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

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

PLA-Based Hybrid and Composite Electrospun Fibrous Scaffolds as Potential Materials for Tissue Engineering

The aim of the study was to manufacture poly(lactic acid)- (PLA-) based nanofibrous nonwovens that were modified using two types of modifiers, namely, gelatin- (GEL-) based nanofibres and carbon nanotubes (CNT). Hybrid nonwovens consisting of PLA and GEL nanofibres (PLA/GEL), as well as CNT-modified PLA nanofibres with GEL nanofibres (PLA + CNT/GEL), in the form of mats, were manufactured using concurrent-electrospinning technique (co-ES). The ability of such hybrid structures as potential scaffolds for tissue engineering was studied. Both types of hybrid samples and one-component PLA and CNTs-modified PLA mats were investigated using scanning electron microscopy (SEM), water contact angle measurements, and biological and mechanical tests. The morphology, microstructure, and selected properties of the materials were analyzed. Biocompatibility and bioactivity in contact with normal human osteoblasts (NHOst) were studied. The coelectrospun PLA and GEL nanofibres retained their structures in hybrid samples. Both types of hybrid nonwovens were not cytotoxic and showed better osteoinductivity in comparison to scaffolds made from pure PLA. These samples also showed significantly reduced hydrophobicity compared to one-component PLA nonwovens. The CNT-contained PLA nanofibres improved mechanical properties of hybrid samples and such a 3D system appears to be interesting for potential application as a tissue engineering scaffold

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

Avian Feathers as Bioindicators of the Exposure to Heavy Metal Contamination of Food

The aim of this study was to determine the possibility of using feathers of blue tit nestlings to assess the level of endogenous accumulation of lead. For this purpose we conducted an experiment with lead application to randomly chosen nestlings from eight randomly drawn broods. Five days after the exposure, feathers of lead-treated nestlings had significantly higher lead concentrations than control nestlings. This result suggests that feathers can be used as reliable non-destructive bioindicators to assess the level of heavy metals originating from contaminated food, which is of great significance for comparative studies on ecological consequences of pollution

The influence of operating conditions of the marine gas turbine engine on the level of emission of pollutants contained in the exhaust

Pollution emission tests from turbine engines used for the main propulsion of vessels require measurement of the concentration of harmful compounds in the exhaust and assessment of the exhaust gases mass generated by the engine. The concentration of harmful compounds can be determined in a direct way by measuring it in the stream of exhaust gases. However, due to the large output of exhaust gases, the mass of exhaust gases must be determined indirectly. To do this it is necessary to carry out a series of tests and analyzes that will enable parameterization of operating conditions. The obtained parameters and functional relations between them can be used to assess the mass of generated exhaust gases. The article presents analyzes related to the methodology for assessing the mass of exhaust gases generated by the main propulsion turbine engine of the vessel, and the manner of their use in the assessment of emission of harmful exhaust gases

Implementation of gas and liquid chromatography in the study of liquid products of microwave-assisted pyrolysis

W niniejszej pracy zbadano możliwości wykorzystania technik chromatografii gazowej GC-FID oraz GC-MS wspomaganych klasyczną chromatografią cieczową LC do badania składników biooleju pochodzącego z pirolizy biomasy stałej. Badania biomasy i produktów jej przerobu mają na celu rozwój technologii paliw proekologicznych i/lub zawierających frakcje otrzymywane z biomasy lub surowców odpadowych. Celem tych działań jest stopniowe zwiększanie wykorzystania źródeł energii pochodzących z surowców odnawialnych przy jednoczesnym ograniczaniu zastosowania surowców kopalnych. Jest to jedno z działań, których efektem ma być ograniczenie emisji GHG. Działanie to jest związane z wytycznymi dyrektyw Unii Europejskiej nakazujących wzrost udziału odnawialnych źródeł energii w transporcie oraz energetyce. Są to dyrektywy 2003/30/WE oraz 2009/28/WE, dotyczące promowania użycia biopaliw lub innych paliw odnawialnych w transporcie oraz wzrostu udziału pozyskiwania energii ze źródeł odnawialnych w różnych sektorach krajów Wspólnoty Europejskiej. Energetyczne wykorzystanie biomasy to jeden z głównych obszarów zainteresowania polityki energetycznej Polski, zbieżnej z celami polityki wyznaczonymi przez Unię Europejską. W niniejszym artykule dokonano przeglądu literatury w zakresie rodzajów biomasy występującej w Polsce oraz zastosowania technik chromatografii gazowej i cieczowej (Py-GC, GC-MS, GC-FID) w badaniu ciekłych produktów procesu pirolizy biomasy. Opracowano warunki chromatograficzne badania produktów ciekłych pirolizy biomasy stałej przy wykorzystaniu reaktora mikrofalowego do pirolizy jako elementu aparatury umożliwiającego badania technikami chromatograficznymi. Przy zastosowaniu dobranych warunków analitycznych wykonano badania ciekłych produktów pirolizy biomasy: miskantu olbrzymiego, słomy, trocin sosnowych, łusek słonecznika i ziaren kawy. Zidentyfikowano składniki biooleju pochodzącego z pirolizy biomasy i zaproponowano metodę oznaczania ilościowego składników biooleju. Wykazano możliwość jednoczesnego zastosowania różnych technik chromatografii gazowej w celu poznania składu chemicznego biooleju pochodzącego z pirolizy mikrofalowej różnego rodzaju biomasy stałej.In this work, the possibilities of implementation of the GC-FID and GC-MS gas chromatography techniques supported by classic LC liquid chromatography to study the components of bio-oil derived from the pyrolysis of solid biomass were examined. Research on biomass and its processing products is aimed at the development of pro-ecological fuels and / or fuels containing fractions obtained from biomass or waste materials. The aim of these activities is to gradually increase the use of energy sources derived from renewable raw materials and limiting the use of fossil raw materials. It is one of the ways to reduce GHG emissions. This action is related to the guidelines of the European Union Directives describing an increase in the share of renewable energy sources in transport and energy – Directives 2003/30/EC and 2009/28/EC – the promotion of the use of biofuels or other renewable fuels in transport and the increase in the share of energy obtained from renewable sources in various sectors of the European Community. The use of energy obtained from biomass is one of the main areas of interest in Poland's energy policy, consistent with the policy objectives set by the European Union. This article describes the types of biomass found in Poland and the use of gas and liquid chromatography techniques (Py-GC, GC-MS, GC-FID) in the study of liquid products of the biomass pyrolysis process. The chromatographic conditions for testing liquid products of solid biomass pyrolysis with the use of a microwave pyrolysis reactor as an element of the apparatus enabling the research with chromatographic techniques were developed. Using selected analytical conditions, tests were carried out on liquid products of biomass pyrolysis: giant miscanthus, straw, pine sawdust, sunflower husks and coffee grounds. The components of bio-oil derived from biomass pyrolysis were identified and a method for the quantification of bio-oil components was proposed. The possibility of the simultaneous application of various gas chromatography techniques to understand the chemical composition of bio-oil from microwave pyrolysis of various types of solid biomass was demonstrated

Emission of particulate matter during aircraft landing operation

The article presents the results of studies conducted in the area adjacent to the airport located in Poznan, to determine the impact of aircraft landing operation on the concentration of particulate matter. Measurements were carried out using Engine Exhaust Particle Sizer Spectrometer 3090, enabling the measurement of the particle size distribution. The research allowed to determine the nature of the emitted particles and adds to the evaluation of impact on air quality. The tests were carried out during four aircraft landing operations. In each of the four cases total concentration of particulates number before landing (reference level) and during the landing of the aircraft was measured. In addition, the size distribution of reference level particles and its change after the landing operation was measured. Based on the conducted research, it was found that landing aircrafts have a significant impact on the concentration of particulate matter in the area adjacent to the airport. A single landing operation causes an substantially increase of the value of particle number concentration