Surfactant Activity Research Articles

Ecotoxicological Evaluation of Products Obtained from Technical Cashew Nutshell Liquid (tCNSL) Proposed as Larvicide to Control Aedes aegypti (Diptera: Culicidae)

The development of new insecticides for vector control that are toxicologically safe and eco-friendly (such as those obtained from industrial by-products) is an important public health concern. Previous research has shown that the obtained tCNSL (technical cashew nutshell liquid) + NatCNSLS (sodium tCNSL sulfonate mixture) emulsion displayed both surfactant properties and larvicidal activity (LC50-24 h 110.6 mg/L). Thus, the emulsion is considered a promising alternative product for the control of Aedes aegypti. The goal of this study was an ecotoxicological evaluation of the tCNSL + NatCNSLS mixture emulsion and its components. In addition, we compared the toxicity of the tCNSL + NatCNSLS mixture emulsion with toxicity data from larvicide currently recommended by the World Health Organization (WHO). Ecotoxicological tests were performed to assess acute toxicity, phytotoxicity, cytotoxicity, genotoxicity, and mutagenicity using Daphnia similis, Pseudokirchneriella subcapitata, Oreochromis niloticus, Allium cepa, and Salmonella enterica serovar Typhimurium. Regarding acute toxicity, D. similis was the most sensitive test organism for the three evaluated products, followed by P. subcapitata and O. niloticus. The highest acute toxicity product was tCNSL. The tCNSL + NatCNSLS mixture emulsion did not show cytotoxic, genotoxic, or mutagenic effects, and showed low acute toxicity to D. similis. In addition, the tCNSL + NatCNSLS mixture emulsion presented a lower or similar toxicological classification to the larvicides recommended by the WHO. Therefore, ecotoxicological tests suggest that the tCNSL + NatCNSLS mixture emulsion can be considered a larvicide environmentally safe way to control Ae. aegypti.

Enhanced permeation by amphiphilic surfactant is spatially heterogenous at membrane and cell level.

In the context of increased interest in permeability enhancement technologies to achieve mucosal delivery of drugs and biologics, we report our study on effects of the amphiphilic surfactant at cell membrane and cell population levels. Our results show that modulation in membrane order and fluidity initially occurs on insertion of individual surfactant molecules into the outer leaflet of membrane lipid bilayer; a process occurring at concentrations below surfactant's critical micellar concentration. The surfactant insertion, and consequent increase in membrane fluidity, are observed to be spatially heterogenous, i.e. manifested as 'patches' of increased membrane fluidity. At the cell population level, spatially heterogeneous activity of surfactant is also manifested, with certain cells displaying high permeability amongst a 'background' population. We propose that this heterogeneity is further manifested in a broad profile of intracellular and nuclear exposure levels to a model drug (doxorubicin) observed in cell population. The study points to heterogeneous nature of surfactant effects at cell membrane and cells in population levels.

An investigation into the principal modes of action of surfactants and how a novel formulation may improve turfgrass quality by increasing the dominance of Agrostis spp. in golf greens

AbstractThe aim of this study was to establish the mechanisms underpinning the observations made in a field trial that suggested that a novel surfactant treatment could promote bentgrasses (Agrostis spp.) in golf greens that contain annual meadow grass (Poa annua L.). Assessments of the effects of three surfactant treatments (named Treatments 1, 2, and 3) on shoot height, biomass accumulation, rhizosheath properties, soil water distribution, and rooting characteristics were made over the course of two experiments carried out under controlled conditions. We found that the leaf extension rate was significantly affected in the two grass species to different extents, depending on the surfactant used. This finding could have positive implications for turf quality in the field for a newly developed formulation (Treatment 3), which was observed to be the case in the field trial that pre‐dated this study. The same treatment also resulted in significant differences in the grasses in terms of rhizosheath size compared with untreated soil. We found that surfactants affected the distribution of water in the soil by increasing the rhizosheath water content to bulk soil water content ratio, potentially maximizing water and nutrient uptake by the roots. The combination of effects observed with use of the novel surfactant treatment may lead to improved water use efficiency and a more desirable sward composition for golf greens.

STUDY OF THE PROPERTIES OF SURFACE-ACTIVE SUBSTANCES DETERMINING THE EFFICIENCY OF DYING AND RINSING OF TEXTILE MATERIALS

The article studies the most important properties of surfactants – foaming and wetting ability, stability in a highly alkaline environment, surface activity. Spectrophotometric method showed the intensifying effect of environmentally friendly surfactants Glucopon 2015 and Carboxypav on the process of colouring natural textile materials with dichlorotriazine, vinyl sulfone and bifunctional dyes. The effect of surfactants of various structures on the state of the active dye in solution and the technical results of colouring cellulose and cotton silk fabrics has been evaluated. A synergistic effect of the solubilising action of surfactants – nonionic alkyl polyglycosides (Glucopon 215) and anionic carboxylates (Carboxypav) on active dyes was revealed.

Toxicity and Control Efficacy of an Organosilicone to the Two-Spotted Spider Mite Tetranychus urticae and Its Crop Hosts.

Simple SummaryThe organosilicone is commonly used as surfactant ingredient in agriculture. Some pilot studies showed pesticidal activities of some organosilicone surfactants. This study examined the toxicity of an organosilicone, Silwet 408, to the two-spotted spider mite Tetranychus urticae and explored the field usage of this chemical in pest control. We tested this chemical on eggs, nymphs, and adults of T. urticae. We applied a two-sprays strategy to enhance the field control efficacy based on the high toxicity of Silwet 408 to nymphs and adults and the lack of toxicity to eggs of T. urticae. However, their phytotoxicity should be taken under consideration. Our study improved our understand of the toxicity and safety of organosilicone surfactants. The results provide a basis for the usage of this chemical in mite control.Organosilicone molecules represent important components of surfactants added to pesticides to improve pest control efficiency, but these molecules also have pesticidal properties in their own right. Here, we examined toxicity and control efficacy of Silwet 408, a trisiloxane ethoxylate-based surfactant, to the two-spotted spider mite (TSSM), Tetranychus urticae and its crop hosts. Silwet 408 was toxic to nymphs and adults of TSSM but did not affect eggs. Field trials showed that the control efficacy of 1000 mg/L Silwet 408 aqueous solution reached 96% one day after spraying but declined to 54% 14 days after spraying, comparable to 100 mg/L cyetpyrafen, a novel acaricide. A second spraying of 1000 mg/L Silwet 408 maintained control efficacy at 97% when measured 14 days after spraying. However, Silwet 408 was phytotoxic to eggplant, kidney bean, cucumber, and strawberry plants, although phytotoxicity to strawberry plants was relatively low and declined further seven days after application. Our study showed that while the organosilicone surfactant Silwet 408 could be used to control the TSSM, its phytotoxicity to crops should be considered.

Skin Cleansing without or with Compromise: Soaps and Syndets.

Products designed to cleanse the skin commonly do so through surfactant action, which leads to the lowering of the surface tension of the skin to facilitate the removal of dirt from its surface. Skin cleansers generally come in one of two types: soap-based and synthetic detergents, or syndets. While the latter can effectively maintain the native skin structure, function and integrity, the former tends to negatively affect the skin by causing barrier disruption, lipid dissolution and pH alteration. Despite this, soap is still often preferred, possibly due to the negative connotations around anything that is not perceived as ‘natural’. It is, therefore, important that the science behind cleansers, especially those designed for the maintenance of healthy skin and the management of common skin conditions such as eczema, be understood by both formulators and end-users. Here, we carefully weigh the advantages and disadvantages of the different types of surfactant—the key ingredient(s) in skin cleansers—and provide insight into surfactants’ physicochemical properties, biological activity and potential effects. Fine-tuning of the complex characteristics of surfactants can successfully lead to an ‘optimal’ skin cleanser that can simultaneously be milder in nature, highly effective and beneficial, and offer minimal skin interference and environmental impact.

Comprehensive Review on Applications of Surfactants in Vaccine Formulation, Therapeutic and Cosmetic Pharmacy and Prevention of Pulmonary Failure due to COVID-19

Our world is under serious threat of environmental degradation, climate change and in association with this the out breaks of diseases as pandemics. The devastating impact of the very recent COVID-19, The sharp increase in cases of Cancer, Pulmonary failure, Heart health has triggered questions for the sustainable development of pharmaceutical and medical sciences. In the search of inclusive and effective strategies to meet today’s demand, improvised methodologies and alternative green chemical, bio-based precursors are being introduced by scientists around the globe. In this extensive review we have presented the potentiality and Realtime applications of both synthetic and bio-based surfactants in bio-medical and pharmaceutical fields. For their excellent unique amphoteric nature and ability to solubilise in both organic and inorganic drugs, surfactants are one of the most potential candidates for bio-medicinal fields such as dermatology, drug delivery, anticancer treatment, surfactant therapy, vaccine formulation, personal hygiene care and many more. The self-assembly property of surfactants is a very powerful function for drug delivery systems that increases the bio-availability of the poorly aqueous soluble pharmaceutical products by influencing their solubility. Over the decades many researchers have reported the antimicrobial, anti-adhesive, antibiofilm, anti-inflammatory, antioxidant activities of surfactants regarding its utility in medicinal purposes. In some reports surfactants are found to have spermicidal and laxative activity too. This comprehensive report is targeted to enlighten the versatile applications of Surfactants in drug delivery, vaccine formulation, Cancer Treatment, Therapeutic and cosmetic Pharmaceutical Sciences and prevention of pulmonary failure due to COVID-19.

Salt Spray and Surfactants Induced Morphological, Physiological, and Biochemical Responses in Callistemon citrinus (Curtis) Plants

The growth and aesthetic value of ornamental plant species used near coastlines are negatively influenced by salt spray. The presence of surfactants could enhance salt damage. To analyze the influences of salt spray and surfactants alone and in combination with each other, individual Callistemon plants were subjected to different treatments for 8 weeks: a solution simulating the composition of seawater (salt spray), a solution containing an anionic surfactant (surfactant), a solution with salt spray and anionic surfactant (salt plus surfactants), and deionized water (control). To study the influence of different climatic conditions, two growing periods, from January to March (I CP) and from May to July (II CP), were established. Salt spray, alone or with surfactant action, influences plants’ growth and aesthetic features in different cycle periods. The percentage of leaf damage significantly increased with salt spray and salt plus surfactants during II CP (~27%). Additionally, the Na+ and Cl− contents were enhanced in the leaves in both CPs, but the contents in the roots were only enhanced in the II CP. The gas exchanges were significantly influenced by the treatments, especially during the II CP, when a reduction in net photosynthesis due to salt spray was observed starting from the second week of stress. At the end of the experiment, in both cycle periods, the leaf proline content increased in the salt spray and salt plus surfactants treatments. In both CPs, PCA revealed that the morphological and physiological parameters were directly associated with the control and surfactants treatments, whereas the mineral contents and biochemical parameters were directly correlated with the salt and salt plus surfactants treatments. The additive effect of surfactant stress, compared to salt stress, did not appear to be significant, with the exception of CP II, and for some parameters, the solubilization action of surfactants was favored by higher temperatures.

Saponins from Albizia procera extract: Surfactant activity and preliminary analysis

We report our results on surface activity and preliminary analytical data of natural surfactant (saponin) from Albizia procera extract. The plant-based extract exhibited moderate reduction of surface tension, low alkalinity, moderate foaming and emulsifying characteristics. The critical micelle concentration is 7.00 × 10−3 g/cc, where the emulsifying power reached a maximum. An abrupt increase in viscosity and conductivity with surfactant concentration was seen in this region. Dirt dispersion results displayed a sharp maximum at the Critical Micelle Concentration. The extracts were analyzed to understand the constituents. The presence of polar and non-polar compounds was seen in Thin Layer Chromatography analysis. Using methanol water solvent system, a good separation of compounds was observed in High Performance Liquid Chromatography. The presence of saponin along with some traces of flavonoids was observed by UV-Visible spectroscopy. Occurrence of triterpenoid saponins were indicated by Fourier Transform Infrared spectroscopy analysis. The results obtained from surface tension, foaming and emulsification highlights the efficiency of Albizia procera extract to be employed as a possible environment friendly surface-active agent. This natural surfactant could find various industrial and domestic applications.

Solubility Enhancement of Poorly Water Soluble Drug by Using β Cyclodextrin

Aceclofenac complex is prepared by kneading method of inclusion complexation. The aim of present work is to improve the solubility and dissolution properties of a poorly water soluble drug aceclofenac, by inclusion complexation technique. Two components namely β cyclodextrin and span 60 were used in this study, β CD is used as complexing agent and span 60 as surfactant which helps in increasing solubility and dissolution. The prepared Aceclofenac complex is evaluated in terms of compatibility, solubility, dissolution behavior with the help of FTIR, DSC, In vitro dissolution studies. The complexation parameter of β CD had an impact on the solubility of drug. The solubility of complexes was progressively improved when compared to pure Aceclofenac drug in water. The prepared Aceclofenac complexes were subjected to dissolution study. At the end of 60 min of dissolution study 22.32±0.42 of pure drug was dissolved. The prepared complexes showed 85.35±0.71 at 60 min. The percent of drug dissolved increased for the complexes prepared with high concentration of β CD. The study showed that complexing property of β CD and surfactant action of span 60 has its influence on both solubility and dissolution of the prepared inclusion complexes. MDT and % DE was evaluated for the all the prepared complexes. Aceclofenac complexes prepared with high concentration of β CD showed lower MDT and higher % DE compared to pure Aceclofenac. The pure and complexed Aceclofenac were characterized by DSC studies. DSC studies showed that there was no appreciable change in the melting endotherm of prepared complexes compared to that of pure drug. The drug release from the above follows Korsemeyer-Peppas model and release mechanism was Non- Fickinian.
 Keywords: Aceclofenac, inclusion complex, kneading method, complexing agent, solubility, dissolution.

Transport of different microplastics in porous media: Effect of the adhesion of surfactants on microplastics

The adhesion of surfactant molecules on the microplastics surface is affected by the surface structure of the microplastics. Little is known about the mobility of different microplastics in the medium under surfactants. In order to reveal the migration of different microplastics under the action of surfactants, the study selected five kinds of microplastics (polyethylene (PE), polypropylene (PP), polystyrene (PS), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA)) and two kinds of surfactants (cetyltrimethylammonium bromide, CTAB and sodium dodecyl benzene sulfonate, SDBS) as the research objects. The column experiment was used to explore the transport behavior of microplastics under different concentrations of surfactants and the convection dispersion model was used to simulate. The dynamic contact angle of the surfactant solution on the microplastics was measured and the adhesion work was calculated by the Young-Dupre equation to reveal the underlying mechanism of microplastics retention in the presence of surfactants. The results showed that the transport ability of microplastics followed the order of PTFE <PMMA <PS <PE <PP, and the mobility under high concentrations of surfactants was greater than that at low concentrations, which was mainly attributed to the difference in the adhesion of the surfactant on the surface of the microplastics, which lead to differences in the migration between the microplastics. When the microplastics were close to each other, if the reaction force of the electrostatic force was greater than the adhesion force of the surfactant molecules on the surface, the surfactant molecules would be separated from the microplastics and the stability of the microplastics would decrease. In addition, the migration ability of microplastics in anionic surfactants was weaker than that of cationic surfactants, because the osmotic and elastic repulsion produced by SDBS were weaker than CTAB. The research results were of great significance for understanding the environmental behavior of microplastics affected by surfactants, and objectively evaluating the transport and fate behavior of microplastics-surfactants in the environment.

Photo‐Reactivity of Surfactants in the Sea‐Surface Microlayer and Subsurface Water of the Tyne Estuary, UK

AbstractWe report the first estimates of total surfactant photo‐reactivity in the sea‐surface microlayer (SML) and in subsurface water (SSW) (Tyne estuary, UK; salinity 0.3–32.0). In addition to temperature, a known driver of surfactant adsorption kinetics, we show that irradiation contributes independently to enhanced interfacial surfactant activity (SA), a notion supported by coincident CDOM photodegradation. We estimate a mean SA production via irradiation of 0.064 ± 0.062 mg l−1 T‐X‐100 equivalents h−1 in the SML and 0.031 ± 0.025 mg l−1 T‐X‐100 equivalents h−1 in the SSW. Using these data, we derive first‐order estimates of the potential suppression of the gas transfer velocity (kw) by photo‐derived surfactants ∼12.9%–22.2% in coastal North Sea water. Given the ubiquitous distribution of natural surfactants in the oceans, we contend that surfactant photochemistry could be a hitherto unrecognized additional driver of air‐sea gas exchange, with potential implications for global trace gas budgets and climate models.

Identification of a Novel Biosurfactant with Antimicrobial Activity Produced by Rhodococcus opacus R7.

Rhodococcus members excrete secondary metabolites, especially compounds which act as biosurfactants. In this work, we demonstrated the ability of Rhodococcus opacus R7 to produce a novel bioactive compound belonging to the class of biosurfactants with antimicrobial properties during the growth on naphthalene. Chemical and biochemical analyses of the isolated compound demonstrated that the biosurfactant could be classified as a hydrophobic peptide. The ESI-full mass spectrometry revealed that the isolated biosurfactant showed a molecular weight of 1292 Da and NMR spectra evidenced the composition of the following amino acid residues: Ala, Thr, Asp, Gly, Ser. Surfactant activity of the R. opacus R7 compound was quantified by the critical micelle dilution (CMD) method and the critical micelle concentration (CMC) was estimated around 20 mg L−1 with a corresponding surface tension of 48 mN m−1. Moreover, biological assays demonstrated that R. opacus R7 biosurfactant peptide exhibited antimicrobial activity against Escherichia coli ATCC 29522 and Staphylococcus aureus ATCC 6538 with the minimum inhibition growth concentration (MIC) values of 2.6 mg mL−1 and 1.7 mg mL−1, respectively. In this study for the first time, a hydrophobic peptide with both biosurfactant and antimicrobial activity was isolated from a bacterium belonging to Rhodococcus genus.

The study of surface activity and anti-corrosion of novel surfactants for carbon steel in 1 M HCl

Three triazine-based surfactants with different hydrophobic chain lengths were synthesized and characterized, namely, 2-(n-Hexylamino)-4,6-bis (3-N, N-dimethylaminopropyl) amino-1,3,5-triazine, 2-(n-Octylamino)-4,6-bis (3-N, N-dimethylaminopropyl) amino-1,3,5-triazine and 2-(n-n-Dodecylamino)-4,6-bis (3-N, N-dimethylaminopropyl) amino-1,3,5-triazine, labelled C6, C8 and C12 respectively. The chemical structure was confirmed by FTIR and 1H NMR. The surface activity was evaluated by surface tension. C12 had a lower critical micelle concentration (CMC) value (0.5 mM) than C6 and C8, which suggested that a lower concentration was required to reach interfacial adsorption saturation, representing better inhibition performance. The corrosion inhibition of surfactants for 45 # carbon steel in 1.0 M HCl was studied by static weight loss measurement, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. Inhibition results showed that C12 was better than C6 and C8 with the maximum inhibition efficiency of 96% at 0.1 mM. The surface analysis had given a clear view of the mechanism of surfactants in inhibiting the corrosion process. Moreover, the Freundlich adsorption isotherm was the best description for the adsorption process of surfactants on 45 # carbon steel in 1.0 M HCl.

Oxygen transfer and bubble sizes occurring in a pilot‐scale cultivation of Bacillus velezensis 83 for the production of poly(γ‐glutamic acid) under two schemes of power drawn

AbstractBACKGROUNDThe influence of power consumption on oxygen transfer during non‐Newtonian and surfactant‐producing microbial fermentations has been scarcely reported. In this work, we study the oxygen transfer and bubble size distributions in a real 100 L fermentation (producing poly(γ‐glutamic acid)) occurring under constant stirring speed (N) and under constant retrofitted power drawn (Pg/V).RESULTSFor constant N fermentations, Pg/V and the volumetric mass transfer coefficient (kLa) decreased 40% and 70% during cultivation, respectively. Fermentations at constant Pg/V showed a decrease similar to that observed for constant N fermentations. Bubble size distributions were also similar for both operational conditions. Although an increase in bubble size was expected at constant N cultivations due to the increasing viscosity of the medium, the Sauter mean diameter (d32) decreased 65%. This singular behavior of d32 was likely caused by surfactin and bacillomycin, metabolites with strong surfactant activity produced by Bacillus velezensis 83 in the cultivations. The use of a constant Pg/V did not counteract the decrease in kLa due to the increase in viscosity. Although the presence of biosurfactants leads to an increase of interfacial transfer area by decreasing d32, the presence of these molecules and the increase in the medium viscosity affected kLa.CONCLUSIONSAn atypical behavior of this system was found, especially in d32, different to that based on common correlations found in the literature. A complex interaction among the multiple factors involved in a real bioprocess for poly(γ‐glutamic acid) production was evidenced. © 2022 Society of Chemical Industry (SCI).

Synthesis, characterization and surface activities of polymeric cationic thiol surfactants in aqueous medium

Synthesis, characterization and surface activities of polymeric cationic thiol surfactants in aqueous medium

Synthesis, interfacial activity and rheological properties of low interfacial tension viscoelastic Gemini surfactants

In order to develop a special surfactant that is suitable for improving oil recovery in low permeability reservoirs, and simultaneously meet the requirements of effectively improving sweep efficiency, displacement efficiency and good injectability, a series of new Gemini surfactants (GAC-3m, m = 14, 16, 18) were synthesized and characterized by FTIR and 1 HNMR. The surface activity, interfacial activity, thickening properties and viscoelasticity of GAC-3m solution were systematically studied. The mechanism of viscosity and elasticity enhancement were also discussed. The results showed that with increasing the carbon number of hydrophobic chain, the surface activity and interface activity of GAC-3m surfactant increased first and then decreased, the viscosity and elasticity gradually increased. The micelle microstructures changed from sheet to network-like, and the structural morphology was gradually complete and compact, which made the viscosity and elasticity of the GAC-3m surfactant solution increase. GAC-3m exhibit fascinating surface activity, interfacial activity and low values of CMC (<4.5 × 10 −4 mol/L), which is conducive to the formation of micelle structure at low concentration. The 0.5% GAC-316 solution can substantially reduce the oil-water interfacial tension to ultralow values (10 −3 mN/m), and also possess attractive viscosity (18.58 mPa s) and viscoelastic properties (tanδ = 0.5 < 1). In accordance with the experimental studies, the novel surfactants (GAC-3m) are a kind of low interfacial tension viscoelastic Gemini surfactant, promising in enhancing the recovery of low permeability reservoirs. The insights gained from this study contribute to enriching the theoretical research of the viscoelastic Gemini surfactant and promote the applications of low interfacial tension viscoelastic Gemini surfactant in the recovery of heterogeneous low permeability reservoirs fields. • A series of new carboxylate Gemini surfactants GAC-3m were synthesized and characterized by FTIR and 1 HNMR. • The interfacial activity, thickening property, viscoelasticity and thickening mechanism of GAC-3m solution were studied. • GAC-3m exhibit fascinating surface activity and low CMC, which is conducive to forming micelle structure at low concentration. • GAC-316 can reduce the interfacial tension to ultralow values, and also possesses attractive viscosity and viscoelasticity. • GAC-3m possess favorable shear-thinning behavior which is desirable for improving mobility control during EOR processes.

Pulmonary Surfactant: A Unique Biomaterial with Life-saving Therapeutic Applications.

Pulmonary surfactant is a complex lipoprotein mixture secreted into the alveolar lumen by type 2 pneumocytes, which is composed by tens of different lipids (approximately 90% of its entire mass) and surfactant proteins (approximately 10% of the mass). It is crucially involved in maintaining lung homeostasis by reducing the values of alveolar liquid surface tension close to zero at end-expiration, thereby avoiding the alveolar collapse, and assembling a chemical and physical barrier against inhaled pathogens. A deficient amount of surfactant or its functional inactivation is directly linked to a wide range of lung pathologies, including the neonatal respiratory distress syndrome. This paper reviews the main biophysical concepts of surfactant activity and its inactivation mechanisms, and describes the past, present and future roles of surfactant replacement therapy, focusing on the exogenous surfactant preparations marketed worldwide and new formulations under development. The closing section describes the pulmonary surfactant in the context of drug delivery. Thanks to its peculiar composition, biocompatibility, and alveolar spreading capability, the surfactant may work not only as a shuttle to the branched anatomy of the lung for other drugs but also as a modulator for their release, leading to innovative therapeutic avenues for the treatment of several respiratory diseases.

One-Pot Preparation of Hydrophilic Polylactide Porous Scaffolds by Using Safe Solvent and Choline Taurinate Ionic Liquid.

Polylactides (PLAs) are a class of polymers that are very appealing in biomedical applications due to their degradability in nontoxic products, tunable structural, and mechanical properties. However, they have some drawbacks related to their high hydrophobicity, lack of functional groups able to graft bioactive molecules, and solubility in unsafe solvents. To circumvent these shortcomings, porous scaffolds for tissue engineering were prepared by vigorously mixing a solution of isotactic and atactic PLA in nontoxic ethyl acetate at 70 °C with a water solution of choline taurinate. The partial aminolysis of the polymer ester bonds by taurine –NH2 brought about the formation of PLA oligomers with surfactant activity that stabilized the water-in-oil emulsion. Upon drying, a negligible shrinking occurred, and mechanically stable porous scaffolds were obtained. By varying the polymer composition and choline taurinate concentration, it was possible to modulate the pore dimensions (30–50 µm) and mechanical properties (Young’s moduli: 1–6 MPa) of the samples. Furthermore, the grafted choline taurinate made the surface of the PLA films hydrophilic, as observed by contact angle measurements (advancing contact angle: 76°; receding contact angle: 40°–13°). The preparation method was very simple because it was based on a one-pot mild reaction that did not require an additional purification step, as all the employed chemicals were nontoxic.

Non-respiratory functions of lungs in experimental intracerebral hemorage during fingolimod injection

Introduction. Intracerebral hemorrhage (ICH) is frequently accompanied by respiratory system complications. One of the correction method of post stroke complications is administration of immunosuppressive drug fingolimod. Theobjective of the study is to investigate non-respiratory lung functions in experimental ICH during fingolimod treatment. Materials and methods. Animals were divided into 3 groups: group 1 with ICH, group 2 with ICH receiving fingolimod and group 3 as reference group. Intracranial hemorrhage was modelled by 160 μl autologic blood injection into lateral brain ventricle (P=0.6; D=1.5; V=3.5). Fingolimod (FTY 720, «Sigma») was administered within 1 hour after ICH (intraabdominal, 1 mg/kg). Biochemistry and functional parameters of the lung surfactant in animals were studied. Phospholipids fractions spectrum was assessed by thin-layer chromatography, superficial surfactant activity by Wilhelmi method. Parameters of water metabolism, pulmonary blood filling were studied by gravimetric method. Level of blood nitric oxide was estimated by amount of nitrates and nitrites stable terminal metabolites. Results. We revealed that experimental ICH causes a decrease of alveolar stability index by 9 %, decrease of total alveolar phospholipids content by 25 % and change of its fraction composition, i.e. decrease of major surface active fraction (phosphatidylcholine) by 68 %, increase of phosphatidic acid amount by 151 % and increase of lisophosphatidylcholine by 163 %. Besides that, experimental ICH is followed by lung edema on the lung blood filling background and increase of blood NO. Fingolimod administration does not affect surfactant surface activity but totally corrects water balance, lung blood filling and blood NO content.