Ultralong Chain Research Articles

A practical and scalable synthesis of ultra-long chain fatty acids avoiding column purification

Fatty acids of vegetable and animal origin are an important renewable feedstock for the chemical industry. Their application has increased multifold during the last two decades. While there are many ways to synthesize fatty acids, the chemical synthesis route offers more advantages in terms of versatility and targeted synthesis. Though remarkable achievements have been made in the field of fatty acid synthesis, it is still in the preliminary stage of optimization. In this paper, we wish to report a more practical & scalable approach for the synthesis of fatty acids with carbon atoms ranging from 20 to 45.

Deep Characterisation of the sn-Isomer Lipidome Using High-Throughput Data-Independent Acquisition and Ozone-Induced Dissociation.

In recent years there has been a significant interest in the development of innovative lipidomics techniques capable of resolving lipid isomers. To date, methods applied to resolving sn-isomers have resolved only a limited number of species. We report a workflow based on ozone-induced dissociation for untargeted characterisation of hundreds of sn-resolved glycerophospholipid isomers from biological extracts in under 20 min, coupled with an automated data analysis pipeline. It provides an order of magnitude increase in the number of sn-isomer pairs identified as compared to previous reports and reveals that sn-isomer populations are tightly regulated and significantly different between cell lines. The sensitivity of this method and potential for de novo molecular discovery is further demonstrated by the identification of unexpected lipids containing ultra-long monounsaturated acyl chains at the sn-1 position.

Effect of different hydrophilic heads on strong interfacial activities of non-edible oil-derived ultra-long chain (UC24:1) Bio-based zwitterionic surfactants for tertiary oil recovery

One of the cross-cutting issues in green petrochemistry is discovering an efficient and sustainable technique for chemically enhanced oil recovery (EOR). Developing eco-friendly and renewable surfactants with strong interfacial activity as greener chemical materials for EOR has been a challenging topic. In this work, a new series of eco-friendly and high-performance ultra-long chain fatty acid-derived bio-based zwitterionic surfactants with different hydrophilic heads (the 2-(dimethyl(3-(tetracos-15-enamido)propyl)ammonio)acetate (TAPAA), 3-(dimethyl(3-(tetracos-15-enamido)propyl)ammonio)− 2-hydroxypropane-1-sulfonate (TAPAHPS), and 4-(dimethyl(3-(tetracos-15-enamido)propyl)ammonio)butane-1-sulfonate (TAPABS)), was developed from the non-edible fatty acid (Z)− 15-tetracosenoic acid (UC24:1) by a simple and effective method. ESI-MS, 1HNMR, and 13C NMR were used for their structural analyses. In alkali- and polymer-free systems, 0.5 g/L concentration of each surfactant could reduce the interfacial tension between Daqing crude oil and simulated formation groundwater to ultra-low value (1.971 × 10−3, 4.44 × 10−3 and 6.538 × 10−4 mN/m for TAPAA, TAPAHPS and TAPABS, respectively). These surfactants also demonstrated strong electrolyte tolerance, up to 2000 mg/L and 200 g/L of Ca2+ and NaCl, respectively. They were also structurally thermal stable up to 75 °C and biodegradable. This work consolidates our hypothesis that ultra-long chain (UC24:1) bio-based zwitterionic surfactants are of greater use than short-chain surfactants or traditional alkali-surfactant-polymer (ASP) systems for EOR applications, as they show strong interfacial activity at lower dosages in alkali- and polymer-free systems.

A green alternative to replace anionic viscoelastic surfactant based fracturing fluid with enhanced properties

Ionic liquid surfactant (ILS) presents a promising alternative for balancing the conflicting relationship of hydrophobicity and water solubility in anionic surfactants. Despite this potential, the utilization of ultra-long chain anionic ILS in viscoelastic surfactant (VES) fracturing fluids has been infrequently reported. In our previous research, we successfully prepared a viscoelastic wormlike micelles (WLMs) by employing an ultra-long chain ILS known as Adamantyl trimethyl ammonium erucate (AdEr) with potassium chloride (KCl). This novel system opens up promising avenues for its application in fracturing fluids. This study aims to comprehensively investigate the impact of temperature on the behavior of AdEr/KCl wormlike micelles, thereby evaluating the fracturing fluid performance. In rheological experiments, we observed that the zero-shear viscosity (η0) of AdEr/KCl WLMs remains at ∼103mPa·s at 90 °C, demonstrating excellent thermal resistance. Molecular dynamic (MD) simulations demonstrated that, as the temperature increased, it initially resulted in the disintegration of the aggregate structure, followed by a remarkable reformation of the same structure. This observed behavior can be attributed to the gradual decrease in polarity of the adamantyl groups as the temperature increases. Finally, the AdEr/KCl-based fracturing fluids, AE-1 and AE-2, not only exhibit outstanding temperature resistance (90 °C and 130 °C, respectively) but also demonstrate exceptional proppant-carrying and oil-induced gel-breaking capabilities. This study promotes the utilization of anionic ILSs in the formulation of environmentally-friendly fracturing fluids, emphasizing the crucial role of understanding temperature-induced changes through MD simulations.

Environmentally friendly wormlike micelles: Rheological behavior and its application in preparing green fracturing fluid

Ionic liquid surfactant (ILS) may be a good alternative to equilibrate the antagonistic relationship between hydrophobicity and water solubility for anionic surfactant. However, the application of ultra-long chain anionic ILS in the viscoelastic surfactant (VES) fracturing fluid was rarely reported up to now. Herein, an ultralong-chain anionic surfactant (abbreviated ChEr) was synthesized from natural erucic acid. As expected, ChEr retained the desirable characteristic of ILSs (melting temperature <100 ℃) and excellent water-solubility (Krafft temperature < 4 ℃). More importantly, ChEr can form elongated wormlike micelles (WLMs) in the presence of inorganic salt potassium chloride (KCl), giving solutions high viscoelasticity. The WLMs solutions were investigated using steady-state and dynamic rheology. Due to the strong van der Waals interaction induced by ChEr's ultra-long hydrophobic tail, zero-shear viscosity (η0) of solutions showed an extraordinarily significant relationship on concentration with an exponent of 8.2, which was more than double the theoretical expected value. The dynamic rheology results demonstrated that as the ChEr concentration increased, the 1:1 ChEr:KCl solution transformed into a gel-like liquid owing to the dense entanglement of WLMs. The salt concentration also had a strong influence on the wormlike micelles. At a KCl to ChEr molar ratio of 2:1, the fluid exhibited the maximum viscoelasticity. Finally, the fracturing fluid system based on ChEr/KCl displayed not only resistance to high temperature (<120 °C) and cyclic shear, but also excellent proppant-carrying and oil-induced gel-breaking capabilities. The present work reveals the remarkable properties of ultra-long chain ILS in forming WLMs and promotes the application of anionic ILS surfactant in the preparation of clean fracturing fluid.

Comparative analysis of intercellular lipid organization and composition between psoriatic and healthy stratum corneum

The lipid composition and organization of the stratum corneum (SC) in patients with psoriasis and healthy subjects were compared using X-ray diffraction, Fourier-transform infrared spectroscopy (FT-IR), and ultraperformance liquid chromatography, combined with time-of-flight mass spectrometry (UPLC-TOFMS). In healthy SC (HSC), SC lipids formed two lamellar phases (long and short periodicity phases). Hexagonal and orthorhombic hydrocarbon-chain packing were observed in the lateral lipid organization at 30 °C via X-ray diffraction. In HSC, the lamellar phases and the hydrocarbon-chain packing organizations changed with elevated temperatures and finally disappeared. In these behaviors, the high-temperature hexagonal hydrocarbon-chain packing organization, which appeared above the orthorhombic hydrocarbon-chain packing organization, transformed to the liquid phase at about 90 °C in HSC. In psoriatic SC (PSC), hexagonal hydrocarbon-chain packing organization disappeared at about 65 °C with elevated temperatures. No high-temperature hexagonal hydrocarbon-chain packing organization were observed in PSC during heating process. Disorder of the hydrocarbon-chain packing of SC lipids was observed in PSC via FT-IR. In UPLC-TOFMS, free fatty acid (FFA) and ceramide (CER) compositions differed between patients with PSC and HSC. Specifically, the levels of ultra-long chain fatty acids containing CER and phytosphingosine-containing CER were decreased, while those of sphingosine and dihydrosphingosine-containing CER and unsaturated FFA were increased in PSC. Furthermore, FFA and CER carbon chain lengths decreased in patients with PSC. These results suggest that the alteration of SC lipid composition and the reduction of carbon chain lengths in PSC lowered the structural transformation temperature, thereby reducing barrier function.

Microphase transitions of Langmuir-Blodgett lipid-assembled monolayers with new types of ceramides, ultra-long-chain ceramide and 1-O-acylceramide

HypothesisIntercellular lipid lamellae, consisting of ceramide, cholesterol, and free fatty acids, are the primary pathways for substances in the stratum corneum (SC). The microphase transition of lipid-assembled monolayers (LAMs), mimicking an initial layer of the SC, would be affected by new types of ceramides: ceramide with ultra-long chain (CULC) and 1-O-acylceramide (CENP) with three chains in different direction. ExperimentsThe LAMs were fabricated with varying the mixing ratio of CULC (or CENP) against base ceramide via Langmuir-Blodgett assembly. Surface pressure-area isotherms and elastic modulus-surface pressure plots were obtained to characterize π-dependent microphase transitions. The surface morphology of LAMs was observed by atomic force microscopy. FindingsThe CULCs favored lateral lipid packing, and the CENPs hindered the lateral lipid packing by lying alignment, which was due to their different molecular structures and conformations. The sporadic clusters and empty spaces in the LAMs with CULC were presumably due to the short-range interactions and self-entanglements of ultra-long alkyl chains following the freely jointed chain model, respectively, which was not noticeably observed in the neat LAM films and the LAM films with CENP. The addition of surfactants disrupted the lateral packing of lipids, thus weakening the LAM elasticity. These findings allowed us to understand the role of CULC and CENP in the lipid assemblies and microphase transition behaviors in an initial layer of SC.

A Comparative Study on CO2-Switchable Foams Stabilized by C22- or C18-Tailed Tertiary Amines

The CO2 aqueous foams stabilized by bioresource-derived ultra-long chain surfactants have demonstrated considerable promising application potential owing to their remarkable longevity. Nevertheless, existing research is still inadequate to establish the relationships among surfactant architecture, environmental factors, and foam properties. Herein, two cases of ultra-long chain tertiary amines with different tail lengths, N-erucamidopropyl-N,N-dimethylamine (UC22AMPM) and N-oleicamidopropyl-N,N-dimethylamine (UC18AMPM), were employed to fabricate CO2 foams. The effect of temperature, pressure and salinity on the properties of two foam systems (i.e., foamability and foam stability) was compared using a high-temperature, high-pressure visualization foam meter. The continuous phase viscosity and liquid content for both samples were characterized using rheometry and FoamScan. The results showed that the increased concentrations or pressure enhanced the properties of both foam samples, but the increased scope for UC22AMPM was more pronounced. By contrast, the foam stability for both cases was impaired with increasing salinity or temperature, but the UC18AMPM sample is more sensitive to temperature and salinity, indicating the salt and temperature resistance of UC18AMPM-CO2 foams is weaker than those of the UC22AMPM counterpart. These differences are associated with the longer hydrophobic chain of UC22AMPM, which imparts a higher viscosity and lower surface tension to foams, resisting the adverse effects of temperature and salinity.

Nonpolar and Ultra-long-chain Ligand to Modify the Perovskite Interface toward High-Efficiency and Stable Wide Bandgap Perovskite Solar Cells

Though tandem solar cells (TSCs) based on wide-bandgap perovskite solar cells (WB-PSCs) as the top sub-cells continuously gain efficiency breakthroughs, the low power conversion efficiency (PCE) of WB-PSCs caused by the defects and interface energy-level mismatch is still a vital issue limiting their performance. Moreover, the stability of the perovskite layer against the moisture and subsequent fabrication process is essential to highly stable TSCs. Herein, a nonpolar material with an ultra-long chain, didodecyldimethylammonium bromide (DDAB), was introduced to WB-PSCs as an interface material for reducing the surface defects and increasing the surface hydrophobicity of the perovskite layer. The DDAB-modified perovskite surface is much more hydrophobic, with a water contact angle of 104.9°. Systemically experimental studies reveal that apart from the passivation on the point defects, DDAB can suppress the formation of PbI2 aggregates, smoothing the perovskite surface and shifting the energy level upward. As a result, the 1.74 eV WB-PSCs with inverted structures exhibit a champion PCE of 18.74% by DDAB modification, compared to the standard device with a PCE of 16.50%. The device stability under a relative humidity of >85% is apparently enhanced by 5-fold. This work provides a concept of screening interface materials for highly efficient and stable WB-PSCs.

Conformations of Three Types of Ultra-Long-Chain Fatty Acids in Multicomponent Lipid Bilayers.

Ultra-long-chain fatty acids (ULCFAs) are biosynthesized in certain types of tissues, but their biological roles remain unknown. Here, we report how the conformation of ULCFAs depends on the length and unsaturated-bond ratio of the ultra-long chains and the composition of the host bilayer membrane using molecular dynamics simulations. The ultra-long chain of ULCFAs flips between the two leaflets and fluctuates among three conformations: elongated, L-shaped, and turned. Furthermore, we found that the saturated ultra-long chain exhibited an elongated conformation more frequently than the unsaturated chain. In addition, the truncation of the ultra-long chain at C26 had little effect on the remaining ULCFAs. ULCFAs respond to lipid-density differences in the two leaflets, and the ratio of the elongated and turned conformations changed to reduce this difference. However, in cholesterol-containing membranes, ULCFAs exhibit no density difference after the flip-flop of cholesterol removes the difference.

Renewable non-edible oils derived long chain (C24.1) bio-based zwitterionic surfactant with ultralow interfacial tension between crude oil and formation brine

A new ultra-long chain monounsaturated 4-(N-nervonicamidopropyl-N,N-dimethylammonium) butane sulfonate (NDAS) zwitterionic surfactant with ultralow interfacial tensions was developed through the modification of nervonic acid derived from renewable non-edible seed oils by a simple and effective method. Its structure was characterized by ESI-HRMS, 1H NMR, and 13C NMR. NDAS surfactant exhibited a strong interfacial activity (∼10−4 mN/m) between the crude oil and the formation brine at a very low surfactant dosage (0.05 g/L) and at high salinity conditions, which is equivalent to 2% (w/w) of dosage of the most traditional surfactants used in the enhanced oil recovery field. Meanwhile, at a very low concentration (0.05 g/L), NDAS demonstrated strong NaCl compatibility up to 100 g/L, Ca2+ ions compatibility up to 200 mg/L, and temperature stability up to 90 °C. The surface tension, emulsification, and biodegradability parameters were also evaluated. This work consolidates our hypothesis that increasing the hydrophobic chain length of a surfactant certainly contributes to the high interfacial activity and good compatibility of salts and temperatures. Hence, it will facilitate the design of a sustainable alternative to petroleum-based chemicals to develop bio-based surfactants and extend the domain of bio-based surfactants to new applications such as in enhanced oil recovery (EOR).

Tape stripping and lipidomics reveal skin surface lipid abnormity in female melasma.

The skin barrier of melasma is involved in the pathogenesis of melasma. Previous studies have shown that there are differences in the expression of epidermal lipid genes in melasma, but little is known about the epidermis lipid composition of melasma. Compared with the non-lesional skin, the content of total lipids, phosphatidicacid, phosphatidylserine, and ceramide (Cer) increased significantly in the lesional skin. Multivariate data analysis indicated that 40 individual Cer lipid species were responsible for the discrimination. In terms of acyl chain length in Cer, the expressions of very long chain (VLC) (C20-C26) and ultra-long chain (ULC) (>C26) increased significantly in the lesional skin. However, Cer[AH] had negative correlations with the activation of melanocytes in the lesional skin. Some lipid species had lower expression in lesional skin with high activation of melanocytes, as well as the high darkness. The epidermal thickness of lesional skin was higher compared with the non-lesional skin. These results suggest that Cer increased significantly in the lesional skin of melasma, possibly as a compensatory mechanism to maintain skin barrier function. Between different groups of darkness and activation of melanocytes, the change of ceramides might have correlation with the pigmentation progress of melasma.

Cerebellar and hepatic alterations in ACBD5-deficient mice are associated with unexpected, distinct alterations in cellular lipid homeostasis

ACBD5 deficiency is a novel peroxisome disorder with a largely uncharacterized pathology. ACBD5 was recently identified in a tethering complex mediating membrane contacts between peroxisomes and the endoplasmic reticulum (ER). An ACBD5-deficient mouse was analyzed to correlate ACBD5 tethering functions with the disease phenotype. ACBD5-deficient mice exhibit elevated very long-chain fatty acid levels and a progressive cerebellar pathology. Liver did not exhibit pathologic changes but increased peroxisome abundance and drastically reduced peroxisome-ER contacts. Lipidomics of liver and cerebellum revealed tissue-specific alterations in distinct lipid classes and subspecies. In line with the neurological pathology, unusual ultra-long chain fatty acids (C > 32) were elevated in phosphocholines from cerebelli but not liver indicating an organ-specific imbalance in fatty acid degradation and elongation pathways. By contrast, ether lipid formation was perturbed in liver towards an accumulation of alkyldiacylglycerols. The alterations in several lipid classes suggest that ACBD5, in addition to its acyl-CoA binding function, might maintain peroxisome-ER contacts in order to contribute to the regulation of anabolic and catabolic cellular lipid pathways.

Mass spectrometry-directed structure elucidation and total synthesis of ultra-long chain (O-acyl)-ω-hydroxy fatty acids

The (O-acyl)-ω-hydroxy FAs (OAHFAs) comprise an unusual lipid subclass present in the skin, vernix caseosa, and meibomian gland secretions. Although they are structurally related to the general class of FA esters of hydroxy FAs (FAHFAs), the ultra-long chain (30-34 carbons) and the putative ω-substitution of the backbone hydroxy FA suggest that OAHFAs have unique biochemistry. Complete structural elucidation of OAHFAs has been challenging because of their low abundance within complex lipid matrices. Furthermore, because these compounds occur as a mixture of closely related isomers, insufficient spectroscopic data have been obtained to guide structure confirmation by total synthesis. Here, we describe the full molecular structure of ultra-long chain OAHFAs extracted from human meibum by exploiting the gas-phase purification of lipids through multi-stage MS and novel multidimensional ion activation methods. The analysis elucidated sites of unsaturation, the stereochemical configuration of carbon-carbon double bonds, and ester linkage regiochemistry. Such isomer-resolved MS guided the first total synthesis of an ultra-long chain OAHFA, which, in turn, confirmed the structure of the most abundant OAHFA found in human meibum, OAHFA 50:2. The availability of a synthetic OAHFA opens new territory for future investigations into the unique biophysical and biochemical properties of these lipids.

A Polymer-Alloy Binder for Structures-Properties Control of Battery Electrodes

The microstructures of electrodes play a critical role in controlling the charge transport in electrode composites. Achieving uniform and stable microstructures for battery electrodes with aid of binder materials is an important task in battery research. Here, we propose a polymer alloy binder rich in amorphous structures to address that need. This alloy binder is fabricated by complexing poly(vinylidene fluoride) and ultra-high molecular weight poly(ethylene oxide). Due to a good compatibility of the two polymers and the ultra-long chain of poly(ethylene oxide), the crystallization of each component is greatly suppressed and more amorphous phase is achieved. The amorphous structure of the alloy binder can dramatically improves the adhesion properties (by ca. 150%), structure uniformity and interface stability of the final electrode simultaneously, as compared with the electrodes with a traditional PVDF binder. As a result, the mechanical flexibility, electrolyte wettability, the electron/ion transport and electrochemical performance of the final electrodes are notably improved as compared with pure PVDF binder. This study brings about a cost-effective binder solution based on polymer alloys for controlling the microstructures/interfaces and properties of battery electrodes.

Effects of Calcium Ions on the Solubility and Rheological Behavior of a C22-Tailed Hydroxyl Sulfobetaine Surfactant in Aqueous Solution.

Effects of calcium ions (Ca2+) on the solubility, aggregate structure, and rheological behavior of a C22-tailed zwitterionic surfactant, erucyl dimethyl amidopropyl hydroxyl sulfobetaine (EHSB), have been investigated in aqueous solution. In comparison with sodium ions (Na+), Ca2+ ions exhibit a much higher efficiency in decreasing the Krafft temperature (TK) of EHSB. Specifically, contrary to Na+ ions which have no obvious effect on the rheological properties of the EHSB solution, Ca2+ ions increase the viscosity of the EHSB solution at lower EHSB concentration, and enhance its elasticity at higher EHSB concentration. Moreover, Ca2+ ions raise the temperature needed for the elastic-to-viscous transition of the EHSB solution at higher concentration. At lower EHSB concentration, the hydrophobic interaction between the ultralong hydrocarbon chains induces a tighter packing of the hydrophobic chains by forming a more stretched configuration, while at higher EHSB concentration, the electrostatic attraction between Ca2+ ions and the sulfonate groups of EHSB induces a tighter packing of the headgroups by forming Ca2+-mediated bridges among the EHSB headgroups. Besides, the above interactions may strengthen the hydrogen bonding of OH groups and/or of C═O amide groups, which in turn facilitates the compact packing of the surfactant molecules in aggregates and promotes the growth and entanglement of wormlike micelles. Thus, the EHSB solution shows Ca2+-dependent rheological behaviors. The solubility and rheological properties of the ultralong chain surfactant solution can be simultaneously improved with the addition of divalent Ca2+ ions.

Single-component solid lipid nanocarriers prepared with ultra-long chain amphiphilic lipids

HypothesisSynthetic sugar alcohol mono-behenates with high melting points, surface activity and resistance to enzymatic lipolysis, are expected to form stable single-component solid lipid nanocarriers (SC-SLNs). The preparation methods and the polar head group of the molecules should affect the size and drug encapsulation efficiency. ExperimentsSC-SLNs of sugar alcohol mono-behenates with varied polar heads were prepared using emulsification-diffusion method and melting-probe sonication method. Model lipophilic drug fenofibrate was formulated into nanocarriers. The drug release was assessed using the lipolysis model. The structure and drug distribution of the nanocarriers were studied using AFM and TEM. FindingsBoth the polar head group of the molecules and the preparation methods affect the particle size and size distribution. Nanocarriers prepared with sorbitol mono-behenates showed the smallest mean size (∼100nm with PdI of 0.26). In addition, they displayed high entrapment efficiency of fenofibrate (95%) and long term drug release. Nanocarriers prepared by emulsification-diffusion method entrapped fenofibrate into lipid bilayers. In contrast, Nanocarriers prepared by melting-probe sonication method had a micelle structure with fenofibrate incorporated into a lipid monolayer. This study provides an insight into the systematic development of novel amphiphilic lipids for solid lipid-based drug delivery system.

Ultralong Fatty Acyl Derivatives As Occlusive Structure Lipids for Cosmetic Applications: Synthesis and Characterization

Finding sustainable and commercially viable sources of occlusive materials, as an alternative to petroleum, is of great interest. Inspired by the fundamental role of long chain fatty acids in maintaining skin barrier, ultralong fatty acyl derivatives with diverse structures (varied acyl chain length and different polar head; i.e. glycerol, ethylene glycol, and diethylene glycol) were synthesized. These molecules can be feasibly obtained via enzymatic esterification of fatty acids or fractionated from commercial glycerides mixture via short path distillation. The molecular packing behaviors of compounds were characterized via differential scanning calorimetry, Fourier transform infrared, and Langmuir isotherm measurements. The structure–property relationship study reveals that a glycerol molecule monoacylated with an ultralong fatty acyl is the derivative which entails the most occlusive properties of the series of ultralong chain fatty acid derivatives. Fast Fourier transform filtering (FFTF) analysis of ...

Localization of methyl-branched ceramide [EOS] species within the long-periodicity phase in stratum corneum lipid model membranes: A neutron diffraction study

The outermost layer of the mammalian skin, the stratum corneum (SC), is a very thin structure and realizes simultaneously the main barrier properties. The penetration barrier for xenobiotica is mostly represented by a complex lipid matrix. There is great interest in the subject of getting information about the arrangement of the lipids, which are mainly ceramides (CER), free fatty acids (FFA) and cholesterol (CHOL). SC lipid model membranes containing synthetically derived lipids in a non-physiological ratio were investigated. To compare the study to a former experiment, a methyl-branched ceramide [EOS] species in presence of the ultra-long chain CER[AP], CHOL and behenic acid (23/10/33/33, wt%) was applied. The membrane structure was studied using the very versatile technique of neutron diffraction. We were able to identify a long-periodicity phase (LPP) with a size of 114Å or 118Å with CER[EOS]-br in a ratio of >60wt% of the ceramides. Furthermore, we figured out two additional coexisting short-periodicity phases (SPP) with repeat distances of 48Å and 45Å, respectively. Partial deuterations of CER[EOS]-br and CER[AP] enabled the localization of the molecules within the multiphase system. CER[EOS]-d3 was present in the LPP, but absent in both SPP. CER[AP]-d3 was determined in both short phases but not localized within the LPP. Besides, we revealed influences of humidity and time with respect to the long-periodicity phase.

Synthetic ultra-long chain fatty acyl based amphiphilic lipids as a dual function excipient for the production of surfactant-free solid lipid nanoparticles (SF-SLNs): a physico-chemical study

Behenoyl (22 : 0) based amphiphilic lipids are synthesized, some of which demonstrate excellent dual functionality as both solid excipients and emulsifiers in producing uniform solid lipid nanoparticles (SLNs).