for differentiation of progenitor mesenchymal-like stem cells obtained from livers of young and old rats.

The presence of stem cells differentiating to hepatocytes and cholangiocytes has been previously reported in livers of young rats. Here, we have isolated, cultured, and characterized mesenchymal stem cells (MSCs) from livers of young and old rats and tested their multipotential for differentiation. The mesenchymal stem cells in liver sections were identified by the presence of markers, respectively for primary stem cells Thy-1 and CD34, for differentiation to early cholangiocytes GST and CK19, and for differentiation to hepatocytes GSTalpha and CK18. Ki67 was detected as the cell proliferation marker. Cells isolated from livers of either age group were tested in a culture for their viability following storage and were characterized for the presence of most of the markers detected in cells in situ. The results revealed age-dependent changes in the number of recovered primary MSCs. In both age groups we have observed cells changing under differentiating conditions to liver cell lineages, such as cholangiocytes and hepatocytes, as well as to non-liver cells such as adipocytes, astrocytes, neuroblasts, and osteoblasts. Our data revealed that from the livers of rats 20 months and older the primary MSCs could be isolated and expanded; however, they were significantly fewer, even though their differentiation multipotential was preserved. The mechanism involved in the differentiation of liver MSCs seemed to depend on a constellation of signals in Notch signalling pathways. Thus, our results support the idea of potential use of liver as a source of MSCs, not only for liver reconstruction but also for cell therapy in general

Comparison of Physicochemical, Mechanical, and (Micro-)Biological Properties of Sintered Scaffolds Based on Natural- and Synthetic Hydroxyapatite Supplemented with Selected Dopants

The specific combinations of materials and dopants presented in this work have not been previously described. The main goal of the presented work was to prepare and compare the different properties of newly developed composite materials manufactured by sintering. The synthetic-(SHAP) or natural- (NHAP) hydroxyapatite serves as a matrix and was doped with: (i) organic: multiwalled carbon nanotubes (MWCNT), fullerenes C60, (ii) inorganic: Cu nanowires. Research undertaken was aimed at seeking novel candidates for bone replacement biomaterials based on hydroxyapatite—the main inorganic component of bone, because bone reconstructive surgery is currently mostly carried out with the use of autografts; titanium or other non-hydroxyapatite -based materials. The physicomechanical properties of the developed biomaterials were tested by Scanning Electron Microscopy (SEM), Dielectric Spectroscopy (BSD), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry (DSC), as well as microhardness using Vickers method. The results showed that despite obtaining porous sinters. The highest microhardness was achieved for composite materials based on NHAP. Based on NMR spectroscopy, residue organic substances could be observed in NHAP composites, probably due to the organic structures that make up the tooth. Microbiology investigations showed that the selected samples exhibit bacteriostatic properties against Gram-positive reference bacterial strain S. epidermidis (ATCC 12228); however, the property was much less pronounced against Gram-negative reference strain E. coli (ATCC 25922). Both NHAP and SHAP, as well as their doped derivates, displayed in good general compatibility, with the exception of Cu-nanowire doped derivates

Nanosilver - does it have only one face?

Silver nanoparticles (NPs) have at least one dimension of a particle smaller than 100 nm and contain 20-15,000 silver atoms. Due to its antibacterial activity nanosilver (NS) is used for medical purposes. NS particles can be obtained by various methods. Potentially, the best method of the NS synthesis for medical purposes is based on a brief flow of electric current between two silver electrodes placed in deionized water. It is accepted that the major antibacterial effect of silver is its partial oxidation and releasing silver ions, which interact with thiol groups of peptidoglicans of bacterial cell wall, and proteins of the cell membrane causing cell lysis. Silver ions can also bind to bacterial DNA preventing its replication and stopping synthesis of bacterial proteins. The rise in exposure to silver NPs has spurred interest into their toxicology. NS undergoes a set of biochemical transformations including accelerated oxidative dissolution in gastric acid, binding to thiol groups of serum and tissue proteins, exchange between thiol groups, sulfides and selenides, binding to selenoproroteins and photoreduction in skin to zerovalent metallic silver. Animal studies have shown that exposure to NS may lead to liver and spleen damage. NS can also stimulate an increased secretion of proinflammatory cytokines by monocytes. As a spectrum of NS applications is still growing, the complex evaluation of a safety of its use becomes an important task. This requires an elucidation of not only the influence of NS on human cells and organism, but also its biotransformation in organism and in environment

Zawartość galektyny-1 i -3 w polipach pierwotnych i nawrotowych nosa i zatok przynosowych

Wstęp: Polipy nosa i zatok przynosowych są jednym z najczęstszych problemów współczesnej laryngologii. Niejednokrotnie, pomimo leczenia operacyjnego, polipy nosa i zatok przynosowych mają tendencję do nawrotów, wymagając ponownego leczenia operacyjnego. Bardzo trudno jest przewidzieć, którzy pacjenci są szczególnie narażeni. Wciąż poszukuje się markerów, które pozwoliłyby stwierdzić, którzy pacjenci znajdują się w grupie szczególnego ryzyka, wymagając tym samym wzmożonego nadzoru klinicznego. Galektyny stanowią grupę glikoprotein, które ostatnio skupiają coraz większą uwagę badaczy. Część cukrowa tych białek może odgrywać rolę w przekazywaniu sygnałów międzykomórkowych. Zainteresowanie laryngologów budzą m.in. galektyny-1 i -3. Stwierdzenie zwiększonej ich zawartości w tkance nowotworowej może obecnie być traktowane jako marker złośliwości nowotworu, który pogarsza rokowanie u pacjentów. Ostatnio przywiązuje się coraz większą uwagę do udziału galektyn w łagodnych zmianach rozrostowych, a do takich właśnie zalicza się polipy nosa i zatok przynosowych. Materiały i metody: W naszej pracy oznaczono zawartość galektyn -1 i -3 w tkance usuniętych polipów pierwotnych (n = 35) i nawrotowych (n = 15). Wyniki: Zawartość galektyny-1 i -3 nie wykazywała istotnych statystycznie różnic pomiędzy polipami pierwotnymi i nawrotowymi. Wnioski: Zawartość galektyny-3 była niższa w polipach nawrotowych, lecz zaobserwowana różnica nie osiągnęła istotności statystycznej (p = 0,07). Ponieważ otrzymana wartość „p” jest bliska granicy istotności, rekomendowane jest poszerzenie przedstawionych badań na większej grupie pacjentów, aby móc w pełni ocenić, czy oznaczanie zawartości galektyny-3 może być pomocne w ocenie ryzyka nawrotu polipów nosa

Galectin-1 and -3 contents in primary and recurrent nasal and paranasal sinus polyps

Introduction: Nasal and paranasal sinus polyps are one of the most common laryngological problems. Often, despite surgical treatment of nasal and paranasal sinus polyps, they grow back and require surgical retreatment. It is very difficult to predict which patients are particularly exposed to it. Markers are still being sought to predict which patients are particularly exposed to regrowth of polyps and thus require increased clinical surveillance. Galectins are a group of glycoproteins that have been intensively studied recently. The sugar part of these proteins can play a role in transmitting intercellular signals. Laryngologists are especially interested in galectins-1 and -3. The determination of their increased content in cancer tissue is considered as a marker of malignancy, which worsens prognosis in patients. Recently, more and more attention has been paid to the role of galectins in benign lesions, and such are the nasal and paranasal sinus polyps. Materials and methods: In our work, the contents of galectin-1 and-3 were determined in the tissue of the surgically removed primary (n = 35) and recurrent polyps (n = 15). R esults: The content of galectin-1 and-3 showed no statistically significant differences between primary and recurrent polyps. Conclusions: The content of galectin-3 was lower in recurrent polyps, however the observed difference did not reach statistical significance (p = 0.07). Since the obtained „p” value is close to the significance limit, it is advisable to broaden the submitted studies to a larger group of patients in order to be able to fully assess whether the determination of the content of galectin-3 may be helpful in assessing the risk of recurrence of nasal and paranasal sinus polyps