Lipid Spheres Research Articles

In situ gel-forming oil as rectally delivering platform of hydrophobic therapeutics for ulcerative colitis therapy

Because of their poor water-soluble properties and non-specific distribution, most hydrophobic therapeutics had limited benefit for patients with ulcerative colitis. Herein, an in-situ oil-based gel has been developed as a rectal delivery vehicle for these therapeutics. In situ gel-forming oil (BBLG) was composed of soybean phosphatidyl choline (40%, w/w), glyceryl dioleate (50%, w/w), and ethanol (10%, w/w). The hydrophobic laquinimod (LAQ) as a model drug was easily dissolved in gel-forming oil and its solubility was reaching to 7 ± 0.1 mg/mL. Importantly, upon contact with the colonic fluids, the gel-forming oil was quickly transited to a semi-solid gel, adhering to the inflamed colon mucosa and forming a protective barrier. Transmission Electron Microscopy showed that the gel network was arranged by the connected lipid spheres and LAQ was non-crystally encapsulated into the lipid spheres. Moreover, the universal adhesive test showed that the adhesive force and the adhesive energy of BBLG toward fresh colon tissues were 711 ± 12 mN and 25 ± 2 J/m2, which was 2.14-fold and 5-fold higher than that of the marketed Poloxamer 407 gel, respectively. Meanwhile, in vivo imaging confirmed that the retention time of BBLG in the colon lumen was more than 8 h after rectal administration. In vivo animal studies showed that BBLG also greatly enhanced the therapeutic impact of LAQ on TNBS-treated rats with ulcerative colitis, as evidenced by reduced disease activity index (DAI) scores and weight loss. Moreover, the colonic inflammation was significantly alleviated and the goblet cells were obliviously restored after treatment. Importantly, the gut mucosa barrier was largely repaired without any formation of fibrosis remodeling. Conclusively, in situ liquid gel may be a potential delivery system of hydrophobic medicines for ulcerative colitis.

Imidacloprid-induced mortality, histopathology and biochemical impairments in the larvae of oriental latrine fly (Chrysomya megacephala).

The concentration-mortality response of third instar larvae of Chrysomya megacephala (Diptera: Calliphoridae) to a synthetic insecticide, imidacloprid, and its impact on histopathological, histochemical, and biochemical parameters were determined in laboratory assays. Larvae displayed a concentration and time-dependent mortality response for the insecticide. Histopathological studies exhibited quite noticeable modifications in the epithelial cells, peritrophic membrane, basement membrane and muscular layer of the larval midgut. The ultrastructural analysis demonstrated alterations in nuclei, lipid spheres, microvilli, mitochondria, rough endoplasmic reticulum and lysosomes. In addition, histochemical tests on the midgut were performed, which revealed a strong reaction for proteins and carbohydrates in the control group and a weak reaction in the group exposed to imidacloprid in a dose and time-dependent manner. Imidacloprid also caused a significant reduction in the total midgut content of carbohydrates, proteins, lipids and cholesterol. Larvae treated with imidacloprid also showed a reduction in the activities of acid and alkaline phosphatases at all concentrations compared to untreated larvae.

In Vitro Antifungal Activity of Dihydrochelerythrine and Proteomic Analysis in Ustilaginoidea virens

Dihydrochelerythrine (DHCHE) is an isoquinoline compound, which has distinct antifungal activity and can induce apoptosis. The antifungal activity of DHCHE against five rice pathogenic fungi was studied in vitro. At the concentration of 7.5 mg/L, DHCHE exhibited the highest efficacy among tested compounds in inhibiting mycelium growth, with an inhibition rate of 68.8% in Ustilaginoidea virens, which was approximately 2.4 times of that of validamycin (28.7%). After exposure to DHCHE, transmission electron micrographs revealed spores showed incomplete organelles, malformed cell walls and nuclear membranes, as well as irregular lipid spheres. Reactive oxygen species accumulation in treated spores was markedly higher than that in control spores. DHCHE induced cell damage increased in a dose-dependent manner, as indicated by the decrease in mitochondrial membrane potential and initiation of apoptosis. The differences of expression levels of Fip1, ACP1, PMS2 and COX13 that are important for oxidative phosphorylation and mismatch repair pathway were significant, which may be some of the reasons for the induction of apoptosis in DHCHE-treated U. virens. The protein levels of Fip1, ACP1, PMS2 and COX13 agreed with protein fold change ratio from parallel reaction monitoring Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway of differentially expressed proteins were further analyzed. These findings will help to elucidate the mechanisms associated with antifungal and pro-apoptotic effects of DHCHE on U. virens, thereby aiding the potential development of novel pesticides.

Salt Stress Inhibits Photosynthesis and Destroys Chloroplast Structure by Downregulating Chloroplast Development-Related Genes in Robinia pseudoacacia Seedlings.

Soil salinization is an important factor limiting food security and ecological stability. As a commonly used greening tree species, Robinia pseudoacacia often suffers from salt stress that can manifest as leaf yellowing, decreased photosynthesis, disintegrated chloroplasts, growth stagnation, and even death. To elucidate how salt stress decreases photosynthesis and damages photosynthetic structures, we treated R. pseudoacacia seedlings with different concentrations of NaCl (0, 50, 100, 150, and 200 mM) for 2 weeks and then measured their biomass, ion content, organic soluble substance content, reactive oxygen species (ROS) content, antioxidant enzyme activity, photosynthetic parameters, chloroplast ultrastructure, and chloroplast development-related gene expression. NaCl treatment significantly decreased biomass and photosynthetic parameters, but increased ion content, organic soluble substances, and ROS content. High NaCl concentrations (100-200 mM) also led to distorted chloroplasts, scattered and deformed grana lamellae, disintegrated thylakoid structures, irregularly swollen starch granules, and larger, more numerous lipid spheres. Compared to control (0 mM NaCl), the 50 mM NaCl treatment significantly increased antioxidant enzyme activity while upregulating the expression of the ion transport-related genes Na+/H+ exchanger 1(NHX 1) and salt overly sensitive 1 (SOS 1) and the chloroplast development-related genes psaA, psbA, psaB, psbD, psaC, psbC, ndhH, ndhE, rps7, and ropA. Additionally, high concentrations of NaCl (100-200 mM) decreased antioxidant enzyme activity and downregulated the expression of ion transport- and chloroplast development-related genes. These results showed that although R. pseudoacacia can tolerate low concentrations of NaCl, high concentrations (100-200 mM) can damage chloroplast structure and disturb metabolic processes by downregulating gene expression.

The eye of the tongue sole Cynoglossus bilineatus (Lacepède, 1802) (Teleostei: Pleuronectiformes)

We report the ocular features of the tongue sole, Cynoglossus bilineatus (Lacepède, 1802), a marine, bottom-dwelling flatfish. In this species, both eyes are located juxtaposed on the same side of the flat head. Histology revealed the sclera to be fibrous (collagenous) in nature. The choroid possesses the choriocapillaris, and adjacent to it, 3–4 rows of iridophores with stacks of cytoplasmic platelets. No choroidal gland is present. The retinal pigment epithelium (RPE) contains scanty melanin granules. Its vitread half is modified into a dense tapetum with lipid spheres (about 0.34 μm in diameter). In juveniles, the tapetal spheres arise by budding from the smooth endoplasmic reticulum of the RPE. There are blood vessels within the retina; the vitreal vessels penetrate the retina and ramify close to the level of the outer limiting membrane. The vessels are capillaries in nature. The photoreceptor layer contains abundant rods, and twin cones and single cones, being arranged into square mosaics. The optic disc is non-pleated and shows pan- cytokeratin immunopositivity, which is related to the bundled cytokeratin filaments detected in astrocytes by electron microscopy. The retinal tapetum and choroidal iridophores help the species to live in a muddy bottom having dim-light environment. The lack of a choroidal gland, hypoxic aquatic condition and presence of a dense retinal tapetum (that limits O2 transport to the photoreceptors) appear to have favored the proliferation of vitreal vessels within the retina in this species. The fibrous sclera has probably arisen to provide structural support to the eye in migration from the lateral to the dorsal aspect of the head during larval metamorphosis.

Liposome mediated pulmonary drug delivery system: An updated review

Liposomes are the sphere-shaped vesicles consisting of one or more phospholipid bilayers. Structurally the liposomal vesicles are the bilayered vesicles that consist of a core of aqueous solution and a lipid spheres that contain no aqueous material. They are generally made up of phospholipids. Liposomal drug delivery systems have been widely used in pulmonary drug delivery for multiple applications which includes optimum solubilization of active pharmaceutical agents, prolonged period of drug release. Moreover, the site avoidance and site-specific drug targeting therapy could be achieved by the liposomal drug delivery system, to inhibit the tissue toxicity of many potent drug substances. In this present review, formulation aspects of liposomes, various aerosolization methods and the characterization methods of liposome formulation and an extensive overview of the use of liposomes as a pulmonary drug delivery system for the treatment of diseases like tuberculosis and lung cancer and are discussed. Liposomes can be used as a successful drug carrier in the fields like lung infection, tumor targeting, genetic transfer, immunomodulation, skin, and topical therapy.

Ultrastructure of the Midgut Adult, Trachyderma philistina (Coleoptera: Tenebrionidae)

In the anterior part of the midgut adult Trachyderma philistina, the apical part showed microvilli in the form of membrane with folds and also microvilli appeared slender and uniform. Between these folds of microvilli appeared a lot of ribosomes and rough endoplasmic reticulum. Secretory vesicles are discharged from part of midgut. A well-developed oval nucleus appeared in the cytoplasm near the apical part of the cell. The nucleus is surrounded by a lot of free ribosomes and rough endoplasmic reticulum. Mitochondria appeared near the apical part of the cell. A well-developed thick basement membrane appeared in the basal part of the anterior midgut of adult beetle Trachyderma philistina. In the middle part of the midgut, a very thick well-developed brush border microvilli appeared. Mitochondria and numerous tracheae appeared through cytoplasm. Rough endoplasmic reticulum appeared throughout the cytoplasm. A lot of secretory vacuoles were observed directed apically. A well-developed oval and circular nucleus appeared near the basal part of the cell and surrounded by numerous rough endoplasmic reticulum A well-developed muscle fiber appeared apically and basally. A very thin basement membrane appeared in the basal part of the cell. The peritrophic membrane is absent in the midgut of adult stage Trachyderma philistine while regenerative cells appeared in the basal part of the middle midgut cell. In the posterior part of the midgut, microvilli appeared in the form of membranes due to the presence of numerous organelles that are discharging into the lumen. Lipid spheres and aggregations of glycogen are present throughout the cell. A thin basement membrane was observed.

Changes in aggregation behavior of raw and cooked salted egg yolks during pickling

In this study, we aimed to investigate the changes in gelation behavior of raw (without heating) and cooked (with heating) salted egg yolks during pickling. Results indicated that the decreasing trend in the main peak T22 of raw and cooked salted egg yolks. Cooked salted egg yolks after 28 days of pickling had a higher release of free lipids as visualized using a confocal laser scanning microscope (CLSM). Transmission electron microscope (TEM) micrographs showed that protein granules were distributed together with lipid spheres in raw and cooked salted egg yolks, and the liberated constituents (lipids and proteins) reorganize and aggregate in cooked salted egg yolks after 28 days of pickling. As the pickling proceeded, the soluble protein content and free sulfhydryl content of raw salted egg yolks, the free sulfhydryl content and surface hydrophobicity of cooked salted egg yolks showed an overall increasing trend, followed by significant decrease. The surface hydrophobicity of raw salted egg yolks exhibited an increasing trend. Differential scanning calorimetry (DSC) results demonstrated that salting can stabilize the protein molecules by an increase in denaturation temperatures. Fourier transform infrared spectroscopy (FTIR) revealed that the secondary structures of egg yolk proteins underwent changes, but no difference in protein patterns of either raw or cooked salted egg yolks was observed by SDS–PAGE during pickling. These results suggested that the characteristic gel of salted egg yolks is formed, as the result of multiple interactions between protein molecules and between protein and lipid molecules.

Study of the influence of coating methods on lipid spheres manufactured on rotor fluidized bed process

Different previous works have shown that various kinds of spheres can be manufactured by rotor granulation in a ‘single-pot process’ using a lipid base: hydrogenated castor oil. This single-pot technology is based on wet granulation where all components are placed in the powder form in the rotor bowl; then, they are continuously suspended in a fluidized air, with a tangentially sprayed liquid solution. This process allows the granulation and manufacturing of sphere during the same time. Previous experiments have studied the influence of the formulation and the manufacturing process parameters on spheres in terms of feasibility and dissolution properties. Both the spraying time and the weight of liquid sprayed were found to be the most relevant parameters that govern the final quality of the sphere. Now, in a second part of the work, a first comparison is made with two different fluid bed methods: the tangential rotor spray and the Wurster bottom spray for coating the lipid spheres previously manufactured with the rotor tangential spray. The external aspect of the coated spheres manufactured has been evaluated with an electronic microscopy analysis and a study of dissolution properties of the active ingredient has been done by USP in vitro dissolution tests.

Adipogenic differentiation of culture-expanded bone marrow derived porcine mesenchymal stem cells

In order to use Mesenchymal stem cell populations for obesity and related metabolic syndrome studies in cell culture system, as a prerequisite, we evaluated the potency of these stem cells to undergo adipogenic differentiation. Porcine stem cells were chosen to study adipogenesis in due to the fact that pig has a natural tendency to get obese and the species is considered to be the most desired biomedical model for human applications. Porcine MSCs have been exposed to adipogenic induction media following a 21day protocol and observed under microscope for detecting stages of differentiation. At the terminal differentiation stage; morphologically, the cells appeared rounded with numerous large cytosolic lipid spheres. Upon staining with Oil Red O, the lipid spheres stained bright red. Based on this, proprietary medium was found to differentiate MSCs more efficiently than medium formulated on previous reports. Both, the differential morphologic feature corresponding to the adipocyte and positive Oil Red O staining confirmed about successful adipogenic differentiation. We envision that stem cell based culture system from porcine species would aid for studying molecular adipogenesis and subsequent identification of therapeutic targets for obesity and other metabolic diseases.

A study of the activity and effectiveness of recombinant fibroblast growth factor (Q40P/S47I/H93G rFGF-1) in anti-aging treatment.

IntroductionFibroblast growth factor 1 (FGF-1) is a powerful mitogen involved in the stimulation of DNA synthesis and the proliferation of a wide variety of cell types. Fibroblast growth factor 1 was genetically modified to improve its thermal stability and resistance to protease degradation without losing its biological activity.AimTo study the impact of Q40P/S47I/H93G rFGF-1 on skin cells, its penetration through the skin and the evaluation of the rFGF-1-cosmetic product properties.Material and methods In vitro studies included the examination of primary fibroblast and keratinocyte viability after the incubation with rFGF-1. The penetration abilities of rFGF-1 in various formulations and carrier systems were examined ex vivo by the Raman spectroscopy. In vivo studies – HF Ultrasound and 3D Imaging System – were used to evaluate the anti-aging properties of creams containing rFGF-1.Results In vitro studies demonstrated that rFGF-1 strongly enhanced the viability of the treated cells. The Raman Spectroscopy analysis indicated that rFGF-1 encapsulated in lipid spheres penetrate through the stratum corneum to the depth of 60 µm, and added to the o/w formulation – could penetrate to a depth of 90 µm. The results obtained from Primos revealed the reduction of the volume and the depth of the wrinkles. Changes in the skin structure in the analyzed areas were evaluated by HF Ultrasonography.ConclusionsRecombinant FGF-1 strongly stimulated fibroblast and keratinocyte proliferation. However, the transition of this protein through the SC required an appropriate carrier system – lipid spheres. All tests – in vitro, ex vivo and in vivo – have proved that rFGF-1 is a substance with a potentially wide spectrum of use.

The role of lipids in activated sludge floc formation

Activated sludge is widely used to treat municipal and industrial wastewater globally and the formation of activated sludge flocculates (flocs) underpins the ability to separate sludge from treated water. Despite the importance of activated sludge flocs to human civilization there have been precious few attempts to rationally design fit for purpose flocs using a bottom-up approach based on a solid scientific foundation. Recently we have been developing experimental models for activated sludge floc formation based on the colonization and consumption of particulate organic matter (chitin and cellulose). In this study we lay the foundation for investigation of activated sludge floc formation based on biofilm formation around spheres of the lipid glycerol trioleate (GT) that form spontaneously when GT is introduced into activated sludge incubations. Sludge biomass was observed to associate tightly with the lipid spheres. An increase in extracellular lipase activity was associated with a decrease in size of the colonized lipid spheres over a 25 day incubation. Bacterial community composition shifted from predominantly Betaproteobacteria to Alphaproteobacteria in GT treated sludge. Four activated sludge bacteria were isolated from lipid spheres and two of them were shown to produce AHL like quorum sensing signal activity, suggesting quorum sensing may play a role in lipid spheres colonization and biodegradation in activated sludge. The development of this experimental model of activated sludge floc formation lays the foundation for rational production of flocs for wastewater treatment using lipids as floc nuclei and further development of the flocculate life-cycle concept.

Development and characterization of pioglitazone loaded liposphere for the effective treatment of diabetes mellitus type 2

Lipospheres which represent novel drug delivery vehicles are water-insoluble lipid spheres forming a solid hydrophobic core, with a layer of phospholipids embedded on the surface of the core. Drugs or other biologically active agents may be contained in the hydrophobic core, adhered to the phospholipids, or a combination thereof. Lipid based carrier system (lipospheres) was adopted to eliminate the toxic effects associated with the use of polymers as carrier and entrapment of high amount of poorly bioavailable lipophilic compound. Due to its poor aqueous solubility of Pioglitazone HCl, was selected as drug candidate to develop lipospheres employing the melt dispersion technique. The Pioglitazone HCl - loaded lipospheres were found to be an effective natural carrier in terms of discrete particle size, encapsulation efficiency, and satisfactory in vitro release characteristics. In the presence of cetyl alcohol, the incorporated phospholipid could combine with drug by hydrophilic and hydrophobic interactions, consequently improved the drug entrapment efficiency and produced the sustained release rate.

A lifeline for lipid rafts?

Study finds raft-like domains in yeast vacuole membrane.

Numerical analysis for transverse microbead trapping using 30 MHz focused ultrasound in ray acoustics regime

Numerical analysis for transverse microbead trapping using 30 MHz focused ultrasound in ray acoustics regime

Single beam acoustic tweezer

Single beam acoustic tweezer, a distant cousin of optical tweezer, has been recently experimentally validated. A prerequisite of acoustic tweezer as in optical tweezer is a sharply focused beam with a steep intensity variation within the dimension of a particle. As the frequency of an acoustic beam reaches 100 MHz or higher, the beam diameter approaches cellular level allowing acoustic tweezing or trapping of a cell. Recent experimental results have shown that at 200 MHz it is possible to trap particles as small as 1 μm and red blood cells (RBC). These results along with the experimental arrangement and potential biomedical applications of acoustic tweezer including measuring RBC deformability will be discussed in detail in this talk.

Single beam acoustic tweezer

Single beam acoustic tweezer, a distant cousin of optical tweezer, has been recently experimentally validated. A prerequisite of acoustic tweezer as in optical tweezer is a sharply focused beam with a steep intensity variation within the dimension of a particle. As the frequency of an acoustic beam reaches 100 MHz or higher, the beam diameter may approach cellular level allowing acoustic tweezing or trapping of a cell. Recent experimental results have shown that it is possible to trap lipid spheres of 100 μm diameter at 30 MHz and 15 μm diameter leukemia cells at 200 MHz. These results along with the experimental arrangement and potential biomedical applications of acoustic tweezer will be discussed in detail in this paper.

High frequency ultrasonic particle sorting

Single particle sorting devices have been used in bioassay compartmentalization and cell sorting. Fluorescence-activated cell sorting (FACS) is a well-known example. This paper presents an acoustically driven particle sorting device integrated with a poly(dimethyl) siloxane (PDMS) microfluidic channel. The device consists of two independent and sequential processes, acoustic sensing and sorting. Hydrodynamically focused lipid microspheres flowing in the channel are non-invasively sensed by a low intensity high frequency ultrasonic beam at 30 MHz for quantitative measurement of backscatter. Following sensing, the particles are sorted via acoustic radiation force or acoustic tweezing by a high intensity beam generated by the same transducer. The device has been successfully used to separate a mixture of 50 μm and 100 μm lipid spheres by size. Its performance and potential applications will be discussed in this paper.

Lipid Spheres as Attractive Nanoscale Drug Delivery Platforms for Cancer Therapy

Summary Several barriers limit the effective tumor delivery and penetration of the nanomedicine candidates as anti-cancer therapeutics, including: [1] heterogeneous tumor circulation caused by abnormal and irregular architecture of the tumor vasculature, [2] intratumoral vascular hyperpermeability contributing to increased interstitial pressure in the targeted tumor that substantially reduces the convective transport of nanoparticles and [3] impaired diffusion in the context of an abnormal and highly dense extracellular collagen matrix in the tumor microenvironment. Lipid spheres represent a promising drug formulation platform for effective delivery of anti-cancer pharmaceuticals to target cancer cells. Lipid spheres, especially microemulsion systems can be used to address various challenges in formulation and clinical use of anti-cancer pharmaceuticals. Due to a number of attributes inherent to lipid sphere nanoparticles, including their large lipid cores for the solubilization of anti-tumor agents, and the relative ease of lipid sphere manufacturing compared to the manufacturing of liposomes, lipid spheres have the potential to emerge as the preferred nanoscale delivery systems of anti-cancer therapeutics. Low Interfacial Tension Lipid Spheres (LIFT-LS) are classical thermodynamically stable microemulsions. LIFT of the nanoscale microemulsion systems and many of their LIFT-associated surface characteristics such as enhanced nanodroplet deformability, flexibility, and ease of emulsification at the contact point between the microemulsion nanodroplets and the target cancer cell membrane may contribute to an improved drug delivery capacity. The ability of the microemulsion nanodroplets to undergo shape changes and fragmentationcoalescence when subjected to environmental perturbations may further facilitate their transport and penetration through the extracellular tumor matrix despite high interstitial tissue pressure that exists inside solid tumors. Dilutable Low Interfacial Tension Lipid Spheres (DLIFT-LS) are a distinct subgroup of LIFT-LS and currently represent the most advanced form of microemulsions. It is our considered opinion that DLIFT-LS are the most suitable lipid spheres for intravenous anti-cancer drug delivery due to their multiple attributes as discussed in this review.

Process Optimization, Characterization, and Release Study In Vitro of an Intravenous Puerarin Lipid Micropheres Loaded with the Phospholipid Complex

A new formulation of puerarin lipid microspheres with the puerarin–phospholipid complex was prepared. A central composite design approach was used for process optimization in order to obtain the acceptable puerarin–phospholipid complex. The physicochemical properties of the complex obtained by optimal parameters were investigated by Fourier transform infrared spectrophotometry (FTIS). The physicochemical characterizations of puerarin lipid microspheres was evaluated. The release study in vitro of puerarin was studied by using microdialysis and pressure ultrafiltration technology. Multiple linear regression analysis for process optimization revealed that the acceptable puerarin–phospholipid complex was obtained wherein the optimal values of X1, X2, and X3 were 3, 60°C, and 3 hours, respectively. The FTIS studies of the complex demonstrated that puerarin and phospholipids were combined by non-covalent bonds, not form new compounds. The mean diameter and entrapment efficiency (%) were 171.35 and 87.94, respectively. The release of puerarin lipid microspheres could be evaluated by using microdialysis and ultrafiltration, but microdialysis seemed to be more suitable for the release study of puerarin lipid spheres. The drug release at three drug concentrations was initially rapid, but reached a plateau value within 30 minutes. Drug release of puerarin from the lipid microspheres occurred via burst release.