Recent Advances in Immunosafety and Nanoinformatics of Two-Dimensional Materials Applied to Nano-imaging

Two-dimensional (2D) materials have emerged as an important class of nanomaterials for technological innovation due to their remarkable physicochemical properties, including sheet-like morphology and minimal thickness, high surface area, tuneable chemical composition, and surface functionalization. These materials are being proposed for new applications in energy, health, and the environment; these are all strategic society sectors toward sustainable development. Specifically, 2D materials for nano-imaging have shown exciting opportunities in in vitro and in vivo models, providing novel molecular imaging techniques such as computed tomography, magnetic resonance imaging, fluorescence and luminescence optical imaging and others. Therefore, given the growing interest in 2D materials, it is mandatory to evaluate their impact on the immune system in a broader sense, because it is responsible for detecting and eliminating foreign agents in living organisms. This mini-review presents an overview on the frontier of research involving 2D materials applications, nano-imaging and their immunosafety aspects. Finally, we highlight the importance of nanoinformatics approaches and computational modeling for a deeper understanding of the links between nanomaterial physicochemical properties and biological responses (immunotoxicity/biocompatibility) towards enabling immunosafety-by-design 2D materials.

Effects of multiwalled carbon nanotubes co-exposure with cadmium on zebrafish cell line: Metal uptake and accumulation, oxidative stress, genotoxicity and cell cycle

Carbon nanotubes presence in the environment increases every year because of exponential industrial production around the world. In aquatic environments, carbon nanotubes can interact with other pollutants based on their adsorbent surface chemistry properties. Heavy metal ions represent one of the biggest concerns in water resources nowadays due to anthropogenic activities, in which cadmium (Cd) is one of the most harmful metal for aquatic organisms. This study investigated the influence of two co-exposure protocols differing by the order of interaction of oxidized multiwalled carbon nanotubes (ox-MWCNT) with Cd in zebrafish liver cell line (ZFL). The ox-MWCNT was characterized, Cd content in culture medium and uptake by cells were quantified using ICP-MS and, the reactive oxygen species (ROS), the biotransformation enzymes activity of phase I and II as well as the antioxidants defenses and oxidative damage were analyzed. The effects on the cell cycle were investigated by flow cytometry and DNA damage by comet assay. The exposure to ox-MWCNT alone decreased the activity of catalase, glutathione peroxidase, and glutathione S-transferase and altered the cell cycle with a reduction of cells in the G2/M phase. Cd exposure alone decreased the activity of catalase and glutathione S-transferase, increased ROS, metallothionein, and lipid peroxidation content and causes genotoxicity in the cells. Despite different incubation protocol, the co-exposure ox-MWCNT-Cd increased the Cd content in ZFL cells after 24 h exposure, increased ROS production and DNA damage without differences between them. Our results showed the modulation of ox-MWCNT on Cd effects and contributed to future co-exposure toxicity investigations and nanosafety regulations involving carbon nanomaterials and aquatic pollutants.

Interactions of oxidized multiwalled carbon nanotube with cadmium on zebrafish cell line: The influence of two co-exposure protocols on in vitro toxicity tests

The widespread production and application of carbon nanotubes (CNT) have raising concerns about their release into the environment and, the joint toxicity of CNT with pre-existing contaminants needs to be assessed. This is the first study that investigated the co-exposure of oxidized multiwalled carbon nanotubes (ox-MWCNT) and cadmium (Cd) using a zebrafish liver cell line (ZFL). Two in vitro co-exposure protocols differing by the order of ox-MWCNT interaction with Cd and fetal bovine serum (FBS) proteins were evaluated. Ox-MWCNT was physical and chemical characterized and its adsorption capacity and colloidal stability in cell culture medium was determined in both protocols. Cytotoxicity was investigated by MTT, neutral red, trypan blue, lactate dehydrogenase assays and the necrosis and apoptosis events were determined using flow cytometer. The Cd presence in medium did not interfere in the protein corona composition of MWCNT but the order of interaction of FBS and Cd interfered in its colloidal stability and metal adsorption rate. The ox-MWCNT increased Cd toxicity at low concentration probably by a "Trojan horse" and/or synergistic effect, and induced apoptosis and necrosis in ZFL cells. Although it was not observed differences of toxicity between protocols, the interaction of ox-MWCNT first with Cd led to its precipitation in cell culture medium and, as a consequence, to a possible false viability result by neutral red assay. Taken together, it was evident that the order of compounds interactions disturbs the colloidal stability and affects the in vitro toxicological assays. Considering that Protocol A showed more ox-MWCNT stability after interaction with Cd, this protocol is recommended to be adopted in future studies.

Covalent functionalization of graphene oxide with d-mannose: evaluating the hemolytic effect and protein corona formation

Graphene oxide mannosylation impacts on RBCs toxicity and plasma protein interactions.

Nanotoxicity of graphene oxide: Assessing the influence of oxidation debris in the presence of humic acid

This study sought to evaluate the toxicological effects of graphene oxide (GO) through tests with Danio rerio (zebrafish) embryos, considering the influence of the base washing treatment and the interaction with natural organic matter (i.e., humic acid, HA). A commercial sample of GO was refluxed with NaOH to remove oxidation debris (OD) byproducts, which resulted in a base washed GO sample (bw-GO). This process decreased the total oxygenated groups in bw-GO and its stability in water compared to GO. When tested in the presence of HA, both GO and bw-GO stabilities were enhanced in water. Although the embryo exposure showed no acute toxicity or malformation, the larvae exposed to GO showed a reduction in their overall length and acetylcholinesterase activity. In the presence of HA, GO also inhibited acid phosphatase activity. Our findings indicate a mitigation of material toxicity after OD removal. The difference in the biological effects may be related to the materials' bioavailability and biophysicochemical interactions. This study reports for the first time the critical influence of OD on the GO material biological reactivity and HA interaction, providing new data for nanomaterial environmental risk assessment and sustainable nanotechnology.

Pyrostegia venusta attenuate the sickness behavior induced by lipopolysaccharide in mice

AIM OF THE STUDY

Pyrostegia venusta (Ker.) Miers (Bignoniaceae) is native to the Brazilian Cerrado and popularly known as "cipó-de-são-joão." In traditional Brazilian medicine, the Pyrostegia venusta are used as a general tonic as well as a treatment for diarrhea, vitiligo, cough, and common diseases of the respiratory system related to infections, such as bronchitis, flu and cold. This study was conducted to evaluate the effects of a hydroethanolic extract of flowers of Pyrostegia venusta on sickness behaviors induced by lipopolysaccharide in mice.

MATERIALS AND METHODS

To evaluate the effects of orally administered Pyrostegia venusta hydroethanolic extract (PvHE) on lipopolysaccharide-induced sickness behaviors, mice were submitted to the forced swim test (FST) and the open field test.

RESULTS

Lipopolysaccharide (LPS, 100 μg/kg, i.p.) administration increased the time spent floating in the FST and depressed locomotor activity in the open field. Pretreatment with PvHE at test doses of 100 and 300 mg/kg, p.o. attenuated the behavioral changes induced by LPS in the FST and open field test. This effect was similar to pretreatment with dexamethasone (1 mg/kg), which is a steroidal drug that inhibits immune and inflammatory responses, including cytokine production.

CONCLUSION

The extract of Pyrostegia venusta attenuated the depressive-like and exploratory behaviors induced by lipopolysaccharide. Thus, our results supported previous claims of the usefulness of these plants in traditional therapies and suggest that these plants may be useful in the treatment of disorders that induced sickness behavior, such as flu and cold.

Anti-inflammatory and antipyretic effects of Sonchus oleraceus in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sonchus oleraceus L. has been used to relieve headaches, general pain, hepatitis, infections, inflammation and rheumatism in Brazilian folk medicine. Nevertheless, scientific information regarding this species is scarce; there are no reports related to its possible anti-inflammatory effects.

AIM OF THE STUDY

This study was aimed at evaluating the scientific basis for the traditional use of Sonchus oleraceus using in vivo inflammatory models.

MATERIALS AND METHODS

Carrageenan-induced paw edema, peritonitis and febrile response induced by lipopolysaccharide tests, as well as fibrovascular tissue growth induced by s.c. cotton pellet implantation were used to investigate the anti-inflammatory activity of Sonchus oleraceus hydroethanolic extract (SoHE) in rats.

RESULTS

The SoHE at test doses of 100-300 mg/kg p.o. clearly demonstrated anti-inflammatory effects by reduced paw edema induced by carragenan, inhibited leukocyte recruitment into the peritoneal cavity and reduced LPS-induced febrile response, and in the model of chronic inflammation using the cotton pellet-induced fibrovascular tissue growth in rats, the SoHE significantly inhibited the formation of granulomatous tissue. The extract administered at 300 mg/kg p.o. had a stronger anti-inflammatory effect than indomethacin (10mg/kg) or dexamethasone (1mg/kg).

CONCLUSION

The hydroethanolic extract of Sonchus oleraceus markedly demonstrated anti-inflammatory action in rats, which supports previous claims of its traditional use.