Characterization of emulgels formulated with phycocyanin and diutan gum as a novel approach for biocompatible delivery systems.

Phycocyanin (PC), a protein derived from algae, is non-toxic and biocompatible. Due to its environmental and sustainable properties, it has been studied as an alternative stabilizer for food emulsions. In this sense, the main objective of this work is to evaluate the effectiveness of PC and its use in combination with diutan gum (DG), a biological macromolecule, to prepare emulgels formulated with avocado oil. Z-potential measurements show that the optimum pH for working with PC is 2.5. Furthermore, the system exhibited a structured interface at this pH. The surface tension did not decrease further above 1.5 wt% PC. Interestingly, emulsions formulated with >1.5 wt% PC showed recoalescence immediately after preparation. Although 1.5 wt% had the smallest droplet size, this emulsion underwent creaming due to the low viscosity of the system. DG was used in combination with PC to increase viscosity and reduce creaming. As little as 0.1 wt% DG was sufficient to form an emulgel when incorporated into the previous emulsion, which exhibited pseudoplastic behaviour and viscoelastic properties with very low creaming rates. However, the use of PC in combination with DG resulted in a non-aggregated and stable emulgel with 1.5 wt% PC and 0.1 wt% DG.

Formulation and Characterization of Sustainable Algal-Derived Nanoemulgels: A Green Approach to Minimize the Dependency on Synthetic Surfactants.

Phycocyanin (PC), a natural protein that is very interesting from the medical point of view due to its potent antioxidant and anti-inflammatory properties, is obtained from algae. This compound is gaining positions for applications in the food industry. The main objective of this work was to obtain nanoemulgels formulated with PC and k-carrageenan (a polymer that is obtained from algae as well). An optimization of the processing parameters (homogenization pressure and number of cycles) and the ratio of PC and a well-known synthetic surfactant (Tween 80) was developed using response surface methodology. The results of this optimization were 25,000 psi, seven cycles, and a 1:1 ratio of PC/Tween80. However, the necessity for the incorporation of a polymer that plays a thickener role was observed. Hence, k-carrageenan (k-C) was used to retard the creaming process that these nanoemulsions suffered. The incorporation of this biopolymer provoked the creation of a network that showed gel-type behavior and flow indexes very close to zero. Thanks to the combined use of these two sustainable and algae-obtained compounds, stable nanoemulgels were obtained. This work has proved that the combined use of PC and k-C has emerged as a sustainable alternative to stabilize dispersed systems for the food industry.

Development of Avocado and Lemon Oil Emulgels Based on Natural Products: Phycocyanin and Pectin.

Phycocyanin (PC), a natural product obtained from algae, is attracting attention due to its health benefits, such as its antioxidant and anti-inflammatory properties. This work studies the use of PC as the main stabilizer in avocado and lemon oil emulgels, a format for drug delivery. The influence of PC concentration on droplet size distribution, rheological properties, and physical stability is studied using a laser diffraction technique, rheological measurements, and multiple light scattering. The 5 wt.% PC emulsions show the lowest droplet size and, consequently, the best stability against creaming and droplet growth. Emulsions formulated with PC as the only stabilizer show a slight pseudoplastic character with an apparent viscosity below 10 mPa·s at 2 Pa. This indicates that these emulsions undergo creaming with aging time. In order to reduce creaming, pectin is incorporated into the 5 wt.% PC emulsion at different concentrations. Interestingly, yield stress and an incipient gel character are observed due to the presence of pectin. This is why the creaming mechanism is reduced. In conclusion, PC forms a layer that protects the interface against coalescence and Ostwald ripening. And, pectin is incorporated to reduce creaming. This research has the potential to make valuable contributions to diverse fields, such as health, medicine, and encapsulation technology.

The PAY test: a new approach for assessing functional performance in children and adolescents with asthma.

OBJECTIVE: To develop, validate, and test the reproducibility of a new test capable of assessing functional performance in children and adolescents (PAY test: Performance Activity in Youth). METHODS: participants without and with asthma were included in the development and validation phases, respectively. The PAY test includes five activities: transition from sitting to standing, walking 10 m, step climbing, shoulder extension and flexion, and star jumps. Participants underwent the Pediatric Glittre test (TGlittre-P test time), modified shuttle test (MST), and cardiopulmonary exercise test (CPET). OUTCOMES: PAY test and TGlittre-P test times, oxygen uptake (VO2peak), and distance walked in the MST. RESULTS: 8 healthy volunteers, aged 12 (7 - 15) years old were included in the development phase and 34 participants with asthma, aged 11 (7 -14) years old, in the validation phase. The PAY test elicited greater physiological responses (VO2peak 33.5 ± 6.9 mL/kg) than the TGlittre-P (VO2peak: 27.4 ± 9.0 mL/kg), but lower than the MST (VO2peak: 48.9 ± 14.2 mL/kg) and CPET (VO2peak: 42.0 ± 8.8 mL/kg), p < .05. Moderate correlation between the PAY test time and the TGlittre-P time (r = 0.70, p < .001) and distance walked in the MST (r = -0.72, p < .001). The PAY test time was longer in participants with asthma than in healthy participants (3.1 [3.0 - 3.3] min vs. 2.3 [2.1 - 2.4 min]), p < .001.; and the test was reproducible (ICC 0.78, CI 95% 0.55-0.90, p < .001). CONCLUSIONS: The PAY test is a valid and reproducible tool for assessing functional performance in children and adolescents with asthma.

The PAY test: a new approach for assessing functional performance in children and adolescents with asthma

Abstract Objective: To develop, validate, and test the reproducibility of a new test capable of assessing functional performance in children and adolescents (PAY test: Performance Activity in Youth). Methods: participants without and with asthma were included in the development and validation phases, respectively. The PAY test includes five activities: transition from sitting to standing, walking 10 m, step climbing, shoulder extension and flexion, and star jumps. Participants underwent the Pediatric Glittre test (TGlittre-P test time), modified shuttle test (MST), and cardiopulmonary exercise test (CPET). Outcomes: PAY test and TGlittre-P test times, oxygen uptake (VO2peak), and distance walked in the MST. Results: 8 healthy volunteers, aged 12 (7 -15) years old were included in the development phase and 34 participants with asthma, aged 11 (7-14) years old, in the validation phase. The PAY test elicited greater physiological responses (VO2peak 33.5 ± 6.9 mL/kg) than the TGlittre-P (VO2peak: 27.4 ± 9.0 mL/kg), but lower than the MST (VO2peak: 48.9 ± 14.2 mL/kg) and CPET (VO2peak: 42.0 ± 8.8 mL/kg), p < .05. Moderate correlation between the PAY test time and the TGlittre-P time (r = 0.70, p < .001) and distance walked in the MST (r = -0.72, p < .001). The PAY test time was longer in participants with asthma than in healthy participants (3.1 [3.0 - 3.3] min vs. 2.3 [2.1 - 2.4 min]), p < .001.; and the test was reproducible (ICC 0.78, CI 95% 0.55-0.90, p < .001). Conclusions: The PAY test is a valid and reproducible tool for assessing functional performance in children and adolescents with asthma.

Influence of Type and Concentration of Biopolymer on ß-Carotene Encapsulation Efficiency in Nanoemulsions Based on Linseed Oil.

Many lipophilic active substances, such as ß-carotene, are sensitive to chemical oxidation. A strategy to protect these ingredients is encapsulation using nanoemulsions. This work analyzes the relationship between the physical stability and encapsulation efficiency of nanoemulsions based on linseed oil. The role of two different polysaccharides, Advanced Performance xanthan gum (APXG) or guar gum (GG) as stabilizers at different concentrations were studied to reach the required physical stability of these systems. This was investigated by means of droplet size distributions, steady-state flow curves, small amplitude oscillatory shear tests, multiple light scattering, and electronic microscopy. The overall results obtained reveal a depletion flocculation mechanism in all the APXG nanoemulsions, regardless of the concentration, and above 0.3 wt.% for GG nanoemulsions. Moreover, it has been demonstrated that enhanced physical stability is directly related to higher values of encapsulation efficiency. Thus, the nanoemulsion formulated with 0.2 wt.% GG, which presented the lowest creaming degree conditioned by depletion flocculation, showed a relative ß-carotene concentration even above 80% at 21 days of aging time. In conclusion, the adequate selection of polysaccharide type and its concentration is a key point for the application of stable nanoemulsions as vehicles for active ingredients.

Microneedling with cutaneous delivery of topical agents for the treatment of melasma: A systematic review.

BACKGROUND: Melasma is an acquired hyperpigmentation disorder. Microneedling is an alternative treatment for melasma especially by improving penetration of pharmacological agents into the skin. OBJECTIVE: The main objective of this review was to systematize and analyze available evidence on the efficacy and safety of microneedling alone or associated with topical agents in reducing skin stains and improving melasma-related quality of life in adult patients. METHODS: Only randomized clinical trials were included. The following databases were consulted: MEDLINE, Embase, Cochrane, and the gray literature. The Cochrane risk-of-bias tool for randomized trials (RoB 2.0) was used to assess risk of bias. RESULTS: The search retrieved 719 records and seven studies were included. A total of 368 participants (96.19% women) were evaluated. Two studies were split-face. Most of the studies evaluated microneedling associated with tranexamic acid. High risk of bias was presented by most studies, especially in the safety outcome. A significant decrease was observed in the MASI, mMASI, or hemi-MASI scores, regardless of the topical agents associated. Meta-analysis was not possible due to the heterogeneity of the studies. CONCLUSION: Based on the results of this review, microneedling can, in association with topical agents or isolated, be used safely in the treatment of melasma in the clinical practice, obtaining results on reduction of stain severity and improvement of patients' quality of life.

Relation between Droplet Size Distributions and Physical Stability for Zein Microfluidized Emulsions.

Zein, a subproduct of the food industry and a protein, possesses limited applications due to its high hydrophobic character. The objective of this research was to investigate the influence of homogenization pressure and cycles on the volumetric mean diameter (D4,3), span values, and Turbiscan Stability Index (TSI) using the response surface methodology for microfluidized emulsions containing zein as a unique stabilizer. Results showed that homogenization pressure seems to be the most influential parameter to obtain enhanced physical stability and droplet size distributions, with the optimum being 20,000 psi. Interestingly, the optimum number of cycles for volumetric diameter, span value, and TSI is not the same. Although a decrease of D4,3 with number of cycles is observed (optimum three cycles), this provokes an increase of span values (optimum one cycle) due to the recoalescence effect. Since physical stability is influenced by D4,3 and span, the minimum for TSI is observed at the middle level of the cycles (2 cycles). This work highlights that not only volumetric diameter, but also span value must be taken into consideration in order to obtain stable zein emulsions. In addition, this study wants to extend the limited knowledge about zein-based emulsions processed with a Microfluidizer device.

Optimization of sonication parameters to obtain food emulsions stabilized by zein: formation of zein-diutan gum/zein-guar gum complexes.

BACKGROUND: Zein as a sole material is not suitable for technological applications since it is not flexible. A possible solution to extend the applications of zein is the formation of zein-polysaccharide complexes. As a first step, sonication parameters were optimized to obtain finer emulsions formulated with zein, rosemary essential oil as food preservative, and sunflower oil, by means of response surface methodology. After the formation of these guar- or diutan-zein complexes the rheological properties of these food emulsions were evaluated. RESULTS: An increase in sonication power, sonication time and cycles provoked a decrease in mean droplet size and a lack of recoalescence. The optimized emulsion was the starting point to form two different complexes: zein with diutan gum and zein with guar gum at different concentrations. Rheological properties as well as the microstructure observed by field emission scanning electron microscopy (FESEM) were analyzed. Interestingly, zein-guar gum complexes did not form a rheological gel; as a consequence, emulsions containing them seem to undergo a destabilization process with aging time. In contrast, emulsions formulated with zein-diutan gum presented a 3D network, observed by FESEM technique and proved by rheological measurements. CONCLUSION: While emulsions containing zein-guar gum complexes did not form networks to stabilize oil droplets, zein-diutan gum complexes did. This work brings to light the importance of the selection of polysaccharide used in food emulsions formulated with zein. © 2021 Society of Chemical Industry.

Mucopolysaccharidosis patients have reduced functional capacity.

INTRODUCTION: Mucopolysaccharidoses (MPSs) are a group of rare diseases caused by an intralysosomal accumulation of glycosaminoglycans, resulting in a multisystemic clinical condition characterized by variable degrees of physical-functional impairment. OBJECTIVE: To evaluate the functional capacity (FC) of MPS patients and compare with a healthy control group. METHODS: This is a cross-sectional study of 6- to 39-year-old patients followed at a medical reference center and compared with their control peers, matched by age and sex. FC was assessed using the Sit-to-Stand Test (SST) and Incremental Shuttle Walk Test (ISWT). Heart rate (HR) and Borg rating of perceived exertion were measured before and after ISWT. HR recovery (HRR) was defined as the HR at the end of the test minus the HR in the second minute after ISWT. RESULTS: Nineteen (19) MPS patients, 69% with type II MPS and mean age 17 ± 11 years were evaluated. Every patient was under enzyme replacement therapy. The time to perform the SST was longer in the MPS group (10.6 ± 2.5 s vs. 6.7 ± 1.2 s; p < .01). The MPS group achieved lower values of distance covered on the ISWT (407.6 ± 329.8 m vs. 1131.9 ± 183.3 m; p < .01), with a significantly higher Borg (6 [5-8] vs. 2 [1-4]; p = .02). The MPS group's HRR was slower than the controls (32.9 ± 20.2 beats per minute [bpm] vs. 69.1 ± 25.9 bpm; p < .001). DISCUSSION: We observed a pronounced reduction in the MPS group's FC compared to their healthy peers and a worse HRR after completing the test.

Impact of Microfluidization on the Emulsifying Properties of Zein-Based Emulsions: Influence of Diutan Gum Concentration.

Microfluidization is a preparation method that can be used to obtain emulsions with submicron droplet sizes. The first objective of this study was to evaluate the influence of homogenization pressure and cycles on droplet sizes using response surface methodology. Secondly, the influence of the diutan gum concentration incorporated in the optimized emulsion on rheological properties, microstructure, and physical stability was investigated. Taking the response surface analysis into account, the emulsion processed at 20,000 psi after four cycles seemed to show the smallest Sauter diameter values. Hence, this emulsion was the starting point to incorporate diutan gum. Interestingly, the formation of a 3D network in the emulsion, observed by FESEM, was provoked by diutan gum. The emulsion formulated with 0.4 wt.% of diutan gum presented rheological gel properties and enhanced physical stability. This work highlights the importance of selecting optimized processing variables using the microfluidization technique and extends the knowledge of using diutan gum in combination with zein.

Processing and Formulation Optimization of Mandarin Essential Oil-Loaded Emulsions Developed by Microfluidization.

Emulsions can be used as delivery systems for bioactive ingredients for their incorporation in food products. Essential oils are natural compounds found in plants that present antioxidant and antimicrobial activity. Therefore, the main goal of this work was to develop emulsions, containing mandarin essential oil stabilized by two food-grade surfactants and guar gum, and to evaluate their physical stability. The initial droplet size of emulsions developed by microfluidization was optimized, obtaining diameters below one micron regardless of the processing conditions. However, the emulsion processed at 25,000 psi and one pass exhibited the lowest mean droplet sizes and polidispersity, and therefore, a higher stability. Different ratios of Tween 80 and Span 80 were assessed as stabilizers. Results obtained indicated that the ratio of surfactants had a significant effect on the mean droplet sizes, physical stability, and rheological properties. Thus, we found that the optimum ratio of surfactants was 75/25 (Tween80/Span80) on account of the lowest droplet mean diameters, lack of coalescence, and a low creaming rate. The rheological characterization of the stable emulsions showed a shear thinning flow behavior, and G″ (loss modulus) values higher than G' (storage modulus) values, in all the frequency range. The rheological behavior may be governed by the guar gum, which was confirmed by field emission scanning electron microscopy (FESEM). This research can be considered as the starting point for future applications of mandarin essential oil in emulsions, which can be incorporated in products as food preservatives.

Characterization of novel nanoemulsions, with improved properties, based on rosemary essential oil and biopolymers.

BACKGROUND: Nowadays, it is of great interest to develop stable and sustainable formulations that act as nanocarriers of active ingredients. In this work, the droplet size distribution, rheology and physical stability of nanoemulsions with improved properties containing rosemary essential oil and biopolymers as a function of the concentration of these polysaccharides were investigated. RESULTS: Mean diameters below 150 nm were achieved, indicating nanostructures were obtained. Regardless of gum type, a gel-like structure and a shear thinning behaviour was achieved. In addition, an increase of G', G″ and viscosity and a decrease of J0 , J1 , J2 , λ1 and λ2 with increasing gum concentration were observed, due to the formation of a three-dimensional network in the aqueous phase. Slight differences between nanoemulsions containing welan or xanthan were found. Creaming, depletion flocculation and gel aggregation were the main destabilization processes at low, intermediate and high gum concentration, respectively. A 0.4 wt% gum nanoemulsion exhibited the best physical stability. CONCLUSION: These stable and sustainable nanoemulsions with improved rheological properties contribute to the development of biodegradable and non-toxic food or agrochemical products. © 2020 Society of Chemical Industry.

Strategies for reducing Ostwald ripening phenomenon in nanoemulsions based on thyme essential oil.

BACKGROUND: White thyme essential oil, which can be incorporated in clean-label and food emulsion-based products, is a natural antimicrobial agent. However, emulsions containing essential oils commonly undergo Ostwald ripening as the main destabilization process. The main objective of this work was to evaluate various strategies for the inhibition of Ostwald ripening so as to develop stable nanoemulsions containing white thyme essential oil as food preservative and Kolliphor EL as surfactant. RESULTS: In a first approach, the influence of the surfactant/dispersed phase ratio and the number of cycles through a microfluidizer on droplet size distribution was evaluated. Unfortunately, these emulsions underwent Ostwald ripening, which was demonstrated by the application of the Lifshitz-Slyozov-Wagner theory. In order to reduce this destabilization mechanism, two different techniques based on the modification of the formulation (addition of rosin gum or Aerosil COK84) were analysed using laser diffraction and multiple light scattering techniques. The addition of rosin gum inhibited the Ostwald ripening mechanism, but only partially. Conversely, the incorporation of Aerosil COK84 to the continuous phase led to a gel-like rheological behaviour which seemed to practically avoid Ostwald ripening. CONCLUSIONS: Aerosil particles cover the droplets and form a three-dimensional network suggesting a Pickering stabilization, which was confirmed using transmission electronic microscopy. The results confirmed the role of Aerosil COK84, not only as a thickener or gelling agent, but also as an Ostwald ripening inhibitor. © 2019 Society of Chemical Industry.

Development of emulgels formulated with sweet fennel oil and rhamsan gum, a biological macromolecule produced by Sphingomonas.

In this work, a current application of rhamsan gum, a biological macromolecule which belongs to the sphingans group, as an efficient stabilizer of emulsions and emulgels is investigated. The main objective of this investigation was 1) to study the influence of glycerol and sweet fennel oil concentration on microfluidized emulsion properties; and 2) to develop stable emulgels stabilized with rhamsan gum. The emulsions and emulgels were characterized by droplet size, rheological properties, physical stability and microstructure. An analysis by surface response methodology of the results obtained revealed that essential oil concentration was the most determining factor affecting emulsion mean droplet sizes and rheological properties. An optimal emulsion with minimum d4,3 was obtained for the sample formulated with 10 wt% sweet fennel oil and 0 wt% glycerol. However, all of these emulsions suffered destabilization by creaming. The results of the rheological characterization of emulsions formulated with the biological macromolecule showed that the addition of 0.2 wt% of rhamsan gum allows an emulgel with enhanced physical stability to be obtained. Thus, we provide valuable information concerning the use of rhamsan gum as emulsion stabilizer and the development of stable emulsions and emulgels for use in the food industry.

Effect of temperature and shear on the microstructure of a microbial polysaccharide secreted by Sphingomonas species in aqueous solution.

Diutan gum is a biological polymer produced by Sphingomonas sp. In aqueous solution it shows gel-like structure under quiescent conditions. However, the flow-induced evolution of its viscoelastic properties and its microstructure are not known. In this work, the viscoelastic moduli were obtained under a flow field, applied in parallel, as a function of the temperature for 0.5 wt% diutan gum aqueous solutions. As both stress and temperature increase a decrease in the viscoelastic properties occurred, due to the fact that the molecular interactions decreased. Nevertheless, at stresses within the zero-shear viscosity region of the flow curves, no changes were observed. In addition, high stress values dampened the effect of the temperature. The results obtained are very interesting from an industrial application perspective.

Saúde sexual e reprodutiva de adolescentes: um panorama da atenção básica de Franco da Rocha / Sexual and reproductive health of adolescents: a panorama of the basic attention of Franco da Rocha

A sexualidade na adolescência se destaca como um campo de descobertas, experiências e inicio de vivências que exigem do(a) adolescente a conquista e o exercício de sua autonomia. Assim , a saúde sexual e reprodutiva dos adolescentes se configura como uma pauta de extrema importância...(AU)

Development of eco-friendly submicron emulsions stabilized by a bio-derived gum.

Many traditional organic solvents are being gradually replaced by ecofriendly alternatives. D-Limonene is a terpenic (bio)-solvent that fulfils the requirements to be considered a green solvent. D-Limonene sub-micron emulsions suffer from Ostwald ripening destabilization. In this study, we examined the influence of the addition of a natural gum (rosin gum) to D-limonene in order to prevent Ostwald ripening. This contribution deals with the study of emulsions formulated with a mixture of D-limonene and rosin gum as dispersed phase and Pluronic PE9400 as emulsifier. The procedure followed for the development of these formulations was based on the application of product design principles. This led to the optimum ratio rosin gum/D-limonene and subsequently to the optimum surfactant concentration. The combination of different techniques (rheology, laser diffraction and multiple light scattering) was demonstrated to be a powerful tool to assist in the prediction of the emulsions destabilization process. Not only did the addition of rosin gum highly increase the stability of these emulsions by inhibiting the Ostwald ripening, but it also reduced the emulsions droplet size. Thus, we found that stable sub-micron D-limonene-in-water emulsions have been obtained in the range 3-6 wt% Pluronic PE-9400 by means of a single-step rotor/stator homogenizing process.

Reference equation for the 2-minute walk test in adults and the elderly.

BACKGROUND: The 2-min walk test (2MWT) has been used in several health conditions, but the interpretation of its results is limited due to a lack of reference values. The aim of this study was to establish a reference equation to predict the distance walked (DW) in the 2MWT for healthy adults and the elderly and to test its reproducibility. METHODS: We evaluated 390 healthy subjects (195 male), 18-89 y old, with normal spirometry and no history of previous chronic diseases. Two 2MWTs were performed on the same day, 30 min apart. To test the reliability of the prediction equation, 70 subjects (35 male) were prospectively included in the study. RESULTS: Men walked farther than women (221 [202-240] vs 199 [164-222] m, respectively; P < .0001). Significant correlations were observed between DW and age (r = -0.50), weight (r = 0.23), height (r = 0.40), and gender (r = 0.35) (P < .001 for all). Age and gender persisted in the model to predict DW (R(2) = 0.51). There was no difference between the DW by the subjects (197 [182-216] m) and that estimated by the prediction equation (197 [179-222] m) (P = .68). CONCLUSIONS: We established a prediction equation that may be used as a reference to interpret performance on the 2MWT of adults and the elderly with different health conditions.