123 results on '"Rubio RG"'
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2. Roles of Polymer Concentration and Ionic Strength in the Deposition of Chitosan of Fungal Origin onto Negatively Charged Surfaces.
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Ormeño-Martínez M, Guzmán E, Fernández-Peña L, Greaves AJ, Bureau L, Ortega F, Rubio RG, and Luengo GS
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This study examines the potential of fungal chitosan derived from Aspergillus niger as a sustainable alternative to traditional petrochemical-based ingredients in cosmetic products. Specifically, the research examines the solubility of fungal chitosan in aqueous solutions of varying ionic strength and its adsorption onto negatively charged surfaces that mimic human hair keratin. The adsorption behavior, water content, and frictional properties of chitosan films were evaluated using a quartz crystal microbalance with dissipation monitoring and a surface force apparatus (SFA). The findings indicated that fungal chitosan exhibits good solubility at a pH of 4.5. Conversely, the adsorption of chitosan is subject to the influence of both polymer concentration and ionic strength. At the lowest ionic strengths, a screening-enhanced adsorption process occurs as a consequence of the reduction in chitosan solubility in the presence of salt. This results in the depletion of polymer chains from the solution and their subsequent deposition. An increase in ionic strength above 15-20 mM results in a worsening of the chitosan-surface interaction, due to the simultaneous screening of both the chitosan and the surface charges. This results in a hindrance to the adsorption process. The deposited films are highly hydrated, and this hydration increases with both polymer concentration and ionic strength. Furthermore, the films exhibit a predominantly elastic behavior, and the response of the films under shear deformations shows a strong dependence on the polymer concentration. These findings contribute to the development of environmentally friendly cosmetic formulations that meet consumer demands for sustainability.
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- 2024
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3. Efficacy and Safety of DaxibotulinumtoxinA for Injection in Cervical Dystonia: ASPEN-1 Phase 3 Randomized Controlled Trial.
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Comella CL, Jankovic J, Hauser RA, Patel AT, Banach MD, Ehler E, Vitarella D, Rubio RG, and Gross TM
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- Adult, Humans, Double-Blind Method, Injections, Intramuscular, Treatment Outcome, Adolescent, Young Adult, Middle Aged, Aged, Aged, 80 and over, Botulinum Toxins, Type A adverse effects, Dystonic Disorders drug therapy, Neuromuscular Agents adverse effects, Torticollis drug therapy, Torticollis chemically induced
- Abstract
Background and Objectives: ASPEN-1 was a phase 3, randomized, double-blind, placebo-controlled study to evaluate the efficacy, duration of response, and safety of 2 doses of DaxibotulinumtoxinA for Injection (DAXI), a novel botulinum toxin type A formulation in participants with cervical dystonia (CD)., Methods: Adults (aged 18-80 years) with moderate-to-severe CD (Toronto Western Spasmodic Torticollis Rating Scale [TWSTRS] total score ≥20) were enrolled at 60 sites across 9 countries in Europe and North America. Participants were randomized (3:3:1) to single-dose intramuscular DAXI 125U, 250U, or placebo and followed for up to 36 weeks after injection. The primary end point was change from baseline in TWSTRS total score averaged across weeks 4 and 6. Key secondary end points included duration of effect, Clinical and Patient Global Impression of Change (CGIC, PGIC), TWSTRS subscale scores, and safety. Multiplicity-adjusted intent-to-treat hypothesis tests with multiple imputation were performed using ANCOVA and Cochran-Mantel-Haenszel analyses., Results: Of 444 individuals screened, 301 were randomized to DAXI 125U (n = 125) or 250U (n = 130) or placebo (n = 46). DAXI 125U and 250U significantly improved the mean TWSTRS total score vs placebo (least squares mean [standard error] difference vs placebo: DAXI 125U, -8.5 [1.93], p < 0.0001; DAXI 250U, -6.6 [1.92], p = 0.0006). The median duration of effect (time from treatment until loss of ≥80% of the peak improvement in average TWSTRS total score achieved at weeks 4 and 6) was 24.0 (95% confidence interval 20.3-29.1) weeks with DAXI 125U and 20.3 (16.7-24.0) weeks with DAXI 250U. Significant improvements were also observed with DAXI in CGIC and PGIC responder rates and TWSTRS subscales. Treatment-related treatment-emergent adverse events (TEAEs) were reported by 29.6% of participants with DAXI 125U, 23.8% with DAXI 250U, and 17.4% with placebo, with injection site pain being the most common overall. The most frequently reported treatment-related TEAEs of interest in DAXI 125U, DAXI 250U, and placebo, respectively, were muscular weakness (4.8%, 2.3%, 0%), musculoskeletal pain (2.4%, 3.1%, 0%), and dysphagia (1.6%, 3.8%, 0%)., Discussion: This study demonstrated that DAXI, at doses of 125U and 250U, is an effective, safe, long-acting, and well-tolerated treatment for CD., Trial Registration Information: ClinicalTrials.gov identifier (NCT03608397, submitted July 11, 2018) and EU Clinical Trials Register (ClinicalTrialsRegister.eu EudraCT identifier 2018-000446-19, submitted September 13, 2018). First participant enrolled on June 11, 2018. Trial registration was performed in accordance with the Food and Drug Administration Amendments Act (FDAAA 801), which stipulates that the responsible party register an applicable clinical trial not later than 21 calendar days after enrolling the first human participant (42 CFR 11.24)., Classification of Evidence: This study provides Class I evidence that in adults with moderate-to-severe idiopathic cervical dystonia, DAXI reduces dystonia more effectively than placebo.
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- 2024
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4. Anomalous Colloidal Motion under Strong Confinement.
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Abelenda-Núñez I, Ortega F, Rubio RG, and Guzmán E
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Diffusion of biological macromolecules in the cytoplasm is a paradigm of colloidal diffusion in an environment characterized by a strong restriction of the accessible volume. This makes of the understanding of the physical rules governing colloidal diffusion under conditions mimicking the reduction in accessible volume occurring in the cell cytoplasm, a problem of a paramount importance. This work aims to study how the thermal motion of spherical colloidal beads in the inner cavity of giant unilamellar vesicles (GUVs) is modified by strong confinement conditions, and the viscoelastic character of the medium. Using single particle tracking, it is found that both the confinement and the environmental viscoelasticity lead to the emergence of anomalous motion pathways for colloidal microbeads encapsulated in the aqueous inner cavity of GUVs. This anomalous diffusion is strongly dependent on the ratio between the volume of the colloidal particle and that of the GUV under consideration as well as on the viscosity of the particle's liquid environment. Therefore, the results evidence that the reduction of the free volume accessible to colloidal motion pushes the diffusion far from a standard Brownian pathway as a result of the change in the hydrodynamic boundary conditions driving the particle motion., (© 2023 The Authors. Small published by Wiley-VCH GmbH.)
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- 2023
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5. Dilution-Induced Deposition of Concentrated Binary Mixtures of Cationic Polysaccharides and Surfactants.
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Fernández-Peña L, Guzmán E, Oñate-Martínez T, Fernández-Pérez C, Ortega F, Rubio RG, and Luengo GS
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This work investigates the effect of dilution on the phase separation process of binary charged polysaccharide-surfactant mixtures formed by two cationic polysaccharides and up to four surfactants of different nature (anionic, zwitterionic, and neutral), as well as the potential impact of dilution-induced phase separation on the formation of conditioning deposits on charged surfaces, mimicking the negative charge and wettability of damaged hair fibers. The results obtained showed that the dilution behavior of model washing formulations (concentrated polysaccharide-surfactant mixtures) cannot be described in terms of a classical complex precipitation framework, as phase separation phenomena occur even when the aggregates are far from the equilibrium phase separation composition. Therefore, dilution-enhanced deposition cannot be predicted in terms of the worsening of colloidal stability due to the charge neutralization phenomena, as common phase separation and, hence, enhanced deposition occurs even for highly charged complexes.
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- 2023
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6. Probing the effect of the capping polyelectrolyte on the internal structure of Layer-by-Layer decorated nanoliposomes.
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Mateos-Maroto A, E F Rubio J, Prévost S, Maestro A, Rubio RG, Ortega F, and Guzmán E
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Hypothesis: The internal organization of polyelectrolyte layers deposited on colloidal templates plays a very important role for the potential applications of these systems as capsules for drug delivery purposes., Experiments: The mutual arrangement of oppositely charged polyelectrolyte layers upon their deposition on positively charged liposomes has been studied by combining up three different scattering techniques and Electronic Spin Resonance, which has provided information about the inter-layer interactions and their effect on the final structure of the capsules., Findings: The sequential deposition of oppositely charged polyelectrolytes on the external leaflet of positively charged liposomes allows modulating the organization of the obtained supramolecular structures, impacting the packing and rigidity of the obtained capsules due to the change of the ionic cross-linking of the multi-layered film as a result of the specific charge of the last deposited layer. The possibility to modulate the properties of the LbL capsules by tuning the characteristics of the last deposited layers offers a very interesting route for the design of materials for encapsulation purposes with their properties controlled almost at will by changing the number of deposited layers and their chemistry., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2023
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7. Association of oppositely charged polyelectrolyte and surfactant in solution: equilibrium and nonequilibrium features.
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Guzmán E, Maestro A, Ortega F, and Rubio RG
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The association of polyelectrolytes and surfactants bearing charges of opposite signs has been for long time considered under an equilibrium framework. However, this is far to provide a true description of the physico-chemical rules of the association process when kinetically arrested nonequilibrium states are formed. This is the result of specific interaction pathways between the polyelectrolyte chains and the surfactant molecules determined by the mixing procedure and the mixture composition. In fact, the specific characteristics of the method used for the mixture can induce local inhomogeneities in the mixture composition which can govern the properties of the obtained supramolecular aggregates, driving to the systems to a situation far from the true equilibrium. This topical review tries to provide to the reader a general perspective of the role of the nonequilibrium aspects in the control of the polyelectrolyte-surfactant association process, and how these impact on the obtained supramolecular nanoassemblies, and their properties., (© 2023 IOP Publishing Ltd.)
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- 2023
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8. Layer-by-Layer Nanoassemblies for Vaccination Purposes.
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Guzmán E, Ortega F, and Rubio RG
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In recent years, the availability of effective vaccines has become a public health challenge due to the proliferation of different pandemic outbreaks which are a risk for the world population health. Therefore, the manufacturing of new formulations providing a robust immune response against specific diseases is of paramount importance. This can be partially faced by introducing vaccination systems based on nanostructured materials, and in particular, nanoassemblies obtained by the Layer-by-Layer (LbL) method. This has emerged, in recent years, as a very promising alternative for the design and optimization of effective vaccination platforms. In particular, the versatility and modularity of the LbL method provide very powerful tools for fabricating functional materials, opening new avenues on the design of different biomedical tools, including very specific vaccination platforms. Moreover, the possibility to control the shape, size, and chemical composition of the supramolecular nanoassemblies obtained by the LbL method offers new opportunities for manufacturing materials which can be administered following specific routes and present very specific targeting. Thus, it will be possible to increase the patient convenience and the efficacy of the vaccination programs. This review presents a general overview on the state of the art of the fabrication of vaccination platforms based on LbL materials, trying to highlight some important advantages offered by these systems.
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- 2023
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9. Efficacy and Safety of DaxibotulinumtoxinA for Injection in the Treatment of Glabellar Lines by Age and Race: Subgroup Analysis of the SAKURA Clinical Trials.
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Solish N, Burgess CM, Weinkle SH, Ablon G, Brown J, Kooken K, and Rubio RG
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- Adult, Humans, Middle Aged, Forehead, Injections, Double-Blind Method, Immunoglobulin A, Treatment Outcome, Botulinum Toxins, Type A, Neuromuscular Agents, Skin Aging
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Background: DaxibotulinumtoxinA for Injection (DAXI) is a novel botulinum toxin type A formulation approved for the treatment of glabellar lines. The efficacy, safety, and extended duration of response of DAXI 40 U for glabellar lines were demonstrated in 2 Phase 3, randomized, double-blind studies (SAKURA 1 and 2) and a Phase 3 open-label trial (SAKURA 3)., Objectives: The aim of this study was to evaluate the efficacy and safety of the first DAXI 40 U treatment received in SAKURA 1, 2, or 3 across age and race subgroups., Methods: Adults with moderate-to-severe glabellar lines (Investigator Global Assessment-Frown Wrinkle Severity [IGA-FWS] and Patient FWS [PFWS] scales) were evaluated for glabellar line severity for ≤36 weeks after the first DAXI treatment. Efficacy and safety were analyzed by age (18-45, >45-55, and >55 years) and race (Asian, Black and African American, and White)., Results: Overall, 2785 patients were included in the efficacy analysis. The proportion of patients achieving none or mild glabellar line severity at maximum frown (IGA-FWS) after DAXI treatment was high in all age and race subgroups (>96% at Week 4). Glabellar line severity of none or mild by composite IGA-FWS and PFWS rating was maintained for a median of 24.0 weeks in all age subgroups, and for 27.0, 25.3, and 24.0 weeks in the Asian, Black and African American, and White subgroups, respectively. Treatment-emergent adverse events were similar across all subgroups., Conclusions: Consistent with the overall study population, DAXI 40 U demonstrated a high response rate and duration of effect of ≥24 weeks across all age and race subgroups., (© The Author(s) 2022. Published by Oxford University Press on behalf of The Aesthetic Society.)
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- 2023
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10. Anomalous Concentration Dependence of Surface Tension and Concentration-Concentration Correlation Functions of Binary Non-Electrolyte Solutions.
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Carbone C, Guzmán E, and Rubio RG
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- Surface Tension, Hot Temperature
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The concentration dependence of the surface tension of several binary mixtures of non-electrolytes has been measured at 298.15 K. The mixtures have been chosen since they presented a so-called "W-shape" concentration dependence of the excess constant pressure heat capacity and high values of the concentration-concentration correlation function. This behavior was interpreted in terms of the existence of anomalously high concentration fluctuations that resemble those existing in the proximities of critical points. However, no liquid-liquid phase separation has been found in any of these mixtures over a wide temperature range. In this work, we have extended these studies to the liquid-air interfacial properties. The results show that the concentration dependence of the surface tension shows a plateau and the mixing surface tension presents a "W-shape" behavior. To the best of our knowledge, this is the first time that this behavior is reported. The weak anomalies of the surface tension near a liquid-liquid critical point suggest that the results obtained cannot be considered far-from-critical effects. The usual approach of substituting the activity by the concentration in the Gibbs equation for the relative surface concentration has been found to lead to large errors and the mixtures to have a fuzzy and thick liquid/vapor interface., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
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- 2023
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11. Treatment of Upper Facial Lines With DaxibotulinumtoxinA for Injection: Results From an Open-Label Phase 2 Study.
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Dover JS, Humphrey SD, Lorenc ZP, Shamban A, Gross TM, Rubio RG, and Vitarella D
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- Humans, Forehead, Face, Injections, Treatment Outcome, Double-Blind Method, Botulinum Toxins, Type A, Skin Aging, Neuromuscular Agents
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Background: Simultaneous treatment of moderate-to-severe upper facial lines is reflective of real-world clinical practice., Objective: To evaluate the efficacy and safety of daxibotulinumtoxinA-lanm for injection (DAXI) for simultaneous treatment of glabellar, forehead, and lateral canthal (LC) lines., Methods: In this open-label, single-arm Phase 2 study, patients (48 enrolled, 94% completed, follow-up 24-36 weeks) received DAXI 40U (glabellar), 32U (forehead), and 48U (LC) lines. Key efficacy endpoints: percentages of patients achieving none/mild wrinkle severity (investigator-rated) for each upper facial line scale at Week 4., Results: At Week 4, most patients achieved none/mild wrinkle severity (investigator-rated): glabellar (96%), forehead (96%), and LC (92%). Median times to loss of none/mild response (investigator- and patient-rated) among all patients were: 24.6 (glabellar), 20.9 (forehead), and 24.9 (LC) weeks; and 25.0, 24.0, and 28.1 weeks, respectively, among Week-4 responders. At Week 4, most patients reported improvements (Global Aesthetic Improvement Scale: 96%-98%) and high satisfaction rates (85%-98%). Five patients experienced treatment-related adverse events: injection-site erythema (3 patients/7 events), facial discomfort (2 patients/2 events), and headache (1 patient/1 event). No patients experienced eyebrow or eyelid ptosis., Conclusion: Simultaneous treatment of upper facial lines with DAXI was well tolerated and demonstrated high response rates, extended duration, and high patient satisfaction., Clinical Trial Registry: https://clinicaltrials.gov/ct2/show/NCT04259086., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society for Dermatologic Surgery, Inc.)
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- 2023
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12. Forces Controlling the Assembly of Particles at Fluid Interfaces.
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Guzmán E, Ortega F, and Rubio RG
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The interaction of particles with fluid interfaces is ubiquitous in synthetic and natural work, involving two types of interactions: particle-interface interactions (trapping energy) and interparticle interactions. Therefore, it is urgent to gain a deep understanding of the main forces controlling the trapping of particles at fluid interfaces, and their assembly to generate a broad range of structures characterized by different degrees of order. This Perspective tries to provide an overview of the main contributions to the energetic landscape controlling the assembly of particles at fluid interfaces, which is essential for exploiting this type of interfacial systems as platforms for the fabrication of interface-based soft materials with technological interest.
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- 2022
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13. Rotating Micro-Spheres for adsorption monitoring at a fluid interface.
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Martín-Roca J, Jiménez M, Ortega F, Calero C, Valeriani C, Rubio RG, and Martínez-Pedrero F
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- Adsorption, Emulsions, Kinetics, Surface-Active Agents chemistry, Water chemistry
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Hypothesis: A broad range of phenomena, such as emulsification and emulsion stability, foam formation or liquid evaporation, are closely related to the dynamics of adsorbing colloidal particles. Elucidation of the mechanisms implied is key to a correct design of many different types of materials., Experiments: Microspheres forced to rotate near a fluid interface exhibit a roto-translational hydrodynamic mechanism that is hindered by capillary torques as soon as the particles protrude the interface. Under these conditions, the time evolution in the ratio of moving spheres provides a direct description of the adsorption kinetics, while microscopy monitoring of particle acceleration\deceleration informs about the adsorption\desorption dynamics. In this work, the proposed strategy is applied at an air/water interface loaded with spherical magnetic particles negatively charged, forced to rotate by the action of a rotating magnetic field., Findings: The proposed method enables the adsorption/desorption dynamics to be followed during the earliest phase of the process, when desorption of a small fraction of particles is detected, as well as to estimate approximated values of the adsorption/desorption constants. The results obtained show that the addition of a monovalent salt or a cationic (anionic) surfactant promotes (inhibits) both adsorption and formation of permanent bonds between particles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)
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- 2022
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14. A broad perspective to particle-laden fluid interfaces systems: from chemically homogeneous particles to active colloids.
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Guzmán E, Martínez-Pedrero F, Calero C, Maestro A, Ortega F, and Rubio RG
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- Emulsions chemistry, Colloids chemistry
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Particles adsorbed to fluid interfaces are ubiquitous in industry, nature or life. The wide range of properties arising from the assembly of particles at fluid interface has stimulated an intense research activity on shed light to the most fundamental physico-chemical aspects of these systems. These include the mechanisms driving the equilibration of the interfacial layers, trapping energy, specific inter-particle interactions and the response of the particle-laden interface to mechanical perturbations and flows. The understanding of the physico-chemistry of particle-laden interfaces becomes essential for taking advantage of the particle capacity to stabilize interfaces for the preparation of different dispersed systems (emulsions, foams or colloidosomes) and the fabrication of new reconfigurable interface-dominated devices. This review presents a detailed overview of the physico-chemical aspects that determine the behavior of particles trapped at fluid interfaces. This has been combined with some examples of real and potential applications of these systems in technological and industrial fields. It is expected that this information can provide a general perspective of the topic that can be exploited for researchers and technologist non-specialized in the study of particle-laden interfaces, or for experienced researcher seeking new questions to solve., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2022
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15. Study of the Dilution-Induced Deposition of Concentrated Mixtures of Polyelectrolytes and Surfactants.
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Fernández-Peña L, Guzmán E, Fernández-Pérez C, Barba-Nieto I, Ortega F, Leonforte F, Rubio RG, and Luengo GS
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Mixtures of polyelectrolytes and surfactants are commonly used in many technological applications where the challenge is to provide well-defined modifications of the surface properties, as is the case of washing formulations in cosmetics. However, if contemporary experimental and theoretical methods can provide insights on their behavior in concentrated formulations, less is known on their behavior under practical use conditions, e.g., under dilution and vectorization of deposits. This makes it difficult to make predictions for specific performance, as, for example, good hair manageability after a shampoo or a comfortable sensorial appreciation after a skin cleanser. This is especially important when considering the formulation of new, more eco-friendly formulations. In this work, a detailed study of the phase separation process induced by dilution is described, as well as the impact on the deposition of conditioning material on negatively charged surfaces. In order to gain a more detailed physical insight, several polyelectrolyte-surfactant pairs, formed by two different polymers and five surfactants that, although non-natural or eco-friendly, can be considered as models of classical formulations, have been studied. The results evidenced that upon dilution the behavior, and hence its deposition onto the surface, cannot be predicted in terms of the behavior of simpler pseudo-binary (mixtures of a polymer and a surfactant) or pseudo-ternary mixtures (two polymers and a surfactant). In many cases, phase separation was observed for concentrations similar to those corresponding to the components in some technological formulations, whereas the latter appeared as monophasic systems. Therefore, it may be assumed that the behavior in multicomponent formulations is the result of a complex interplay of synergistic interactions between the different components that will require revisiting when new, more eco-sustainable ingredients are considered.
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- 2022
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16. Polyelectrolyte Multilayered Capsules as Biomedical Tools.
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Mateos-Maroto A, Fernández-Peña L, Abelenda-Núñez I, Ortega F, Rubio RG, and Guzmán E
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Polyelectrolyte multilayered capsules (PEMUCs) obtained using the Layer-by-Layer (LbL) method have become powerful tools for different biomedical applications, which include drug delivery, theranosis or biosensing. However, the exploitation of PEMUCs in the biomedical field requires a deep understanding of the most fundamental bases underlying their assembly processes, and the control of their properties to fabricate novel materials with optimized ability for specific targeting and therapeutic capacity. This review presents an updated perspective on the multiple avenues opened for the application of PEMUCs to the biomedical field, aiming to highlight some of the most important advantages offered by the LbL method for the fabrication of platforms for their use in the detection and treatment of different diseases.
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- 2022
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17. Overview of DaxibotulinumtoxinA for Injection: A Novel Formulation of Botulinum Toxin Type A.
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Solish N, Carruthers J, Kaufman J, Rubio RG, Gross TM, and Gallagher CJ
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- Botulinum Toxins, Type A administration & dosage, Botulinum Toxins, Type A adverse effects, Clinical Trials as Topic, Delayed-Action Preparations, Dose-Response Relationship, Drug, Humans, Hydrogen-Ion Concentration, Neuromuscular Agents administration & dosage, Neuromuscular Agents adverse effects, Skin Aging drug effects, Torticollis drug therapy, Botulinum Toxins, Type A therapeutic use, Neuromuscular Agents therapeutic use, Peptides chemistry
- Abstract
Botulinum toxin type A (BoNTA) products are widely used for therapeutic and aesthetic indications, but there is a need for longer-lasting treatments that maintain symptom relief between injections and reduce the frequency of re-treatment. DaxibotulinumtoxinA for Injection (DAXI) is a novel BoNTA product containing highly purified 150-kDa core neurotoxin and is the first to be formulated with a proprietary stabilizing excipient peptide (RTP004) instead of human serum albumin. The positively charged RTP004 has been shown to enhance binding of the neurotoxin to neuronal surfaces, which may enhance the likelihood of neurotoxin internalization. DAXI produces robust, extended efficacy across both aesthetic and therapeutic indications. In an extensive glabellar lines clinical program, DAXI showed a high degree of efficacy, a consistent median time to loss of none or mild glabellar line severity of 24 weeks, and median time until return to baseline of up to 28 weeks. In adults with cervical dystonia, DAXI at 125 U and 250 U significantly improved Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total scores, with a median duration of efficacy of 24 and 20 weeks, respectively, which compares favorably with the 12-14 weeks' duration reported for approved BoNTA products. Overall, DAXI was well tolerated, and the consistent extended duration of effect suggests that DAXI has the potential to improve the management of both aesthetic and therapeutic conditions., (© 2021. The Author(s).)
- Published
- 2021
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18. Pattern Formation upon Evaporation of Sessile Droplets of Polyelectrolyte/Surfactant Mixtures on Silicon Wafers.
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Perrin L, Akanno A, Guzman E, Ortega F, and Rubio RG
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- Surface Tension, Polyelectrolytes chemistry, Polyethylenes chemistry, Quaternary Ammonium Compounds chemistry, Silicon chemistry, Surface-Active Agents chemistry
- Abstract
The formation of coffee-ring deposits upon evaporation of sessile droplets containing mixtures of poly(diallyldimethylammonium chloride) (PDADMAC) and two different anionic surfactants were studied. This process is driven by the Marangoni stresses resulting from the formation of surface-active polyelectrolyte-surfactant complexes in solution and the salt arising from the release of counterions. The morphologies of the deposits appear to be dependent on the surfactant concentration, independent of their chemical nature, and consist of a peripheral coffee ring composed of PDADMAC and PDADMAC-surfactant complexes, and a secondary region of dendrite-like structures of pure NaCl at the interior of the residue formed at the end of the evaporation. This is compatible with a hydrodynamic flow associated with the Marangoni stress from the apex of the drop to the three-phase contact line for those cases in which the concentration of the complexes dominates the surface tension, whereas it is reversed when most of the PDADMAC and the complexes have been deposited at the rim and the bulk contains mainly salt.
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- 2021
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19. Particle-laden fluid/fluid interfaces: physico-chemical foundations.
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Guzmán E, Abelenda-Núñez I, Maestro A, Ortega F, Santamaria A, and Rubio RG
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Particle-laden fluid/fluid interfaces are ubiquitous in academia and industry, which has fostered extensive research efforts trying to disentangle the physico-chemical bases underlying the trapping of particles to fluid/fluid interfaces as well as the properties of the obtained layers. The understanding of such aspects is essential for exploiting the ability of particles on the stabilization of fluid/fluid interface for the fabrication of novel interface-dominated devices, ranging from traditional Pickering emulsions to more advanced reconfigurable devices. This review tries to provide a general perspective of the physico-chemical aspects associated with the stabilization of interfaces by colloidal particles, mainly chemical isotropic spherical colloids. Furthermore, some aspects related to the exploitation of particle-laden fluid/fluid interfaces on the stabilization of emulsions and foams will be also highlighted. It is expected that this review can be used for researchers and technologist as an initial approach to the study of particle-laden fluid layers., (© 2021 IOP Publishing Ltd.)
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- 2021
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20. Static and Dynamic Self-Assembly of Pearl-Like-Chains of Magnetic Colloids Confined at Fluid Interfaces.
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Martínez-Pedrero F, González-Banciella A, Camino A, Mateos-Maroto A, Ortega F, Rubio RG, Pagonabarraga I, and Calero C
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Magnetic colloids adsorbed at a fluid interface are unique model systems to understand self-assembly in confined environments, both in equilibrium and out of equilibrium, with important potential applications. In this work the pearl-chain-like self-assembled structures of superparamagnetic colloids confined to a fluid-fluid interface under static and time-dependent actuations are investigated. On the one hand, it is found that the structures generated by static fields transform as the tilt angle of the field with the interface is increased, from 2D crystals to separated pearl-chains in a process that occurs through a controllable and reversible zip-like thermally activated mechanism. On the other hand, the actuation with precessing fields about the axis perpendicular to the interface induces dynamic self-assembled structures with no counterpart in non-confined systems, generated by the interplay of averaged magnetic interactions, interfacial forces, and hydrodynamics. Finally, how these dynamic structures can be used as remotely activated roller conveyors, able to transport passive colloidal cargos at fluid interfaces and generate parallel viscous flows is shown. The latter can be used in the mixture of adsorbed molecules and the acceleration of surface-chemical reactions, overcoming diffusion limitations., (© 2021 The Authors. Small published by Wiley-VCH GmbH.)
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- 2021
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21. Fabrication of Robust Capsules by Sequential Assembly of Polyelectrolytes onto Charged Liposomes.
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Ruano M, Mateos-Maroto A, Ortega F, Ritacco H, Rubio JEF, Guzmán E, and Rubio RG
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- Capsules, Microscopy, Electron, Transmission, Polyelectrolytes, Liposomes, Nanoparticles
- Abstract
This work presents a simple methodology for coating small unilamellar liposomes bearing different degrees of positive charge with polyelectrolyte multilayers using the sequential layer-by-layer deposition method. The liposomes were made of mixtures of 1,2-dioleyl- sn -glycero-3-phosphocoline and dimethyl dioctadecyl ammonium bromide (DODAB) and coated by alternated layers of the sodium salt of poly(4-styrenesulfonate) (PSS) and poly(allylamine) (PAH) as polyanions and polycations, respectively. The results show that the zeta potential of the liposomes was not very sensitive to the mole fraction of DODAB in the membrane, X
D , in the range 0.3 ≤ XD ≤ 0.8. We were able to coat the liposomes with up to four polymer bilayers. The growth of the capsule size was followed by dynamic light scattering, and in some cases, by cryo-transmission electron microscopy, with good agreement between both techniques. The thickness of the layers, measured from the hydrodynamic radius of the coated liposome, depends on the polyelectrolyte used, so that the PSS layers adopt a much more packaged conformation than the PAH layers. An interesting finding is that the PSS amount needed to reach the isoelectric point of the capsules increases linearly with the charge density of the bare liposomes, whereas the amount of PAH does not depend on it. As expected, the preparation of the multilayers has to be done in such a way that when the system is close to the isoelectric point, the capsules do not aggregate. For this, we dropped the polyelectrolyte solution quickly, stirred it fast, and used dilute liposome suspensions. The method is very flexible and not limited to liposomes or polyelectrolyte multilayers; also, coatings containing charged nanoparticles can be easily made. Once the liposomes have been coated, lipids can be easily eliminated, giving rise to polyelectrolyte nanocapsules (polyelectrosomes) with potential applications as drug delivery platforms.- Published
- 2021
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22. Polyelectrolyte Multilayers on Soft Colloidal Nanosurfaces: A New Life for the Layer-By-Layer Method.
- Author
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Mateos-Maroto A, Abelenda-Núñez I, Ortega F, Rubio RG, and Guzmán E
- Abstract
The Layer-by-Layer (LbL) method is a well-established method for the assembly of nanomaterials with controlled structure and functionality through the alternate deposition onto a template of two mutual interacting molecules, e.g., polyelectrolytes bearing opposite charge. The current development of this methodology has allowed the fabrication of a broad range of systems by assembling different types of molecules onto substrates with different chemical nature, size, or shape, resulting in numerous applications for LbL systems. In particular, the use of soft colloidal nanosurfaces, including nanogels, vesicles, liposomes, micelles, and emulsion droplets as a template for the assembly of LbL materials has undergone a significant growth in recent years due to their potential impact on the design of platforms for the encapsulation and controlled release of active molecules. This review proposes an analysis of some of the current trends on the fabrication of LbL materials using soft colloidal nanosurfaces, including liposomes, emulsion droplets, or even cells, as templates. Furthermore, some fundamental aspects related to deposition methodologies commonly used for fabricating LbL materials on colloidal templates together with the most fundamental physicochemical aspects involved in the assembly of LbL materials will also be discussed.
- Published
- 2021
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23. Build-Up of a 3D Organogel Network within the Bilayer Shell of Nanoliposomes. A Novel Delivery System for Vitamin D 3 : Preparation, Characterization, and Physicochemical Stability.
- Author
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Ghiasi F, Eskandari MH, Golmakani MT, Rubio RG, and Ortega F
- Subjects
- Particle Size, Cholecalciferol, Liposomes
- Abstract
The inherent thermodynamic instability of liposomes during production and storage has limited their widespread applications. Therefore, a novel structure of food-grade nanoliposomes stabilized by a 3D organogel network within the bilayer shell was developed through the extrusion process and successfully applied to encapsulate vitamin D
3 . A huge flocculation and a significant reduction of zeta potential (-17 mV) were observed in control nanoliposomes (without the organogel shell) after 2 months of storage at 4 °C, while the sample with a gelled bilayer showed excellent stability with a particle diameter of 105 nm and a high negative zeta potential (-63.4 mV), even after 3 months. The development of spherical vesicles was confirmed by TEM. Interestingly, the gelled bilayer shell led to improved stability against osmotically active divalent salt ions. Electron paramagnetic resonance confirmed the higher rigidity of the shell bilayer upon gelation. The novel liposome offered a dramatic increase in encapsulation efficiency and loading of vitamin D3 compared to those of control.- Published
- 2021
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24. A Large, Open-Label, Phase 3 Safety Study of DaxibotulinumtoxinA for Injection in Glabellar Lines: A Focus on Safety From the SAKURA 3 Study.
- Author
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Green JB, Mariwalla K, Coleman K, Ablon G, Weinkle SH, Gallagher CJ, Vitarella D, and Rubio RG
- Subjects
- Adult, Aged, Aged, 80 and over, Botulinum Toxins, Type A adverse effects, Female, Humans, Injections, Male, Middle Aged, Neuromuscular Agents adverse effects, Botulinum Toxins, Type A therapeutic use, Forehead, Neuromuscular Agents therapeutic use, Skin Aging drug effects
- Abstract
Background: SAKURA 3 was a Phase 3, open-label, repeat-dose safety study of DaxibotulinumtoxinA for Injection (DAXI); a component of the largest Phase 3 clinical development program of an aesthetic neuromodulator in glabellar lines., Objective: To evaluate the use of DAXI (40U) up to 3 treatments for moderate or severe glabellar lines., Methods: Eligible subjects rolled over from the placebo-controlled trials (n = 477) or were de novo (n = 2,214) and received 1 to 3 treatments over a maximum of 84 weeks. Safety and efficacy were evaluated at least every 4 weeks up to Week 36 (Treatments 1 and 2) and Week 12 (Treatment 3). Select subjects could be retreated after Week 12 if glabellar lines returned to baseline., Results: Safety results are reported for 2,691 subjects, of which 882 received a second treatment and 568 a third. Treatment-related adverse events (AEs) occurred in 17.8% of subjects, which were generally mild and resolved. No serious AEs were treatment-related. Eyelid ptosis occurred in 0.9% of treatments. Adverse events were consistent across treatments and no new safety signals were observed., Conclusion: The safety of DAXI in this large open-label safety study confirms the findings from the pivotal Phase 3 trials, providing reassurance in its overall safety profile., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society for Dermatologic Surgery, Inc.)
- Published
- 2021
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25. DaxibotulinumtoxinA for Injection for the Treatment of Glabellar Lines: Efficacy Results From SAKURA 3, a Large, Open-Label, Phase 3 Safety Study.
- Author
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Fabi SG, Cohen JL, Green LJ, Dhawan S, Kontis TC, Baumann L, Gross TM, Gallagher CJ, Brown J, and Rubio RG
- Subjects
- Adult, Aged, Aged, 80 and over, Botulinum Toxins, Type A adverse effects, Female, Humans, Injections, Male, Middle Aged, Neuromuscular Agents adverse effects, Botulinum Toxins, Type A therapeutic use, Forehead, Neuromuscular Agents therapeutic use, Skin Aging drug effects
- Abstract
Background: DaxibotulinumtoxinA for Injection (DAXI) is botulinum toxin Type A formulated with a novel peptide excipient. Two pivotal, single-treatment, placebo-controlled trials demonstrated efficacy and safety for moderate or severe glabellar lines., Objective: To further evaluate DAXI in a large, open-label, repeat-treatment study., Methods: Subjects (n = 2,691) were enrolled from the preceding pivotal trials or de novo and received 40U DAXI. Those who received repeat treatments could be retreated when they returned to baseline on the Investigator Global Assessment-Frown Wrinkle Severity (IGA-FWS) and Patient FWS (PFWS) scales at/after 12 weeks and up to 36 weeks after treatment., Results: High (>96%) response rates (none or mild severity) on the IGA-FWS scale were seen after each of the 3 treatments, with peak response between Weeks 2 to 4. At Week 24, ≥32% had a response of none or mild severity. Peak response rates of ≥92% were observed at Weeks 2 to 4 on the PFWS scale. The median duration for return to moderate or severe severity was 24 weeks. The safety profile was favorable and consistent with previous trials., Conclusion: DaxibotulinumtoxinA for Injection efficacy was highly consistent across treatment cycles. These results confirm the previously observed efficacy rates and duration of response., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society for Dermatologic Surgery, Inc.)
- Published
- 2021
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26. Behavior of the water/vapor interface of chitosan solutions with an anionic surfactant: effect of polymer-surfactant interactions.
- Author
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Akanno A, Guzmán E, Ortega F, and Rubio RG
- Abstract
The adsorption of mixtures formed by chitosan and sodium lauryl ether sulfate (SLES) at the water/vapor interface has been studied on the basis of their impact on the equilibrium surface tension of the interface, and the response of such an interface to mechanical deformations. The analysis of the surfactant binding to the chitosan chains evidenced that the chitosan-SLES solutions were mixtures of polyelectrolyte-surfactant complexes and a non-negligible amount of free surfactant molecules. The interfacial properties showed two well-differentiated regions for interfacial adsorption as a function of the SLES concentration: (i) at a low surfactant concentration, co-adsorption of chitosan and SLES occurs, and (ii) at high concentrations, the surface is mostly occupied by SLES molecules. This behavior may be interpreted in terms of a complex equilibration mechanism of the interfacial layers, where different coupled dynamic processes may be involved. Furthermore, the use of the time-concentration superposition principle has confirmed the different dynamic behaviors of the chitosan-SLES adsorption as a function of the SLES concentration. This work sheds light on some of the most fundamental bases governing the physico-chemical behavior of mixtures formed by a biopolymer and a surfactant, where their complex behavior is governed by an intricate balance of bulk and interfacial interactions.
- Published
- 2020
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27. A closer physico-chemical look to the Layer-by-Layer electrostatic self-assembly of polyelectrolyte multilayers.
- Author
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Guzmán E, Rubio RG, and Ortega F
- Abstract
The fabrication of polyelectrolyte multilayer films (PEMs) using the Layer-by-Layer (LbL) method is one of the most versatile approaches for manufacturing functional surfaces. This is the result of the possibility to control the assembly process of the LbL films almost at will, by changing the nature of the assembled materials (building blocks), the assembly conditions (pH, ionic strength, temperature, etc.) or even by changing some other operational parameters which may impact in the structure and physico-chemical properties of the obtained multi-layered films. Therefore, the understanding of the impact of the above mentioned parameters on the assembly process of LbL materials plays a critical role in the potential use of the LbL method for the fabrication of new functional materials with technological interest. This review tries to provide a broad physico-chemical perspective to the study of the fabrication process of PEMs by the LbL method, which allows one to take advantage of the many possibilities offered for this approach on the fabrication of new functional nanomaterials., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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28. Impact of the bulk aggregation on the adsorption of oppositely charged polyelectrolyte-surfactant mixtures onto solid surfaces.
- Author
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Fernández-Peña L, Abelenda-Nuñez I, Hernández-Rivas M, Ortega F, Rubio RG, and Guzmán E
- Abstract
The understanding of the deposition of oppositely charged polyelectrolytes-surfactant mixtures onto solid surfaces presents a high interest in current days due to the recognized impact of the obtained layers on different industrial sectors and the performance of several consumer products (e.g. formulations of shampoos and hair conditioners). This results from the broad range of structures and properties that can present the mixed layers, which in most of the cases mirror the association process occurring between the polyelectrolyte chains and the oppositely charged surfactants in the bulk. Therefore, the understanding of the adsorption processes and characteristics of the adsorbed layers can be only attained from a careful examination of the self-assembly processes occurring in the solution. This review aims to contribute to the understanding of the interaction of polyelectrolyte-surfactant mixtures with solid surfaces, which is probably one of the most underexplored aspects of these type of systems. For this purpose, a comprehensive discussion on the correlations between the aggregates formed in the solutions and the deposition of the obtained complexes upon such association onto solid surfaces will be presented. This makes it necessary to take a closer look to the most important forces driving such processes., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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29. DaxibotulinumtoxinA for Injection has a prolonged duration of response in the treatment of glabellar lines: Pooled data from two multicenter, randomized, double-blind, placebo-controlled, phase 3 studies (SAKURA 1 and SAKURA 2).
- Author
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Bertucci V, Solish N, Kaufman-Janette J, Yoelin S, Shamban A, Schlessinger J, Snyder D, Gallagher C, Liu Y, Shears G, and Rubio RG
- Subjects
- Botulinum Toxins, Type A adverse effects, Facial Muscles drug effects, Female, Forehead, Humans, Injections, Intramuscular, Male, Neuromuscular Agents adverse effects, Patient Satisfaction, Time Factors, Botulinum Toxins, Type A therapeutic use, Cosmetic Techniques, Neuromuscular Agents therapeutic use, Skin Aging drug effects
- Abstract
Background: DaxibotulinumtoxinA for Injection (DAXI) is a novel botulinum toxin type A in clinical development. Phase 2 data have shown it offers a more prolonged duration of response than onabotulinumtoxinA., Objective: To further evaluate the efficacy, duration of response, and safety of 40 U DAXI compared with placebo in the treatment of glabellar lines., Methods: Two identical, multicenter, randomized, double-blind, placebo-controlled, phase 3 studies were performed (NCT03014622 and NCT03014635 on www.clinicaltrials.gov). Participants with moderate or severe glabellar lines were randomly assigned (2:1) to receive 40 U DAXI or placebo into the corrugator/procerus muscles. Glabellar line severity was assessed by investigators and participants for up to 36 weeks (≥24 weeks)., Results: Among 609 participants enrolled (405 DAXI, 204 placebo), 92% completed. DAXI was significantly more effective than placebo in reducing glabellar line severity and maintained none or mild glabellar line severity for a median of 24.0 weeks. It was also generally well tolerated-treatment-related adverse effects were most commonly headache (6.4% vs 2.0%) and injection site pain (3.7% vs 3.9%)., Limitations: The study population was predominantly female and white and received only a single treatment., Conclusions: DAXI offers a prolonged duration of response for glabellar line reduction and is well tolerated., (Copyright © 2019 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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30. Controlled disassembly of colloidal aggregates confined at fluid interfaces using magnetic dipolar interactions.
- Author
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Martínez-Pedrero F, Ortega F, Codina J, Calero C, and Rubio RG
- Abstract
Hypothesis: Field induced assembling/disassembling of paramagnetic colloids is strongly influenced by the configuration of the applied field, the surface chemistry of the particles, the nearby presence of an external boundary or the particle density. The trapping of the particles at fluid-fluid interface is expected to promote different assembling/disassembling routes together with new approaches for controlled manipulation of self-assembled structures and the fabrication of new functional patterned surfaces., Experiments: We study the reversible disassembly itineraries that emerge in linear aggregates of micrometer-sized magnetic particles adsorbed onto a fluid interface when the applied field is abruptly tilted out of the confining surface: the unzipping of chains laterally aggregated, the partial fragmentation of the chains, the gradual separation of the monomers and the abrupt colloidal explosion., Findings: By combining experiments, simulations and theoretical arguments, we elucidate different dissociation mechanisms strongly influenced by subtle changes in the orientation of the applied field, the particle's position relative to the confining interface and the mutual induction of the particles. Moreover, we show that the understanding of the mechanisms can be applied to pinpoint exactly particle detachments in two-dimensional binary mixtures., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
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31. Effect of molecular structure of eco-friendly glycolipid biosurfactants on the adsorption of hair-care conditioning polymers.
- Author
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Fernández-Peña L, Guzmán E, Leonforte F, Serrano-Pueyo A, Regulski K, Tournier-Couturier L, Ortega F, Rubio RG, and Luengo GS
- Subjects
- Adsorption, Biomimetics, Glycolipids metabolism, Hair chemistry, Humans, Models, Molecular, Molecular Structure, Polymers administration & dosage, Surface-Active Agents metabolism, Glycolipids chemistry, Hair drug effects, Materials Testing, Polyethylenes chemistry, Polymers chemistry, Quaternary Ammonium Compounds chemistry, Surface-Active Agents chemistry
- Abstract
Pseudo-binary mixtures of different glycolipids, four different rhamnolipids (RL) and an alkyl polyglucoside (APG), with poly(diallyl-dimethylammonium chloride) (PDADMAC) have been studied in relation to their adsorption onto negatively charged surfaces to shed light on the impact of the molecular structure of surfactants from natural sources (instead of synthetic surfactant, such as sodium laureth sulfate) on the adsorption of hair-conditioning polymers. For this purpose, the self-assembly of such mixtures in aqueous solution and their adsorption onto negatively charged surfaces mimicking the negative charge of damaged hair fibres have been studied combining experiments and self-consistent field (SCF) calculations. The results show that the specific physico-chemical properties of the surfactants (charge, number of sugar rings present in surfactant structure and length of the hydrocarbon length) play a main role in the control of the adsorption process, with the adsorption efficiency and hydration being improved in relation to conventional sulfate-based systems for mixtures of PDADMAC and glycolipids with the shortest alkyl chains. SCF calculations and Energy Dispersive X-Ray Spectroscopy (EDS) analysis on real hair confirmed such observations. The results allow one to assume that the characteristic of the surfactants, especially rhamnolipids, conditions positively the adsorption potential of polyelectrolytes in these model systems. This study provides important insights on the mechanisms underlying the performance of more complex but eco-friendly washing formulations., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2020
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32. DaxibotulinumtoxinA for Injection for the Treatment of Glabellar Lines: Results from Each of Two Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 3 Studies (SAKURA 1 and SAKURA 2).
- Author
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Carruthers JD, Fagien S, Joseph JH, Humphrey SD, Biesman BS, Gallagher CJ, Liu Y, and Rubio RG
- Subjects
- Adult, Botulinum Toxins, Type A administration & dosage, Double-Blind Method, Female, Forehead, Humans, Male, Middle Aged, Neuromuscular Agents administration & dosage, Young Adult, Botulinum Toxins, Type A pharmacology, Injections, Neuromuscular Agents pharmacology, Skin Aging drug effects
- Abstract
Background: DaxibotulinumtoxinA for Injection (DAXI) is a novel botulinum toxin type A formulation in clinical development. A phase 2 dose-ranging study identified an optimal dose and demonstrated efficacy with a median duration of 24 weeks., Methods: In two phase 3, multicenter, randomized, double-blind, placebo-controlled studies (SAKURA 1 and SAKURA 2), subjects with moderate or severe glabellar lines at maximum frown were assigned randomly to receive placebo or 40 U of DAXI. Glabellar lines were evaluated at least every 4 weeks for at least 24 weeks until severity returned to baseline (≤36 weeks)., Results: Overall, 609 subjects were enrolled (DAXI, n = 405; placebo, n = 204). DAXI was significantly more effective than placebo in achieving the primary efficacy outcome (≥2-point improvement in glabellar line severity at maximum frown at week 4 according to both investigator and subject ratings): 73.6 percent versus 0.0 percent (SAKURA 1), and 74.0 percent versus 1.0 percent (SAKURA 2) (both p < 0.0001). Composite investigator and subject ratings of maximum frown after DAXI treatment showed that glabellar line severity of none or mild was maintained for a median of 24.0 weeks (SAKURA 1) and 23.9 weeks (SAKURA 2), and glabellar line severity did not return to baseline levels for a median of 27.7 and 26.0 weeks, respectively. DAXI was generally well tolerated, with the most common adverse events related to DAXI treatment being headache (SAKURA 1, 7.0 percent; SAKURA 2, 5.9 percent) and injection-site pain (5.0 percent and 2.4 percent, respectively)., Conclusions: Results from both studies were highly consistent. DAXI may offer a prolonged duration of response (median, ≥24 weeks) and is generally well tolerated., Clinical Question/level of Evidence: Therapeutic, I.
- Published
- 2020
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33. Influence of temperature on dynamic surface properties of spread DPPC monolayers in a broad range of surface pressures.
- Author
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Bykov AG, Guzmán E, Rubio RG, Krycki MM, Milyaeva OY, and Noskov BA
- Subjects
- Elasticity, Particle Size, Pressure, Surface Properties, 1,2-Dipalmitoylphosphatidylcholine chemistry, Thermodynamics
- Abstract
This work is focused on the study of the dynamic surface properties of spread monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), which is the main component of the pulmonary surfactant (PS), in the region of high surface pressures and at different temperatures. The increase of temperature from 25 to 35 °C led to a decrease of surface elasticity in the high surface pressure range corresponding to physiological conditions inside alveoli during breathing. Furthermore, the obtained results evidenced that the relaxation processes in spread DPPC monolayer were accelerated with the increase of temperature, which resulted in two different effects. On one hand, it led to the increase of hysteresis of surface pressure isotherms, which was an important condition for maximizing air penetration into alveoli; whereas on the other hand, it prevented reaching extremely high surface pressure, which could result in a premature alveolar collapse., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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34. Alveolar macrophage secretion of vesicular SOCS3 represents a platform for lung cancer therapeutics.
- Author
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Speth JM, Penke LR, Bazzill JD, Park KS, de Rubio RG, Schneider DJ, Ouchi H, Moon JJ, Keshamouni VG, Zemans RL, Lama VN, Arenberg DA, and Peters-Golden M
- Subjects
- A549 Cells, Alveolar Epithelial Cells cytology, Alveolar Epithelial Cells metabolism, Animals, Bronchoalveolar Lavage Fluid cytology, Bronchoalveolar Lavage Fluid immunology, Carcinogenesis drug effects, Carcinogenesis immunology, Carcinogenesis pathology, Carcinoma, Non-Small-Cell Lung drug therapy, Carcinoma, Non-Small-Cell Lung pathology, Extracellular Vesicles immunology, Extracellular Vesicles metabolism, Female, Humans, Injections, Intralesional, Liposomes, Lung Neoplasms drug therapy, Lung Neoplasms pathology, Macrophages, Alveolar cytology, Macrophages, Alveolar metabolism, Mice, Primary Cell Culture, Rats, Recombinant Proteins administration & dosage, Respiratory Mucosa cytology, Respiratory Mucosa immunology, Respiratory Mucosa metabolism, STAT3 Transcription Factor immunology, STAT3 Transcription Factor metabolism, Suppressor of Cytokine Signaling 3 Protein administration & dosage, Suppressor of Cytokine Signaling 3 Protein genetics, Tumor Microenvironment drug effects, Tumor Microenvironment immunology, Xenograft Model Antitumor Assays, Carcinoma, Non-Small-Cell Lung immunology, Lung Neoplasms immunology, Macrophages, Alveolar immunology, Suppressor of Cytokine Signaling 3 Protein metabolism
- Abstract
Lung cancer remains the leading cause of cancer-related death in the United States. Although the alveolar macrophage (AM) comprises the major resident immune cell in the lung, few studies have investigated its role in lung cancer development. We recently discovered a potentially novel mechanism wherein AMs regulate STAT-induced inflammatory responses in neighboring epithelial cells (ECs) via secretion and delivery of suppressors of cytokine signaling 3 (SOCS3) within extracellular vesicles (EVs). Here, we explored the impact of SOCS3 transfer on EC tumorigenesis and the integrity of AM SOCS3 secretion during development of lung cancer. AM-derived EVs containing SOCS3 inhibited STAT3 activation as well as proliferation and survival of lung adenocarcinoma cells. Levels of secreted SOCS3 were diminished in lungs of patients with non-small cell lung cancer and in a mouse model of lung cancer, and the impaired ability of murine AMs to secrete SOCS3 within EVs preceded the development of lung tumors. Loss of this homeostatic brake on tumorigenesis prompted our effort to "rescue" it. Provision of recombinant SOCS3 loaded within synthetic liposomes inhibited proliferation and survival of lung adenocarcinoma cells in vitro as well as malignant transformation of normal ECs. Intratumoral injection of SOCS3 liposomes attenuated tumor growth in a lung cancer xenograft model. This work identifies AM-derived vesicular SOCS3 as an endogenous antitumor mechanism that is disrupted within the tumor microenvironment and whose rescue by synthetic liposomes can be leveraged as a potential therapeutic strategy for lung cancer.
- Published
- 2019
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35. On the autonomous motion of active drops or bubbles.
- Author
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Ryazantsev YS, Velarde MG, Guzman E, Rubio RG, Ortega F, and Montoya JJ
- Abstract
Thermo-capillary stresses on the surface of a drop can be the result of a non-isothermal surface chemical conversion of a reactant dissolved in the host fluid. The strength of heat production (with e.g. absorption) on the surface is ruled by the diffusion of the reactant and depends on the state of motion of the drop. Such thermo-capillary stresses can provoke the motion of the drop or its motionless state in the presence of an external body force. If in the balance of forces, including indeed viscous drag, the net resultant force vanishes there is the possibility of autonomous motion with constant velocity of the drop. Focusing on drops with radii in the millimeter range provided here is a quantitative study of the possibility of such autonomous motion when the drop, considered as active unit, is seat of endo- or exo-thermic reactive processes that dominate its motion. The framework is restricted to Stokes flows in the hydrodynamics, negligible heat Peclet number while the solute Peclet number is considered very high. A boundary layer approximation is used in the description of reactant diffusion. Those processes eventually end up in the action being expressed by surface tension gradients and the Marangoni effect. Explicit expressions of the force acting on the drop and the velocity fields inside and outside the drop are provided. Some significant particular cases are discussed to illustrate the usefulness of the theory., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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36. Phosphatidylinositol 4-phosphate is a major source of GPCR-stimulated phosphoinositide production.
- Author
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de Rubio RG, Ransom RF, Malik S, Yule DI, Anantharam A, and Smrcka AV
- Subjects
- Animals, Cell Line, Tumor, Cell Membrane metabolism, Cells, Cultured, Embryo, Mammalian cytology, Fibroblasts cytology, Fibroblasts metabolism, Golgi Apparatus metabolism, HEK293 Cells, Humans, Mice, Inbred C57BL, Microscopy, Confocal, Myocytes, Cardiac cytology, Myocytes, Cardiac metabolism, Signal Transduction, Type C Phospholipases metabolism, Diglycerides metabolism, Phosphatidylinositol Phosphates metabolism, Phosphatidylinositols metabolism, Receptors, G-Protein-Coupled metabolism
- Abstract
Phospholipase C (PLC) enzymes hydrolyze the plasma membrane (PM) lipid phosphatidylinositol 4,5-bisphosphate (PI4,5P
2 ) to generate the second messengers inositol trisphosphate (IP3 ) and diacylglycerol (DAG) in response to receptor activation in almost all mammalian cells. We previously found that stimulation of G protein-coupled receptors (GPCRs) in cardiac cells leads to the PLC-dependent hydrolysis of phosphatidylinositol 4-phosphate (PI4P) at the Golgi, a process required for the activation of nuclear protein kinase D (PKD) during cardiac hypertrophy. We hypothesized that GPCR-stimulated PLC activation leading to direct PI4P hydrolysis may be a general mechanism for DAG production. We measured GPCR activation-dependent changes in PM and Golgi PI4P pools in various cells using GFP-based detection of PI4P. Stimulation with various agonists caused a time-dependent reduction in PI4P-associated, but not PI4,5P2 -associated, fluorescence at the Golgi and PM. Targeted depletion of PI4,5P2 from the PM before GPCR stimulation had no effect on the depletion of PM or Golgi PI4P, total inositol phosphate (IP) production, or PKD activation. In contrast, acute depletion of PI4P specifically at the PM completely blocked the GPCR-dependent production of IPs and activation of PKD but did not change the abundance of PI4,5P2 Acute depletion of Golgi PI4P had no effect on these processes. These data suggest that most of the PM PI4,5P2 pool is not involved in GPCR-stimulated phosphoinositide hydrolysis and that PI4P at the PM is responsible for the bulk of receptor-stimulated phosphoinositide hydrolysis and DAG production., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)- Published
- 2018
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37. Magnetic Biohybrid Vesicles Transported by an Internal Propulsion Mechanism.
- Author
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Mateos-Maroto A, Guerrero-Martínez A, Rubio RG, Ortega F, and Martínez-Pedrero F
- Subjects
- Rotation, Transport Vesicles metabolism, Hydrodynamics, Lipids, Magnetics, Models, Biological
- Abstract
Some biological microorganisms can crawl or swim due to coordinated motions of their cytoskeleton or the flagella located inside their bodies, which push the cells forward through intracellular forces. To date, there is no demonstration of synthetic systems propelling at low Reynolds number via the precise actuation of the material confined within an enclosing lipid membrane. Here, we report lipid vesicles and other more complex self-assembled biohybrid structures able to propel due to the advection flows generated by the actuated rotation of the superparamagnetic particles they contain. The proposed swimming and release strategies, based on cooperative hydrodynamic mechanisms and near-infrared laser pulse-triggered destabilization of the phospholipid membranes, open new possibilities for the on-command transport of minute quantities of drugs, fluid or nano-objects. The lipid membranes protect the confined substances from the outside environment during transportation, thus enabling them to work in physiological conditions.
- Published
- 2018
- Full Text
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38. Equilibration of a Polycation-Anionic Surfactant Mixture at the Water/Vapor Interface.
- Author
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Akanno A, Guzmán E, Fernández-Peña L, Llamas S, Ortega F, and Rubio RG
- Abstract
The adsorption of concentrated poly(diallyldimethylammonium chloride) (PDADMAC)-sodium lauryl ether sulfate (SLES) mixtures at the water/vapor interface has been studied by different surface tension techniques and dilational viscoelasticity measurements. This work tries to shed light on the way in which the formation of polyelectrolyte-surfactant complexes in the bulk affects the interfacial properties of mixtures formed by a polycation and an oppositely charged surfactant. The results are discussed in terms of a two-step adsorption-equilibration of PDADMAC-SLES complexes at the interface, with the initial stages involving the diffusion of kinetically trapped aggregates formed in the bulk to the interface followed by the dissociation and spreading of such aggregates at the interface. This latter process becomes the main contribution to the surface tension decrease. This work aids our understanding of the most fundamental basis of the physicochemical behavior of concentrated polyelectrolyte-surfactant mixtures which present complex bulk and interfacial interactions with interest in both basic and applied sciences.
- Published
- 2018
- Full Text
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39. Injectable DaxibotulinumtoxinA in Cervical Dystonia: A Phase 2 Dose-Escalation Multicenter Study.
- Author
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Jankovic J, Truong D, Patel AT, Brashear A, Evatt M, Rubio RG, Oh CK, Snyder D, Shears G, and Comella C
- Abstract
Background: Injectable daxibotulinumtoxinA (an investigational botulinum toxin, RT002) may offer a more prolonged duration of response-and therefore less frequent dosing-than onabotulinumtoxinA., Objectives: To perform a phase 2, open-label, dose-escalation study to assess the efficacy and safety of daxibotulinumtoxinA in cervical dystonia., Methods: Subjects with moderate-to-severe isolated cervical dystonia were enrolled in sequential cohorts to receive a single open-label, intramuscular dose of injectable daxibotulinumtoxinA of up to 200 U ( n = 12), 200-300 U ( n = 12), or 300-450 U ( n = 13; https://clinicaltrials.gov identifier NCT02706795)., Results: Overall, 33/37 enrollees completed the trial. DaxibotulinumtoxinA was associated with mean reductions in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score of 16.8 (38%) at week 4, 21.3 (50%) at week 6, and 12.8 (30%) at week 24. The proportion of subjects who were responders (achieved ≥ 20% reduction in TWSTRS-Total score) was 94% at week 6 and 68% at week 24. The median duration of response (time until > 20% of the improvement in TWSTRS-Total score achieved at week 4 was no longer retained or re-treatment was needed) was 25.3 weeks (95% CI, 20.14-26.14 weeks). There were no serious adverse events and there was no apparent dose-related increase in the incidence of adverse events. The most common treatment-related adverse events were dysphagia (14%) and injection site erythema (8%)., Conclusions: Preliminary assessments suggest that injectable daxibotulinumtoxinA at doses up to 450 U is well tolerated and may offer prolonged efficacy in the treatment of cervical dystonia. Further studies involving larger numbers of patients are now warranted.
- Published
- 2018
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40. Linear shear rheology of aging β-casein films adsorbing at the air/water interface.
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Martínez-Pedrero F, Tajuelo J, Sánchez-Puga P, Chulia-Jordan R, Ortega F, Rubio MA, and Rubio RG
- Subjects
- Rheology, Caseins chemistry, Membranes, Artificial, Shear Strength
- Abstract
In this work, the viscoelasticity of fragile β-casein films has been followed using different macro- and microrheological techniques. The modulus of the complex surface viscosity |η
∗ | varies with time, allowing for the monitoring of the protein adsorption and annealing. β-casein adsorption creates a soft glassy gel at the interface that experiences an aging process. Macrorheological experiments with multiple probe sizes in addition to microrheological experiments demonstrated the consistency of the surface rheological properties over a broad range of viscosities. Surface pressure measurements were performed to complement the characterization of the processes., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2018
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41. Evaporation of Nanosuspensions on Substrates with Different Hydrophobicity.
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Perrin L, Pajor-Swierzy A, Magdassi S, Kamyshny A, Ortega F, and Rubio RG
- Abstract
Liquid drop evaporation on surfaces is present in many industrial and medical applications, e.g., printed electronics, spraying of pesticides, DNA mapping, etc. Despite this strong interest, a theoretical description of the dynamic of the evaporation of complex liquid mixtures and nanosuspensions is still lacking. Indeed, one of the aspects that have not been included in the current theoretical descriptions is the competition between the kinetics of evaporation and the adsorption of surfactants and/or particles at the liquid/vapor and liquid/solid interfaces. Materials formed by an electrically isolating solid on which a patterned conducting layer was formed by the deposits left after drop evaporation have been considered as very promising for building electrical circuits on flexible plastic substrates. In this work, we have done an exhaustive study of the evaporation of nanosuspensions of latex and hydrophobized silver nanoparticles on four substrates of different hydrophobicity. The advancing and receding contact angles as well as the time dependence of the volume of the droplets have been measured over a broad range of particle concentrations. Also, mixtures of silver particles and a surfactant, commonly used in industrial printing, have been examined. Furthermore, the adsorption kinetics at both the air/liquid and solid/liquid interfaces have been measured. Whereas the latex particles do not adsorb at the solid/liquid and only slightly reduce the surface tension, the silver particles strongly adsorb at both interfaces. The experimental results of the evaporation process were compared with the predictions of the theory of Semenov et al. (Evaporation of Sessile Water Droplets: Universal Behavior in the Presence of Contact Angle Hysteresis. Colloids Surf. Physicochem. Eng. Asp. 2011, 391 (1-3), 135-144) and showed surprisingly good agreement despite that the theory was developed for pure liquids. The morphology of the deposits left by the droplets after total evaporation was studied by scanning electronic microscopy, and the effects of the substrate, the particle nature, and their concentrations on these patterns are discussed.
- Published
- 2018
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42. Towards understanding the behavior of polyelectrolyte-surfactant mixtures at the water/vapor interface closer to technologically-relevant conditions.
- Author
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Llamas S, Fernández-Peña L, Akanno A, Guzmán E, Ortega V, Ortega F, Csaky AG, Campbell RA, and Rubio RG
- Abstract
Polyelectrolyte-surfactant mixtures and their interactions with fluid interfaces are an important research field due to their use in technological applications. Most of the existing knowledge on these systems is based on models in which the polyelectrolyte concentration is around 50 times lower than that used in commercial formulations. The present work marks a step to close the gap on the understanding of their behavior under more practically-relevant conditions. The adsorption of concentrated mixtures of poly(diallyldimethyl-ammonium) chloride and sodium N-lauroyl-N-methyltaurate at the water/vapor interface with a crude mixing protocol has been studied by different surface tension techniques, Brewster angle microscopy, neutron reflectometry, and several bulk characterization techniques. Kinetically-trapped aggregates formed during mixing influence the interfacial morphology of mixtures produced in the equilibrium one-phase region, yet fluctuations in the surface tension isotherm result depending on the tensiometric technique applied. At low bulk surfactant concentrations, the free surfactant concentration is very low, and the interfacial composition matches the trend of the bulk complexes, which is a behavior that has not been observed in studies on more dilute mixtures. Nevertheless, a transition to synergistic co-adsorption of complexes and free surfactant is observed at the higher bulk surfactant concentrations studied. This transition appears to be a special feature of these more concentrated mixtures, which deserves attention in future studies of systems with additional components.
- Published
- 2018
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43. Comparing Injectable DaxibotulinumtoxinA and OnabotulinumtoxinA in Moderate and Severe Glabellar Lines: Additional Analyses From a Phase 2, Randomized, Dose-Ranging, Double-Blind, Multicenter Study.
- Author
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Bertucci V, Humphrey S, Carruthers J, Solish N, Muhn C, Swift A, Rubio RG, Shears G, and Rosen N
- Abstract
Background: Injectable daxibotulinumtoxinA (RT002) is an investigational botulinum toxin Type A. Published Phase 2 data show that, compared with 20U onabotulinumtoxinA, 40U daxibotulinumtoxinA is associated with a significantly greater response rate and significantly longer duration of response (median 24 weeks), and appears generally safe and well tolerated (www.clinicaltrials.gov NCT02303002)., Objective: To evaluate whether these efficacy and safety findings are influenced by baseline glabellar line severity., Materials and Methods: In the Phase 2, randomized, dose-ranging, parallel-group, double-blind, multicenter study, subjects with moderate or severe glabellar lines at maximum frown were randomly assigned to 20U, 40U, or 60U daxibotulinumtoxinA, 20U onabotulinumtoxinA, or placebo. Efficacy was evaluated by investigators for ≥24 weeks., Results: Data from the per protocol population (n = 191) stratified by baseline glabellar line severity (125 moderate, 66 severe) suggest that the clinical advantage of 40U daxibotulinumtoxinA over 20U onabotulinumtoxinA is maintained for a range of efficacy outcomes regardless of whether glabellar lines are moderate or severe at baseline. Statistical evaluations were not completed due to the limited size of each subgroup., Conclusion: 40U daxibotulinumtoxinA appears to offer a clinical efficacy advantage over 20U onabotulinumtoxinA in both moderate and severe glabellar lines-with a greater advantage observed in severe glabellar lines.
- Published
- 2017
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44. Injectable DaxibotulinumtoxinA for the Treatment of Glabellar Lines: A Phase 2, Randomized, Dose-Ranging, Double-Blind, Multicenter Comparison With OnabotulinumtoxinA and Placebo.
- Author
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Carruthers J, Solish N, Humphrey S, Rosen N, Muhn C, Bertucci V, Swift A, Metelitsa A, Rubio RG, Waugh J, Quiring J, Shears G, and Carruthers A
- Subjects
- Botulinum Toxins, Type A administration & dosage, Dose-Response Relationship, Drug, Double-Blind Method, Female, Humans, Injections, Intramuscular, Male, Middle Aged, Neuromuscular Agents administration & dosage, Treatment Outcome, Botulinum Toxins, Type A therapeutic use, Neuromuscular Agents therapeutic use, Skin Aging drug effects
- Abstract
Background: Injectable daxibotulinumtoxinA (RT002) is an investigational botulinum toxin Type A in clinical development. It is formulated with a proprietary peptide and offers the potential of a longer acting neurotoxin therapy., Objective: To compare the safety, efficacy, and duration of response of daxibotulinumtoxinA with onabotulinumtoxinA and placebo [www.clinicaltrials.gov NCT02303002]., Methods: In this Phase 2, randomized, dose-ranging, parallel-group, double-blind, multicenter study, subjects with moderate or severe glabellar lines at maximum frown were randomly assigned to 20U, 40U, or 60U daxibotulinumtoxinA, 20U onabotulinumtoxinA, or placebo. Glabellar line severity was evaluated by investigators and subjects at least every 4 weeks, for at least 24 weeks., Results: Overall, 268 subjects enrolled. Statistical and clinical superiority were observed for 40U and 60U daxibotulinumtoxinA over 20U onabotulinumtoxinA for a range of efficacy outcomes despite the study not being powered to detect statistically significant differences between these active treatment groups., Conclusion: The 40U dose of daxibotulinumtoxinA was well tolerated (e.g., absence of ptosis) and had the most favorable risk: benefit profile. Compared with 20U onabotulinumtoxinA, it exhibited a significantly greater response rate and a significantly longer duration of response (median of 24 weeks vs 19 weeks; p = .030).
- Published
- 2017
- Full Text
- View/download PDF
45. Layer-by-Layer polyelectrolyte assemblies for encapsulation and release of active compounds.
- Author
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Guzmán E, Mateos-Maroto A, Ruano M, Ortega F, and Rubio RG
- Subjects
- Drug Liberation, Fluorescent Dyes chemistry, Hydrogen Bonding, Hydrogen-Ion Concentration, Hydrophobic and Hydrophilic Interactions, Kinetics, Osmolar Concentration, Static Electricity, Surface Properties, Temperature, Acrylic Resins chemistry, Drug Compounding methods, Drug Delivery Systems, Polyelectrolytes chemistry, Polyethylenes chemistry, Polyvinyls chemistry, Quaternary Ammonium Compounds chemistry
- Abstract
Soft assemblies obtained following the Layer-by-Layer (LbL) approach are accounted among the most interesting systems for designing biomaterials and drug delivery platforms. This is due to the extraordinary versatility and flexibility offered by the LbL method, allowing for the fabrication of supramolecular multifunctional materials using a wide range of building blocks through different types of interactions (electrostatic, hydrogen bonds, acid-base or coordination interactions, or even covalent bonds). This provides the bases for the building of materials with different sizes, shapes, compositions and morphologies, gathering important possibilities for tuning and controlling the physico-chemical properties of the assembled materials with precision in the nanometer scale, and consequently creating important perspective for the application of these multifunctional materials as cargo systems in many areas of technological interest. This review studies different physico - chemical aspects associated with the assembly of supramolecular materials by the LbL method, paying special attention to the description of these aspects playing a central role in the application of these materials as cargo platforms for encapsulation and release of active compounds., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
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46. Thermo- and soluto-capillarity: Passive and active drops.
- Author
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Ryazantsev YS, Velarde MG, Rubio RG, Guzmán E, Ortega F, and López P
- Abstract
A survey is provided of a variety of problems where a passive or an active drop experiences directed motion consequence of the action of an external or internal agent or a combination of both. An active drop is capable of reacting by engendering autonomous, self-propelled motion in favor or against the agent. The phenomena involved offer diverse complexity but one way or another the drop motion finally rests on thermo- or soluto-capillarity hence on interfacial tension gradients. Accordingly, here a minimal mathematical framework underlying such drop motions is provided when direct external temperature or solute gradients, illumination, internal heat generation or surface chemical reaction are incorporated into the physico-chemical-hydrodynamics., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
47. Targeted calcium influx boosts cytotoxic T lymphocyte function in the tumour microenvironment.
- Author
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Kim KD, Bae S, Capece T, Nedelkovska H, de Rubio RG, Smrcka AV, Jun CD, Jung W, Park B, Kim TI, and Kim M
- Subjects
- Animals, Calcium metabolism, Cell Line, Tumor, HEK293 Cells, Humans, Immunotherapy, Adoptive methods, Interferon-gamma genetics, Interferon-gamma immunology, Interferon-gamma metabolism, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Neoplasms, Experimental genetics, Neoplasms, Experimental therapy, T-Lymphocytes, Cytotoxic metabolism, T-Lymphocytes, Cytotoxic transplantation, T-Lymphocytes, Regulatory metabolism, Tumor Burden genetics, Tumor Burden immunology, Tumor Microenvironment genetics, Calcium immunology, Neoplasms, Experimental immunology, T-Lymphocytes, Cytotoxic immunology, T-Lymphocytes, Regulatory immunology, Tumor Microenvironment immunology
- Abstract
Adoptive cell transfer utilizing tumour-targeting cytotoxic T lymphocytes (CTLs) is one of the most effective immunotherapies against haematological malignancies, but significant clinical success has not yet been achieved in solid tumours due in part to the strong immunosuppressive tumour microenvironment. Here, we show that suppression of CTL killing by CD4
+ CD25+ Foxp3+ regulatory T cell (Treg) is in part mediated by TGFβ-induced inhibition of inositol trisphosphate (IP3 ) production, leading to a decrease in T cell receptor (TCR)-dependent intracellular Ca2+ response. Highly selective optical control of Ca2+ signalling in adoptively transferred CTLs enhances T cell activation and IFN-γ production in vitro, leading to a significant reduction in tumour growth in mice. Altogether, our findings indicate that the targeted optogenetic stimulation of intracellular Ca2+ signal allows for the remote control of cytotoxic effector functions of adoptively transferred T cells with outstanding spatial resolution by boosting T cell immune responses at the tumour sites.- Published
- 2017
- Full Text
- View/download PDF
48. Phase Diagram of Fatty Acid Langmuir Monolayers from Rheological Measurements.
- Author
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Tajuelo J, Guzmán E, Ortega F, Rubio RG, and Rubio MA
- Abstract
Langmuir monolayers of fatty acids and alcohols are two-dimensional systems with a rich equilibrium phase diagram. We have explored the temperature and surface-pressure-dependent shear response of monolayers formed by fatty acids of different chain lengths and a fatty alcohol. This has been accomplished with an interfacial shear rheometer utilizing magnetic tweezers and equipped with a refined temperature control and acquisition system. Our rheological results have allowed us to draw a phase diagram from the viscoelastic properties of these 2-D systems and show new phenomena that strongly depend on temperature: the existence of a maximum in viscosity at the L2' phase, the behavior of the elastic modulus to the storage modulus ratio at the L2 phase, and the increase or decrease in viscosity at the L2-LS phase transition. In addition, we unambiguously show that the LS phase displays a counterintuitive behavior in which the loss modulus increases with temperature. We demonstrate, through isothermal surface pressure sweeps and isobaric temperature sweeps, that the exponential dependence of the loss modulus on temperature at the LS phase appears for all hydrophobic tail lengths studied and for both acid and alcohol head groups.
- Published
- 2017
- Full Text
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49. Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control.
- Author
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Lucia A, Toloza AC, Guzmán E, Ortega F, and Rubio RG
- Abstract
Background: Essential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control., Methods: Micellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test., Results: The poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α -terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%., Discussion: Since these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations., Competing Interests: The authors declare there are no competing interests.
- Published
- 2017
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50. Comment on "Formation of polyelectrolyte multilayers: ionic strengths and growth regimes" by K. Tang and A. M. Besseling, Soft Matter, 2016, 12, 1032.
- Author
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Guzmán E, Ortega F, and Rubio RG
- Abstract
Tang and Besseling recently published a study on the growth of polyelectrolyte multilayers formed by poly(diallyl-dimethylammonium chloride), PDADMAC, and the sodium salt of poly(4-styrenesulfonate), PSSNa. They described the different growth regimes appearing in the (PDADMAC + PSS)
n multilayers within a scenario in which the appearance of interdiffusion of the polyelectrolyte chains within the multilayer architecture plays a central role in the transition between the different regimes. However, this account contrasts, without an apparent explanation, with previous experimental evidence reported in the literature.- Published
- 2016
- Full Text
- View/download PDF
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