Metal nanoparticles and pesticides under global climate change: Assessing the combined effects of multiple abiotic stressors on soil microbial ecosystems.

The soil is a vital resource that hosts many microorganisms crucial in biogeochemical cycles and ecosystem health. However, human activities such as the use of metal nanoparticles (MNPs), pesticides and the impacts of global climate change (GCCh) can significantly affect soil microbial communities (SMC). For many years, pesticides and, more recently, nanoparticles have contributed to sustainable agriculture to ensure continuous food production to sustain the significant growth of the world population and, therefore, the demand for food. Pesticides have a recognized pest control capacity. On the other hand, nanoparticles have demonstrated a high ability to improve water and nutrient retention, promote plant growth, and control pests. However, it has been reported that their accumulation in agricultural soils can also adversely affect the environment and soil microbial health. In addition, climate change, with its variations in temperature and extreme water conditions, can lead to drought and increased soil salinity, modifying both soil conditions and the composition and function of microbial communities. Abiotic stressors can interact and synergistically or additively affect soil microorganisms, significantly impacting soil functioning and the capacity to provide ecosystem services. Therefore, this work reviewed the current scientific literature to understand how multiple stressors interact and affect the SMC. In addition, the importance of molecular tools such as metagenomics, metatranscriptomics, proteomics, or metabolomics in the study of the responses of SMC to exposure to multiple abiotic stressors was examined. Future research directions were also proposed, focusing on exploring the complex interactions between stressors and their long-term effects and developing strategies for sustainable soil management. These efforts will contribute to the preservation of soil health and the promotion of sustainable agricultural practices.

Silver, copper and copper oxide nanoparticles in the fight against human viruses: progress and perspectives.

The rapid development of nanomedicine has created a high demand for silver, copper and copper oxide nanoparticles. Due to their high reactivity and potent antimicrobial activity, silver and copper-based nanomaterials have been playing an important role in the search for new alternatives for the treatment of several issues of concern, such as pathologies caused by bacteria and viruses. Viral diseases are a significant and constant threat to public health. The most recent example is the pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this context, the object of the present review is to highlight recent progress in the biomedical uses of these metal nanoparticles for the treatment and prevention of human viral infections. We discuss the antiviral activity of AgNPs and Cu-based NPs, including their actions against SARS-CoV-2. We also discuss the toxicity, biodistribution and excretion of AgNPs and CuNPs, along with their uses in medical devices or on inert surfaces to avoid viral dissemination by fomites. The challenges and limitations of the biomedical use of these nanoparticles are presented.

Silver nanoparticles: Toxicity in model organisms as an overview of its hazard for human health and the environment.

Silver nanoparticles (AgNPs) have attracted remarkable attention due to their powerful antimicrobial action as well as their particular physicochemical properties. This has led to their application in a wide variety of products with promising results. However, their interaction with the environment and toxicity in live terrestrial or aquatic organisms is still a matter of intense debate. More detailed knowledge is still required about the toxicity of AgNPs, their possible uptake mechanisms and their adverse effects in live organisms. Several studies have reported the interactions and potential negative effects of AgNPs in different organisms. In this review, we report and discuss the current state of the art and perspectives for the impact of AgNPs on different organisms present in the environment. Recent progress in interpreting uptake, translocation and accumulation mechanisms in different organisms and/or living animals are discussed, as well as the toxicity of AgNPs and possible tolerance mechanisms in live organisms to cope with their deleterious effects. Finally, we discuss the challenges of accurate physicochemical characterization of AgNPs and their ecotoxicity in environmentally realistic conditions such as soil and water media.

The nanotechnology among US: are metal and metal oxides nanoparticles a nano or mega risk for soil microbial communities?

Metal nanoparticles and metal oxides nanoparticles (MNPs/MONPs) have been widely included in a great diversity of products and industrial applications and they are already a part of our everyday life. According to estimation studies, their production is expected to increase exponentially in the next few years. Consequently, soil has been suggested as the main sink of MNPs/MONPs once they are deliberately or accidentally released into the environment. The potential negative perturbations that may result on soil microbial communities and ecological processes are resulting in concerns. Several nano-toxicological studies of MNPs/MONPs, reported so far, have focused on aquatic organisms, animals, and soil invertebrates. However, during recent years, the studies have been oriented to understand the effects of MNPs/MONPs on microbial communities and their interaction with soil components. The studies have suggested that MNPs/MONPs are one of the most toxic type to soil biota, amongst different types of nanomaterials. This may threaten soil health and fertility, since microbial communities are known to support important biological processes and ecosystem services such as the nutrient cycling, whereby their protection against the environmental pollution is imperative. Therefore, in this review we summarize the actual knowledge available from the last five years (2013-2018) and gaps about the potential negative, positive or neutral effects produced on soil by different classes of MNPs/MONPs. A particular emphasis has been placed on the associated soil microorganisms and biological processes. Finally, perspectives about future research are discussed.

Chitosan nanoparticles for nitric oxide delivery in human skin.

The use of nanoparticle-based transdermal delivery systems is a promising approach to efficiently carry and deliver therapeutic agents for dermal and systemic administration. Nitric oxide (NO) is a key molecule that plays important roles in human skin such as the control of skin homeostasis, skin defense, control of dermal blood flow, and wound healing. In addition, human skin contains stores of NO derivatives that can be mobilized and release free NO upon UV irradiation with beneficial cardiovascular effects, for instance the control of blood pressure. In this work, the NO donor precursor glutathione (GSH) was encapsulated (encapsulation efficiency of 99.60%) into ultra-small chitosan nanoparticles (CS NPs) (hydrodynamic size of 30.65 ± 11.90 nm). GSH-CS NPs have a core-shell structure, as revealed by atomic force microscopy and X-ray photoelectron spectroscopy, in which GSH is protected in the nanoparticle core. Nitrosation of GSH by nitrous acid led to the formation of the NO donor S-nitrosogluthathione (GSNO) into CS NPs. The GSNO release from the CS NPs followed a Fickian diffusion described by the Higuchi mathematical model. Topical application of GSNO-CS NPs in intact human skin significantly increased the levels of NO and its derivatives in the epidermis, as assayed by confocal microscopy, and this effect was further enhanced by skin irradiation with UV light. Therefore, NO-releasing CS NPs are suitable materials for transdermal NO delivery to local and/or systemic therapies.

Topical S-nitrosoglutathione-releasing hydrogel improves healing of rat ischaemic wounds.

Topical application of the nitric oxide (NO) donor S-nitrosoglutathione (GSNO) is known to exert beneficial effects on wound healing. The aim of this study was to evaluate, for the first time, the effect of topical application of GSNO on the healing of ischaemic wounds. Wistar rats were submitted to two parallels incisions on their backs; the skin was separated from the underlying tissue, the incisions were sutured and an excisional wound was made between the parallel incisions to create an ischaemic condition surrounding the wound. The animals were separated into a control group, which received a hydrogel vehicle without GSNO, and a GSNO-treated group, which received a GSNO-containing hydrogel. The animals were treated for 7 days consecutively with one daily application. The GSNO-treated group displayed higher rates of wound contraction and re-epithelization, lower amounts of inflammatory cells, an increase in collagen fibre density and organization and a decrease in the neovascularization compared to control. These results show that topical application of GSNO is effective in the treatment of ischaemic wounds, leading to a significant improvement in the wound healing. Therefore, topical GSNO-containing hydrogels have potential for the therapeutic treatment of ischaemic diabetic and venous ulcers.

Impacto en la administración de un donante de óxido nítrico en gel en el flujo sanguíneo clitoridiano, medido por eco-Doppler / Impact of topic administration of nitric oxide donor gel in the clitoridian blood flow, assessed by Doppler ultra-sound

Objetivo: Evaluar el impacto de las moléculas del donante de óxido nítrico (NO) en el gel F-127 plurónico, aplicado tópicamente en el clítoris, sobre el flujo sanguíneo clitoridiano de mujeres jóvenes voluntarias, usando eco-Doppler. Método: Veinte mujeres sanas mayores de edad, sexualmente activas y sin alteraciones sexuales en su historia clínica fueron enroladas para la medición mediante eco-Doppler de la velocidad del pico sistólico, velocidad diastólica y tasa de resistencia en las arterias clitoridianas previo a la aplicación del donante del NO en gel, a fin de observar los valores basales del flujo en ellas y comparar los valores pre y post. Resultados: Las velocidades sistólica, diastólica y resistencia de base, y 15min posterior a la aplicación del gel, fueron significativamente diferentes (p=0,002, p=0,043, p=0,005, respectivamente). Los resultados muestran el aumento de las velocidades sistólicas y diastólicas a nivel de las arterias clitoridianas en casi 2,5 veces después de 15min de la administración del gel, lo que traduce un aumento en el flujo sanguíneo clitoridiano. Conclusión: El uso del donante de NO en gel S-nitrosoglutation aumenta, significativamente, el flujo sanguíneo del clítoris. Esto podría ser usado terapéuticamente en algunos casos de disfunción sexual(AU)

Objective: This study aims to evaluate of the impact of NO molecules in Pluronic F-127 gel, applied topically in the clitoris, on the clitoridian blood flow of healthy volunteer women, using the Doppler ultra-sound. Method: A total of 20 healthy women over 18 years old and sexually active with no sexual hormones alteration were enrolled. The Doppler ultra-sound procedure was performed on the artery of the clitoris in patients without the NO donor gel, and then after fifteen minutes of its application the same procedure was done again, to compare the values. Results: The hemodynamic results showed, that this formulation was responsible for the increase of the systolic and diastolic speeds in about 2,5 times after 15min of the administration of the gel. The initial resistance index was increased in 1.2 due to the local venous congestion in only 15min after the administration of gel. Indicating that this product can be used to promote the dilatation of the artery of the clitoris to treat women with sexual dysfunction. Conclusion: The use of topic hidrogel as a donor drug in the clitoris of women resulting in a local vasodilatation, without systemic effects. These findings suggest that this preparation may be useful in the management of selected cases of female sexual dysfunction(AU)

[Impact of topic administration of nitric oxide donor gel in the clitoridian blood flow, assessed by Doppler ultra-sound]. / Impacto en la administración de un donante de óxido nítrico en gel en el flujo sanguíneo clitoridiano, medido por eco-Doppler.

OBJECTIVE: This study aims to evaluate of the impact of NO molecules in Pluronic F-127 gel, applied topically in the clitoris, on the clitoridian blood flow of healthy volunteer women, using the Doppler ultra-sound. METHOD: A total of 20 healthy women over 18 years old and sexually active with no sexual hormones alteration were enrolled. The Doppler ultra-sound procedure was performed on the artery of the clitoris in patients without the NO donor gel, and then after fifteen minutes of its application the same procedure was done again, to compare the values. RESULTS: The hemodynamic results showed, that this formulation was responsible for the increase of the systolic and diastolic speeds in about 2,5 times after 15 min of the administration of the gel. The initial resistance index was increased in 1.2 due to the local venous congestion in only 15 min after the administration of gel. Indicating that this product can be used to promote the dilatation of the artery of the clitoris to treat women with sexual dysfunction. CONCLUSION: The use of topic hidrogel as a donor drug in the clitoris of women resulting in a local vasodilatation, without systemic effects. These findings suggest that this preparation may be useful in the management of selected cases of female sexual dysfunction.

S-nitrosoglutathione-containing hydrogel accelerates rat cutaneous wound repair.

BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization.

S-nitrosoglutathione-containing hydrogel increases dermal blood flow in streptozotocin-induced diabetic rats.

BACKGROUND: Endothelial dysfunction is characterized by decreased vasodilatory capacity of the arterioles mainly due to the reduced release of nitric oxide (NO). Application of NO donors may prevent or even reverse the consequences of endothelial dysfunction, such as diabetic leg ulcers. OBJECTIVES: To investigate the vasodilatory capacity and the possible side-effects of topical application of an NO donor-containing hydrogel in diabetic rats. METHODS: S-nitrosoglutathione (GSNO) was incorporated in Pluronic F127 hydrogel and applied on the foot sole skin of healthy and streptozotocin-induced diabetic rats. Blood flow was monitored using a laser-Doppler probe. Nitrotyrosine formation, a possible side-effect of GSNO action, was evaluated by Western blotting of skin protein extracts. Systemic circulatory side-effects were investigated by monitoring blood pressure and heart rate during the application. RESULTS: The hydrogel alone did not induce any changes in microvascular flow, while GSNO-containing hydrogel caused a twofold increase in perfusion. This effect was similar in diabetic and healthy animals. Topical GSNO application did not increase the nitrotyrosine content of skin proteins, nor did it have any effect on blood pressure or heart rate. CONCLUSIONS: Dermal application of GSNO may be an effective treatment for promoting the local vasodilation in both healthy and diabetic states, without inducing protein nitration or alterations in blood pressure or heart rate.

Topically applied S-nitrosothiol-containing hydrogels as experimental and pharmacological nitric oxide donors in human skin.

BACKGROUND: Nitric oxide (NO) has a wide range of functions in the skin, and topical NO donors have several potential clinical applications. However, currently available donors are either unstable on the skin surface, release low concentrations of NO, or have a short duration of action. Endogenous S-nitrosothiols (RSNOs) store and transport NO within the body and can be used as exogenous sources of NO. OBJECTIVES: To study in vitro and in vivo the chemical and biological behaviour of two RSNO species, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylcysteine (SNAC), in an easily applied hydrogel, and to correlate dermal nitrite concentration with erythema following application of the RSNOs. To assess the suitability of GSNO and SNAC as biologically effective NO donors for clinical research and as potential therapeutic agents. METHODS/PATIENTS: GSNO (0.3 mol g(-1)) and SNAC (0.6 mol g(-1)) were incorporated in Synperonic F-127 hydrogels (Uniquema, Belgium). The in vitro kinetics of decomposition were measured by spectrophotometry at 37 degrees C. The RSNO-containing hydrogels were applied to the forearm skin of eight subjects. Blood flow was measured by laser Doppler for 3 h following application of NO donors and dermal nitrite simultaneously measured in microdialysate in four subjects. RESULTS: The mean peak blood flow achieved was 250. At blood flow values of < 250, dermal nitrite correlated closely with blood flow and could be defined by the equation: blood flow = (nitrite concentration x 0.66) + 120, (P = 0.013). At higher blood flows there was a paradoxical fall in dermal nitrite concentration. CONCLUSIONS: Topical RSNOs produce a consistent, sustained and biologically effective release of NO on human skin in vivo, which offers advantages over currently available topical NO donors. Dermal nitrite concentration--the oxidation product of NO--is directly correlated with blood flow at low and moderate levels of blood flow. At high levels of blood flow, there is a reduction in dermal nitrite, which is presumed to be due to increased blood scavenging.