Design and simulation of a caprylic acid enzymatically modified phosphatidylcholine micelle using a coarse-grained molecular dynamics simulations approach.

Computationally simulated micelle models provide useful structural information on the molecular and biological sciences. One strategy to study the self-aggregation process of surfactant molecules that make up a micelle is through molecular dynamics (MD) simulations. In this study, a theoretical approach with a coarse-grained MD simulation (CG-MD) was employed to evaluate the critical micellar concentration (CMC), the micellization process, building a tridimensional (3D) model system of a micelle using data from the experimentally enzymatically modified phospholipids (PL) by phospholipase A1 (PA1). This required enzymatic interesterification of soybean phosphatidylcholine (PC) with caprylic acid, along with purification and characterization by chromatographic techniques to measure the esterified fatty acids and the corresponding PL composition. The number of molecules used in the CG-MD simulation system was determined from the experimental CMC data which was 0.025%. The molecular composition of the system is: 1 C 18:2, 2 C 8:0/8:0, 3 C 8:0/18:3n-9, 4 C 8:0/18:0, 5 C8:0/18:2n-6, 6 C8:0/18:1n-9, and 7 C 8:0/16:0. According to our theoretical results, the micelle model is structurally stable with an average Rg of 3.64 ± 0.10 Å, and might have an elliptical form with a radius of 24.6 Å. Regarding CMC value there was a relationship between the experimental data of the modified PLs and the theoretical analysis by GC-MD, which suggest that the enzymatic modification of PLs does not affect their self-aggregation properties. Finally, the micellar system obtained in the current research can be used as a simple and useful model to design optimal biocompatible nanoemulsions as possible vehicles for bioactive small molecules.Communicated by Ramaswamy H. Sarma.

Encapsulation of Lactobacillus gasseri: Characterization, Probiotic Survival, In Vitro Evaluation and Viability in Apple Juice.

The development of functional foods containing probiotic bacteria has become increasingly relevant to improve and maintain health. However, this is often limited to dairy food matrices given the complexity involved in maintaining a stable system together with high microbial viability in matrices such as juices. The objective of this study was to develop and characterize sodium alginate capsules loaded with Lactobacillus gasseri ATCC® 19992 ™ (LG). Cell viability under in vitro gastrointestinal conditions and during storage in apple juice were evaluated. The capsules were prepared by ionic gelation and an emulsification process was performed as pretreatment using two homogenization methods: magnetic stirring (AM) and Ultraturrax® rotor-stator homogenizer (UT). Cell viability after encapsulation was similar in the two processes: 65%. At the end of the in vitro gastrointestinal evaluation, the non-encapsulated probiotic cells did not show any viability, while the AM system was able to retain 100% of its viability and the UT retained 79.14%. The morphology of the capsules consisted of a continuous and homogeneous surface. Cell viability of LG encapsulated in apple juice stored at 4 °C for 21 days was 77% for AM, 55.43% for UT, and 63.10% for free LG.

Betulinic Acid Nanogels: Rheological, Microstructural Characterization and Evaluation of their Anti-inflammatory Activity.

BACKGROUND: Betulinic Acid (BA) is a lipophilic compound with proven beneficial results in topical inflammation. Nanogels (NG) are carriers of bioactive compounds with properties that make them good candidates to treat skin diseases. OBJECTIVE: The objective of this study was to evaluate the anti-inflammatory activity of BA carried in NG. METHODS: NG were composed of a nanoemulsion and a crosslinking agent (Carbopol 940®) applied at three concentrations (0.5, 1, and 1.5 %) and three activation times (6, 12 and 24 h). In order to select the optimal formulation, the NG were characterized mechanically and micro-structurally followed by evaluation of the BA anti-inflammatory activity in an in vivo model of auricular edema. We determined the edema inhibition activity as percent weight. Additionally, the anti-inflammatory activity of NG was validated through histological analysis. RESULTS: The formulation with the best viscoelastic properties was the one prepared with 0.5% carbopol and 6 h of activation. Microstructural examination of this formulation showed mostly spherical structures with a mean diameter of 65 nm. From the evaluation of edema and the histological analyses, we established that the NG of BA produced 52% inhibition. In contrast, a conventional gel and free BA produced 28% and 19% inhibition, respectively. CONCLUSION: The NG of BA were found to be good vehicles to treat skin inflammation.

Curcumin Nanoemulsions Stabilized with Modified Phosphatidylcholine on Skin Carcinogenesis Protocol.

BACKGROUND: Cancer is one of the main causes of death by disease; several alternative treatments have been developed to counteract this condition. Curcumin (diferuloylmethane), extracted from the rhizome of Curcuma longa, has antioxidant, anti-inflammatory, and anti-cancer properties; however, it has low water solubility and poor intestinal absorption. Carrier systems, such as nanoemulsions, can increase the bioavailability of lipophilic bioactive compounds. OBJECTIVE: To evaluate the effect of curcumin nanoemulsions prepared with lecithin modified with medium-chain fatty acids as an emulsifier, on the expression of the Cdk4, Ccne2, Casp8 and Cldn4 genes involved in the carcinogenesis process in K14E6 transgenic mice. METHODS: The emulsifier was prepared by interesterification of medium-chain fatty acids, pure lecithin, and immobilized phospholipase-1 on Duolite A568. An Ultraturrax homogenizer and a Branson Ultrasonic processor were used for the preparation of nano-emulsions, and a Zetasizer evaluated the particle size. qRT-PCR analysis was performed to quantify the cancer-related genes expressed in the K14E6 mice. The development and evolution of skin carcinogenesis were assessed through histological analysis to compare cell morphology. RESULTS: Ca 59% of the MCFA were incorporated via esterification into the PC within 12 hours of the reaction. An emulsifier yield used to formulate the NE of 86% was achieved. Nanoemulsions with a particle size of 44 nm were obtained. The curcumin nano-emulsion group had a 91.81% decrease in the tumorigenesis index and a reduction in tumor area of 89.95% compared to the sick group. Histological analysis showed that the group administered with free curcumin developed a microinvasive squamous cell carcinoma, as opposed to the group with nanoemulsion which presented only a slight inflammation. In gene expression, only a significant difference in Cdk4 was observed in the nanoemulsion group.

Anti-inflammatory Activity of Curcumin in Gel Carriers on Mice with Atrial Edema.

Curcumin is a bioactive compound with proven antioxidant and anti-inflammatory activities, but has low water solubility and dermal absorption. The inflammatory process is considered as the biological response to damage induced by various stimuli. If this process fails to self-regulate, it becomes a potential risk of cancer. The objective of this work was to evaluate the anti-inflammatory activity of curcumin administered to mice with induced atrial edema using two topical vehicles: organogels and O/W-type nanogels at pH 7, Organogels and O/W-type nanogels at pH 7 were prepared, characterized and the anti-inflammatory activity was assessed. A histopathological analysis of mouse ears was performed and two gel formulations were selected. Thermograms of organogels indicated that increasing the gelling agent improved the stability of the system. Deformation sweeps confirmed a viscoelastic behavior characteristic of gels in both systems. During the anti-inflammatory activity evaluations, the nanogels demonstrated greater activity (61.8 %) than organogels; Diclofenac® (2-(2,6-dichloranilino) phenylacetic acid), used as a control medication achieved the highest inhibition (85.4%); however, the drug produced the death of 2 (40%) of the study subjects caused by secondary adverse events. Histopathological analysis confirmed the data.

A Specific Thin Layer Chromatography Method for the Identification and Separation of Medium Chain Acylglycerols.

Medium chain fatty acids (MCFAs), have gained nutritional relevance in the past few years. They are continuously used in obtaining structured lipids like medium chain acylglycerols (MCAs) for various purposes. However, because of their chemical structure pertaining carbon chain length and the presence of saturated and unsaturated fatty acids, sensitive detection techniques are required for their correct identification and separation. In the present work, a specific thin layer chromatography (TLC) method for MCAs was developed. The proposed method consisted of the use of a mixture of hexane: acetone (70:30 v/v) as mobile phase, since it proved effectiveness for the separation of compounds of interest (MCAs) as well as having the necessary sensitivity to separate different species of monoacylglycerols (MAGs), diacylglycerols (DAGs) and triacylglycerols (TAGs) of MCFAs. For observation of the compounds, a single oxidizing agent was not sufficient, thus a combination of visualization reagents was used (first a 10 % solution of sulphuric acid in methanol followed by a 10 % solution of phosphomolybdic acid in methanol) achieving the correct visualization of the desired compounds.

Structured Mono- and Diacylglycerols with a High Content of Medium Chain Fatty Acids.

In the present work, direct enzyme-catalysed esterification of medium chain fatty acids (MCFA) from three different sources (Medium chain triacylglycerols, MCT; saponified MCT and a mixture of free MCFA) was evaluated to obtain structured mono- and diacylglycerols. The esterifications were carried out mixing the different sources of MCFA with glycerol at two weight ratios (1:1 and 4:1, w/w), using three immobilized lipases: Novozym 435, Lipozyme RM IM and Lipozyme TL IM; different reaction times (t = 0, 15, 30, 60, 120 min); enzyme loadings (5, 10 or 15% with respect to the total weight of substrates). The extent of esterification was determined by gas chromatography (GC) analysis of the acylglycerols produced. The highest incorporation of free MCFA into glycerol was obtained for a 1:1 (w/w) glycerol to free MCFA ratio, 5% of Novozym 435, at 50°C, 300 rpm, 10% of molecular sieves and a commercial MCFA mixture as starting material. Under these conditions, incorporation of at least 90% of MCFA into glycerol was achieved after 30 min of reaction.