Interakcije nanodelcev z imunskim sistemom

When nanoparticles enter the body, their interactions with cells are almost unavoidable. Unintended nanoparticle interaction with immune cells may elicit a molecular response that can have toxic effects and lead to greater susceptibility to infectious diseases, autoimmune disorders, and cancer development. As evidenced by several studies, nanoparticle interactions with biological systems can stimulate inflammatory or allergic reactions and activate the complement system. Nanoparticles can also stimulate immune response by acting as adjuvants or as haptens. Immunosuppressive effects have also been reported. This article gives a brief review of in vitro and in vivo research evidencing stimulatory or suppressive effects of nanoparticles on the immune system of mammals. In order to ensure safe use of nanosized particles, future research should focus on how their physical and chemical properties influence their behaviour in the biological environment, as they not only greatly affect nanoparticle-immune system interactions but can also interfere with experimental assays.Ko nanodelci vstopijo v organizem, pridejo v kontakt s celicami imunskega sistema. Nezaželene interakcije nanodelcev z imunskim sistemom lahko sprožijo molekularni odziv, ki lahko pripelje do toksičnih učinkov in povečane dovzetnosti organizma za okužbe, avtoimunska obolenja ter razvoj raka. Dosedanje raziskave so pokazale, da nanodelci lahko sprožijo vnetne in alergijske reakcije, lahko pa tudi aktivirajo sistem komplementa. Nanodelci lahko delujejo kot adjuvansi ali kot hapteni. Obstajajo pa tudi poročila, ki kažejo na sposobnost nanodelcev, da zavrejo imunski odziv. V članku bomo povzeli ugotovitve dosedanjih raziskav in vitro ter in vivo, ki so bile narejene na področju proučevanja vplivov nanodelcev na stimulacijo ali supresijo imunskega sistema sesalcev. Za zagotovitev varne uporabe nanodelcev moramo razumeti kako fizikalno-kemijske lastnosti nanodelcev vplivajo na njihovo obnašanje v biološkem okolju. Lastnosti nanodelcev moramo upoštevati tudi ob izvajanju poskusov, da se izognemo lažnim rezultatom zaradi potencialne interference nanodelcev z dejavniki v eksperimentalnem okolju. Čeprav je bilo do sedaj narejenih že več nanotoksikoloških raziskav, je vpliv nanodelcev na imunski sistem še vedno slabo razumljen. Sposobnost nanodelcev za modulacijo imunskega odziva narekuje potrebo po nadaljnjih raziskavah interakcij nanodelcev z imunskim sistemom

Inhibicija aktivnosti acetilkolinesteraze u zemaljskog jednakonošca Porcellio scaber kao mogući pokazatelj prisutnosti organofosfornih spojeva u hrani

This paper describes the toxicity of organophosphorus pesticide diazinon in juvenile and adult terrestrial isopods Porcellio scaber (Isopoda, Crustacea). The woodlice were exposed to different concentrations of diazinon added to food (5, 10, 50, and 100 or 150 µg/g dry food). Weight change and food assimilation efficiency were determined two and four weeks after the exposure. The activity of acetylcholinesterase (AChE) in surviving animals was measured at the end of the experiment. The results show that woodlice exposed to diazinon do not significantly differ from controls in growth and feeding rate. The reduction of AChE activity was observed at the lowest diazinon exposure (5 and 10 µg/g dry food). These results suggest that AChE activity might prove a useful biomarker, indicating low levels of organophosphates in food.Autori su istraživali toksičnost organofosfornog pesticida diazinona za nezrele i odrasle forme zemaljskog jednakonošca Porcellio scaber. Kukci su eksponirani različitim koncentracijama diazinona dodanog lišću od lijeske, hrani kojom se ti kukci hrane. Kontrolna skupina hranjena je jednakom hranom bez dodatka diazinona. Primijenjene koncentracije diazinona bile su 5, 10, 50 i 100 ili 150 µg/g suhog lista. Autori su mjerili promjenu tjelesne težine i učinak asimilirane hrane, i to nakon 2 i 4 tjedna trajanja ekspozicije. Na kraju pokusa u preživjelih kukaca mjerili su aktivnost acetilkolinesteraze Ellmanovom metodom. Rezultati su pokazali da se kukci eksponirani diazinonu ne razlikuju značajno od kontrolne skupine u pogledu rasta i hranjenja. Aktivnost acetilkolinesteraze, međutim, bila je smanjena već u kukaca eksponiranih najnižim koncentracijama diazinona (5 i 10 µg/g suhe hrane). Ovi rezultati upućuju na to da bi aktivnost acetilkolinesteraze u zemaljskih jednakonožaca mogla biti dobar biološki pokazatelj ekspozicije organofosfornim spojevima u hrani

Izbjegavanje uzimanja hrane Oniscus assellusa kao pokazatelj kakvoće hrane

This paper describes a study of behavioural response in terrestrial isopod Oniscus asellus when offered two food pellets of different quality. One group had a choice of sterilised food and food pellets covered with mould. The other group had a choice of uncontaminated and cadmium-dosed food. During the behavioural test, the animals were monitored by a video camera and each visit to food pellets and time spent around it was counted. The results show that animals spent significantly less time near sterilised and cadmium-dosed food than with uncontaminated or mould-covered food. Discrimination between offered food pellets showed that avoidance behaviour can be used as an indicator of different food quality.Autori su istraživali ponašanje Oniscus asellusa (Crustacea, Izopoda) pri uzimanju različitih pripravaka hrane, a sa svrhom da se utvrdi mogućnost primjene ovakvih testova u vrednovanju kakvoće hrane. Ispitivanim pokusnim životinjama, pomno odabranim i razvrstanim u skupine, nuđena je hrana od usitnjenog sušenog lišća lijeske, želatine i hrane za ribe pomiješana s demineraliziranom vodom. Jednoj je skupini životinja nuđen izbor takve hrane kontaminirane plijesnima i jednake, ali sterilizirane hrane, a drugoj skupini jednaka hrana kojoj je dodan samo nitrat (koji je bio i u ispitivanoj hrani skupa s kadmijem) i ona kontaminirana kadmijevim nitratom (200 mg/kg hrane). Pri praćenju ponašanja pokusnih životinja autori su se koristili videokamerom. Utvrdili su da je skupina koja je imala na izbor pljesnivu i steriliziranu hranu preferirala pljesnivu, a druga je skupina očito izbjegavala hranu kojoj je pridodan kadmijev nitrat. Autori smatraju da bi ovakvi pokusi mogli pripomoći utvrđivanju onečišćenja hrane kadmijem

The Experimental Monitoring of the Water Regime in the Reka River

Reka Reka, s prispevno površino 422 km2 , ponika v Škocjanskih jamah, ki jih je UNESCO leta 1986 proglasil za svetovno dediščino. V sedemdesetih letih je bila Reka ena od najbolj onesnaženih rek v Sloveniji. V času visokih vod leta 1999 in 2000 smo izvedli meritve hitrosti, kalnosti, vrste fizikalnih in kemičnih parametrov ter teste strupenosti. Glavni cilji teh pionirskih meritev so bili preveriti mersko opremo v terenskih pogojih visokih voda, zbrati čimveč podatkov ter primerjati uporabnost opreme.The river Reka, with 422 square kilometres of drainage area sinks into the Škocijan Cave system, which was proclaimed by UNESCO as a World Heritage Site in 1986. In the seventies, the Reka river was one of most polluted rivers in Slovenia. During floods in 1999 and 2000, experimental measurements of velocity, water level, suspended sediment transport, chemical parameters and toxicity tests were conducted. The main tasks in the first stage of the investigation: check the equipment in field conditions and test the toxicity of water in particular cross sections. In the paper, the measurements and some discussion of the results and applicability of equipment are presented

Toxicological Profile of Nanostructured Bone Substitute Based on Hydroxyapatite and Poly(lactide-co-glycolide) after Subchronic Oral Exposure of Rats

Novel three-dimensional (3D) nanohydroxyapatite-PLGA scaffolds with high porosity was developed to better mimic mineral component and microstructure of natural bone. To perform a final assessment of this nanomaterial as a potential bone substitute, its toxicological profile was particularly investigated. Therefore, we performed a comet assay on human monocytes for in vitro genotoxicity investigation, and the systemic subchronic toxicity investigation on rats being per oral feed with exactly administrated extract quantities of the nano calcium hydroxyapatite covered with tiny layers of PLGA (ALBO-OS) for 120 days. Histological and stereological parameters of the liver, kidney, and spleen tissue were analyzed. Comet assay revealed low genotoxic potential, while histological analysis and stereological investigation revealed no significant changes in exposed animals when compared to controls, although the volume density of blood sinusoids and connective tissue, as well as numerical density and number of mitosis were slightly increased. Additionally, despite the significantly increased average number of the Ki67 and slightly increased number of CD68 positive cells in the presence of ALBO-OS, immunoreactive cells proliferation was almost neglected. Blood analyses showed that all of the blood parameters in rats fed with extract nanomaterial are comparable with corresponding parameters of no feed rats, taken as blind probe. This study contributes to the toxicological profiling of ALBO-OS scaffold for potential future application in bone tissue engineering

The biological fate of silver nanoparticles from a methodological perspective

We analyzed the performance and throughput of currently available analytical techniques for quantifying body burden and cell internalization/distribution of silver nanoparticles (Ag NPs). Our review of Ag NP biological fate data shows that most of the evidence gathered for Ag NPs body burden actually points to total Ag and not only Ag NPs. On the other hand, Ag NPs were found inside the cells and tissues of some organisms, but comprehensive explanation of the mechanism(s) of NP entry and/or in situ formation is usually lacking. In many cases, the methods used to detect NPs inside the cells could not discriminate between ions and particles. There is currently no single technique that would discriminate between the metals species, and at the same time enable localization and quantification of NPs down to the cellular level. This paper serves as an orientation towards selection of the appropriate method for studying the fate of Ag NPs in line with their properties and the specific question to be addressed in the study. Guidance is given for method selection for quantification of NP uptake, biodistribution, precise tissue and cell localization, bioaccumulation, food chain transfer and modeling studies regarding the optimum combination of methods and key factors to consider

Microplastics, chlorpyrifos and their mixtures modulate immune processes in the terrestrial crustacean Porcellio scaber

Highlights • Immune parameters are slightly changed upon exposure to plastic fibres or crumb rubber. • Chlorpyrifos caused significant changes in Porcellio scaber immune parameters. • Microplastics decreased the bioavailability of chlorpyrifos for P. scaber. • Mixtures of plastic fibres and chlorpyrifos resulted in greater response in haemocyte count.Microplastics and agrochemicals are common pollutants in terrestrial ecosystems. Their interaction during coexistence in soils may influence their fate and adverse effects on terrestrial organisms. The aim of this study was to investigate how the exposure to two types of microplastics; polyester fibres, and crumb rubber; induce changes in immune parameters of Porcellio scaber and if the co-exposure of microplastics affects the response induced by the organophosphate pesticide chlorpyrifos. A number of immune parameters, such as total haemocyte count, differential haemocyte count, and phenoloxidase-like activity were assessed. In addition, the acetylcholinesterase (AChE) activity in the haemolymph was evaluated as a measure of the bioavailability of chlorpyrifos. After three weeks of exposure, the most noticeable changes in the measured immune parameters and also a significantly reduced AChE activity were seen in chlorpyrifos-exposed animals. Both types of microplastic at environmentally relevant concentrations caused only slight changes in immune parameters which were not dependent on the type of microplastic, although the two types differed significantly in terms of the chemical complexity of the additives. Mixtures of chlorpyrifos and microplastics induced changes that differed from individual exposures. For example, alterations in some measured parameters suggested a reduced bioavailability of chlorpyrifos (AChE activity, haemocyte viability) caused by both types of microplastics exposure, but the increase of haemocyte count was promoted by the presence of fibres implying their joint action. In conclusion, this study suggests that immune processes in P. scaber are slightly changed upon exposure to both types of microplastics and microplastics can significantly modulate the effects of other co-exposed chemicals. Further research is needed on the short-term and long-term joint effects of microplastics and agrochemicals on the immunity of soil invertebrates

Extracellular vesicles from blood plasma as mediators of anti-inflammatory effects, oxidative stress and angiogenesis in HUVEC

Introduction: Blood plasma is used in regenerative medicine for more than 30 years as it was found to have impact on angiogenesis and proliferation of endothelial cells. This effect was initially ascribed to growth factors and cytokines, however, particularly in the last decade researchers are focusing on platelet-derived extracellular vesicles (PEVs) that are also present in the platelet rich plasma. Methods: We prepared platelet and extracellular vesicles-rich plasma (PVRP) by centrifugation of the human blood, and differential (ultra) centrifugation of PVRP to isolate PEVs. We exposed Human Umbilical Vein Endothelial Cells (HUVEC) to 5% PEVs for 24 hours and assessed inflammation markers (Interleukin(IL)-1beta, IL-6 and Tumor necrosis factor (TNF)-alpha using ELISA tests), oxidative stress markers (Cholinesterase (ChE) and glutathione S-transferase (GST) activity by spectrophotometry, as well reactive oxygen species (ROS) and lipid droplets (LD) by flow cytometry). We observed morphological changes in HUVEC indicating angiogenesis by using optical microscopy. Results: We found that after 24 hours caused a decrease of the concentration of IL-6, IL-1beta and TNF-alpha. Also, ChE and GST activity and ROS count were decreased. LD production, which is triggered in need to protect the cells from free radicals and oxidative stress damage, was however higher. Treatment of the cells had impact on cell morphology with progressed formation of the tubes and cell connecting, which is regarded as the beginning of HUVEC angiogenesis process. Discussion: Beneficial effect of PVRP in healing and regeneration may include suppression of inflammation and oxidative stress by PEVs.Small New World 2.0 4-5 September 2023., Graz, Austri

Influence of various sterilization procedures on TiO2 nanotubes used for biomedical devices

Sterilization is the final surface treatment procedure of all implantable devices and is one of the key factors which have to be considered before implementation. Since different sterilization procedures for all implantable devices influence mechanical properties as well as biological response, the influence of different sterilization techniques on titanium nanotubes was studied. Commonly used sterilization techniques such as autoclaving, ultra-violet light sterilization, hydrogen peroxide plasma sterilization as well as the not so frequently used gaseous oxygen plasma sterilization were used. Three different nanotube diameters; 15 nm, 50 nm and 100 nm were employed to study the effects of various sterilization techniques. It was observed that autoclave sterilization resulted in destruction of nanotubular features on all three studied nanotube diameters, while UV-light and both kinds of plasma sterilization did not cause any significant morphological changes on the surfaces. Differences between the sterilization techniques employed influenced cytocompatibility, especially in the case of nanotubes with 100 nm diameter. © 2016 Elsevier B.V.Slovenian Research Agency (ARRS) [J1-4109, J1-4136, J3-4108, P3-0314, P2-0232]; Ministry of Education, Youth and Sports of the Czech Republic [L01504

Gold nanoparticles (AuNPs) impair LPS-driven immune responses by promoting a tolerogenic-like dendritic cell phenotype with altered endosomal structures

Dendritic cells (DCs) shape immune responses by influencing T-cell activation. Thus, they are considered both an interesting model for studying nano-immune interactions and a promising target for nano-based biomedical applications. However, the accentuated ability of nanoparticles (NPs) to interact with biomolecules may have an impact on DC function that poses an unexpected risk of unbalanced immune reactions. Here, we investigated the potential effects of gold nanoparticles (AuNPs) on DC function and the consequences for effector and memory T-cell responses in the presence of the microbial inflammatory stimulus lipopolysaccharide (LPS). Overall, we found that, in the absence of LPS, none of the tested NPs induced a DC response. However, whereas 4-, 8-, and 11 nm AuNPs did not modulate LPS-dependent immune responses, 26 nm AuNPs shifted the phenotype of LPS-activated DCs toward a tolerogenic state, characterized by downregulation of CD86, IL-12 and IL-27, upregulation of ILT3, and induction of class E compartments. Moreover, this DC phenotype was less proficient in promoting Th1 activation and central memory T-cell proliferation. Taken together, these findings support the perception that AuNPs are safe under homeostatic conditions; however, particular care should be taken in patients experiencing a current infection or disorders of the immune system