Photocatalytic degradation of Rhodamine B dye by nanostructured powder systems containing nanoencapsulated curcumin or ascorbic acid and ascorbyl palmitate liposomal.

Due to inadequate treatment and incorrect management, wastewater with dyes has a great toxic potential as an environmental liability, representing a major concern. In this context, this work aims to investigate the potential application of nanostructured powdery systems (nanocapsules and liposomes) in the photodegradation of Rhodamine B (RhB) dye, under UV and visible irradiation. Curcumin nanocapsules and liposomes containing ascorbic acid and ascorbyl palmitate were prepared, characterized, and dried using the spray drying technique. The drying processes of the nanocapsule and the liposome showed yields of 88% and 62%, respectively, and, after aqueous resuspension of the dry powders, it was possible to recover the nanocapsule size (140 nm) and liposome size (160 nm). The dry powders were characterized by Fourier transform infrared spectroscopy (FTIR), N2 physisorption at 77 K, X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS-UV). Under UV irradiation, 64.8% and 58.48% of RhB were removed with nanocapsules and liposomes, respectively. While under visible radiation, nanocapsules and liposomes were able to degrade 59.54% and 48.79% of RhB, respectively. Under the same conditions, commercial TiO2 showed degradation of 50.02% (UV) and 42.14% (visible). After 5 cycles of reuse, there was a decrease of about 5% for dry powders under UV irradiation and 7.5% under visible irradiation. Therefore, the nanostructured systems developed have potential application in heterogeneous photocatalysis for the degradation of organic pollutants, such as RhB, as they demonstrated superior photocatalytic performance to commercial catalysts (nanoencapsulated curcumin > ascorbic acid and ascorbyl palmitate liposomal > TiO2).

Impact of free curcumin and curcumin nanocapsules on viability and oxidative status of neural cell lines.

Curcumin is an active polyphenol substance found in the highest concentrations in the roots of Curcuma longa. Its health benefits have led to recent increases in the consumption of curcumin. It has anti-inflammatory and antioxidant activities and is a potent neuroprotective against diseases of the brain. Nevertheless, its low bioavailability and its relative difficulty crossing the blood-brain barrier limit curcumin's use for these purposes. Curcumin-loaded nanoparticles may be an effective treatment for several diseases although there is a paucity of studies reporting its safety in the central nervous system (CNS). Therefore, this study aimed to identify non-neurotoxic concentrations of free curcumin and two nanoformulations of curcumin. Cell lines BV-2 and SH-SY5Y, both originating from the CNS, were evaluated after 24, 48, and 72 h of treatment with free curcumin and nanocapsules We measured viability, proliferation, and dsDNA levels. We measured levels of reactive oxygen species and nitric oxide as proxies for oxidative stress in culture supernatants. We found that free curcumin was toxic at 10 and 20 µM, principally at 72 h. Nanoformulations were more neurotoxic than the free form. Safe concentrations of free curcumin are between 1-5 µM, and these concentrations were lower for nanoformulations. We determined the ideal concentrations of free curcumin and nanocapsules serving as a basis for studies of injuries that affect the CNS.

Detection of new phytochemical compounds from Vassobia breviflora (Sendtn.) Hunz: antioxidant, cytotoxic, and antibacterial activity of the hexane extract.

Vassobia breviflora (Sendtn.) Hunz is a plant of the Solanaceae family from South America and there are no apparent studies reported on the biological activity of the hexane extract. The aim of this investigation was to conduct phytochemical analyses using ESI-TOF-MS, while antioxidant activities were evaluated by the following methods 1,1-diphenyl-2-picrylhydrazyl (DPPH) 2,2"-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical capture (ABTS), ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), and total oxidant status (TOS). Antimicrobial activities were performed by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiofilm formed. Cytotoxicity was measured by MTT and dsDNA PicoGreen tests, beyond the production of reactive oxygen species (ROS) determined by Dichlorodihydrofluorescein diacetate (DCFH-DA). The hexane extract showed the presence of 5 (choline, pantothenic acid, calystegine B, lanciphodylactone I, and 15"-cis-zeaxanthin) compounds detected. V. breviflora extract demonstrated reliable results utilizing different antioxidant methods. In antibacterial activity, V. breviflora extract exhibited inhibitory, bactericidal, and antibiofilm action in biofilm-forming bacteria. The hexane extract exhibited cytotoxicity against melanoma, lung cancer, glioblastoma, leukemia, uterine colon, and hepatocarcinoma tumor cells. In addition, all tested strains resulted in increased production of ROS. This plant extract may be considered in future as an alternative for development of new therapeutic options aimed at the treatment of diverse pathologies.

Eucalyptus oil nanoemulsions against eggs and larvae of Haemonchus contortus.

Haemonchus contortus is a highly pathogenic and prevalent helminth that causes many deaths in sheep herds. Anthelmintics are usually employed to overcome this issue; however, they do not guarantee immediate and lasting efficacy because of the occurrence of drug-resistant parasites. Among substances that are used in scientific studies for parasitic control, essential oils are known to have different pharmacological properties. However, they demonstrate instability owing to several factors, and therefore, nanoemulsification is considered an alternative to control the instability and degradability of these compounds. The objective of this study was to evaluate the cytotoxicity of nanoemulsions containing essential oil of Eucalyptus globulus against the blood of healthy sheep and to verify their activity against the parasite H. contortus in sheep. The results presented adequate nanotechnological characteristics (diameter 72 nm, PDI 0.2, zeta -11 mV, and acidic pH) and adequate morphology. Further, the corona effect and cytotoxic profiles of the free oil and nanoemulsion against blood cells from healthy sheep were evaluated. The tests results did not present a toxicity profile. For evaluating efficacy, we observed an important anthelmintic action of the nanoemulsion containing oil in comparison to the free oil; the results demonstrate a potential role of the nanoemulsion in the inhibition of egg hatchability and the development of larvae L1 to L3 (infective stage). Based on these results, we developed an important and potential anthelmintic alternative for the control of the parasite H. contortus.

Evaluation of the in vivo safety of tucumã oil nanocapsules in an experimental model of silver catfish Rhamdia quelen.

The aim of this study was to evaluate the toxicity of tucumã oil nanocapsules from the Amazon region in silver catfish, Rhamdia quelen. Fish were exposed to water treated with different concentrations of tucumã nanocapsules, white, solubilized oil and surfactant vehicles. After three days of exposure, fish were euthanized and liver, gills and brain removed for analysis of the dichlorofluorescein, nitric oxide and PicoGreen® assays. Plasma was collected for assay of hepatic transaminases. The nanocapsules had a diameter of 221 ± 1.27 nm, confirmed by atomic force microscopy. The oil nanocapsules were not toxic to this species of fish, but white nanocapsules and surfactant increased the levels of reactive oxygen species. Thus, nanocapsules are promising for the transport of tucumã oil. In view of the anti-inflammatory properties of this oil, it is possible to envisage its application in skin diseases for example, since they present essentially inflammatory conditions.HighlightsThe most abundant carotenoid in tucumã oil was all-trans-beta-carotene.Nanocapsules are good carriers for tucumã oil.Tucumã oil nanocapsules does nothas toxicity effect in catfish.

Açaí (Euterpe oleracea Mart.) presents anti-neuroinflammatory capacity in LPS-activated microglia cells.

INTRODUCTION: Neuropsychiatric diseases are responsible for one of the highest burden of morbidity and mortality worldwide. These illnesses include schizophrenia, bipolar disorder, and major depression. Individuals affected by these diseases may present mitochondrial dysfunction and oxidative stress. Additionally, patients also have increased peripheral and neural chronic inflammation. The Brazilian fruit, açaí, has been demonstrated to be a neuroprotective agent through its recovery of mitochondrial complex I activity. This extract has previously shown anti-inflammatory effects in inflammatory cells. However, there is a lack of understanding of potential anti-neuroinflammatory mechanisms, such as cell cycle involvement. OBJECTIVE: The objective of this study is to evaluate the anti-neuroinflammatory potential of an açaí extract in lipopolysaccharide-activated BV-2 microglia cells. METHODS: Açaí extract was produced and characterized through high performance liquid chromatography. Following açaí extraction and characterization, BV-2 microglia cells were activated with LPS and a dose-response curve was generated to select the most effective açaí dose to reduce cellular proliferation. This dose was then used to assess reactive oxygen species (ROS) production, double-strand DNA release, cell cycle modulation, and cytokine and caspase protein expression. RESULTS: Characterization of the açaí extract revealed 10 bioactive molecules. The extract reduced cellular proliferation, ROS production, and reduced pro-inflammatory cytokines and caspase 1 protein expression under 1 µg/mL in LPS-activated BV-2 microglia cells but had no effect on double strand DNA release. Additionally, açaí treatment caused cell cycle arrest, specifically within synthesis and G2/Mitosis phases. CONCLUSION: These results suggest that the freeze-dried hydroalcoholic açaí extract presents high anti-neuroinflammatory potential.

Development, characterisation, stability study and antileukemic evaluation of nanoemulsions containing Astrocaryum aculeatum extract.

The objective of this work was to produce and characterise nanoemulsions containing tucumã extract and to evaluate the performance of the nanostructure and the free compound regarding antitumor activity, cytotoxicity, and oxidative metabolism in NB4/APL cells. The nanoemulsions showed adequate physicochemical characteristics (average size approx. 200 nm, polydispersity index less than 0.3, negative zeta potential and acid pH) maintained stable up to 90 days of storage in refrigeration condition. The nanoformulations did not present protein corona formation. Blank nanoemulsion treatments showed moderate toxicity. Furthermore, the nanoemulsion loaded with extract showed better antileukemic results than the free extract. However, nanoemulsions can be promising carriers of natural compounds, emphasising their biological properties and constituting alternatives in treating diseases.

Protective Effect of Indomethacin-loaded Polymeric Nanoparticles Against Oxidative Stress-Induced Cytotoxicity in Human Breast Adenocarcinoma Cell Model / Efeito Protetor de Nanopartículas Poliméricas com Indometacina contra Citotoxicidade Induzida por Estresse Oxidativo em Modelo Celular de Adenocarcinoma de Mama Humano / Efecto Protector de Nanopartículas Poliméricas con Indometacina contra la Citotoxicidad Inducida por Estrés Oxidativo en Modelo de Células de Adenocarcinoma de Mama Humano

Introduction: Anti-inflammatory drugs are being utilized to treat cancer because of its inflammatory microenvironment. Objective: The objective of this study is to investigate the antioxidant potential of indomethacin and its genotoxicity, since free or loaded in polymeric nanocapsules using MCF-7 (human breast cancer) cells as an in vitro model. Method: Development of indomethacin-loaded polyepsilon-caprolactone (PCL) nanocapsules by interfacial deposition method. It is characterized by pH determination by potentiometer, mean diameter and polydispersity index by dynamic light scattering; zeta potential by electrophoretic mobility; encapsulation efficacy by high performance liquid chromatography method; corona effect formation; 2',7'-dichlorofluorescin diacetate (DCFH-DA) method by spectrofluorimetric assay; nitric oxide (NO) determination by spectrophotometric and genotoxicity assay by plasmid DNA cleavage method. Results: The results showed a mild acidic pH (4.78 ± 0.10), sizes around 200 nm and PDI<0.2 with a zeta potential around -20 mV and encapsulation efficiency of 99% (1 mg mL-1), showing a dose-dependent corona formation profile in 24h incubation. Conclusion: DCFH-DA assay showed no production of reactive oxygen species (ROS) while NO determination showed that Ind-OH-NC from 26.7 to 100 µM increased reactive nitrogen species (RNS), demonstrating antioxidant potential against MCF-7 cells. No sample at the concentrations evaluated induced DNA cleavage, being considered a safe treatment

Introdução: Anti-inflamatórios estão sendo empregados para tratamento de câncer por causa do seu ambiente inflamado. Objetivo: Investigar o potencial antioxidante da indometacina e sua genotoxicidade, livre ou carreada em nanocápsulas poliméricas, usando como modelo in vitrocélulas MCF-7 (câncer de mama humano). Método: Desenvolvimento de nanocápsulas de poliepsilon-caprolactona (PCL) por método de deposição interfacial, caracterizada por determinação de pH por potenciômetro; diâmetro médio e índice de polidispersão por espalhamento dinâmico de luz; potencial zeta por mobilidade eletroforética; eficiência de encapsulação por cromatografia líquida de alta eficiência; formação de efeito corona; método de 2',7'-diclorofluoresceína diacetato (DCFH-DA) por ensaio espectrofluorimétrico; determinação de óxido nítrico (NO) por espectrometria e ensaio de genotoxicidade por método de clivagem do DNA plasmidial. Resultados: Os resultados mostraram leve pH ácido (4,78 ± 0,10), tamanhos em torno de 200 nm e PDI<0,2 com potencial zeta em torno de -20 mV e eficiência de encapsulação de 99% (1 mg mL-1), apresentando perfil de formação de corona dose-dependente em 24 horas de incubação. Conclusão: O ensaio DCFH-DA mostrou que não há produção de espécies reativas de oxigênio (ROS), enquanto a determinação de NO mostrou que Ind-OH-NC de 26,7 a 100 µM aumentou as espécies reativas de nitrogênio (RNS), demonstrando potencial antioxidante contra MCF-7. Nenhuma amostra nas concentrações avaliadas induziu clivagem do DNA, sendo considerado um tratamento seguro

Introducción: Se están utilizando antiinflamatorios para tratamiento de cáncer debido a su entorno inflamado. Objetivo: Investigar el potencial antioxidante de la indometacina y su genotoxicidad, libre o acarreada en nanocápsulas poliméricas utilizando como modelo in vitro células MCF-7 (cáncer de mama humano). Método: Desarrollo de nanocápsulas de poli epsilon-caprolactona (PCL) por método de deposición interfacial, caracterizada por determinación de pH por potenciómetro; diámetro medio e índice de polidispersión por esparcimiento dinámico de luz; potencial zeta por movilidad electroforética; eficiencia de encapsulación por cromatografía líquida de alta eficiencia; formación de efecto corona; método de 2',7'-diclorofluoresceína diacetato (DCFH-DA) por ensayo espectrofluorímetro; determinación de óxido nítrico (NO) por espectrometría y ensayo de genotoxicidad por método de clivaje del ADN plasmídico. Resultados: Los resultados mostraron ligero pH ácido (4,78 ± 0,10), tamaños alrededor de 200 nm y PDI<0,2 con potencial zeta alrededor de -20 mV y eficiencia de encapsulación de 99% (1 mg mL-1), presentando perfil de formación de corona dosis-dependiente en 24h de incubación. Conclusión: El ensayo DCFDA mostró que no hay producción de especies reactivas de oxígeno (ROS) mientras que la determinación de NO mostró que Ind-OH-NC de 26,7 a 100 µM aumentó las especies reactivas de nitrógeno (RNS), demostrando potencial antioxidante contra MCF-7. Ninguna muestra en las concentraciones evaluadas indujo clivaje del ADN, siendo considerado un tratamiento seguro

Protective Effect of Indomethacin-loaded Polymeric Nanoparticles Against Oxidative Stress-Induced Cytotoxicity in Human Breast Adenocarcinoma Cell Model / Efeito Protetor de Nanopartículas Poliméricas com Indometacina contra Citotoxicidade Induzida por Estresse Oxidativo em Modelo Celular de Adenocarcinoma de Mama Humano / Efecto Protector de Nanopartículas Poliméricas con Indometacina contra la Citotoxicidad Inducida por Estrés Oxidativo en Modelo de Células de Adenocarcinoma de Mama Humano

Anti-inflammatory drugs are being utilized to treat cancer because of its inflammatory microenvironment. Objective: The objective of this study is to investigate the antioxidant potential of indomethacin and its genotoxicity, since free or loaded in polymeric nanocapsules using MCF-7 (human breast cancer) cells as an in vitro model. Method: Development of indomethacin-loaded polyepsilon-caprolactone (PCL) nanocapsules by interfacial deposition method. It is characterized by pH determination by potentiometer, mean diameter and polydispersity index by dynamic light scattering; zeta potential by electrophoretic mobility; encapsulation efficacy by high performance liquid chromatography method; corona effect formation; 2',7'-dichlorofluorescin diacetate (DCFH-DA) method by spectrofluorimetric assay; nitric oxide (NO) determination by spectrophotometric and genotoxicity assay by plasmid DNA cleavage method. Results: The results showed a mild acidic pH (4.78 ± 0.10), sizes around 200 nm and PDI PDI<0.2 with a zeta potential around -20 mV and encapsulation efficiency of 99% (1 mg mL-1), showing a dose-dependent corona formation profile in 24h incubation. Conclusion: DCFH-DA assay showed no production of reactive oxygen species (ROS) while NO determination showed that Ind-OH-NC from 26.7 to 100 µM increased reactive nitrogen species (RNS), demonstrating antioxidant potential against MCF-7 cells. No sample at the concentrations evaluated induced DNA cleavage, being considered a safe treatment

Introdução: Anti-inflamatórios estão sendo empregados para tratamento de câncer por causa do seu ambiente inflamado. Objetivo: Investigar o potencial antioxidante da indometacina e sua genotoxicidade, livre ou carreada em nanocápsulas poliméricas, usando como modelo in vitro células MCF-7 (câncer de mama humano). Método: Desenvolvimento de nanocápsulas de poliepsilon-caprolactona (PCL) por método de deposição interfacial, caracterizada por determinação de pH por potenciômetro; diâmetro médio e índice de polidispersão por espalhamento dinâmico de luz; potencial zeta por mobilidade eletroforética; eficiência de encapsulação por cromatografia líquida de alta eficiência; formação de efeito corona; método de 2',7'-diclorofluoresceína diacetato (DCFH-DA) por ensaio espectrofluorimétrico; determinação de óxido nítrico (NO) por espectrometria e ensaio de genotoxicidade por método de clivagem do DNA plasmidial. Resultados: Os resultados mostraram leve pH ácido (4,78 ± 0,10), tamanhos em torno de 200 nm e PDI<0,2 com potencial zeta em torno de -20 mV e eficiência de encapsulação de 99% (1 mg mL-1), apresentando perfil de formação de corona dose-dependente em 24 horas de incubação. Conclusão: O ensaio DCFH-DA mostrou que não há produção de espécies reativas de oxigênio (ROS), enquanto a determinação de NO mostrou que Ind-OH-NC de 26,7 a 100 µM aumentou as espécies reativas de nitrogênio (RNS), demonstrando potencial antioxidante contra MCF-7. Nenhuma amostra nas concentrações avaliadas induziu clivagem do DNA, sendo considerado um tratamento seguro

Introducción: Se están utilizando antiinflamatorios para tratamiento de cáncer debido a su entorno inflamado. Objetivo: Investigar el potencial antioxidante de la indometacina y su genotoxicidad, libre o acarreada en nanocápsulas poliméricas utilizando como modelo in vitro células MCF7 (cáncer de mama humano). Método: Desarrollo de nanocápsulas de poli epsilon-caprolactona (PCL) por método de deposición interfacial, caracterizada por determinación de pH por potenciómetro; diámetro medio e índice de polidispersión por esparcimiento dinámico de luz; potencial zeta por movilidad electroforética; eficiencia de encapsulación por cromatografía líquida de alta eficiencia; formación de efecto corona; método de 2',7'-diclorofluoresceína diacetato (DCFH-DA) por ensayo espectrofluorímetro; determinación de óxido nítrico (NO) por espectrometría y ensayo de genotoxicidad por método de clivaje del ADN plasmídico. Resultados: Los resultados mostraron ligero pH ácido (4,78 ± 0,10), tamaños alrededor de 200 nm y PDI<0,2 con potencial zeta alrededor de -20 mV y eficiencia de encapsulación de 99% (1 mg mL-1), presentando perfil de formación de corona dosis-dependiente en 24h de incubación. Conclusión: El ensayo DCFDA mostró que no hay producción de especies reactivas de oxígeno (ROS) mientras que la determinación de NO mostró que Ind-OH-NC de 26,7 a 100 µM aumentó las especies reactivas de nitrógeno (RNS), demostrando potencial antioxidante contra MCF-7. Ninguna muestra en las concentraciones evaluadas indujo clivaje del ADN, siendo considerado un tratamiento seguro

Vitamin C as a shelf-life extender in liposomes

Abstract The objective of this study was to evaluate the influence of vitamin C (VC) on the stability of stored liposomes under different climatic conditions. Liposomal formulations containing 1 mg/mL of VC (LIP-VC) and blank formulations (LIP-B) were prepared by the reverse-phase evaporation method. After preparation, they were characterized according to their refractive index, average vesicle diameter, polydispersity index (PDI), zeta potential, pH, content, encapsulation efficiency (EE%), morphology, stability and antioxidant activity. For stability, LIP-VC and LIP-B were stored in different climatic conditions (4 °C, 25 °C and 40 °C) for 30 days. The LIP-VC presented 1.3365 refractive index, 161 nm of mean diameter, 0.231 PDI, -7.3 mV zeta potential, 3.2 pH, 19.4% EE%, spherical morphology, 1 mg/mL of VC content, and antioxidant activity of 12 and 11.4 μmol of TE/mL for the radical DPPH and ABTS+, respectively. During stability, the LIP-B stored in 40 °C showed an instability in the parameters: PDI, vesicle size and zeta potential after 15 days, while the LIP-VC remained stable in its size and PDI for 30 days. After that, it is shown that VC can be used as an antioxidant and stabilizer in liposomes to increase the stability and shelf-life of vesicles.

Phytochemical analysis and evaluation of the antioxidant and antiproliferative effects of Tucumã oil nanocapsules in breast adenocarcinoma cells (MCF-7).

In this work was to develop an inedited nanocapsule with tucumã oil (Astrocaryum vulgare). The oil presents of phytosterols (squalene and ß-sitosterol), all-trans-beta-carotene, acids oleic and palmitic. Antioxidant activity showed a good performance in DPPH and ABTS assays. The nanocapsules were prepared and demonstrated in their characterization particle size (206 ± 0.69 nm). The cytogenotoxicity evaluation was performed using the MTT, dichlorofluorescein, nitric oxide and dsDNA PicoGreen® assays. Antitumor efficacy assays in MCF-7 cells demonstrated that free oil and tucumã nanocapsules had IC50 of 130 and 50 µg/mL, respectively. Thus, previous studies of toxicity are relevant, as they generate future subsidies, aiming at the potential application of nanostructures and in addition, the promising effect of NCs of tucumã oil on the antiproliferative effect in breast adenocarcinoma cells was evidenced.

Nanobiopesticides: development and inseticidal activity of nanoemulsions containing lemongrass or eucalyptus oils.

The bioinsecticides, like essential oils, are a promising alternative in pest control. However, these oils have some limitations, such as instability and low solubility. These limitations can be circumvented through nanotechnology, with the nanoemulsification of these compounds. Therefore, the objective of this study was to prepare, characterize and explore the insecticidal activity against adult flies of nanoemulsions containing essential oil of lemongrass or eucalyptus. The nanoemulsions were prepared by the high-energy method and presented droplet size smaller than 125 nm, with polydispersity index of 0.2, pH acid and spherical morphology. The insecticidal activity was evaluated by the Topical Application Method and Exposure Impregnated Paper Exposure, where it was possible to demonstrate a potential insecticidal effect of lemongrass oil in the concentrations of 10, 30 and 50 µL/mL against Musca domestica and Lucilia cuprina and the potentiation of this effect when nanoemulsified this oil against L. cuprina.

Simvastatin-loaded nanoemulsions: development, characterization, stability study and toxicity assays.

Aim: The aim of this study is to prepare and characterize simvastatin-loaded nanoemulsions (SIM-LN) as well as evaluate their physicochemical properties and toxicity. Methodology & results: The SIM-LN were prepared, their characteristics evaluated for 30 days, and after that, the SIM-LN toxicity was evaluated using Vero cell culture and the in vivo model of Caenorhabditis elegans. The prepared SIM-LN had an average droplet size of 139 ± 22 nm, with high encapsulation rate (>98.4%). The storage at room temperature proved to be the most optimal condition. Toxicity assays demonstrated no toxicity. Conclusion: It was demonstrated that the surfactants used as emulsifiers optimized the properties without side effects, because no toxicity was measured in preliminary tests.

Hydrogel containing silibinin nanocapsules presents effective anti-inflammatory action in a model of irritant contact dermatitis in mice.

The current study developed an innovative Pemulen® TR2 hydrogel containing silibinin-loaded pomegranate oil-based nanocapsules (HP-NC SB) intending cutaneous application. The formulation anti-inflammatory activity in an in vivo model and biometric studies on the skin of healthy volunteers were also performed. The nanocapsules were prepared using the interfacial deposition of preformed polymer technique and the hydrogels were obtained by thickening of nanocapsules suspension with Pemulen® TR2. Formulations with free compound, vehicle and blank nanocapsules were also produced. The hydrogels were evaluated concerning pH, silibinin content, particle size, spreadability profile, rheology, in vitro drug release, cutaneous permeation, bioadhesive potential and cutaneous biometry evaluation. Furthermore, a model of contact dermatitis croton oil-induced in mice was performed to evaluate the hydrogels anti-inflammatory potential. The formulations presented adequate characteristics for skin administration: particle within nanometric size, pH values in the acid range, silibinin content close theoretical values (1 mg/g) and non-Newtonian pseudoplastic behavior. Nano-based hydrogels showed high bioadhesive properties, increased silibinin in vitro release profile and its retention in the stratum corneum. The best anti-inflammatory effect was exhibited by HP-NC SB, which reduced both ear edema and inflammatory cells infiltration in comparison to the induced group. Furthermore, cutaneous biometric evaluation showed that formulations containing free or nanoencapsulated silibinin caused no modification in normal skin conditions (pH, tissue hydration, transepidermal water loss and erythema). In summary, the results demonstrated that the Pemulen® TR2 hydrogel containing NC SB was successfully developed, indicating its potential as an alternative treatment for irritant contact dermatitis.

Evaluation of cytotoxicity, genotoxicity and ecotoxicity of nanoemulsions containing Mancozeb and Eugenol.

Mancozeb is a fungicide widely used in agriculture, mostly against the pathogen Glomerella cingulata responsible for the rot of ripe grape, but presents high toxicity. Strategies are sought to reduce the toxicity of this fungicide and alternative treatments are welcome. An alternative could be the use of clove oil, which has Eugenol as its major compound, and has antifungal potential against G. cingulata, however, Eugenol is susceptible to degradation processes which may compromise its efficacy. The nanoencapsulation of Mancozeb and Eugenol is a possible strategy to overcome the limitations of toxicity, solubility and instability of these compounds. Therefore, the objective of this study is to develop nanoemulsions containing Mancozeb (0.1 mg/mL) and Eugenol (33 mg/mL), isolated or associated, and evaluate the safety of these formulations through cytotoxicity, genotoxicity and ecotoxicity tests. Nanoemulsions were developed by the spontaneous emulsification method, cytotoxicity and genotoxicity were evaluated in healthy human cells through MTT, Dichlorofluorescein diacetate and Picogreen tests, and ecotoxicity assessment was carried out using the chronic toxicity test in springtails. After preparation, the physicochemical characterization of the nanoemulsions were performed which presented mean particle size between 200 and 300 nm, polydispersity index less than 0.3, negative zeta potential and acid pH. The nanoencapsulation was able to avoid the reduction of the cell viability caused by Mancozeb, while Eugenol was shown to be safe for cell use in both free and nanostructured forms, however the association of the two active compounds showed toxicity in the higher doses of Mancozeb. In the ecotoxicity tests, both free Mancozeb and Eugenol forms presented high toxic potential for soil, whereas the nanoencapsulation of these compounds did not cause a reduction in number of springtails. Therefore, from the tests performed, it was possible to observe that nanoencapsulation of Mancozeb and Eugenol is a safe alternative for the application of these compounds mainly in agriculture.

Nanoemulsions containing Cymbopogon flexuosus essential oil: Development, characterization, stability study and evaluation of antimicrobial and antibiofilm activities.

The increase of microbial resistance generates the search for new substances with antimicrobial potential. The essential oil of Cymbopogon flexuosus (Lemongrass) stands out in the literature for its antimicrobial, insecticide and antioxidant properties, but it has high volatilization and low stability, and the nanoencapsulation of this oil could be an alternative to overcome these limitations. Thus, the objective of this study was to develop, for the first time, nanoemulsions containing the essential oil of C. flexuosus, through a method that does not use organic solvent and with temperature control to avoid the volatilization of the oil, characterize and evaluate of stability and the antimicrobial and antibiofilm activities of these nanoemulsions. Nanoemulsions presented adequate physicochemical characteristics (average size less than 200 nm, polydispersity index less than 0.3, negative zeta potential and acid pH) which were maintained during 90 days of storage, and the nanoencapsulation of the C. flexuosus oil enhanced its therapeutic efficacy against the microorganisms evaluated in this study compared to the free oil. These results are very promising because among the microorganisms that the nanoemulsion containing C. flexuosus was able to inhibit the formation of biofilm are the bacteria Pseudomonas aeruginosa and Staphylococcus aureus, which were recently listed by the World Health Organization as priority pathogens for development of new antibiotics.

Antibiofilm activity of nanoemulsions of Cymbopogon flexuosus against rapidly growing mycobacteria.

Rapidly growing mycobacteria (RGM) are opportunistic microorganisms that can cause both local and disseminated infections. When in biofilm, these pathogens become highly resistant to antimicrobials used in clinical practice. Composed abundantly of polymeric substances, biofilms delay the diffusion of antimicrobials, preventing the drug from penetrating the deeper layers and having an effective action. Therefore, the search for new and alternative therapeutic options has become of fundamental importance. Natural products fall into these options, especially essential oils. However, these oils present problems, such as low miscibility in water (which decreases its bioavailability) and degradation by light and temperature. Thus, the objective of this work was to explore the action of free essential oil and nanoemulsions of Cymbopogon flexuosus on strains of RGM, in planktonic and sessile forms. In this work, standard strains of Mycobacterium fortuitum (ATCC 6841), Mycobacterium massiliense (ATCC 48898) and Mycobacterium abscessus (ATCC 19977) were used. The susceptibility of the microorganisms in planktonic form was obtained by conventional microdilution techniques and by cell viability curve. The analysis of the antibiofilm activity was performed by a semi-quantitative macrotechnique. The nanoemulsion exhibited significant antimicrobial activity, with minimum inhibitory concentration values lower than those presented by the free essential oil, against strains in the planktonic state. However, both were efficient in destroying the already formed biofilm, whereas only the free oil inhibited the formation of mycobacterial biofilm. This study demonstrated the therapeutic potential of C. flexuosus essential oil, especially in its nanostructured form, which can be demonstrated against infections caused by rapidly growing mycobacteria.

Antimicrobial and antibiofilm activities of nanoemulsions containing Eucalyptus globulus oil against Pseudomonas aeruginosa and Candida spp.

Candida species are the main responsible microorganisms for causing fungal infections worldwide, and Candida albicans is most frequently associated with infectious processes. Pseudomonas aeruginosa is a gram-negative bacterium commonly found in immunocompromised patients. The infection persistence caused by these microorganisms is often related to antimicrobial resistance and biofilm formation. In this context, the objective of the present study was to prepare and characterize nanoemulsions containing Eucalyptus globulus oil and to verify its antimicrobial and antibiofilm activities against P. aeruginosa and Candida spp. The nanoemulsions had a size of approximately 76 nm, a polydispersity index of 0.22, a zeta potential of - 9,42 mV and a pH of approximately 5.0. The E. globulus oil was characterized by gas chromatography, being possible to observe its main components, such as 1-8-Cineol (75.8%), p- Cymene (7.5%), α-Pinene (7.4%) and Limonene (6.4%). The antimicrobial activity of the nanoemulsion was determined from the macrodilution tests and the cell viability curve, where the minimum fungicidal concentration of 0.7 mg/mL for C. albicans and 1.4 mg/mL for C. tropicalis and C. glabrata were obtained. However, the nanoemulsions did not present antimicrobial activity against P. aeruginosa, since it contains only 5% of the oil, being ineffective for this microorganism. The nanoencapsulated oil action against the formed biofilm was evaluated by atomic force microscopy and calcofluor staining, and the nanoemulsion was more efficient for two of the three Candida species when compared to free oil.

Nanostructured cinnamon oil has the potential to control Rhipicephalus microplus ticks on cattle.

The aim of this study was to evaluate the capacity of pure and nanostructured cinnamon oil to control the infestation and reproductive efficiency of Rhipicephalus microplus on dairy cows. In vitro (stage I)-engorged female ticks were immersed in concentrations of 1.0, 5.0 and 10% of cinnamon oil on its pure form, and 0.5, 1.0, and 5.0% of the nanostructured form. 10% cinnamon oil (pure form) showed 100% efficacy, whereas concentrations of 1 and 5% were 62 and 97% efficacious, respectively. Nanocapsules and nanoemulsions containing cinnamon oil at 5% showed 95 and 97% efficacy, respectively. In vivo (stage II)-16 naturally tick-infested cows were divided into four groups of four animals each: Group A was composed of dairy cows sprayed with Triton (control); Group B was composed of dairy cows sprayed with cinnamon oil in its pure form (5%), whereas groups C and D were composed of dairy cows sprayed with nanocapsules and nanoemulsions, respectively, containing cinnamon oil at 0.5%. The ticks on each animal were counted on days 0, 1, 4 and 20 after spraying. Animals sprayed with pure and nanoencapsulated cinnamon oil carried significantly fewer ticks on days 1 and 4 post-treatment and were free of ticks on day 20 post-treatment. Ticks collected from these dairy cows (24 h after application) had impaired oviposition and larval inhibition, resulting in 90.5 and 100% efficacy when using pure and nanocapsules, respectively. In conclusion, the pure and nanostructured forms of cinnamon oil interfered with tick reproduction, whereas a significant acaricidal effect was found when applied onto cattle.

Evaluation of Stability and In Vitro Security of Nanoemulsions Containing Eucalyptus globulus Oil.

Essential oil of Eucalyptus globulus presents several pharmacological properties. However, their therapeutic efficacy may be affected by limitations due to several conditions, rendering it difficult to obtain stable and effective pharmaceutical formulations. The use of nanotechnology is an alternative to improve their characteristics aiming to ensure their stability and effectiveness. Furthermore, studies about the possible toxic effects of nanostructures are necessary to evaluate safety when the formulation comes into contact with human cells. Hence, in this paper, we evaluate for the first time the stability and in vitro cytogenotoxicity of nanoemulsions containing Eucalyptus globulus in peripheral blood mononuclear cells. As a result, the stability study found that the best condition for storage up to 90 days was refrigeration (4°C); it was the condition that best preserved the nanometric features. The content of the major compounds of oil was maintained after nanoencapsulation and preserved over time. In tests to evaluate the safety of this formulation, we can conclude that, at a low concentration (approximately 0.1%), Eucalyptus globulus nanoemulsion did not cause toxicity in peripheral blood mononuclear cells and also showed a protective effect in cells against possible damage when compared to oil in free form.