Amphiphilic Compounds Research Articles

Smart synthesis of highly porous metal oxide powders with the self-assembly of amphiphilic organic compounds.

Supramolecular chemistry-mediated synthesis has thus far been employed for the design of ordered mesoporous structures surrounded by various metal oxides that are helpful as nanometer-scaled unique reaction containers with high specific surface area, large pore volume and uniform mesopores useful for the storage and mass transport of large-sized molecules. The evaporation-induced self-assembly (EISA) process is very powerful for fabricating mesoporous metal oxide films with the rapid evaporation of solvents. Although a similar EISA process is also applied to synthesize mesoporous metal oxide powders using the room-temperature drying process with slow evaporation of solvents, the control of the evaporation rate should be quantified for the complete reproduction of high-quality metal oxide powders. In this feature article, I introduce our recent challenge in synthesizing highly porous metal oxides in powder form with the smart optimization of synthetic conditions by combining several EISA processes to eliminate the mismatch of the rate of solvent evaporation, inducing the self-assembly of amphiphilic organic molecules.

Amphiphilic Low-Molecular-Weight Gelators Bearing β-S-N-Acetylglucosamine Linked to a Tartaric Acid Scaffold: Synthesis, Self-Assembly and Wheat Germ Agglutinin Binding.

The self-assembly of carbohydrate-based amphiphiles can lead to colloidal soft materials such as supramolecular gels featuring highly desirable characteristics like biodegradability and biocompatibility. The report herein presents the synthesis, characterization and supramolecular self-assembly, physical gelation and wheat lectin binding of two structurally related amphiphilic compounds having β-S-N-acetylglucosamine residues linked to a 2,3-diacyl-N,N'-dipropargylated-l-tartaric diamide. A 1-thio-β-N-acetyl-d-glucosamine precursor attached to a conveniently functionalized linker with an azido group was synthesized by means of a one-pot procedure followed by deprotection. A click reaction successfully led to the two amphiphiles, which differed in length of the fatty acid attached to the tartaric acid scaffold. Although both compounds are poorly soluble in water and organic solvents, the difference in terms of hydrophilic moieties provided them with distinct supramolecular gelation properties. While the presence of an octadecyl chain produced a hydrogelator, the dodecadecyl homologue would only form weak gels in DMSO. SEM and rheology experiments confirmed the characteristic fibrillar morphology and viscoelastic properties, in agreement with the presence of physical gels. Both amphiphiles were able to interact reversibly with wheat germ agglutinin (WGA), a lectin that specifically recognizes GlcNAc residues, indicating a potential use in the food industry, as a gluten sensitivity manager, as well as in health-related industries, for example, for drug delivery systems.

Highly Efficient Red Thermally Activated Delayed Fluorescence Nanoparticles for Real‐Time in Vivo Time‐Resolved Luminescence Imaging

AbstractThermally activated delayed fluorescence (TADF) nanoparticles are used importantly in time‐resolved luminescence imaging for eliminating the background signals from scattering and short‐lived autofluorescence. However, TADF nanoparticles are seldom used for real‐time time‐resolved luminescence imaging, due to their limited luminescence efficiency and lifetimes. To detect delayed fluorescence, multiple excitation cycles with adequate delay times are usually required, leading to long detecting durations and low imaging speed. Herein, highly efficient red TADF nanoparticles are developed through doping a guest molecule, TPAAQ (2,6‐bis[4‐(diphenylamino) phenyl] anthraquinone), in a host (4,4′‐bis(carbazol‐9‐yl)biphenyl, CBP) matrix. With a low doping concentration, the nanoparticles can exhibit obvious TADF with luminescence lifetimes over 0.1 ms and photoluminescence quantum yield up to 35%. A cell‐penetrating peptide is used together with the amphiphilic compound for assembling nanoparticles, which can easily penetrate cells and greatly increase the TADF signals for luminescence lifetime imaging. Thanks to the long‐lived and highly efficient TADF, real‐time in vivo time‐gated luminescence imaging of zebrafish is realized on a chopper‐based wide‐field microscope. This low‐cost time‐resolved luminescence imaging method showed a great potential for real‐time detection of life activities in many organisms with high autofluorescence.

Synthesis and application of a new antibacterial surfactant from apricot kernel oil

Food emulsifier are mostly prepared from a lipophilic lipid tail with a hydrophilic sugar head. In this study, the lipophilic tail was obtained from apricot kernels, which are food waste, and the hydrophilic head was gluconic acid instead of sugar, in order to draw attention to the non-cyclic poly hydroxyl compounds. Thus, oleic acid of apricot kernel was used as the lipophilic moiety of the prepared surfactant. So, apricot kernel was grinned and dried, oil was extracted using soxhlet apparatus, Physical and chemical parameters and fatty acids composition of the extracted oil had been determined. The extracted oil was then hydrolyzed into glycerol and a mixture of free fatty acids. The fatty acids mixture was separated. Then, oleic acid was extracted individually in pure form using supercritical CO2 extractor, it was then confirmed according to its melting point, Gas chromatography–mass spectrometry (GC–MS) after esterification, elemental analysis, Proton nuclear magnetic resonance (H1NMR), and mass spectrometry (MS) to detect the corresponding molecular ion peak. The pure individual oleic acid was converted to hydroxy stearic acid, which was then converted to an amphiphilic compound (surfactant) via esterification reaction with the hydrophilic gluconic acid, and afforded a new surfactant known as 2,3,4,5-tetrahydroxy-6-((9-((-2,3,4,5,6-pentahydroxyhexanoyl) oxy)octadecanoyl) oxy)hexanoic acid or stearyl gluconate for simplification. The structures elucidation of all synthesized compound was established according to elemental analysis and spectral data (Fourier transform infrared IR, 1H NMR, 13C NMR and MS). Moreover, the prepared compound was tasted for its antibacterial activity, and showed good activities against some types of bacteria. The surface-active properties, foamability, foaming stability and emulsion stability of stearyl gluconate were studied and compared with the properties of the well-known surfactant sucrose stearate, and it was clear that, the activity of stearyl gluconate as a surfactant was higher than that of sucrose stearate. Moreover, establishment of safety of this compound was performed using albino rats by acute oral toxicity and kidney and liver functions of these mice. On the other hand, the prepared surfactant was used in the production of low fat—free cholesterol mayonnaise as egg replacer. Texture properties and the sensory evaluation of the prepared mayonnaise showed that the properties were improved by using the new prepared surfactant. Thus, the prepared gluconyl stearate can be used as a safe food additive.

A research article on polymeric surfactant and its applications

Polymeric surfactants represent a distinctive class of amphiphilic compounds that combine the versatility of polymers with the surfactant properties crucial for interfacial phenomena. This research article will focus on the basis of polymeric surfactants and their applications in various domains. Characterisation techniques, including spectroscopy, microscopy, and rheology, are employed to elucidate polymeric surfactants' structural features and self-assembly behaviour. Understanding these characteristics is pivotal for optimising their performance in diverse applications. The applications of polymeric surfactants span a broad spectrum, focusing on their use in emulsion polymerisation, drug delivery, enhanced oil recovery, and environmental remediation. Their unique structure imparts advantages such as improved stability, controlled release, and enhanced efficiency in various processes.

Macromolecular Size and Architecture of Humic Substances Used in the Dyes’ Adsorptive Removal from Water and Soil

Humic substances are naturally occurring materials composed of complex biogenic mixtures of substituted aromatic and aliphatic hydrocarbon core materials derived from the degradation and decomposition of dead plant and animal matter. They are ubiquitous in both terrestrial and aquatic systems constituting biotic pools and are characterized by unique properties; they are amphiphilic redox compounds with exceptional chelating features. Humic substances play a crucial role in both agriculture and the environment as carbon sequestrators, soil improvers, plant health promoters, as well as stabilizers of soil aggregates and regulators of organic/inorganic nutrients bioavailability. This review article attempts to summarize current knowledge about the molecular nature and characterization techniques employed for the study of humic substances worldwide as the chemistry of their components differs markedly and depends on natural processes, several abiotic and biotic factors, the origin of the organic matter, and their complexation with inorganic, e.g., metal-ion, compounds. This work is equally concerned with the association of humic substances with dyes, a notorious pollutant, responsible for various environmental issues generally arising from the discharge of untreated effluents into soils and water bodies. Azo dyes, in particular, negatively affect soil microbial communities, as well as plant germination and growth. The aim is to feature the potential contribution of humic substances as novel materials for environment-friendly and sustainable processes.

The Synergistic Activity of Rhamnolipid Combined with Linezolid against Linezolid-Resistant Enterococcus faecium.

Enterococci resistance is increasing sharply, which poses a serious threat to public health. Rhamnolipids are a kind of amphiphilic compound used for its bioactivities, while the combination of nontraditional drugs to restore linezolid activity is an attractive strategy to treat infections caused by these pathogens. This study aimed to investigate the activity of linezolid in combination with the rhamnolipids against Enterococcus faecium. Here, we determined that the rhamnolipids could enhance the efficacy of linezolid against enterococci infections by a checkerboard MIC assay, a time-kill assay, a combined disk test, an anti-biofilm assay, molecular simulation dynamics, and mouse infection models. We identified that the combination of rhamnolipids and linezolid restored the linezolid sensitivity. Anti-biofilm experiments show that our new scheme can effectively inhibit biofilm generation. The mouse infection model demonstrated that the combination therapy significantly reduced the bacterial load in the feces, colons, and kidneys following subcutaneous administration. This study showed that rhamnolipids could play a synergistic role with linezolid against Enterococcus. Our combined agents could be appealing candidates for developing new combinatorial agents to restore antibiotic efficacy in the treatment of linezolid-resistant Enterococcus infections.

Primary amine citrate-based supramolecular designer solvent: Preconcentration of ochratoxin A for determination in foods by liquid chromatography

BackgroundSupramolecular solvents are nanostructured liquids that are separated from colloidal solutions of amphiphilic compounds as a result of self-assembly of amphiphiles and coacervation under changing conditions. They are considered to be designer solvents as their properties can be tailored to a specific analytical task by controlling the conditions of their formation (amphiphile, coacervation inducer, medium, concentration of components). The discovery of new extraction systems based on supramolecular solvents and their application to relevant analytical tasks are of great importance for the advancement of environmentally-friendly sample preparation. ResultsA novel green liquid-phase microextraction approach involving in situ formation of 1-octylamine citrate followed by preconcentration of ochratoxin A from aqueous extract of food sample in supramolecular solvent droplets was developed. The extraction system was carefully characterized. The density of the solvent allowed it to be to retrieved from the extraction system by its solidification. The alkaline nature of the obtained extract allowed the use of acetic acid for its dissolution instead of more toxic organic solvents followed by high-performance liquid chromatography with fluorometric detection. An excellent extraction recovery of 99 % and a satisfactory enrichment factor of 8.3 were achieved. The limit of detection was 0.5 μg kg−1, while the calibration plot was linear over the range of 1.5–50 μg kg−1. Cereal and roasted coffee bean samples were successfully analyzed with a relative bias less than 20 %. SignificanceIn the present work, a phenomenon of supramolecular solvent formation based on primary amine citrate was presented for the first time. Tetrabutylammonium bromide was investigated as a coacervation agent in an extraction system, and possible interactions responsible for its ability to induce phase separation in a micellar solution of primary amine citrate were described. The critical micelle concentration of 1-octylamine citrate in aqueous solution of tetrabutylammonium bromide was firstly determined.

An Insight into Anion Extraction by Amphiphiles: Hydrophobic Microenvironments as a Requirement for the Extractant Selectivity.

Coupling of electron-deficient urea units with aliphatic chains gives rise to amphiphilic compounds that bind to phosphate and benzoate anions in the hydrogen bonding competitive solvent (DMSO) with KAss = 6 580 M-1 and KAss = 4 100 M-1, respectively. The anchoring of these receptor moieties to the dendritic support does not result in a loss of anion binding and enables new applications. Due to the formation of a microenvironment in the dendrimer, the high selectivity of the prepared compound toward benzoate is maintained even in the presence of aqueous media during extraction experiments. In the presence of binding sites at 5 mM concentration, the amount of benzoate corresponding to the full binding site occupancy is transferred into the chloroform phase from its 10 mM aqueous solution. A thorough investigation of the extraction behavior of the dendrimer reported here, supported by a series of molecular dynamics simulations, provides new insight into the fundamental principles of extraction of inorganic anions by amphiphiles.

Sugar-Based Monoester Surfactants: Synthetic Methodologies, Properties, and Biological Activities.

Glycolipids are biocompatible and biodegradable amphiphilic compounds characterized by a great scientific interest for their potential applications in various technological areas, including pharmaceuticals, cosmetics, agriculture, and food production. This report summarizes the available synthetic methodologies, physicochemical properties, and biological activity of sugar fatty acid ester surfactants, with a particular focus on 6-O-glucose, 6-O-mannose, 6-O-sucrose, and 6'-O-lactose ones. In detail, the synthetic approaches to this class of compounds, such as enzymatic lipase-catalyzed and traditional chemical (e.g., acyl chloride, Steglich, Mitsunobu) esterifications, are reported. Moreover, aspects related to the surface activity of these amphiphiles, such as their ability to decrease surface tension, critical micelle concentration, and emulsifying and foaming ability, are described. Biological applications with a focus on the permeability-enhancing effect across the skin or mucosa, antimicrobial and antifungal activities, as well as antibiofilm properties, are also presented. The information reported here on sugar-based ester surfactants is helpful to broaden the interest and the possible innovative applications of this class of amphiphiles in different technological fields in the future.

Liposome Based Near-Infrared Sensors for the Selective Detection of Hydrogen Sulfide.

Cyanine dye-based new amphiphilic compound NIR-Amp has been synthesised. NIR-Amp was embedded with phospholipids DOPC and DPPC to form liposomes based nanoscale chemical sensors NIR-Lip1 and NIR-Lip2. Here, two different phospholipids were used to demonstrate the influence of lipid structure, composition and fluidity on sensing of nanosensors. Both the probes show NIR absorption maximum at 790 nm and emission maximum at 815 nm. H2 S-triggered thiolation resulted a remarkable change in color from green to pale yellow. A decrease in UV-Vis absorption and emission in the NIR region was observed only with H2 S. NIR-Lip1 and NIR-Lip2 are highly selective for H2 S with a LOD of 0.57 μM and 1.24 μM, respectively. It was observed that in a solid-like gel state, NIR-Lip1 is slightly more sensitive towards H2 S than fluid-like NIR-Lip2. The H2 S sensing mechanism was confirmed by ESI-mass and infrared (IR) spectroscopic analysis. Based on the high sensitivity and selectivity, NIR-Lip1 was employed to detect H2 S in vegetable samples. Further, the probes are found to be non-toxic and established for H2 S fluorescence imaging in live cells.

Kinetic study of azobenzene photoisomerization under ambient lighting

Laboratory illumination is sufficiently intense to produce a photostationary state (PSS) of amphiphilic azobenzene compounds in water. We observed [cis]PSS/[trans]PSS ratios equal to 0.33–1.2 in D2O and 0.37 – 3.8 in dimethyl sulfoxide-d6. ortho-Fluoroazobenzene amphiphiles produced 2–3 times more cis-isomer at equilibrium compared to non-fluorinated compounds which is explained by the isomeric variation in optical absorption profiles. Isomerization kinetics were measured using UV–Vis spectroscopy and the ratio of trans-to-cis over cis-to-trans rates does not quantitatively correlate with the observed PSS. The kinetics define the timescale of ambient photoisomerization where the half-life for PSS formation is 40 min for the fluorinated compounds and 80 min for non-fluorinated compounds.

Combinatorial Screening of Cationic Lipidoids Reveals How Molecular Conformation Affects Membrane-Targeting Antimicrobial Activity.

The search for next-generation antibacterial compounds that overcome the development of resistance can be facilitated by identifying how to target the cell membrane of bacteria. Understanding the key molecular features that enable interactions with lipids and lead to membrane disruption is therefore crucial. Here, we employ a library of lipid-like compounds (lipidoids) comprising modular structures with tunable hydrophobic and hydrophilic architecture to shed light on how the chemical functionality and molecular shape of synthetic amphiphilic compounds determine their activity against bacterial membranes. Synthesized from combinations of 8 different polyamines as headgroups and 13 acrylates as tails, 104 different lipidoids are tested for activity against a model Gram-positive bacterial strain (Bacillus subtilis). Results from the combinatorial screening assay show that lipidoids with the most potent antimicrobial properties (down to 2 μM) have intermediate tail hydrophobicity (i.e., c log P values between 3 and 4) and lower headgroup charge density (i.e., longer spacers between charged amines). However, the most important factor appeared to be the ability of a lipidoid to self-assemble into an inverse hexagonal liquid crystalline phase, as observed by small-angle X-ray scattering (SAXS) analysis. The lipidoids active at lowest concentrations, which induced the most significant membrane damage during propidium iodide (PI) permeabilization assays, were those that aggregated into highly curved inverse hexagonal liquid crystal phases. These observations suggest that the introduction of strong curvature stress into the membrane is one way to maximize membrane disruption and lipidoid antimicrobial activity. Lipidoids that demonstrated the ability to furnish this phase consisted of either (i) branched or linear headgroups with shorter linear tails or (ii) cyclic headgroups with 4 bulky nonlinear tails. On the contrary, lipidoids previously observed to adopt disc-like conformations that pack into bicontinuous cubic phases were significantly less effective against B. subtilis. The discovery of these structure-property relationships demonstrates that it is not simply a balance of hydrophobic and hydrophilic moieties that govern membrane-active antibacterial activity, but also their intrinsic curvature and collective behavior.

Development and characterisation of novel terpenoid-based hydrophobic deep eutectic solvents for sustainable extraction of bioactive antioxidants from Rosmarinus officinalis L

With the increasing demand for sustainability and green practices in industrial operations, deep eutectic solvents (DES) emerge as promising alternatives to organic solvents for the extraction of bioactive compounds. However, the inclusion of DES in industrial processes is severely limited by their hig density and viscosity as it hinders mass transfer. Additionally, low selectivity towards medium and amphiphilic bioactive compounds leads to unfavourable efficiency. This study aimed to develop, characterise, and evaluate low-density novel terpenoid-based DESs, containing fatty acid and alcohol, as effective hydrophobic extractants. The formation and stability of the newly developed DES were confirmed by validating the hydrogen bonds. The density as a function of temperature was investigated, revealing that all the developed hydrophobic DES had densities lower than water. The polarity of the solvents was assessed as it plays a vital role in the “solvation” of the bioactive compounds through Nile red assay. Although the hydrophobic DES had lower polarity than organic solvents, the screened DES showed a higher extraction yield of amphiphilic compounds of carnosic acid and carnosol, demonstrating their effectiveness. This is due to the high van der Waals interactions between the amphiphilic compounds and the alkyl chain of fatty acids and alcohols in the DES. Overall, the low density and high selectivity of the new hydrophobic DES developed in this study were found to be viable extractants for the sustainable extraction of bioactive compounds, particularly amphiphilic compounds.

Poly(vinyl pyrrolidone) derivatives as PEG alternatives for stealth, non-toxic and less immunogenic siRNA-containing lipoplex delivery

The recent approval of Onpattro® and COVID-19 vaccines has highlighted the value of lipid nanoparticles (LNPs) for the delivery of genetic material. If it is known that PEGylation is crucial to confer stealth properties to LNPs, it is also known that PEGylation is responsible for the decrease of the cellular uptake and endosomal escape and for the production of anti-PEG antibodies inducing accelerated blood clearance (ABC) and hypersensitivity reactions. Today, the development of PEG alternatives is crucial. Poly(N-vinyl pyrrolidone) (PNVP) has shown promising results for liposome decoration but has never been tested for the delivery of nucleic acids. Our aim is to develop a series of amphiphilic PNVP compounds to replace lipids-PEG for the post-insertion of lipoplexes dedicated to siRNA delivery. PNVP compounds with different degrees of polymerization and hydrophobic segments, such as octadecyl, dioctadecyl and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), were generated. Based on the physicochemical properties and the efficiency to reduce protein corona formation, we showed that the DSPE segment is essential for the integration into the lipoplexes. Lipoplexes post-grafted with 15% DSPE-PNVP30 resulted in gene silencing efficiency close to that of lipoplexes grafted with 15% DSPE-PEG. Finally, an in vivo study in mice confirmed the stealth properties of DSPE-PNVP30 lipoplexes as well as a lower immune response ABC effect compared to DSPE-PEG lipoplexes. Furthermore, we showed a lower immune response after the second injection with DSPE-PNVP30 lipoplexes compared to DSPE-PEG lipoplexes. All these observations suggest that DSPE-PNVP30 appears to be a promising alternative to PEG, with no toxicity, good stealth properties and lower immunological response.

Lipid based drug delivery systems for oral, transdermal and parenteral delivery: Recent strategies for targeted delivery consistent with different clinical application

Lipid-based drug delivery systems (LBDDS) are valuable and biocompatible nano-carriers for the vehiculation and potential delivery of various hydrophilic, hydrophobic, or amphiphilic compounds. LBDDS have the advantage of targeted drug delivery, as free drugs may have poor targeting, higher systemic toxicity, and possibilities of drug resistance. There is various type of lipid carrier systems for drug delivery based on the properties of drugs and clinical applications; nanoemulsion, microemulsion, lipid vesicles, and lipid nanoparticles. The era of targeted drug delivery is advancing from the superficial convention vesicles to the second generation of LBDDS by modulating the surface chemistry through modifying/surface functionalizing the lipid layer composition. The surfaces of lipid vehicles have been modified with small molecules, antibodies, peptides, and enzymes for targeted drug delivery and reduced toxicity. In this regard, polyethylene glycosylation (PEGylation) on the lipid surface was the first novel approach that improves blood circulation time and curtails opsonin resistance and clearance. However, multi-drug and multi-receptor strategies in the targeted-liposomal approach may be an innovative pathway to overcoming drug resistance while treating certain tumors. Several second-generation conventional drug delivery systems among liposomal formulations are at various stages of clinical trials. This review recapitulates the types of lipid formulations, characterization, and their applications in clinical aspects. Additionally, discuss the strategies for enhancement of disease targeting by surface functionalization with various entities to improve the drug delivery system.

A lysosomes and mitochondria dual-targeting AIE-active NIR photosensitizer: Constructing amphiphilic structure for enhanced antitumor activity and two-photon imaging.

Development of lysosomes and mitochondria dual-targeting photosensitizer with the virtues of near-infrared (NIR) emission, highly efficient reactive oxygen generation, good phototoxicity and biocompatibility is highly desirable in the field of imaging-guided photodynamic therapy (PDT) for cancer. Herein, a new positively charged amphiphilic organic compound (2-(2-(5-(7-(4-(diphenylamino)phenyl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)vinyl)-3-methylbenzo[d]thiazol-3-ium iodide) (ADB) based on a D-A-π-A structure is designed and comprehensively investigated. ADB demonstrates special lysosomes and mitochondria dual-organelles targeting, bright NIR aggregation-induced emission (AIE) at 736​nm, high singlet oxygen (1O2) quantum yield (0.442), as well as good biocompatibility and photostability. In addition, ADB can act as a two-photon imaging agent for the elaborate observation of living cells and blood vessel networks of tissues. Upon light irradiation, obvious decrease of mitochondrial membrane potential (MMP), abnormal mitochondria morphology, as well as phagocytotic vesicles and lysosomal disruption in cells are observed, which further induce cell apoptosis and resulting in enhanced antitumor activity for cancer treatment. In vivo experiments reveal that ADB can inhibit tumor growth efficiently upon light exposure. These findings demonstrate that this dual-organelles targeted ADB has great potential for clinical imaging-guided photodynamic therapy, and this work provides a new avenue for the development of multi-organelles targeted photosensitizers for highly efficient cancer treatment.

Multiheaded Cationic Surfactants with Dedicated Functionalities: Design, Synthetic Strategies, Self-Assembly and Performance.

Contemporary research concerning surfactant science and technology comprises a variety of requirements relating to the design of surfactant structures with widely varying architectures to achieve physicochemical properties and dedicated functionality. Such approaches are necessary to make them applicable to modern technologies, such as nanostructure engineering, surface structurization or fine chemicals, e.g., magnetic surfactants, biocidal agents, capping and stabilizing reagents or reactive agents at interfaces. Even slight modifications of a surfactant's molecular structure with respect to the conventional single-head-single-tail design allow for various custom-designed products. Among them, multicharge structures are the most intriguing. Their preparation requires specific synthetic routes that enable both main amphiphilic compound synthesis using appropriate step-by-step reaction strategies or coupling approaches as well as further derivatization toward specific features such as magnetic properties. Some of the most challenging aspects of multicharge cationic surfactants relate to their use at different interfaces for stable nanostructures formation, applying capping effects or complexation with polyelectrolytes. Multiheaded cationic surfactants exhibit strong antimicrobial and antiviral activity, allowing them to be implemented in various biomedical fields, especially biofilm prevention and eradication. Therefore, recent advances in synthetic strategies for multiheaded cationic surfactants, their self-aggregation and performance are scrutinized in this up-to-date review, emphasizing their applications in different fields such as building blocks in nanostructure engineering and their use as fine chemicals.

Oil displacement properties of surfactin: a comparative study

Abstract Biosurfactants are amphiphilic compounds synthesized from plants and microorganisms and are known for their high biodegradability, low toxicity, and eco-friendliness. They have diverse applications in industrial and environmental fields, including oil recovery, bioremediation, and cleaning up hydrocarbons from polluted areas. Surfactin is a potent lipopeptide biosurfactant produced by Bacillus subtilis bacteria. In this study, we produced surfactin by B. subtilis using cassava wastewater as the fermentation medium. This production was monitored by high performance liquid chromatography (HPLC). Approximately 600 mg L−1 of surfactant was produced. The oil displacement test was then performed to evaluate the effectiveness of crude and purified surfactin compared to a synthetic surfactant and a biosurfactant. Three types of surfactants were tested: the synthetic surfactant sodium lauryl sulfate (SDS), the commercial biosurfactant rhamnolipid (Rh), and surfactin in its crude form and purified one – after acid precipitation. The analysis results indicated that surfactin, in both its crude and purified forms, was more effective at dispersing oil than the other surfactants tested, even at lower concentrations. This suggests that biosurfactants have great potential as a more sustainable and effective alternative to petroleum-derived synthetic surfactants. Surfactin can be applied without the need for downstream processes.

From Wastewater Treatment Plants to the Oceans: A Review on Synthetic Chemical Surfactants (SCSs) and Perspectives on Marine-Safe Biosurfactants

Synthetic chemical surfactants (SCSs) are a versatile group of amphiphilic chemical compounds synthesized from fossil fuel precursors which have found use in various industrial applications. Their global usage is estimated to be over 15 million tons annually, which has resulted in unabated environmental damage and potential toxicological effects to humans and other organisms. Current societal challenges to ensure environmental protection and reduce reliance on finite resources have led to an increased demand for sustainable and environmentally friendly alternatives, such as biosurfactants, to replace these toxic pollutants. Biosurfactants are biodegradable, non-toxic, and generally environmentally compatible amphiphilic compounds. Although there is enormous potential for microbial biosurfactants to replace SCSs, the key challenge limiting their commercialization relates to their low yields and substantial cost for production compared to that for the SCSs. In this review, we discuss the release of SCSs, with wastewater treatment plants (WWTPs) as the major point source of their release into the ocean, and we then delve into the consequences of these pollutants on marine organisms and humans. We then explore microbial biosurfactants as a replacement for SCSs, with a focus on rhamnolipids, and end with some perspectives on current and future work for commercializing microbial biosurfactants.