Effect of temporal thermal stress on Penaeus vannamei: Growth performance and physiological plasticity.

The present study evaluated the effect of temporal periods of hypothermia and hyperthermia, followed by an optimal temperature recovery phase on the growth, survival, and physiological response of Penaeus vannamei. Post-larvae were exposed to stress periods for 7 and 14 days at 22 °C and 32 °C each, followed by a recovery phase at 28 °C to complete seven experimental weeks, and were compared with a control group maintained at 28 °C. Weight gain, specific growth rate, feed intake, feed conversion ratio, and survival were weekly determined. Muscle, hepatopancreas, and hemolymph were sampled on the 14th day of the recovery phase for biochemical composition, and antioxidant and digestive enzyme activities determination. The shrimp presented a higher growth rate during short-term hyperthermia in contrast to shrimp under hypothermia that presented compensatory growth after thermal stress when the temperature was restored at 28 °C. Hyperthermia increased 12-13% the feed intake while this was diminished 21-29% by the hypothermia periods. Shrimp undergo metabolic adjustments following thermal stress, with short hypothermia increasing the lipase activity and lipid storage in the hepatopancreas, while short hyperthermia also enhances chymotrypsin activity and leads to higher protein and lipid accumulation. Conversely, prolonged hyperthermia induces greater energy consumption, depleting lipid and glycogen stores, while hypothermia causes scarce mobilization of energy reserves during recovery phase. Antioxidant enzyme activities were not affected by short-thermal stress (7d), while prolonged thermal stress (14d) significantly affected SOD, CAT, and GPx activities. The present study provides important insights into the physiological plasticity of P. vannamei during recovery from thermal stress.

Effectiveness and chemical insights: Exploring interactions between nanomicelles and monoterpenoids for head lice treatment.

This study evaluates the pediculicidal activity of nanoformulations containing different binary essential oil component mixtures (eugenol:linalool, 1,8 -cineole:linalool, and eugenol:thymol) using immersion bioassays. These have allowed us to evaluate the knockdown time affecting 50% of the individuals (KT50). In addition, the type of interaction between the components in each mixture was established in terms of the combination index (IC). The KT50 values were 6.07; 8.83; 7.17 and 27.23 h for linalool, 1,8 -cineole, eugenol, and thymol, respectively. For the eugenol:linalool mixtures, the efficacy was lower or equal to that obtained for the nanoformulations of the pure compounds, with values of KT50 about 13.33, 8.16 and 6.71 h for mixtures with ratios 3:1, 1:1 and 1:3, respectively. These mixtures present IC > 1, evidencing antagonistic interaction, which is enhanced with eugenol content. In the case of the binary mixtures of 1,8 -cineole: linalool, KT50 values were similar to those obtained for eugenol:linalool mixtures with similar ratios. In this case, IC assumes values close to unity, suggesting additive interactions independently of the mixture composition. On the other side, mixtures of eugenol:thymol with 1:1 and 1:3 ratios showed values of 9.40 and 32.93 h, while the mixture with a 3:1 ratio showed the greatest effectiveness (KT50 of 4.42 h). Eugenol:thymol mixtures show synergistic interaction (IC < 1) for combinations 3:1 and 1:1, while no interaction was observed for 1:3 combination. This indicates that eugenol enhances thymol activity. These results must be considered an important step forward to the development of effective pediculicidal nanoformulations based on botanical compounds.

Anomalous Colloidal Motion under Strong Confinement.

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.

A Broad-Host-Range Phage Cocktail Selectively and Effectively Eliminates Vibrio Species from Shrimp Aquaculture Environment.

The protective effects of a phage cocktail composed of vB_Vc_SrVc2 and vB_Vc_SrVc9 were tested in Pacific white shrimp (Litopenaeus vannamei) postlarvae, which were originally isolated from diseased shrimps and selected due to their broad-host-range properties against several pathogenic Vibsrio species. We used culture-dependent and culture-independent approaches to explore its effect on bacterial communities associated with shrimp postlarvae. Both methods revealed that the levels of Vibrio species were significantly reduced after phage cocktail administration. Phage-treated shrimp also exhibisuppted lesser damage and higher lipid accumulation in B cells of the hepatopancreas, as revealed by histopathological examination. Taken together, this study provides clear evidence that phage therapy can selectively and effectively reduce Vibrio species, thereby providing an environmentally safe alternative to the prophylactic use of antibiotics in shrimp aquaculture.

Use of Trehalose as an Additive to Bacteriophage Vb_Pd_PDCC-1: Long-Term Preservation Analysis and Its Biocontrol Against Vibrio diabolicus Infection.

Phage therapy is a promising alternative to control bacterial diseases and the increasing problem of antibiotic resistance. In this sense, this research evaluates the viability of lyophilized vibrio phage vB_Pd_PDCC-1 using trehalose as a preservative excipient at different concentrations (4, 2, 1, and 0.5% w/v) and its potential for phage therapy application against a pathogenic bacteria Vibrio diabolicus in brine shrimp nauplii (Artemia franciscana). The lyophilized phages were stored at 4 and 23 °C and rehydrated using biological sterile saline solution to test their viability at days 1, 15, and 60 post-lyophilization. The results showed that trehalose is beneficial in maintaining the viability of post-lyophilization phages (without titer losses) at 4 °C and even at room temperature (23 °C). When lyophilized phages with 4% w/v trehalose concentration were stored at 23 °C, they had not titer losses among the trials; viability and titer concentration were maintained up to 60 days at log 7. The use of lyophilized phage PDCC-1 increased brine shrimp survival and reduced Vibrio concentrations. The present study has identified trehalose as a promising lyophilization excipient to effectively preserve lyophilized bacteriophages for biotechnological applications and long-term storage.

Anomalous Concentration Dependence of Surface Tension and Concentration-Concentration Correlation Functions of Binary Non-Electrolyte Solutions.

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.

Forces Controlling the Assembly of Particles at Fluid Interfaces.

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.

Evaluating the Impact of Hydrophobic Silicon Dioxide in the Interfacial Properties of Lung Surfactant Films.

The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying the potential adverse effects associated with pollutant inhalation. The surface pressure-area isotherms of lung surfactant (LS) films including increasing amounts of particles revealed that particle incorporation into LS monolayers modifies the organization of the molecules at the water/vapor interface, which alters the mechanical resistance of the interfacial films, hindering the ability of LS layers for reducing the surface tension, and reestablishing the interface upon compression. This influences the normal physiological function of LS as is inferred from the analysis of the response of the Langmuir films upon the incorporation of particles against harmonic changes of the interfacial area (successive compression-expansion cycles). These experiments evidenced that particles alter the relaxation mechanisms of LS films, which may be correlated to a modification of the transport of material within the interface and between the interface and the adjacent fluid during the respiratory cycle.

Effect of functional diets on intestinal microbiota and resistance to Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease (AHPND) of Pacific white shrimp (Penaeus vannamei).

AIMS: The present study evaluated the effect of four functional diets and a reference diet on the survival and intestinal bacterial community of shrimp Penaeus vannamei infected with acute hepatopancreatic necrosis disease (AHPND). METHODS AND RESULTS: After 42 days of feeding trail, shrimp were inoculated with a Vibrio parahaemolyticus (CIB-0018-3) carrying the plasmid encoding for the PirAB toxins responsible for AHPND. After 120 h postinfection (hpi), shrimp fed with a diet containing 2% of a mix with Curcuma longa and Lepidium meyenii (TuMa) and a diet containing 0.2% of vitamin C (VitC) showed a significantly higher survival (85%) compared to the remaining treatments (50%-55%) (p < 0.05). Infected shrimp fed with TuMa diet, showed a significant reduction of Vibrionales, and VitC diet promoted an increase of Alteromonadales. CONCLUSIONS: Our findings suggest that the TuMa diet conferred protection against AHPND and could be attributed to a combined effect of antibacterial properties against Vibrionales, and promoting a desirable bacterial community in the shrimp intestine, while the VitC diet protection could be attributed to their antioxidant capacity and in a lower proportion to a bacterial modulation in shrimp gut. SIGNIFICANCE AND IMPACT OF THE STUDY: Acute hepatopancreatic necrosis disease is a devastating disease that significantly affects aquaculture production of shrimps. Therefore, the use of functional diets that promote resistance to AHPND represents a valuable tool to reduce the mortality of farmed shrimp.

Fabrication of Robust Capsules by Sequential Assembly of Polyelectrolytes onto Charged Liposomes.

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, XD, 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.

Assessment of bacteriophage vB_Pd_PDCC-1 on bacterial dynamics during ontogenetic development of the longfin yellowtail (Seriola rivoliana).

The Seriola genus includes species of worldwide commercial importance due to its rapid growth and easy adaptability to confinement conditions. However, like other fish species, large mortalities occur during their early life stages, where the main problems are caused by opportunistic bacteria. Disease control strategies are thus urgently needed. The present study aimed to evaluate the efficacy of phage vB_Pd_PDCC-1 during the early development of longfin yellowtail (Seriola rivoliana), as well as its effect on microbial communities. This broad-host-range phage was added to the culture every 3 days starting from the egg-stage until 12 days after hatching (DAH) at a concentration of 1.41×1010 plaque-forming units (PFU) per mL and at a multiplicity of infection (MOI) of 1. The results showed positive effects (p<0.05) on egg hatching, survival, growth, and pigmentation area in treated larvae. Moreover, high-throughput sequencing analysis of 16S rRNA genes showed that phage administration did not produce significant changes (p>0.05) in the composition and structure of the associated microbiota. However, sequences affiliated to the Gammaproteobacteria class were displaced by those belonging to the Alphaproteobacteria class over time regardless of the treatment received. At the family level, there was a decrease in Rhodobacteraceae, Pseudoalteromonadaceae, and Flavobacteriaceae in both groups over time. To our best knowledge, this study represents the first attempt to evaluate the effect of a phage as a biological control agent during ontogenetic development of longfin yellowtail larvae. KEY POINTS: • Phages can be used against proliferation of Vibrio in fish cultures. • Seriola includes several important commercial fish species due to its rapid growth. • Phages do not cause significant changes in the associated microbiota.

Pattern Formation upon Evaporation of Sessile Droplets of Polyelectrolyte/Surfactant Mixtures on Silicon Wafers.

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.

Behavior of the water/vapor interface of chitosan solutions with an anionic surfactant: effect of polymer-surfactant interactions.

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.

Surfactantless Emulsions Containing Eugenol for Imidacloprid Solubilization: Physicochemical Characterization and Toxicity against Insecticide-Resistant Cimex lectularius.

Synthetic insecticides have been used for a long time as one of the most effective tools for insect pest control. However, the re-emergence of insect pests and their fast development of resistance, as has occurred for pyrethroid-resistant bed bugs Cimex lectularius L., make it necessary to develop new and safe strategies for effective pest control. This has fostered the research on new eco-sustainable formulations based on essential oils, which allows reducing the impact associated with the intensive use of synthetic insecticides on the environment and their effects on human health. This research explores the stability of water/eugenol/ethanol surfactantless emulsions loaded with imidacloprid (0.003 wt%), and their toxicity against a resistant bed bug strain. The results have shown that these emulsions enable the solubilization of a poorly water-soluble drug, such as the imidacloprid, without any significant modification of their stability. Furthermore, the application of the obtained formulations against the pyrethroid-resistant bed bug results in mortality in the 50-85% range upon topical and spray applications, with the increase of the eugenol content enhancing the effectiveness of the formulations. It may be expected that the ternary water/eugenol/ethanol mixtures could be further developed in the preparation of ready to use formulations, enabling the dispersion of insecticides for pest control.

Surfactant-Like Behavior for the Adsorption of Mixtures of a Polycation and Two Different Zwitterionic Surfactants at the Water/Vapor Interface.

The bulk and interfacial properties of solutions formed by a polycation (i.e., poly(diallyl-dimethylammonium chloride), PDADMAC) and two different zwitterionic surfactants (i.e., coco-betaine (CB) and cocoamidopropyl-betaine (CAPB)) have been studied. The bulk aggregation of the polyelectrolyte and the two surfactants was analyzed by turbidity and electrophoretic mobility measurements, and the adsorption of the solutions at the fluid interface was studied by surface tension and interfacial dilational rheology measurements. Evidence of polymer-surfactant complex formation in bulk was only found when the number of surfactant molecules was closer to the number of charged monomers in solutions, which suggests that the electrostatic repulsion associated with the presence of a positively charged group in the surfactant hinders the association between PDADMAC and the zwitterionic surfactant for concentrations in which there are no micelles in solution. This lack of interaction in bulk is reflected in the absence of an influence of the polyelectrolyte in the interfacial properties of the mixtures, with the behavior being controlled by the presence of surfactant. This work has evidenced the significant importance of the different interactions involved in the system for controlling the interaction and complexation mechanisms of in polyelectrolyte-surfactant mixtures.

Relación entre el índice lipoproteínas de baja densidad (LDL)/lipoproteínas de alta densidad (HDL) con enzimas antioxidantes y el índice oxLDL/HDL.

INTRODUCTION: The low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index is a predictive factor for atherosclerosis, which is associated with oxidative modifications. OBJECTIVE: To assess the association of the index with oxidative stress markers. METHODS: 444 subjects were included and were clinically, anthropometrically and biochemically characterized; superoxide dismutase, glutathione peroxidase 3 (GPx3), magnesium and oxidized LDL (oxLDL) index (oxLDL/HDL) were quantified. RESULTS: A decrease of 1.014 units in the LDL/HDL index was associated with a superoxide dismutase increase of 1 unit/mL (p = 0.030), while a decrease of 0.023 units was associated with a GPx3 increase of 1 nmol/min/mL (p < 0.0005). An increase of one unit in the index was associated with an increase of 0.831 in the oxLDL/HDL index (p < 0.05). After controlling for the effect of gender, age, smoking, obesity and insulin resistance, a reduction of 0.001 per index unit was associated with an increase of 1 µg/g of magnesium in the nails (p = 0.020). CONCLUSIONS: The LDL/HDL index shows an inverse relationship with the antioxidant status and a direct relationship with oxidation status, regardless of other cardiovascular and oxidative stress risk factors.

INTRODUCCIÓN: El índice de lipoproteínas de baja densidad (LDL)/lipoproteínas de alta densidad (HDL) es un factor predictivo de aterosclerosis, la cual está asociada con modificaciones oxidativas. OBJETIVO: Evaluar la asociación del índice con marcadores de estrés oxidativo. MÉTODO: Se incluyeron 444 sujetos, caracterizados clínica, antropométrica y bioquímicamente; se cuantificó superóxido dismutasa, glutation peroxidasa 3 (GPx3), magnesio e índice LDL oxidadas (oxLDL/HDL). RESULTADOS: La disminución en 1.014 unidades del índice LDL/HDL se asoció con aumento de 1 unidad/mL de superóxido dismutasa (p = 0.030) y la de 0.023 unidades con aumento de 1 nmol/minuto/mL de GPx3 (p < 0.0005). El aumento en 1 unidad del índice se asoció con aumento de 0.831 unidades en el índice oxLDL/HDL (p < 0.05). Después de controlar el efecto del sexo, edad, fumar, obesidad y resistencia a la insulina, la reducción de 0.001 por unidad del índice se asoció con aumento de 1 µg/g de magnesio en uñas (p = 0.020). CONCLUSIONES: El índice LDL/HDL presenta relación inversa con el estado antioxidante y relación directa con el estado de oxidación, independientemente de otros factores de riesgo cardiovascular y de estrés oxidativo.

Relationship of the low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index with antioxidant enzymes and with the oxLDL/HDL index.

INTRODUCTION: The low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index is a predictive factor for atherosclerosis, which is associated with oxidative modifications. OBJECTIVE: To assess the association of the index with oxidative stress markers. METHODS: 444 subjects were included and were clinically, anthropometrically and biochemically characterized; superoxide dismutase, glutathione peroxidase 3 (GPx3), magnesium and oxidized LDL (oxLDL) index (oxLDL/HDL) were quantified. RESULTS: A decrease of 1.014 units in the LDL/HDL index was associated with a superoxide dismutase increase of 1 unit/mL (p = 0.030), while a decrease of 0.023 units was associated with a GPx3 increase of 1 nmol/min/mL (p < 0.0005). An increase of one unit in the index was associated with an increase of 0.831 in the oxLDL/HDL index (p < 0.05). After controlling for the effect of gender, age, smoking, obesity and insulin resistance, a reduction of 0.001 per index unit was associated with an increase of 1 µg/g of magnesium in the nails (p = 0.020). CONCLUSIONS: The LDL/HDL index shows an inverse relationship with the antioxidant status and a direct relationship with oxidation status, regardless of other cardiovascular and oxidative stress risk factors.

Equilibration of a Polycation-Anionic Surfactant Mixture at the Water/Vapor Interface.

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.

Tuning Interfacial Properties and Processes by Controlling the Rheology and Structure of Poly( N-isopropylacrylamide) Particles at Air/Water Interfaces.

By combining controlled experiments on single interfaces with measurements on solitary bubbles and liquid foams, we show that poly( N-isopropylacrylamide) (PNIPAM) microgels assembled at air/water interfaces exhibit a solid to liquid transition changing the temperature, and that this is associated with the change in the interfacial microstructure of the PNIPAM particles around their volume phase transition temperature. We show that the solid behaves as a soft 2D colloidal glass, and that the existence of this solid/liquid transition offers an ideal platform to tune the permeability of air bubbles covered by PNIPAM and to control macroscopic foam properties such as drainage, stability, and foamability. PNIPAM particles on fluid interfaces allow new tunable materials, for example foam structures with variable mechanical properties upon small temperature changes.