Emilia Galdiero

Toxicity Effects of Functionalized Quantum Dots, Gold and Polystyrene Nanoparticles on Target Aquatic Biological Models: A Review

Nano-based products are widespread in several sectors, including textiles, medical-products, cosmetics, paints and plastics. Nanosafety and safe-by-design are driving nanoparticle (NP) production and applications through NP functionalization (@NPs). Indeed, @NPs frequently present biological effects that differ from the parent material. This paper reviews the impact of quantum dots (QDs), gold nanoparticles (AuNPs), and polystyrene-cored NPs (PSNPs), evidencing the role of NP functionalization in toxicity definition. Key biological models were taken into consideration for NP evaluation: Saccharomyces cerevisiae, fresh- (F) and saltwater (S) microalgae (Raphidocelis subcapitata (F), Scenedesmus obliquus (F) and Chlorella spp. (F), and Phaeodactylum tricornutum (S)), Daphnia magna, and Xenopus laevis. QDs are quite widespread in technological devices, and they are known to induce genotoxicity and oxidative stress that can drastically change according to the coating employed. For example, AuNPs are frequently functionalized with antimicrobial peptides, which is shown to both increase their activity and decrease the relative environmental toxicity. P-NPs are frequently coated with NH2− for cationic and COOH− for anionic surfaces, but when positively charged toxicity effects can be observed. Careful assessment of functionalized and non-functionalized NPs is compulsory to also understand their potential direct and indirect effects when the coating is removed or degraded.

Porins and Lipopolysaccharide Induce Apoptosis in Human Spermatozoa

ABSTRACT Treatment of human spermatozoa with porins or lipopolysaccharide (LPS) increases spontaneous apoptosis in these cells. Porins and LPS were extracted from Salmonella enterica serovar Typhimurium and Pasteurella multocida and were mixed with human spermatozoa for detection of levels of apoptosis.

Peptide inhibitors against herpes simplex virus infections

Herpes simplex virus (HSV) is a significant human pathogen causing mucocutaneous lesions primarily in the oral or genital mucosa. Although acyclovir (ACV) and related nucleoside analogs provide successful treatment, HSV remains highly prevalent worldwide and is a major cofactor for the spread of human immunodeficiency virus. Encephalitis, meningitis, and blinding keratitis are among the most severe diseases caused by HSV. ACV resistance poses an important problem for immunocompromised patients and highlights the need for new safe and effective agents; therefore, the development of novel strategies to eradicate HSV is a global public health priority. Despite the continued global epidemic of HSV and extensive research, there have been few major breakthroughs in the treatment or prevention of the virus since the introduction of ACV in the 1980s. A therapeutic strategy at the moment not fully addressed is the use of small peptide molecules. These can be either modeled on viral proteins or derived from antimicrobial peptides. Any peptide that interrupts protein–protein or viral protein–host cell membrane interactions is potentially a novel antiviral drug and may be a useful tool for elucidating the mechanisms of viral entry. This review summarizes current knowledge and strategies in the development of synthetic and natural peptides to inhibit HSV infectivity. Copyright

An integrated study on antimicrobial activity and ecotoxicity of quantum dots and quantum dots coated with the antimicrobial peptide indolicidin

This study attempts to evaluate the antimicrobial activity and the ecotoxicity of quantum dots (QDs) alone and coated with indolicidin. To meet this objective, we tested the level of antimicrobial activity on Gram-positive and Gram-negative bacteria, and we designed an ecotoxicological battery of test systems and indicators able to detect different effects using a variety of end points. The antibacterial activity was analyzed against Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 1025), Escherichia coli (ATCC 11229), and Klebsiella pneumoniae (ATCC 10031), and the results showed an improved germicidal action of QDs-Ind. Toxicity studies on Daphnia magna indicated a decrease in toxicity for QDs-Ind compared to QDs alone, lack of bioluminescence inhibition on Vibrio fisheri, and no mutations in Salmonella typhimurium TA 100. The comet assay and oxidative stress experiments performed on D. magna showed a genotoxic and an oxidative damage with a dose–response trend. Indolicidin retained its activity when bound to QDs. We observed an enhanced activity for QDs-Ind. The presence of indolicidin on the surface of QDs was able to decrease its QDs toxicity.

Interactions between bovine endothelial cells and Pasteurella multocida: association and invasion.

We investigated the association and the invasion of a bovine aortic endothelial cell (BAEC) line by Pasteurella multocida to study the potential role of internalized bacteria and possible intracellular survival during Pasteurella infections. Our data indicate that P. multocida is able to adhere to and to invade BAECs. The density of the bacterial population plays a defined role for an optimal mechanism of interaction between bacteria and cells, as does the incubation period of association and invasion. The optimal bacteria/cells ratio was found to be 100/1, while the optimal infection time was approximately 4 h of incubation. Bacterial internalization was dependent on microfilament and microtubule stability. The invasion ability of P. multocida in the presence of cytochalasin D was reduced by 60%; in the presence of colchicine it was reduced by 97% and in the presence of nocodazole it was reduced by 95%. Our data show that internalized P. multocida did not induce mortality of invaded endothelial cells. Some Pasteurella cells were able to survive and undergo exocytosis.

Induction of cytokine mRNA expression in U937 cells by Salmonella typhimurium porins is regulated by different phosphorylation pathways

Lipopolysaccharide (LPS) and porins of Gram-negative outer membranes are the main pathogenic factors implicated in the clinical syndrome of septic shock. The biological activity of porins and LPS are similar, but they occur by different mechanisms. It seems that porins act through different intracellular pathways with respect to LPS. In this study we analyzed the role of several inhibitors of the MEK/ERK signal pathway on the induction of proinflammatory and immunological cytokines in U937 cell line stimulated by Salmonella typhimurium porins and compared it to the cytokine induction after LPS stimulation. We investigated the effects of p38 MAP kinase inhibitor SB-203580, MEK/ERK kinase inhibitor PD-098059 and Raf-1 inhibitor forskolin, and demonstrated that they modulate cytokine mRNA expression in a different manner as a consequence of the use of porins or LPS as stimuli. TNF-α and IL-1β mRNA expression is decreased by PD-098059 after stimulation with LPS but not with porins in differentiated U937 cells. IL-10 mRNA expression is inhibited by SB-203580 and PD-098059 after stimulation with porins in U937 cells. IL-6 and IL-8 mRNA expression is not changed by PD-098059 or SB-203580, after stimulation either with porins or LPS. Furthermore, mRNA expression of the studied cytokines, except for GM-CSF, is not changed using forskolin.

Modulation of apoptosis in mice treated with Echinacea and St. John's wort.

Apoptosis, or programmed cell death (PCD), is a physiological active cellular suicide process that occurs in non-contiguous cells, and is usually not associated with inflammation. The apoptotic process can be modulated by various stimuli, including hormones, cytokines, growth factors, and some chemotherapeutic agents. To determine whether Echinacea purpurea and Hypericum perforatum are able to regulate the process of apoptosis in vivo and to define the role of the Fas-Ag and Bcl-2 signal transduction cascade, we have orally treated groups of mice with these vegetable drugs for 14 days. The splenic lymphocytes from mice treated with E. purpurea and H. perforatum at the two dose levels used (30 and 100 mg kg(-1) per day) were shown to be significantly more resistant to apoptosis than those from mice treated only with the vehicle. In addition, mice treated with the natural substances showed a decrease in Fas-Ag expression and an increase in Bcl-2 expression. In conclusion, our results shown that in vivo the studied drugs modulate apoptosis in mice splenic lymphocytes and that this action could be mediated in part by a decrease in Fas-Ag expression and in part by an increase in Bcl-2 expression.

Review of a viral peptide nanosystem for intracellular delivery

Abstract. The internalization of bioactive molecules is one of the most critical problems to overcome in theranostics. In order to improve pharmacokinetic and pharmacodynamic properties, synthetic transporters are widely investigated. A new nanotechnological transporter, gH625, is based on a viral peptide sequence derived from the herpes simplex virus type 1 glycoprotein H (gH) that has proved to be a useful delivery vehicle, due to its intrinsic properties of inducing membrane perturbation. The peptide functionalization with several kinds of nanoparticles like quantum dots, dendrimers, and liposomes could be of particular interest in biomedical applications to improve drug release within cells, to increase site-specific action, and eventually to reduce related cytotoxicity.

Neutrophil Adhesion and Transmigration through Bovine Endothelial Cells in vitro by Protein H and LPS of Pasteurella Multocida

This study describes an in vitro investigation on the role of Pasteurella multocida cells and its isolated protein H and LPS on neutrophil adhesion and migration through bovine endothelial cell monolayers. P. multicoda cells, protein H and LPS increased the adhesion and transmigration of neutrophils through BAEC. The bacteria/cell ratio of 100 for P. multocida, protein H concentration 0.05-0.2 microM and LPS concentration 0.5-1.0 microM respectively, induced the maximum adhesion and transmigration of neutrophils through BAEC. The optimal time of incubation with bacteria or bacterial products was 4-6 h. Our results confirm the role of Gram-negative bacteria and of components of the outer membrane such as protein H or LPS in activating the neutrophils and in promoting the adhesion and cells transmigration from the vessels to the site of inflammation.

Evidence for IL-6 promoter nuclear activation in U937 cells stimulated with Salmonella enterica serovar Typhimurium porins

Interleukin-6 (IL-6) is a pleiotropic cytokine and plays an active role in inflammatory and immune responses, contributing to a multitude of physiological and pathophysiological processes. In this study, we address the molecular mechanism of IL-6 transcriptional induction and propose a correlation between activated NF-kappaB localization and IL-6 expression. In particular, we detected, by ChIP assay, that occupation of the IL-6 gene promoter site is dependent on activated NF-kappaB. In fact, after porin stimulation, the NF-kappaB p65 subunit is activated, translocates to the nucleus and binds to the IL-6 promoter sequence.Elucidation of the host signaling pathways and identification of the transcription factors that contribute to IL-6 expression, may aid in the understanding of host susceptibility to gram-negative infections and in identifying new therapeutic strategies in a variety of infectious diseases.