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Nanoparticles from silk fibroin and Amazon oils: Potential larvicidal activity and oviposition deterrence against Aedes aegypti
Abstract and Figures
This work reports the preparation of nanoparticles of silk fibroin with esters obtained from the oils of two Amazonian plant species (Carapa guianensis Aublet and Bertholletia excelsa) with excellent physicochemical properties and activity against the larvae of the vector Aedes aegypti. The temporal stability of the nanoparticles was evaluated for 50 days at temperatures of 4 ºC and 32 ºC. The size of the nanoparticle was satisfactory, with sizes ranging from 207 ± 2.3 nm to 540.8 ± 23.8 nm, and PdI values ranging from 0.294 to 0.560, and zeta potential from − 37.9 ± 0.3 mV to − 62.9 ± 0.7 mV. Study of the morphology of nanoparticles, by transmission electron microscopy analysis, clearly showed spherical shapes. The nanoparticles presented slow and controlled release that induced a high mortality rate in the 3rd larval instar of Ae. aegypti, with LC 50 of 27.45 μg. mL − 1 for FABE-Cg-SF-NPs and LC 50 of 21.14 μg.mL − 1 for FABE-Be-SF-NPs, after 48 h of exposure. In addition, they were able to inhibit oviposition by Ae. aegypti. However, the nanoparticles did not present significant teratogenic effects on zebrafish embryos up to 72 h post-fertilization. Thus, the formation of nanoparticles by butyl esters in silk fibroin may become an (eco)alternative and effective in the control of Ae. aegypti larvae.
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... The fatty acid obtained from the Tecoma stans pericarps exhibited an effect on C. quinquefasciatus larvae, with 81.67% mortality in 250 μg.mL − 1 [51]. Marinho et al. [53] used fatty acid butyl esters from oils of two Amazonian plant species (Carapa guianensis Aublet and Bertholletia excelsa), combined with silk fibroin, against the larvae of the vector Aedes aegypti. A high mortality rate was The concentration values presented by the mixture of all the acids in DDPO are lower than those of palmitic, stearic, and oleic acids. ...
Increased consumption of palm oil results in more palm oil by-products. To meet environmental sustainability goals, deodorizing distillate palm oil (DDPO) also calls attention to diversifying its technological or commercial application. Because of this, the present work, to present new economic-scientific alternatives for this by-product, aimed to evaluate the larvicide effect of DDPO as to investigate the synergistic effect of the combination of these free fatty acids (FFA’s) present in the composition of DDPO, against larvae of the 3rd instar of Ae. aegypti. The DDPO larvicide assay showed a high mortality rate, with an LC50 of 6.18 μg.mL− 1 at 24 h and 8.73 μg.mL− 1 at 48 h of treatment. In addition, the results of LC50, among saturated fatty foods and between the combination of free fatty acids (myristic, lauric, stearic, and oleic) with palmitic acid were met positively by second-degree polynomial regression analysis. Finally, the study of molecular docking, corroborated the potential inhibitors of the binding of juvenile hormones. Together, the results suggest that DDPO can be a potential natural larvicide agent, making it an alternative to the excessive use of synthetic insecticides, thus minimizing its impacts on the environment, and promoting new technologies for the use of this palm oil by-product.
Graphic Abstract
... These AI values were less than 4 mg KOH/g, which approves batches C7 to CM1 for edible purposes. In a study by Marinho et al. [37], silk fibroin nanoparticles with esters obtained from Brazil nut oil with low acidity indices promoted potential larvicidal activity and oviposition deterrence against Aedes aegypti. In several studies, Brazil nut oils with a low acidity index have already been used to treat depression in children and adolescents, preventing the non-degeneration of nervous tissue, among other cardiovascular pathologies that can be avoided [38,39]. ...
Brazil nut oil is highly valued in the food, cosmetic, chemical, and pharmaceutical industries, as well as other sectors of the economy. This work aims to use the Fourier transform infrared (FTIR) technique associated with partial least squares regression (PLSR) and principal component analysis (PCA) to demonstrate that these methods can be used in a prior and rapid analysis in quality control. Natural oils were extracted and stored for chemical analysis. PCA presented two groups regarding the state of degradation, subdivided into super-degraded and partially degraded groups in 99.88% of the explained variance. The applied PLS reported an acidity index (AI) prediction model with root mean square error of calibration (RMSEC) = 1.8564, root mean square error of cross-validation (REMSECV) = 4.2641, root mean square error of prediction (RMSEP) = 2.1491, R2cal (calibration correlation coefficient) equal to 0.9679, R2val (validation correlation coefficient) equal to 0.8474, and R2pred (prediction correlation coefficient) equal to 0, 8468. The peroxide index (PI) prediction model showed RMSEC = 0.0005, REMSECV = 0.0016, RMSEP = 0.00079, calibration R2 equal to 0.9670, cross-validation R2 equal to 0.7149, and R2 of prediction equal to 0.9099. The physical–chemical analyses identified that five samples fit in the food sector and the others fit in other sectors of the economy. In this way, the preliminary monitoring of the state of degradation was reported, and the prediction models of the peroxide and acidity indexes in Brazil nut oil for quality control were determined.
The seed oil of Carapa guianensis, known as crabwood oil (CWO), is distinguished for its medicinal and cosmetics applications, attributed to its bioactive components and lipid profile. CWO and its dry and solvent fractionation were studied, with a focus on physicochemical functionality and the partitioning of known bioactive compounds, such as limonoids and sterols. Important bioactive components, including limonoids and sterols, were partitioned depending on the fractionation method; in particular, there is a direct dependence on solvent polarity. There was a very strong solid fraction yield–solvent polarity with a high linear slope of −121.3%. The partitioning of the lipids is significant enough to drive measurable and predictable changes in the physical properties. Palmitic (P: C16:0) and oleic (O: C18:1) fatty acids account for about 60% of the total fatty acid composition of the TAGs of CWO and its fractions. The most abundant limonoid is methyl angolensate (from 28 to 39%), followed by Trichilin A (from 13% to 22%). Gedunin and Andirobin were more abundant in the liquid fractions, whereas Carapanolides (less than 1.3%) were more present in the olein fractions. The crystallization and melting temperatures of the solid fractions were up to 26 °C, compared to 11 °C for CWO, and were particularly strongly correlated to the polarity of the solvents. The SFC profile indicated semi-solid fats, with the solid fractions showing up to 19% at 18 °C, twice the SFC in CWO. The fractions demonstrated a wide range of distinguishable microstructures. The shapes include well-organized spherulites and needle-like and rod-like crystals with sizes varying from 5 to 250 µ, suggesting that they are likely to have different flow characteristics and feel to the skin and mouth. There is a potential to make unique compositions with significantly different properties, with antimicrobial and antifungal efficacy due to the bioactive components of CWO through fractionation, using polarity as a predictive tool.
Baicalein (BA) is a flavonoid with wide-ranging pharmacological activity. However, its biological evaluation is hampered by its low solubility in aqueous medium, making forms of incorporation that improve its solubility necessary. In the present study, BA was combined with a solution of silk fibroin protein (SF), a biomaterial used too as a drug carrier, to evaluate the anti-inflammatory potential of this combination, in vivo, in an experimental model, zebrafish (Danio rerio). Baicalein-silk fibroin (BASF) improved the DPPH (2,2‐diphenyl‐1‐picryl‐hydrazyl‐hydrate) free radical scavenging rate (95%) in comparison with BA in solution. The acute toxicity study and histopathological analysis in zebrafish showed that BASF has low cytotoxic potential, except for the maxim dose of 2000 mg/kg. The use of BA in combination with SF enhanced the anti-inflammatory effect of flavonoids by inducing inflammatory peritoneal edema through carrageenan and achieved 77.6% inhibition of abdominal edema at a dose of 75 mg/kg. The results showed that the BASF, significantly increases the bioavailability and therapeutic effect of flavonoids and several results observed in this study may help in the development of new drugs.
Mosquitoes can be vectors of pathogens and transmit diseases to both animals and humans. Species of the genus Culex are part of the cycle of neglected diseases, especially Culex quinquefasciatus, which is an anthropophilic vector of lymphatic filariasis. Natural products can be an alternative to synthetic insecticides for vector control; however, the main issue is the poor water availability of some compounds from plant origin. In this context, nanoemulsions are kinetic stable delivery systems of great interest for lipophilic substances. The objective of this study was to investigate the larvicidal activity of the Hyptis suaveolens essential oil nanoemulsion on Cx. quinquefasciatus. The essential oil showed a predominance of monoterpenes with retention time (RT) lower than 15 min. The average size diameter of the emulsions (sorbitan monooleate/polysorbate 20) was ≤ 200 nm. The nanoemulsion showed high larvicidal activity in concentrations of 250 and 125 ppm. CL50 values were 102.41 (77.5253–149.14) ppm and 70.8105 (44.5282–109.811) ppm after 24 and 48 h, respectively. The mortality rate in the surfactant control was lower than 9%. Scanning micrograph images showed changes in the larvae’s integument. This study achieved an active nanoemulsion on Cx. quinquefasciatus through a low-energy-input technique and without using potentially toxic organic solvents. Therefore, it expands the scope of possible applications of H. suaveolens essential oil in the production of high-added-value nanosystems for tropical disease vector control.
This work developd nanomaterials formulated from annatto seed oily extract (ASE), myristic acid (tetradecanoic acid), and their fatty acid esters. The annatto seed oily extract was obtained using only soybean oil (ASE + SO) and Brazil nut oil (ASE + BNO). The UV/VIS analysis of the oily extracts showed three characteristic peaks of the bixin molecule at 430, 456 and 486 nm. The lipid nanoparticles obtained using myristic acid and ASE + BNO or only BNO showed better results than the oil soybean extract, i.e., the particle size was <200 nm, PDI value was in the range of 0.2–0.3, and had no visual physical instability as they kept stable for 28 days at 4 °C. Lipid nanoemulsions were also produced with esters of myristic acid and ASE + BNO. These fatty acid esters significantly influenced the particle size of nanoemulsions. For instance, methyl tetradecanoate led to the smallest particle size nanoemulsions (124 nm), homogeneous size distribution, and high physical stability under 4 and 32 °C for 28 days. This work demonstrates that the chemical composition of vegetable oils and myristic acid esters, the storage temperature, the chain length of fatty acid esters (FAE), and their use as co-lipids improve the physical stability of lipid nanoemulsions and nanoparticles from annatto seed oily extract.
Nanotechnology is one of the most intensively exploited approaches to improve cancer therapies. The role of the nanocarriers is to deliver the cargo safely to the tumor but also to enhance the treatment with additional therapeutic modalities and functions such as imaging or sustained drug release. Polymeric materials are often chosen for the role due to the controllable synthesis and properties such as size, shape and easy surface modification. In addition, certain materials enable combined treatment resulting in a synergistic therapeutic outcome. However, such particles are often easily recognized by the immune system and cleared from the bloodstream. Biological membranes have been intensively researched as perfect candidates for improving the biosafety and targeting properties of anticancer therapeutics. Different origins of reported membrane-coated drug delivery systems include red blood cells, cancer cells, platelet, and others. Each type of membrane source equips the nanoformulations with additional biological activities, such as prolonged blood retention, immune escape or targeting of the tumor sites. This review summarizes the efforts put into developing the biomimetic polymeric nanocarriers for efficient cancer treatment.
Endophytic fungi are microorganisms capable of colonizing the interior of plant tissues without causing damage to them. The study of the secondary metabolites produced by their vast biodiversity fungal is relevant for the discovery of new products for biotechnological and agrochemical applications. In addition, extract of the endophytic fungus Aspergillus sp., isolated from the almonds of Bertholletia excelsa Humn & Bonlp collected in the Brazilian Amazon, oviposition deterrent, and larvicidal activity of against Aedes aegypti. In the oviposition deterrence test was observed that females able to lay eggs preferred the control oviposition sites (46.6%). Furthermore, the extract showed larvicidal activity with LC50 26.86 µg/mL at 24 h and 18.75 µg/mL at 48 h. Molecular docking studies showed the compound Aspergillol B a potent larvicide by to inhibit the acetylcholinesterase enzyme (− 7.74 kcal/mol). These results indicate that compounds from secondary metabolites of Aspergillus sp., isolated from almonds of B. excelsa, are useful biological potential against vectors A. aegypti.
Functional oils and fats of nanoemulsion as a food nutrient transport system is considered to be effective and safe. The article expounds Composition, physicochemical properties, preparation methods and application research status on Functional oils and fats of nanoemulsion, to give more nutritional and functional of the Functional oils and fats, recommendations focus on the interaction with real food matrix between may study, optimization, explore new mechanism and preparation methods of the Functional oils and fats of nanoemulsion, in order to provide a theoretical basis for the further study of bioactive compounds or food components, and to effectively meet the urgent needs of the food industry for the high quality raw materials of the Functional oils and fats of nanoemulsion system, a wide range of bioactive compounds or food components are particularly considered.
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With the advancement of technologies, the evolution of nanoscience is occurring at a rapid pace. The demand for nanomaterials in various industries has increased. However, they may pose an increased risk upon exposure to living organisms, demanding toxicological studies. Alt-hough risk assessment of nanomaterials is a challenge due to their varieties in sizes and variabil-ity in properties, different methodologies of toxicity screenings have been used successfully to evaluate the potential risks. Although nanotechnology has contributed to technology develop-ment and well-being, information in these fields is still incomplete. Fortunately, those areas are under continuous research, and there are increasing experimental efforts in determining the envi-ronmental effects on humans exposed to nanoparticles. Since the field of nanotechnology is continuously expanding, we need medium- to high throughput nanotoxicity screenings to deter-mine any potential risks caused by nanomaterials. Zebrafish, a well-established model for mammalian research, have advantages when used in these toxicity screenings. This review de-scribes various kinds of toxicities induced in zebrafish embryos by different kinds of nanopar-ticles. A significant number of experimental data from toxicological studies are also presented that determine nanomaterials’ effects, which can be modulated or further mitigated to create a positive impact on living organisms.
Polyunsaturated fatty acids oxidize easily due to their chemical structure, causing a reduction of their nutritional properties. Nanostructured systems may be an alternative to protect fatty acids against oxidation, improving solubility and stability. Consequently, nutritional value of food is maintained as well as the sensory characteristics (color, flavor, texture, and aroma) when fatty acids are added to food products. The present study is a narrative review to introduce the potential benefits of omega-3 unsaturated fatty acids nanoparticles incorporated in food products. The literature review includes publications in English and Portuguese issued between March 1985 and March 2019, in PubMed, ScienceDirect and Web of Science databases. Manual searches were conducted in the articles references lists of the articles included to identify other relevant studies. There were studies that evaluated the stability of fatty acids in food products such as bread, fruit juice, milk, yogurt, and meat. In this study, the most used nanostructured systems for the incorporation of fatty acids were the nanocapsules and the nanoliposomes. Currently, the nanostructured system demonstrates a potential to improve protection of polyunsaturated fatty acids against oxidization and thermal degradation. In this way, they maintain their functional properties and their bioavailability increases and therapeutic efficacy and sensory properties are improved. There are several methodologies being tested, which makes it difficult to identify the most efficient formulation to protect fatty acids. Nanostructured systems seem to be the best alternative to protect polyunsatured fatty acids from oxidization. The encapsulation efficiency, particle’s size and type are relevant factors to be considered to evaluate oxidization. In conclusion, the review showed that currently it is impossible to determine the most efficient methodology. Besides, nanoformulations should follow international guidelines to present more standardized and therefore more efficient particles.
The scientific community is becoming increasingly interested in identifying, characterizing, and delivering nutraceuticals, which constitutes a multi-billion-dollar business. These bioactive agents are claimed to exhibit several health benefits, including the prevention and treatment of diseases such as arthritis, cancer, osteoporosis, cataracts, Alzheimer’s, and Huntington’s diseases, heart, brain and metabolic disorders, etc. Nutraceuticals are typically consumed as part of a regular human diet and are usually present within foods, comprising vegetable oil, although at low levels and variable composition. Thus, it is difficult to control the type, amount and frequency of their ingestion by individuals. Nanoformulations about vegetable oil-based bioactive compounds with nutraceutical properties are useful for overcoming these issues, while improving the uptake, absorption, and bioavailability in the body. The purpose of this current study is to review papers on such nanoformulations, particularly those relevant for health benefits and the prevention and management of diseases, as well as bioactives extracted from vegetable oils enhancing the drug effectiveness, retrieved through bibliographic databases by setting a timespan from January 2000 to April 2020 (about 1758 records).
This study compared the in vitro anthelmintic activity of Copaifera reticulata oleoresin (200, 400, 600, 800 and 1,000 mg/L) and of nanoemulsions prepared with this oleoresin (50, 100, 150, 200 and 250 mg/L) against monogeneans on the gills of Colossoma macropomum. The major compounds present in the oleoresin of C. reticulata were γ‐macrocarpene (14.2%), α‐bergamotene (13.6%), β‐selinene (13.4%) and β‐caryophyllene (11.7%). All concentrations of the nanoemulsion and the oleoresin without nanoformulation showed anthelmintic efficacy against monogeneans, and higher concentrations led to more rapid parasite mortality. Structural damages to the tegument of the parasites exposed to C. reticulata oleoresin were observed with scanning electron microscopy. At two hours of exposure, fish showed 100% tolerance to all nanoemulsion concentrations used in the in vitro assays, whereas 100% mortality was shown in the fish exposed to the oleoresin without nanoformulation after one hour. The results of this study suggest that nanoemulsions with oleoresin of C. reticulata have advantages in the control and treatment of monogenean infections in C. macropomum when compared to the oleoresin without nanoformulation. In addition, since nanoemulsions with the C. reticulata oleoresin are safe to control monogeneans, the efficacy of these nanoformulations may be assayed in therapeutic baths to treat C. macropomum infected by monogeneans.
One of the major challenges we face as humankind is supplying a growing world population with sufficient and healthy foods. Although from a worldwide perspective sufficient food is produced, locally, the situation can be dire. Furthermore, the production needs to be increased in a sustainable manner for future generations, which also implies prevention of food waste, and making better use of the available resources. How to contribute to this as food technologists is an ultimate question, especially since the tools that can investigate processes at relevant time scales, and dimensions, are lacking. Here we propose the use of microtechnology and show examples of how this has led to new insights in the fields of ingredient isolation (filtration), and emulsion/foam formation, which will ultimately lead to better-defined products. Furthermore, microfluidic tools have been applied for testing ingredient functionality, and for this, various examples are discussed that will expectedly contribute to making better use of more sustainably sourced starting materials (e.g., novel protein sources). This review will wrap up with a section in which we discuss future developments. We expect that it will be possible to link food properties to the effects that foods create in vivo. We thus expand the scope of this review that is technical in nature, toward physiological functionality, and ultimately to rational food design that is targeted to improve human health.
This study reports the synthesis of fatty acid amides (FAA), analogous to anandamide, prepared from Brazil nut oil (BNO), using Amano lipase from Pseudomonas fluorescens as a catalyst of direct aminolysis, with a good yield (95-68%). The anti-inflammatory effects of BNO and FAA were evaluated by the carrageenan-induced paw edema method. Analysis of the formation of edema showed that these FAA, at all dose used, significantly reduced the development of edema.
Purpose
Poly (lactic-co-glycolic acid) has received much academic attention for developing nanotherapeutics and FDA has approved it for several applications. An important parameter that dictates the bioavailability and hence the biological effect of the drug is drug release from its delivering system. This study offers a comparative mathematical analysis of drug release from Poly (lactic-co-glycolic acid)–based nanoparticles to suggest a general model explaining multi-mechanistic release they provide.
Methods
Eight release models, zero order, first order, Higuchi, Hixson-Crowell, the square root of mass, the three-second root of mass, Weibull and Korsmeyer-Peppas, as well as the second degree polynomial equation were applied to 60 data sets. The models analysed regarding several types of errors, regression parameters and average Akaike information criterion.
Results and discussion
Most of the data sets present the highest R², the lowest overall error and AIC for the Weibull model. Weibull model with the mean AIC = -36.37 and mean OE = 7.24 and the highest NE less than 5, 10, 15 and 20 % in most of the cases best fits the release data from various PLGA-based drug delivery systems that are studied. Weibull model seems to show enough flexibility to describe various release patterns PLGA provides.
In this study, the essential oil (EO) from leaves of Croton linearis Jacq was extracted and characterized by GC/MS. The EO hydrophilic-lipophilic balance required (rHLB) for nanoemulsion (NE) development was determined by the Griffin’ method. For evaluating the larvicidal effect against Aedes aegypti, the preparation process of NE was optimized, using a central composite design. It was also evaluated the possible toxic effect of NE in nontarget species. The leaves of C. linearis contain 1.50% of EO, enclosing 61 volatile compounds, mainly eucalyptol (26.66%). The best surfactant, oil:water ratio (4.5–5.0-91.5; % w:w:w), allows to achieve the optimal NE, using a stirring speed of 800 rpm, the addition rate of 0.5 ml/min, and a stirring time of 30 min. NE (with particle size = 163 nm) showed a larvicide effect (LC50 = 17.86 μg/mL) more potent than the whole EO (LC50 = 64.24 μg/mL). NE showed neither hemolytic effect nor cytotoxicity, and it was classified as a nontoxic product, according to the OECD class toxicity test (IC50 > 2000 mg/kg). This product arises in a new green bio-larvicide that could be used for mosquito control.
Nanoemulsions have small droplet size and are kinetically stable colloidal systems. They have enhanced functional properties in comparison to conventional emulsions. The composition and structure of the nanoemulsions can be controlled for the encapsulation and effective delivery of bioactive lipophilic compounds. Nanoemulsions have potential application in the food industry for the delivery of nutraceuticals, coloring and flavoring agents, and antimicrobials. The nanoemulsion formulations of active ingredients can be used for developing biodegradable coating and packaging films to enhance the quality, functional properties, nutritional value, and shelf life of foods. This review focuses on preparation of food grade nanoemulsions using high-energy methods and low-energy approaches and their characterization for physical properties, stability, and microstructure. The application of nanoemulsion formulations for sustainable food processing and improving the delivery of functional compounds, such as colorants, flavoring agents, nutraceuticals, and preservatives or antimicrobial agents in foods has been discussed.
Ucuùba fat is fat obtained from a plant found in South America, mainly in Amazonian Brazil. Due to its biocompatibility and bioactivity, Ucuùba fat was used for the production of ketoconazole-loaded nanostructured lipid carriers (NLC) in view of an application for the treatment of onychomycosis and other persistent fungal infections. The development and optimization of Ucuùba fat-based NLC were performed using a Box-Behnken design of experiments. The independent variables were surfactant concentration (% w/v), liquid lipids concentration (% w/v), solid lipids concentration (% w/v), while the outputs of interest were particle size, polydispersity index (PDI) and drug encapsulation efficiency (EE). Ucuùba fat-based NLC were produced and the process was optimized by the development of a predictive mathematical model. Applying the model, two formulations with pre-determined particle size, i.e., 30 and 85 nm, were produced for further evaluation. The optimized formulations were characterized and showed particle size in agreement to the predicted value, i.e., 33.6 nm and 74.6 nm, respectively. The optimized formulations were also characterized using multiple techniques in order to investigate the solid state of drug and excipients (DSC and XRD), particle morphology (TEM), drug release and interactions between the formulation components (FTIR). Furthermore, particle size, surface charge and drug loading efficiency of the formulations were studied during a one-month stability study and did not show evidence of significant modification.
As the use of nanoparticles (NPs) is increasing, the potential toxicity and behavior of NPs in living systems need to be better understood. Our goal was to evaluate the developmental toxicity and bio-distribution of two different sizes of fluorescently-labeled SiO2 NPs, 25 and 115 nm, with neutral surface charge or with different surface functionalization, rendering them positively or negatively charged, in order to predict the effect of NPs in humans. We performed a zebrafish embryo toxicity test (ZFET) by exposing the embryos to SiO2 NPs starting from six hours post fertilization (hpf). Survival rate, hatching time, and gross morphological changes were assessed at 12, 24, 36, 48, 60, and 72 hpf. We evaluated the effect of NPs on angiogenesis by counting the number of sub-intestinal vessels between the second and seventh intersegmental vessels and gene expression analysis of vascular endothelial growth factor (VEGF) and VEGF receptors at 72 hpf. SiO2 NPs did not show any adverse effects on survival rate, hatching time, gross morphology, or physiological angiogenesis. We found that SiO2 NPs were trapped by the chorion up until to the hatching stage. After chemical removal of the chorion (dechorionation), positively surface-charged SiO2 NPs (25 nm) significantly reduced the survival rate of the fish compared to the control group. These results indicate that zebrafish chorion acts as a physical barrier against SiO2 NPs, and removing the chorions in ZFET might be necessary for evaluation of toxicity of NPs.
Background
The mosquito Aedes aegypti is the primary vector of several arboviruses, such as dengue, chikungunya and Zika, and represents a major public health problem in Southeast Asia. In Laos, where dengue is reemerging, several Ae. aegypti populations from the capital Vientiane have shown resistance to the organophosphate temephos, a commonly-used larvicide for public health interventions.
Methods
Here, we tested the insecticide susceptibility of a wild larval population of Ae. aegypti against Bacillus thuringiensis israelensis (Bti), diflubenzuron, pyriproxyfen and spinosad. Residual efficacies of Bti (VectobacWG®), diflubenzuron (Killmos®) and temephos (Abate®) were then evaluated under simulated field conditions against the wild Ae. aegypti population.
Results
The larval bioassays showed that the wild Ae. aegypti strain was moderately resistant to temephos and spinosad (resistance ratio, RR < 5) and fully susceptible to the other insecticides (RR = 1). The simulated field trial bioassays showed that all of the insecticides tested remained above the WHO acceptable larvicide threshold after 28 weeks.
Conclusions
These results suggest that Bti and diflubenzuron may be promising alternative larvicides for controlling dengue vectors in water-storage containers in Laos, especially against Ae. aegypti populations, in which resistance to temephos has been detected.
The worldwide invasion of arthropod-borne viruses (arboviruses) in recent decades is responsible for emerging public health threats. Some factors like climate change, urbanisation and uncontrolled population growth are fuelling their widespread. Arboviruses incorporate a vast collection of genetically diverse viral pathogens including that of dengue, Zika and chikungunya. These viruses are peculiar as they are zoonotic and are a serious harm to the society, with no particular therapy to neutralise their effect. So it is the need of the hour to develop an effective treatment against infections caused by them. This review focuses on some of the common families of mosquito-borne arboviruses and their most known members that are a threat to mankind and discusses their genome organisation, worldwide spread and negative influence on public health.
A new silk fibroin-based nanoparticles (FNPs) have been successfully developed utilizing crosslinker EDC (EDC-FNPs) or cationic polymer poly(ethyleneimine) (PEI-FNPs). All developed crosslinked FNPs show a similar spherical particle size of ~ 300 nm. Depending on the amount of EDC or the addition of PEI, the zeta potential could be controlled favorably and range from − 15 mV to + 30 mV. Particle structures and crystallinity index are determined and compared using different techniques; X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), differential scanning calorimetry and nuclear magnetic resonance (NMR). The most reliable crystallinity calculation methods are based on FT-IR and NMR. The degree of fibroin crystallinity increases with increasing EDC content, whereas PEI reduces it. Exceptionally, XRD shows a reverse order of crystallinity due to the inability to detect short-range ordered structures. Proposed schematic particle structures match all experimental data. In conclusion, the crosslinked fibroin-based nanoparticle properties could be manipulated by using carbodiimide or PEI crosslinkers. In addition, both EDC-FNPs and PEI-FNPs showed high potential as a drug delivery system. © 2018 Springer Science+Business Media, LLC, part of Springer Nature
The essential oil from Rosmarinus officinalis L. (OERO) has bioactive compounds with anti-inflammatory activity. The objective of this study was to evaluate the anti-inflammatory potency of nanoemulsions containing essential oil of Rosmarinus officinalis L. (NOERO, NECHA, NECULT, and NECOM) in vitro and in vivo. This study was accomplished in a quantitative format through tests with diphenyl picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), cellular antioxidant activity (CCA), determination of nitric oxide production, cellular viability and anti-inflammatory activity in zebrafish. OERO's were submitted to the analysis-coupled gas chromatography-mass spectrometry (GC-MS), which highlighted 1,8-cineol and camphor as major compounds. NOEROs were obtained by a low-energy method and presenting the medium size smaller than 200 nm. The efficiency of encapsulation by spectrometry and gas chromatographic analysis was 67.61 and 75.38%, respectively. In the CCA assay, all of the samples presented percentage values of inhibition similar to the quercetin pattern, indicating antioxidant activity. In the test for determination of NO·, all of the samples inhibited the production of NO· when compared to LPS, and NOEROS were more effective than OEROS to 5 µg/mL. In the cell viability assay, the cells remained viable after contact with the samples, demonstrating an absence of cytotoxicity. This study showed that all nanoemulsions (NECHA, NECULT, and NECOM) showed no toxicity to macrophages, besides demonstrating antioxidant activity and potentiation of the essential oil effect in the proliferation of viable fibroblasts. Nanoemulsions has also shown the ability to potentiate the anti-inflammatory action of essential oils by exerting immunomodulatory activity by inhibiting the production of the pro-inflammatory mediator nitric oxide. The results obtained with NECHA in zebrafish confirm the hypothesis that prominent terpenic compounds, alpha-pinene, 1,8-cineole, and camphor, became more available at the target sites, inhibiting the inflammatory process in this animal species.
Infectious diseases are the leading cause of mortality worldwide, with viruses in
particular making global impact on healthcare and socioeconomic development. In addition,
the rapid development of drug resistance to currently available therapies and adverse
side effects due to prolonged use is a serious public health concern. The development of
novel treatment strategies is therefore required. The interaction of nanostructures with
microorganisms is fast-revolutionizing the biomedical field by offering advantages in both
diagnostic and therapeutic applications. Nanoparticles offer unique physical properties
that have associated benefits for drug delivery. These are predominantly due to the particle
size (which affects bioavailability and circulation time), large surface area to volume ratio
(enhanced solubility compared to larger particles), tunable surface charge of the particle with
the possibility of encapsulation, and large drug payloads that can be accommodated. These
properties, which are unlike bulk materials of the same compositions, make nanoparticulate
drug delivery systems ideal candidates to explore in order to achieve and/or improve
therapeutic effects. This review presents a broad overview of the application of nanosized
materials for the treatment of common viral infections.
Nanoemulsion-based delivery systems are particularly effective tools for incorporating omega-3 polyunsaturated lipids into many foods and beverages. In this study, the impact of carrier oil type and concentration on the formation and stability of fish oil-in-water nanoemulsions was determined. Three carrier oils with different physicochemical and sensory properties were evaluated: medium chain triglycerides (MCT); lemon oil; and thyme oil. Nanoemulsions (d < 200 nm) were fabricated from oil phases containing lemon oil and MCT at all ratios with fish oil (0–100%), but only from thyme oil at high fish oil contents (75–100%). This effect was attributed to the high susceptibility of the nanoemulsions containing high levels of thyme oil to Ostwald ripening. Nanoemulsions fabricated from all carrier oils were physically stable (no increase in droplet size) during storage at 20 °C for 42 days when formulated from 75% fish oil and 25% carrier oil. However, carrier oil type did have an appreciable impact on the oxidative stability of these nanoemulsions, with the rate of lipid oxidation decreasing in the following order: MCT » lemon oil > thyme oil. This effect was attributed to the presence of high levels of natural antioxidants (phenolics) within the lemon and thyme oils. These results show that selection of an appropriate carrier oil type and concentration can lead to the formation of fish oil nanoemulsions with good physical and chemical stability.
Arboviruses have been emerging in different parts of the world due to genetic changes in the virus, alteration of the host and vector population dynamics, or because of anthropogenic environmental factors. These viruses’ capacity for adaptation is notable, as well as the likelihood of their emergence and establishment in new geographic areas. In Brazilian epidemiologic scenario, the most common arboviruses are DENV, CHIKV, and ZIKV, although others may spread in the country. Little is yet known of the impact of viral co-circulation, which would theoretically result in more intense viremia or other immunological alterations that could trigger autoimmune diseases, such as Guillain-Barré syndrome. The impact on morbidity and mortality intensifies as extensive epidemics lead to a high number of affected individuals, severe cases, and implications for health services, mainly due to the absence of treatment, vaccines, and effective prevention and control measures.
Introduction: Perillyl alcohol (POH) is a hydroxylated monocyclic monoterpene found in lemon and lavender essential oils, among others. It's widely recognized by antitumoral activity. Despite the great potential of nanoformulations for pharmaceutics, to the date the obtainment a perillyl alcohol-nanoemulsion (NPOH) and its toxicity investigation were not previously reported. On this context, the present study aim to evaluate the toxicity of NPOH on zebrafish (Danio rerio). Lethal concentration (LC50), effects on behaviour and acute administrations effects (48h) on histopathological parameters of the gills, liver and kidneys were performed.
The Aedes aegypti mosquito is a vector of several diseases, including dengue, yellow fever and the Zika virus. Synthetic insecticides such as chlorpyrifos and chlorothalonil have been used to control this vector, despite causing damage to both the environment and humans. Research into natural active compounds with a low environmental impact is therefore required. The present study developed an environmentally friendly formulation of silk fibroin (SF) combined with fatty acid esters [ethyl (FAEE-SF), propyl (FAPE-SF) and butyl (FABE-SF)] from A. murumuru fat, which was effective against larvae of the Ae. aegypti vector. The FABE-SF nanoparticle induced a higher mortality rate in Ae. aegypti larvae after 48 h (LC50 = 21.35 μg/mL). The stability of the nano was monitored for 21 days, and FABE-SF exhibited greater stability throughout this period, with average particle, zeta and PDI values of around 217.5 ± 0.85 nm, −25.6 ± 3.24 mV and 0.338 ± 0.01, respectively. This is the first work of its type to identify the larvicidal activity of fatty acid esters from A. murumuru, combined with silk fibroin, against Ae. aegypti.
This study investigated for the first time the anthelmintic efficacy of therapeutic baths with Copaifera reticulata oleoresin and nanoemulsion with this oleoresin against monogeneans of Colossoma macropomum, as well as the haematological and histological effects in this fish. In the therapeutic baths of three consecutives were used 100 mg/L of C. reticulata oleoresin or 250 mg/L of nanoemulsion containing C. reticulata oleoresin. Therapeutic baths with 100 mg/L of C. reticulata oleoresin had anthelmintic an efficacy of 48.5% against monogeneans (Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri), while baths with nanoemulsion of C. reticulata oleoresin had not anthelmintic efficacy, which was discussed. Baths for 1 h with 100 mg/L of C. reticulata oleoresin or 2 h with 250 mg/L of C. reticulata nanoemulsion increased levels of plasma total protein and glucose, mean corpuscular volume (MCV) and neutrophils number in C. macropomum and decreased in the number of total leucocytes and lymphocytes. In the gills of fish exposed and controls occurred detachment of the epithelium, hyperplasia and hypertrophy, resulting in moderate fusion of the secondary lamellae. Therefore, therapeutic baths with C. reticulata oleoresin and nanoemulsion of C. reticulata oleoresin have a low toxicity to C. macropomum, as there were few changes to the blood parameters.
Herein, the effects of the concentration (0.1%–1.0%, w/v) and addition sequence of tea saponin (TS) on the physical stability, oxidative stability, rheological properties, and in vitro digestion of the emulsions stabilized by heat-induced soy protein isolate nanoparticles (SPs) were investigated. The results revealed that the concentration and addition sequence of TS have significant impact on the microstructure, stability, rheological properties, and in vitro digestion of the emulsions. TS was shown to not only fill the interfacial gaps but also adsorb on the particle surfaces, contributing to interfacial wettability. With increasing TS concentration, interfacial tension decay is clearly observed. Further, TS endows the droplets with electrostatic repulsion and steric resistance, preventing their flocculation, coalescence, and oxidation. Finally, in vitro digestion experiments demonstrated that the presence of TS delayed the lipid digestion of the emulsions.
Curtains with light-to-heat conversion capacity can warm up a room under solar radiation and improve the thermal energy efficiency of buildings, thereby reducing energy consumption during winter. Herein, a photothermal silk fibroin aerogel is synthesized by freeze-drying and curing method, using silk fibroin (SF) as template and scaffold, copper sulfide nanoparticles (CuS NPs) as photothermal conversion material, polyethylene glycol (PEG) as plasticizer, and polydimethylsiloxane (PDMS) as the package agent. The results reveal that SF as the template may guide the growth of CuS NPs, and the introduction of PEG improves the flexibility of the prepared CuS@SF aerogel. The composite CuS@SF-PEG/PDMS aerogel not only preserves the initial characteristics of SF aerogel but also integrates hydrophobic, rapid antibacterial ability, high-performance photothermal conversion efficiency, and stable switching effect. The lightweight, self-heating SF-based aerogel can be applied to the preparation of home textiles such as smart curtains. Additionally, it can be used as absorbent for cleaning up viscous oil from water, which could expand the applications of SF-based biomaterials toward meeting the requirements of sustainable developments.
Arboviruses are medically important viruses that cause high rates of infection all over the world. In addition, the severity of the symptoms and the inadequate diagnostic methods represent a challenge far beyond eradicating the vector. The lack of specific treatments for arbovirus infections reflects the imminent need for new research for safe and efficient medicines to treat these infections. Nanotechnology is an innovative approach currently used as a platform for developing new treatments, thus improving the biopharmaceutical properties of drugs. It can also be applied to the development of diagnostic devices, improving their detection capacity. The purpose of this paper is to review recent research on the use of nanotechnology for developing new treatments and detection devices for arbovirus infections. Interestingly, it was found that only a few studies report on the use of nanotechnology to treat arbovirus infections and that most of these reports focus on the fabrication of diagnostic tools. Also, some papers report on the use of nanotechnology for the development of vaccines, which in association with mosquito eradication programs could effectively reduce the high rates of infections by these viruses.
In this project, the CeO 2 NP s were synthesized using pollen grains of Brassica napus as a capping agent and reducing agent. The nanoceria were characterized by FTIR, FESEM, TEM, PXRD, and DLS. To increase the bioavailability, the nanoemulsion of cerium nanoparticle was prepared. The TEM images have revealed particles with spherical morphology and mean particle sizes of ca. 23.2±4.0 nm. The prepared sample after calcination at 500 °C showed the characteristic peaks of nanoceria with a good crystallinity. Chorioallantoic membrane (CAM) test results showed by increasing the concentration of biosynthesized CeO 2 NP s , the size and number of blood vessels were reduced. Also, the cytotoxicity test using MTT showed little toxicity of the biosynthetic CeO 2 NP s on the human foreskin fibroblast cell, whereas synthetic CeO 2 NP s destroyed ovarian cancer cells (A2780) which depends on the time and concentration of the NPs. The results of this research show excessive promise for drug treatments and pharmacological technology.
Thymol (THY), a monoterpene phenol, is used as a natural biocide. To circumvent its chemical instability, we have proposed THY‐loaded biogenic silica nanoparticle (BSiO2#THY); however, the toxicity of this system for aquatic organisms is unknown. Thus, this study aimed to evaluate the toxicogenetic effects induced by THY, BSiO2 nanoparticle (NP), and BSiO2#THY on Artemia salina and zebrafish (Danio rerio) early‐life stages. We also investigated the impact of BSiO2 aggregation in the different exposure media (saline and freshwater). BSiO2#THY (LC50‐48h = 1.06 mg/L) presented similar toxic potential as THY (LC50‐48h = 1.03 mg/L) for A. salina, showing that BSiO2 had no influence on BSiO2#THY toxicity. As BSiO2 aggregated and sedimented faster in A. salina aqueous medium than in the other medium, this NP had lower interaction with this microcrustacean. Thus, BSiO2#THY toxicity for A. salina is probably due to the intrinsic toxicity of THY. For zebrafish early‐life stages, BSiO2#THY (LC50‐96h of 13.13 mg/L) was more toxic than free THY (LC50‐96h of 25.60 mg/L); however, BSiO2 NP has no toxicity for zebrafish early‐life stages. The lower aggregation of BSiO2 in the freshwater medium compared to the saline medium may have enhanced THY's availability for this aquatic organism. BSiO2#THY also significantly induced sublethal effects as THY, and both were genotoxic for zebrafish. In conclusion, although BSiO2#THY still needs improvements to ensure its safety for freshwater ecosystems, BSiO2 NP seems to be a safe nanocarrier for agriculture. This article is protected by copyright. All rights reserved.
This paper report the use of Carapa guianensis Abul. (Meliaceae) oil and derivates [fatty acid ethyl ester (FAEE's) and free fatty acid (FFA's)] associate with silk fibroin (SF), and its activity against the larvae of the vector Aedes aegypti. The emulsions FFA2-SF derived from AO2, that mostly contained unsaturated fatty acids, presented the best results against the larvae of Ae. aegypti after a 48 h period (LC 50 = 16.79 mg.mL − 1), causing structural alterations to the vector. It is suggested that the biopolymeric matrix of silk fibroin increases the biodistribution and bioavailability of active in medium aqueous. This is the first work of its type which has pointed larvicidal activity of the free fatty acid from C. guianensis, associate with silk fibroin against Aedes aegypti.
The oxidation of lipids and proteins often occurs at the oil-water interface in emulsions, and so emulsifiers may influence the oxidative stability of these systems. The objective of this work was to assess the influence of mixed plant-based emulsifiers, almond protein isolate (API) and camellia saponin (CS), on the physical and oxidative stability of walnut oil-in-water emulsions. Initially, a 5 wt% walnut oil emulsion was formulated using 0.5 wt% API as an emulsifier, then different levels of CS (1.0–2.0 wt%) were added. Experiments were carried out under conditions where the API and CS had different charges: pH 3 (protein positive, saponin negative) and pH 7 (both negative). Analysis of the surface-potential and interfacial protein concentration indicated that mixed API-CS interfacial layers were present at the oil droplet surfaces, with the main driving forces for adsorption being electrostatic and/or hydrophobic interactions. Emulsions prepared with the mixed emulsifier system had greater resistance to droplet flocculation than those stabilized by API alone when incubated at 45 °C for 0, 3, and 6 days. Markers of lipid oxidation (hydroperoxides and TBARS) and protein oxidation (carbonyl formation, sulfhydryl loss, intrinsic fluorescence loss, and electrophoresis) were recorded during storage. These measurements showed that API-CS-coated droplets were more resistant to oxidation than API-coated ones. Oxidation was faster at pH 3 than pH 7, which was mainly linked to the higher water-solubility and chemical reactivity of the transition metals under acidic conditions. Our results indicate that a combination of almond protein and camellia saponin is suitable for forming plant-based emulsions with high physical and chemical stability.
The Aedes aegypti mosquito is a vector that causes various diseases such as chikungunya fever, dengue and Zika, and therefore constitutes a public health problem. The present study was carried out to evaluate the larvicidal activity of different crude extracts (methanolic, hydroethanolic and hexanic) from leaves of Acmella oleracea solubilized in fibroin solution, as an alternative to the organic solvents that are used against Aedes aegypti. Using the Probit analysis, the hexane extract showed LC50 of 2.23 μg/mL after 24 h, whereas the hydroethanolic and the methanolic extracts showed LC50 of 28.42 μg/mL and 39.67 μg/mL, respectively. These extracts also did not show toxicity towards Chlorella vulgaris after 30 days, which suggests that they can be used without causing environmental damage. Thus, A. oleracea extract dissolved in fibroin solution could be an alternative for controlling Ae. aegypti without causing damage to the environment.
Thyme oil in water nanomulsion was prepared under subcritical water conditions using water and saponin, as solvent and emulsifier, respectively. Gas chromatography revealed that there were 44 bioactive components in the extracted thyme essential oil which, thymol and carvacrol were two mains of them. Experiments were designed based on central composite design and effects of amounts of saponin and thyme essential oil were evaluated on particle size, polydispersity index (PDI) and zeta potential of the prepared nanoemulsions using response surface methodology. Obtained results revealed that more desirable thyme oil nanoemulsions with minimum particle size (184.51 nm) and PDI (0.514), and maximum zeta potential (− 22.51 mV) were prepared using 0.94 g of saponin and 0.28 mL of thyme essential oil. Furthermore, results indicated that prepared nanoemulsion using obtained optimum production conditions had relatively high antioxidant activity (24%) and high antibacterial and antifungal activities against Staphylococcus aureus and Penicillium digitatum.
User- and eco-friendly approaches to manage immature stages of mosquitoes are urgently needed in order to minimize the undesirable impact of synthetic pesticides on nature and mankind. Plant-derived pesticides are considered as user- and environmental friendly. In this study, attempts have been made to develop water dispersible tablet (WT), containing neem (Azadirachta indica) oil as a mosquitocide. The tablet dispersion with concentration of 40 mg/L exhibited 98% mortality against third instars larvae of Anopheles culicifacies followed by residual effect upto sixth week. Ovicidal effect on freshly laid eggs were observed. Oviposition deterrent activity of tablet suspension was also assessed, which showed reduction in egg laying of gravid female by 89%. The tablet suspension was found to be non-toxic to the non-target fish, Poecilia reticulate.
The incorporation of nanotechnology as a means for nanopesticides is in the early stage of development. The main idea behind this incorporation is to lower the indiscriminate use of conventional pesticides to be in line with safe environmental applications. Nanoencapsulated pesticides can provide controlled release kinetics, while efficiently enhancing permeability, stability, and solubility. Nanoencapsulation can enhance the pest-control efficiency over extended durations by preventing the premature degradation of active ingredients (AIs) under harsh environmental conditions. This review is thus organized to critically assess the significant role of nanotechnology for encapsulation of AIs for pesticides. The smart delivery of pesticides is essential to reduce the dosage of AIs with enhanced efficacy and to overcome pesticide loss (e.g., due to leaching and evaporation). The future trends of pesticide nanoformulations including nanomaterials as AIs and nanoemulsions of biopesticides are also explored. This review should thus offer a valuable guide for establishing regulatory frameworks related to field applications of these nano-based pesticides in the near future.
Arboviruses are a diverse group of vector-borne viruses, many of whose members are the cause of significant human morbidity and mortality. Over the last 30 years, the emergence and/or resurgence of arboviruses have posed a considerable global health threat. The ongoing geographical expansion of the dengue viruses (DENV), along with the explosive outbreaks of West Nile virus (WNV), Chikungunya virus (CHIKV) and more recently, Zika virus (ZIKV) have all served as reminders that new epidemics may emerge at any time from this diversity. A clearer understanding of what mechanisms drive these dramatic changes in vector-host transmission cycles that result in the human population becoming significantly more exposed, will help to prepare us for the next emerging epidemic/pandemic. This Chapter seeks to provide a brief overview of the arboviruses, their mode of transmission and some of the known factors that drive their expansion.
Vegetable oils are commonly used as components in many cosmetic products intended for daily care due to their high beneficial and multifunctional effect on skin. The general objective of this study was to develop new nanostructured lipid carrier (NLC) formulations containing vegetable oils and enrich them with α-tocopherol (TOC) in order to explore their potential as effective and safe advanced biocosmetic prototypes. The influence of lipids composition and physical state on the production and physicochemical properties of vegetable oil NLCs and enriched nanoparticles with TOC (TOC-NLCs), as a model bioactive antioxidant compound, was studied. Sunflower, sweet almond, olive and coconut oils were successfully used in the development of free and loaded NLCs. The formulations of free lipid nanoparticles with each vegetable oil presented an appropriate nanoscale size from approximately 120–350 nm and good physical stability with zeta potential values ranging between −45.6 to −65.9 mV. Likewise, the TOC-NLCs demonstrated suitable particle sizes from approximately 240–315 nm and zeta potential values raging between −45.6 to −55.1 mV, being then verified that these parameters were affected by differences on the lipids core composition. TOC-NLCs presented a high entrapment efficiency with values above 79.4% and also assured a controlled release of TOC, independently of the percentage of incorporated active compound. Differential scanning calorimetry results showed that the incorporation of TOC and the increase of its concentration on NLCs lipids matrix caused a decrease on the onset and melting temperatures, indicating a reduced crystallinity of the obtained vegetable oil TOC-NLCs. These lipid nanoparticles and free NLCs presented good antioxidant activity with scavenging activity values above 56.7%, which was improved by the encapsulation of TOC (scavenging activity values above 64.3%) and demonstrated the ability to be incorporated in long-term stable cosmetic products based on stability studies performed during 8 months.
The formation, stability, and performance of oil-in-water emulsions may be improved by using combinations of two or more different emulsifiers, rather than an individual type. This article provides a review of the physicochemical basis for the ability of mixed emulsifiers to enhance emulsion properties. Initially, an overview of the most important physicochemical properties of emulsifiers is given, and then the nature of emulsifier interactions in solution and at interfaces is discussed. The impact of using mixed emulsifiers on the formation and stability of emulsions is then reviewed. Finally, the impact of using mixed emulsifiers on the functional performance of emulsifiers is given, including gastrointestinal fate, oxidative stability, antimicrobial activity, and release characteristics. This information should facilitate the selection of combinations of emulsifiers that will have improved performance in emulsion-based products.
The use of chemicals is often related to suicide attempts and acute poisoning, which account for a significant number of hospital admissions. The differential diagnosis of patients exposed to poisoning is intricate and varies according to the substance used. The identification of drugs and drug abuse in cases of poisoning often requires time-consuming and complex techniques, such as chromatography. The use of vibrational spectroscopy such as Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) enables the quick identification of toxic substances using no reagents or markers. This study aims to apply these techniques in the long term to identify and quantify substances found at the locations of suicide attempts, poisonings, and even drug consumption sites, including crack samples containing a cocaine base and adulterants commonly seized in drug busts, such as caffeine, lidocaine, and sodium carbonate. In this study, Raman and FTIR spectra of ternary mixtures of crack with caffeine and sodium carbonate and crack with lidocaine and sodium carbonate were obtained. These spectra were used for building multivariate models based on partial least squares (PLS) for determining the composition of the samples quantitatively. High correlation coefficients (r > 0.98) and small cross-validation prediction errors (< 6%) were obtained for both Raman and FTIR spectral models. The results showed that PLS regression enables crack quantification in ternary mixtures using both Raman and FTIR spectroscopy, allowing for quick medical intervention or determination of the cause of death in cases of cocaine toxicity.
Copaiba oil is used as a popular medicine in the Amazonian forest region, especially due to its anti-inflammatory properties. In this paper, we describe the formulation of hydrogel containing copaiba oil nanoemulsions (with positive and negative charges), its skin permeation, and its anti-inflammatory activity in two in vivo models: mouse ear edema and rat paw edema. Three hydrogels were tested (Carbopol(®), hydroxyethylcellulose and chitosan), but only Carbopol(®) and hydroxyethylcellulose hydrogels presented good stability and did not interfere with the nanoemulsions droplet size and polydispersity index. In skin permeation assay, both formulations, positively charged nanoemulsion (PCN) and negatively charged nanoemulsion (NCN), presented a high retention in epidermis (9.76 ± 2.65 μg/g and 7.91 ± 2.46 μg/cm(2), respectively) followed by a smaller retention in the dermis (2.43 ± 0.91 and 1.95 ± 0.56 μg/cm(2), respectively). They also presented permeation to the receptor fluid (0.67 ± 0.22 and 1.80 ± 0.85 μg/cm(2), respectively). In addition, anti-inflammatory effect was observed to NCN and PCN with edema inhibitions of 69 and 67% in mouse ear edema and 32 and 72% in rat paw edema, respectively. Histological cuts showed the decrease of inflammatory factors, such as dermis and epidermis hyperplasia and inflammatory cells infiltration, confirming the anti-inflammatory effect from both copaiba oil nanoemulsions incorporated in hydrogel.
This work evaluated the potential of a volatile oil extracted from Syagrus coronata seeds for the control of Aedes aegypti. The oil was extracted by hydrodistillation, characterized by gas chromatography-mass spectrometry (GC-MS), and evaluated for larvicidal and ovicidal activities, as well as for influence on the choice of oviposition site by females. The effects of the oil on swimming activity of larvae were also investigated. The oil extraction showed a yield of 0.41% and GC-MS revealed that 98.42% of the composition corresponded to the following fatty acids: octanoic acid (40.55%), decanoic acid (17.39%) and dodecanoic acid (40.48%). The oil promoted the death of A. aegypti larvae, with LC50 of 21.07 ppm, but had no ovicidal action. The octanoic, decanoid and dodecanoic acids showed larvicidal activity with LC50 of 51.78, 24.01 and 19.72 ppm, respectively. The swimming activity of larvae incubated with the oil during 1 and 3 h was significantly (p < 0.05) lower than that of control (0.2% Tween 80, v/v) larvae. The S. coronata oil and the octanoic acid (both at 50 ppm) showed a deterrent effect on oviposition. In conclusion, the essential oil of S. coronata seed was able to promote death of A. aegypti larvae and exerted a deterrent effect on pregnant females. The results indicated that the larvicidal activity is due to the action of decanoic and dodecanoic acids while the oviposition deterrent effect is probably linked to the presence of octanoic acid.