Enzymatic Synthesis and Characterization of MLM-type Structured Lipid Using Grapeseed Oil and Capric Acid.

The objectives were to optimize the reaction conditions for C10:0 incorporation into grapeseed (GS) oil, characterize the structured lipid (SL) product, and study the changes in antioxidant activity of the SL. Taguchi method was used to optimize C10:0 incorporation by combining parameters in a total of 9 experiments. Lipozyme ® RM IM (Rhizomucor miehei immobilized lipase) and Lipozyme ® 435 (Candida antarctica recombinant immobilized lipase) were used as biocatalysts for the acidolysis reactions. C10:0 incorporation and triacylglycerol (TAG) species of the SL were analyzed to determine optimal conditions and enzyme type that gave higher incorporation. The optimal conditions were the same for both enzymes as follows: substrate molar ratio 1:3 (GS oil: C10:0), enzyme load 5% (w/w) of substrates, temperature 65℃, and time 12 h. HPLC analysis of SL gave MLM-type TAG species of 11.51±0.11 mol% and 12.68±0.34 mol% for Lipozyme ® RM IM and Lipozyme ® 435, respectively. GC analysis indicated that C10:0 incorporated at the sn-1,3 positions of the SL were 46.03±0.55 mol% and 47.28±1.22 mol%, respectively, for Lipozyme ® RM IM and Lipozyme ® 435. However, the total C10:0 incorporated into TAG species with Lipozyme ® RM IM was significantly higher (60.08±0.04 mol%) compared to 50.78±0.44 mol% for Lipozyme ® 435. Scaled-up (300 g) acidolysis reaction and characterization were done on SL synthesized using Lipozyme ® RM IM. SL reaction product was purified using short path distillation and fully characterized in terms of lipid classes, tocopherol, thermal behavior, and oxidative stability. The yield of purified scaled-up SL after short path distillation (SPD) was 72.96 wt%. The antioxidant in SL was reduced after SPD due to loss of tocopherols. This MLM-type-SL synthesized within 12 h using Lipozyme ® RM IM had a high content of C10:0 and may have functional and health benefits.

Head-to-Head Comparison of Caco-2 Transwell and Gut-on-a-Chip Models for Assessing Oral Peptide Formulations.

Oral delivery of potent peptide drugs provides key formulation challenges in the pharmaceutical industry: stability, solubility, and permeability. Intestinal permeation enhancers (PEs) can overcome the low oral bioavailability by improving the drug permeability. Conventional in vitro and ex vivo models for assessing PEs fail to predict efficacy in vivo. Here, we compared Caco-2 cells cultured in the conventional static Transwell model to a commercially available continuous flow microfluidic Gut-on-a-Chip model. We determined baseline permeability of FITC-Dextan 3 kDa (FD3) in Transwell (5.3 ± 0.8 × 10-8 cm/s) vs Chip (3.2 ± 1.8 × 10-7 cm/s). We screened the concentration impact of two established PEs sodium caprate and sucrose monolaurate and indicated a requirement for higher enhancer concentration in the Chip model to elicit equivalent efficacy e.g., 10 mM sodium caprate in Transwells vs 25 mM in Chips. Fasted and fed state simulated intestinal fluids (FaSSIF/FeSSIF) were introduced into the Chip and increased basal FD3 permeability by 3-fold and 20-fold, respectively, compared to 4-fold and 4000-fold in Transwells. We assessed the utility of this model to peptides (Insulin and Octreotide) with PEs and observed much more modest permeability enhancement in the Chip model in line with observations in ex vivo and in vivo preclinical models. These data indicate that microfluidic Chip models are well suited to bridge the gap between conventional in vitro and in vivo models.

Prebiotic Membranes and Micelles Do Not Inhibit Peptide Formation During Dehydration.

Cycles of dehydration and rehydration could have enabled formation of peptides and RNA in otherwise unfavorable conditions on the early Earth. Development of the first protocells would have hinged upon colocalization of these biopolymers with fatty acid membranes. Using atomic force microscopy, we find that a prebiotic fatty acid (decanoic acid) forms stacks of membranes after dehydration. Using LC-MS-MS (liquid chromatography-tandem mass spectrometry) with isotope internal standards, we measure the rate of formation of serine dipeptides. We find that dipeptides form during dehydration at moderate temperatures (55 °C) at least as fast in the presence of decanoic acid membranes as in the absence of membranes. Our results are consistent with the hypothesis that protocells could have formed within evaporating environments on the early Earth.

Prebiotic Peptide Synthesis and Spontaneous Amyloid Formation Inside a Proto-Cellular Compartment.

Cellular life requires a high degree of molecular complexity and self-organization, some of which must have originated in a prebiotic context. Here, we demonstrate how both of these features can emerge in a plausibly prebiotic system. We found that chemical gradients in simple mixtures of activated amino acids and fatty acids can lead to the formation of amyloid-like peptide fibrils that are localized inside of a proto-cellular compartment. In this process, the fatty acid or lipid vesicles act both as a filter, allowing the selective passage of activated amino acids, and as a barrier, blocking the diffusion of the amyloidogenic peptides that form spontaneously inside the vesicles. This synergy between two distinct building blocks of life induces a significant increase in molecular complexity and spatial order thereby providing a route for the early molecular evolution that could give rise to a living cell.

A modified quick, easy, cheap, effective, rugged, and safe method with hydrophobic natural deep eutectic solvent as extractant and analyte protectant for analyzing pyrethroid residues in tomatoes.

In this work, a novel quick, easy, cheap, effective, rugged, and safe technique with hydrophobic natural deep eutectic solvent as both extractant and analyte protectant was developed and combined with gas chromatography-tandem mass spectrometry to analyze pyrethroid residues in tomatoes. Eight hydrophobic natural deep eutectic solvents were first evaluated as analyte protectants and those with decanoic acid or lactic acid as hydrogen bond donor were demonstrated to be effective in compensating for the matrix effects of pyrethroids in the gas chromatography system. Hence, they were added to solvent standards for correcting the quantitation errors instead of matrix-matched calibration standards. Then the abilities of these acid-based deep eutectic solvents to extract pyrethriods from tomatoes were evaluated. Results showed the recoveries of all pyrethroids reached to over 80% with only 5 mL menthol:decanoic acid (1:1) used, and good phase separation was easily achieved without the addition of inorganic salt in the extraction step, indicating hydrophobic natural deep eutectic solvent could be a green substitute for acetonitrile in the quick, easy, cheap, effective, rugged, and safe extraction. Compared with the conventional method, the proposed protocol improved the recoveries, reduced the matrix effects, and simplified the extraction step, demonstrating to be an effective, fast, and green method.

A head-to-head Caco-2 assay comparison of the mechanisms of action of the intestinal permeation enhancers: SNAC and sodium caprate (C10).

Salcaprozate sodium (SNAC) and sodium caprate (C10) are the two leading intestinal permeation enhancers (PEs) in oral peptide formulations in clinical trials. There is debate over their mechanism of action on intestinal epithelia. The aims were: (i) to compare their effects on the barrier function by measuring transepithelial electrical resistance (TEER), permeability of FITC-4000 (FD4) across Caco-2 monolayers, and on immunohistochemistry of tight junction (TJ)-associated proteins; and (ii) to compare cellular parameters using conventional end-point cytotoxicity assays and quantitative high content analysis (HCA) of multiple sub-lethal parameters in Caco-2 cells. C10 (8.5 mM) reversibly reduced TEER and increased FD4 permeability across monolayers, whereas SNAC had no effects on either parameter except at cytotoxic concentrations. C10 exposure induced reorganization of three TJ proteins, whereas SNAC only affected claudin-5 localization. High concentrations of C10 and SNAC were required to cause end-point toxicology changes in vitro. SNAC was less potent than C10 at inducing lysosomal and nuclear changes and plasma membrane perturbation. In parallel, HCA revealed that both agents displayed detergent-like features that reflect initial membrane fluidization followed by changes in intracellular parameters. In conclusion, FD4 permeability increases in monolayers in response to C10 were in the range of concentrations that altered end-point cytotoxicity and HCA parameters. For SNAC, while HCA parameters were also altered in a similar overall pattern as C10, they did not lead to increased paracellular flux. These assays show that both agents are primarily surfactants, but C10 has additional TJ-opening effects. While these in vitro assays illucidate their epithelial mechanism of action, clinical experience suggests that they over-estimate their toxicology in the dynamic intestinal environment.

Molecular hybridization of grape seed extract: Synthesis, structural characterization and anti-proliferative activity in vitro.

The grape seed extract (GSE) hybridized with medium-chain saturated fatty acids (decanoic acid) exhibited higher lipophilicity, antioxidant activity, and anti-proliferative activity than its parents. The chemical structures of individual hybridized GSE derivatives were identified as 3'-O-decanoyl catechin, 3'-O-decanoyl epicatechin, 3', 5'-2-O-decanoyl epigallocatechin, and 3', 4', 3″, 5″-4-O-decanoyl epicatechin gallate by HPLC-MS2 and 1H and 13C NMR. For growth inhibitory effect on HepG2 cells, hybridized GSE derivatives (EC50 = 44.38 µg/mL) were significantly (p < 0.01) stronger than natural GSE (EC50 = 60.83 µg/mL) due to increased lipophilicity. The effects of GSE derivatives on apoptosis and cell cycle in HepG2 cells were further evaluated by flow cytometry. The results showed that the percentage of apoptotic cells increased markedly in the presence of hybridized GSE derivatives. Moreover, hybridized GSE derivatives were capable of inducing cell cycle arrest in G1 phase. This research suggests that hybridized GSE derivatives are effective lipophilic antioxidants and show the potential as adjuvant therapy for cancer.

Co-delivery of brinzolamide and miRNA-124 by biodegradable nanoparticles as a strategy for glaucoma therapy.

Co-delivery nanoparticles with characteristics of intracellular precision release drug have been generally accepted as an effective therapeutic strategy for eye diseases. In this study, we designed a new co-delivery system (miRNA/NP-BRZ) as a lasting therapeutic approach to prevent the neuro-destructive after the long-term treatment of glaucoma. Neuroprotective and intraocular pressure (IOP) response were assessed in in vivo and in vitro models of glaucoma. At the meaning time, we describe the preparation of miRNA/NP-BRZ, drug release characteristics, intraocular tracing, pharmacokinetic and pharmacodynamics study and toxicity test. We found that miRNA/NP-BRZ could remarkably decrease IOP and significantly prevent retinal ganglion cell (RGC) damages. The new formula of miRNA-124 encapsulated in PEG-PSA-BRZ nanoparticles exhibits high encapsulation efficiency (EE), drug-loading capacity (DC), and stable controlled-release efficacy (EC). Moreover, we also verified that the miRNA/NP-BRZ system is significantly neuroprotective and nontoxic as well as lowering IOP. This study shows our co-delivery drug system would have a wide potential on social and economic benefits for glaucoma.

Development of organic solvents-free mode of solidification of floating organic droplet-based dispersive liquid-liquid microextraction for the extraction of polycyclic aromatic hydrocarbons from honey samples before their determination by gas chromatography-mass spectrometry.

In this study, a green mode of solidification of floating organic droplet-based dispersive liquid-liquid microextraction has been developed for the extraction of 16 polycyclic aromatic hydrocarbons from honey samples before their determination by gas chromatography-mass spectrometry. In this method, an appropriate volume of menthol:decanoic acid deep eutectic solvent (as an extraction solvent) is added on a sugar cube (as a disperser agent). In the following, the cube is released into the diluted honey sample placed in a tube. After manual shaking a cloudy state is obtained as a result of dispersing the extraction solvent droplets throughout the sample solution and the analytes are extracted into them. After placing the tube in an ice bath, the droplet of the extractant is solidified on the top of the solution. This drop is taken and after dissolving in acetonitrile, an aliquot of the solution is injected into the separation system. Under optimum conditions, the suggested approach had high extraction recoveries (76-93%) and enrichment factors (380-465), low limits of detection (14-52 ng/kg) and quantification (47-173 ng/kg), and satisfactory repeatability (relative standard deviation ≤ 9%).

In matrix formation of deep eutectic solvent used in liquid phase extraction coupled with solidification of organic droplets dispersive liquid-liquid microextraction; application in determination of some pesticides in milk samples.

In this work, a liquid-phase extraction procedure and dispersive liquid-liquid microextraction method based on deep eutectic solvents were combined and used for the simultaneous extraction of different classes of pesticides; including carbaryl, hexythiazox, pretilachlor, iprodione, famoxadone, sethoxydim and fenazaquin from milk samples. In the first step, a deep eutectic solvent was synthesized in milk sample and simultaneously, was used for extraction of the analytes along with precipitation of milk proteins. To assist the formation of the deep eutectic solvent and increasing the mass transfer rate of the analytes, ultrasonic irradiations was used. In the second step, the collected organic phase from pervious step was mixed (as dispersive solvent) with a water-immiscible deep eutectic solvent (ChCl: decanoic acid) and injected into deionized water. The cloudy solution was placed into an ice bath and the extraction solvent was solidified on the top of the solution. After removing the solid phase by a spatula, it was melted at room temperature and 1 µL of the extraction solvent was injected into the separation system. Under the optimum extraction conditions, low limits of detection and quantification within the ranges of 0.90-3.9 and 3.1-13 ng mL-1 were achieved, respectively. Precision of the method expressed as relative standard deviation was in the ranges of 3.8-5.3 and 4.8-6.9 for intra- and inter-day (n = 5) precision, respectively, at a concentration of 50 ng mL-1 of each analyte. Extraction recoveries and enrichment factors were between 64 and 89% and 320 and 445, respectively. Lastly, several milk samples were successfully analyzed using the proposed method.

New Hydroxydecanoic Acid Derivatives Produced by an Dndophytic Yeast Aureobasidium pullulans AJF1 from Flowers of Aconitum carmichaeli.

Endophytes have been recognized as a source for structurally novel and biologically active secondary metabolites. Among the host plants for endophytes, some medicinal plants that produce pharmaceuticals have been reported to carry endophytes, which could also produce bioactive secondary metabolites. In this study, the medicinal plant Aconitum carmichaeli was selected as a potential source for endophytes. An endophytic microorganism, Aureobasidium pullulans AJF1, harbored in the flower of Aconitum carmichaeli, was cultured on a large scale and extracted with an organic solvent. Extensive chemical investigation of the extracts resulted in isolation of three lipid type compounds (1-3), which were identified to be (3R,5R)-3,5-dihydroxydecanoic acid (1), (3R,5R)-3-(((3R,5R)-3,5-dihydroxydecanoyl)oxy)-5-hydroxydecanoic acid (2), and (3R,5R)-3-(((3R,5R)-5-(((3R,5R)-3,5-dihydroxydecanoyl)oxy)-3-hydroxydecanoyl)oxy)-5-hydroxydecanoic acid (3) by chemical methods in combination with spectral analysis. Compounds 2 and 3 had new structures. Absolute configurations of the isolated compounds (1-3) were established using modified Mosher's method together with analysis of NMR data for their acetonide derivatives. All the isolates (1-3) were evaluated for antibiotic activities against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and their cytotoxicities against MCF-7 cancer cells. Unfortunately, they showed low antibiotic activities and cytotoxic activities.

Unveil the Anticancer Potential of Limomene Based Therapeutic Deep Eutectic Solvents.

Deep eutectic solvents have been recently reported as an interesting alternative to improve the therapeutic efficacy of conventional drugs, hence called therapeutic deep eutectic solvents (THEDES). The main objective of this work was to evaluate the potential of limonene (LIM) based THEDES as new possible systems for cancer treatment. LIM is known to have antitumor activity, however it is highly toxic and cell viability is often compromised, thus this compound is not selective towards cancer cells. Different THEDES based on LIM were developed to unravel the anticancer potential of such systems. THEDES were prepared by gently mixing saturated fatty acids menthol or ibuprofen (IBU) with LIM. Successful THEDES were obtained for Menthol:LIM (1:1), CA:LIM (1:1), IBU:LIM (1:4) and IBU:LIM(1:8). The results indicate that all the THEDES present antiproliferative properties, but IBU:LIM (1:4) was the only formulation able to inhibit HT29 proliferation without comprising cell viability. Therefore, IBU:LIM (1:4) was the formulation selected for further assessment of anticancer properties. The results suggest that the mechanism of action of LIM:IBU (1:4) is different from isolated IBU and LIM, which suggest the synergetic effect of DES. In this work, we unravel a methodology to tune the selectivity of LIM towards HT29 cell line without compromising cell viability of healthy cells. We demonstrate furthermore that coupling LIM with IBU leads also to an enhancement of the anti-inflammatory activity of IBU, which may be important in anti-cancer therapies.

Biodegradable Polyester of Poly (Ethylene glycol)-sebacic Acid as a Backbone for ß -Cyclodextrin-polyrotaxane: A Promising Gene Silencing Vector.

BACKGROUND: Polyrotaxane, a macromolecular interlocked assembly, consisting of cyclodextrin has excellent inclusion capabilities and functionalization capacity, which makes it a versatile material as a vector for gene delivery applications. OBJECTIVE: A biodegradable linear aliphatic polyester axle composed of Polyethylene Glycol (PEG) and Sebacic Acid (SA) was used to fabricate the ß-Cyclodextrin (ß-CD) based polyrotaxane as a cationic polymeric vector and evaluated for its potential gene silencing efficiency. METHODS: The water-soluble aliphatic polyester was synthesized by the solvent esterification process and characterized using viscometry, GPC, FT-IR and 1H NMR spectroscopy. The synthesized polyester was further evaluated for its biodegradability and cellular cytotoxicity. Hence, this water-soluble polyester was used for the step-wise synthesis of polyrotaxane, via threading and blocking reactions. Threading of ß-CD over PEG-SA polyester axle was conducted in water, followed by end-capping of polypseudorotaxane using 2,4,6-trinitrobenzenesulfonic acid to yield polyester-based polyrotaxane. For gene delivery application, cationic polyrotaxane (PRTx+) was synthesized and evaluated for its gene loading and gene silencing efficiency. RESULTS AND DISCUSSION: The resulting novel macromolecular assembly was found to be safe for use in biomedical applications. Further, characterization by GPC and 1H NMR techniques revealed successful formation of PE-ß-CD-PRTx with a threading efficiency of 16%. Additionally, the cellular cytotoxicity assay indicated biosafety of the synthesized polyrotaxane, exploring its potential for gene delivery and other biomedical applications. Further, the biological profile of PRTx+: siRNA complexes was evaluated by measuring their zeta potential and gene silencing efficiency, which were found to be comparable to Lipofectamine 3000, the commercial transfecting agent. CONCLUSION: The combinatory effect of various factors such as biodegradability, favourable complexation ability, near zero zeta potentials, good cytotoxicity properties of poly (ethylene glycol)-sebacic acid based ß-Cyclodextrin-polyrotaxane makes it a promising gene delivery vector for therapeutic applications.

Robust and nanoparticle-free superhydrophobic cotton fabric fabricated from all biological resources for oil/water separation.

Traditional superhydrophobic cotton fabrics (SCFs) for oil/water separation were usually fabricated by surface coating with inorganic nanoparticles combined with nonrenewable and nonbiodegradable or even toxic fossil-based chemicals, which would lead to secondary environmental pollution after their lifetime. In this study, we report robust, nanoparticle-free, fluorine-free SFC, which was prepared by acid etching followed by surface coating with epoxidized soybean oil resin (CESO) and subsequent modification with stearic acid (STA). No toxic compound and no nanoparticle were included within the SCF and all the raw materials including cotton fabric, CESO and STA are biodegradable and derived from biological resources. The SCF showed excellent mechanical stability and chemical/environmental resistances. The superhydrophobicity of the SFC survived from mechanical abrasion, tape peeling, ultrasonication, solvent erosion and low/high temperature exposure. The SCF also exhibited good acid/alkali resistance with contact angle over 150° toward different pH water droplets. Moreover, the SCF could efficiently separate oil/water mixtures with efficiency above 97.9% and the superhydrophobicity remained after reusing for at least 10 times. The fully biological-derived SCF with excellent mechanical and chemical resistances exhibit great potential for separation of oil/water mixtures.

Synthesis and antiproliferative activity of culicinin D analogues containing simplified AHMOD-based residues.

Culicinin D is a 10 amino acid peptaibol containing a rare and synthetically challenging (2S,4S,6R)-AHMOD residue, that exhibits potent antiproliferative activity against MDA-MB-468 cells. An SAR study focusing on replacement of the AHMOD residue was undertaken, culminating in the revelation that a 6-hydroxy or 6-keto substituent was essential to retain potent low nanomolar antiproliferative activity.

Friction and Adsorption Properties of Oleic Acid-Based Gemini Amphiphile at Silica/Ester Oil Interfaces.

We characterized the friction and adsorption properties of an oleic acid-based gemini amphiphile having two carboxylic acid headgroups. We employed silica as a solid material, and diethyl sebacate and bis (2-ethylhexyl) sebacate as polar ester oils. Oleic acid and stearic acid were used as comparative amphiphilic materials. These amphiphiles were soluble in the ester oils, and the solubility of the gemini amphiphile was lower than that of the other two amphiphiles. Quartz crystal microbalance with dissipation monitoring measurements suggested that the gemini amphiphile had greater adsorption capability than the two comparative amphiphiles. The greater adsorption density of the gemini amphiphile resulted in the formation of a rigid interfacial film, as suggested by the normal force curves obtained by atomic force microscopy (AFM). We assessed the friction property of these systems using a ball-on-plate-type friction analyzer and by friction-mode AFM (friction force curve). These measurements confirmed that the gemini amphiphile had a smaller kinetic friction coefficient than that of the other two amphiphiles. These results suggest the potential of the gemini amphiphile as a friction modifier in polar oils.

Biomimetic hydroxyapatite/poly xylitol sebacic adibate/vitamin K nanocomposite for enhancing bone regeneration.

Hydroxyapatite (HAP) is a significant bone mineral that establishes bone strength. HAP composites in combination with biodegradable and bioactive polymer poly xylitol sebacic adipate (PXSA) would result in a constant release at target sites. Numerous studies have shown that vitamin K (VK) might possess a vital function in bone metabolism. The purpose of the present study was to inspect the synthesized composite HAP/PXSA/VK in developing polymeric biomaterials composite for the application of bone tissue regeneration. FTIR, X-ray diffraction, SEM and TEM techniques were applied to characterize the prepared composites. The release of VK from the HAP/PXSA/VK composite was evidenced through UV-Vis spectroscopy. In vitro studies proved that the HAP/PXSA/VK composite is appropriate for mesenchymal stem cell culture. Compared to pure HAP prepared following the same method, HAP/PXSA/VK composite provided favourable microstructures and good biodegradation distinctiveness for the application of tissue engineering, as well as tissue in-growth characteristics and improved scaffold cell penetration. This work reveals that the HAP/PXSA/VK composites have the potential for applications in bone tissue engineering.

Detection of Mast Cells Expressing c-Kit Using Antibody Covalently Bound to Gelatin Elongated from Surface of Immunosensor Based on Surface Plasmon Resonance.

An immunosensor based on surface plasmon resonance was applied to detect mast cells expressing c-Kit. Sufficient detection of the mast cells was achieved by covalent immobilization of gelatin firstly on the sensor surface and followed by covalent binding of the anti-c-Kit antibody to lysine residues in the gelatin molecules through bis(sulfosuccinimidyl)suberate (BS3) treatment. By using BS3, which is a homo-bifunctional reagent, the lysine residues of the anti-c-Kit antibody easily bound to the lysine residues of the gelatin in the physiological condition. The lower limit of detection was 104 cells/mL.

Dispersible hydrolytically sensitive nanoparticles for nasal delivery of thyrotropin releasing hormone (TRH).

Nose-to-brain delivery of drugs is affected by nanoparticles (NPs) deposited on the olfactory surface and absorbed directly into the brain. Thyrotropin releasing hormone (TRH), a water soluble drug used for treating suicidal patients, was incorporated into a fast degrading poly(sebacic anhydride) (PSA) NPs. NPs were prepared by a solvent-antisolvent process under strict anhydrous environment to obtain high TRH loading and to avoid premature PSA degradation and TRH release. PSA and TRH were dissolved in a mixture of dichloromethane and ethanol and added dropwise to a dispersion of mannitol particles in heptane as an antisolvent. Mannitol powder was included in the antisolvent, so that formed NPs adhered to the mannitol microparticles for easy isolation and immediate dispersion in water prior to use. The size, surface charge, and morphology of the TRH-PSA NPs were determined using dynamic light scattering (DLS), zeta-potential, and Scanning Electron Microscopy (SEM), respectively. The NPs prepared were uniform and spherical of ~250 nm. Further, the in vitro release profile of TRH from NPs lasted for 12 h with most TRH released within the first hour in water. Concentration dependent cell toxicity studies revealed low toxicity level at low concentrations of the NPs. Surface adsorption of the NPs was also uniform on the cell surface as examined through the odyssey near infrared fluorescence (NIR) images using Indocyanine green (ICG). The NPs are designed to enable direct delivery to the olfactory epithelium using a refillable nasal atomizer that deposits mist onto the olfactory neuro-epithelium.

In situ phase transition of microemulsions for parenteral injection yielding lyotropic liquid crystalline carriers of the antitumor drug bufalin.

In this work, we used the small angle X-ray scattering (SAXS) method for controlled preparation of in situ forming sustained-release carriers for the antitumor drug bufalin (BUF), which has very poor solubility and a considerable cardiotoxicity in a non-encapsulated state. To that aim, we exploited the pseudo-ternary phase diagram of an oil(O)/surfactant(S)/water(W) system containing medium chain capric/caprylic triglycerides (MCT) and a co-surfactant blend of Macrogol (15)-hydroxystearate (Solutol HS 15) and sorbitan monooleate (Span 80). Two compositions with different oil contents (sample B and C) were selected from the microemulsion region of the phase diagram in order to study the effect of the aqueous environment on their structural behavior. A phase transition from a microemulsion (ME) to a liquid crystalline phase (LC) was established by SAXS upon progressive dilution. The drug bufalin (BUF) was encapsulated in the microemulsions with low viscosity, whereas the release of the drug occurred from the in situ generated lamellar liquid crystalline structures. The formulations were characterized by SAXS, dynamic light scattering (DLS), cryogenic transmission electron microscopy (Cryo-TEM), rheology, drug loading and encapsulation efficiency, and in vitro release profiles. A correlation was suggested between the structures of the in situ phase-transition formed LCME formulations, the differences in their viscosities and drug release profiles. The performed cytotoxicity, cell apoptosis and pharmacokinetic experiments showed an enhanced bioavailability of BUF after encapsulation. These results suggest potential clinical applications for the obtained safe in situ phase-transition sustained-release formulations of BUF.