Formulation and Characterization of Bovine Serum Albumin-Loaded Niosome

Abstract

Niosomal vesicle, as a unique novel drug delivery system, is synthesized by non-ionic surfactants. Both hydrophilic and lipophilic drugs and also biomacromolecular agents, such as peptides and proteins can be encapsulated in this vesicular particle. Regarding polypeptide-based component loading, and delivery potential of the niosome, some valuable studies have been conducted in recent years. However, exploring the full potential of this approach requires fine tuned optimization and characterization approaches. Therefore, this study was conducted to achieve the following two goals. First, formulation and optimization of bovine serum albumin (BSA) load and release behavior as a function of cholesterol (CH) to sorbitan monostearate (Span 60) molar ratio. Second, investigating a cost- and time-effective polypeptide detecting method via methyl orange (MO) dye. To this aim, BSA-loaded niosomes were prepared by reversed-phase evaporation technique. The effect of CH to Sorbitan monostearate (Span 60) molar ratio on noisome entrapment efficiency (EE%) and release profile of BSA was studied using a ultraviolet (UV) spectrophotometer technique (NanoDrop 2000/2000c).Niosome with a 60% CH content showed the highest BSA EE% and release behavior. Then, BSA was dyed using MO in an acidic solution and used in BSA-niosome formulation. The MO-colored protein, loaded into the vesicles, was successfully assessed by an inverted light microscope, in order to observe the protein location in the vesicle. The results obtained in this study can be useful for various applications in different fields, including pharmaceutical, cosmetics, and drug delivery in biomedical and tissue engineering.

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Fusion Method for Solubility and Dissolution Rate Enhancement of Ibuprofen Using Block Copolymer Poloxamer 407

ABSTRACT

Aim of current research was to prepare ibuprofen-poloxamer 407 binary mixtures using fusion method and characterize them for their physicochemical and performance properties. Binary mixtures of ibuprofen and poloxamer were prepared in three different ratios (1:0.25, 1:0.5, and 1:0.75, respectively) using a water-jacketed high shear mixer. In vitro dissolution and saturation solubility studies were carried out for the drug, physical mixtures, and formulations for all ratios in de-ionized water, 0.1 N HCl (pH = 1.2), and phosphate buffer (pH = 7.2). Thermal and physical characterization of samples was done using modulated differential scanning calorimetry (mDSC), X-ray powder diffraction (XRD), and infrared spectroscopy (FTIR). Flow properties were evaluated using a powder rheometer. Maximum solubility enhancement was seen in acidic media for fused formulations where the ratio 1:0.75 had 18-fold increase. In vitro dissolution studies showed dissolution rate enhancement for physical mixtures and the formulations in all three media. The most pronounced effect was seen for formulation (1:0.75) in acidic media where the cumulative drug release was 58.27% while for drug, it was 3.67%. Model independent statistical methods and ANOVA based methods were used to check the significance of difference in the dissolution profiles. Thermograms from mDSC showed a characteristic peak for all formulations with T_peak of around 45°C which suggested formation of a eutectic mixture. XRD data displayed that crystalline nature of ibuprofen was intact in the formulations. This work shows the effect of eutectic formation and micellar solubilization between ibuprofen and poloxamer at the given ratios on its solubility and dissolution rate enhancement.

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Luftemboli via intraossøs nål?

På sykehuset fikk mannen i 60-årene flere venekanyler i overekstremitetene. Den intraossøse nålen ble fjernet etter å ha vært åpen rundt en halvtime mens pasienten lå i sjokkleie.

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Double-sided fresnel zone plates as high performance optics in X-ray microscopy

X-ray microscopy describes a range of analytical techniques, specialized for the characterization of organic and inorganic samples using high energy photons. It takes advantage of the high penetration depth, high resolution and chemical sensitivity of X-rays and allows for the study of extended samples in their native environment without extensive sample preparation. Many of these experimental methods employ diffractive X-ray optics, like Fresnel zone plate lenses to obtain high spatial resolution or the better utilization of the incoming flux. Since improving the efficiency of zone plates can increase the throughput, quality and resolution of measurements, there is a constant demand for high efficiency and high resolution X-ray optics. Stacking is an established concept for extending the capabilities of zone plate optics. By stacking two zone plates in each other's optical near field, they act as a single zone plate with combined optical transmission profile, that would be infeasible to make as a single optical element. Yet the existing implementations of stacking suffer from issues regarding complexity and stability. This work presents the development of an alternative solution to conventional zone plate stacking, that circumvents most of its drawbacks. By patterning two zone plates on the front and back sides of a membrane, double-sided zone plates can deliver the advantages of stacked zone plates as inherently monolithic, single-chip optical elements. Double-sided blazed zone plates with two complementary binary zone plates on the two sides of the membrane were produced to provide an effective four level transmission profile. This allowed to bypass the fundamental limitations of binary zone plates by providing up to 54.7% diffraction efficiency at 6.2 keV while having 200 nm smallest half-pitch and a reasonable working distance. For high resolution zone plates, structure height is the main limiting factor. Therefore by patterning two identical zone plates on the two sides of the membrane, one can double the effective structure height. This provided us with a significant gain in focusing efficiency at high photon energies, as we have successfully measured 9.9% focusing efficiency at 9 keV with 30 nm smallest half-pitch, while preserving diffraction limited optical performance. Stacking two complementary zone plates for multiplying their spatial frequencies opens the possibility for ultra-high resolution zone plate optics. We have successfully produced and tested interlaced zone plate optics down to 7 nm smallest half-pitch while still maintaining practical aperture sizes. This thesis is a comprehensive summary of the work performed for the fabrication and characterization of the high performance zone plates representing each concept and provides possible examples for their future use.

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Impaired topological architecture of brain structural networks in idiopathic Parkinson’s disease: a DTI study

Abstract

Parkinson’s disease (PD) is considered as a neurodegenerative disorder of the brain central nervous system. But, to date, few studies adopted the network model to reveal topological changes in brain structural networks in PD patients. Additionally, although the concept of rich club organization has been widely used to study brain networks in various brain disorders, there is no study to report the changed rich club organization of brain networks in PD patients. Thus, we collected diffusion tensor imaging (DTI) data from 35 PD patients and 26 healthy controls and adopted deterministic tractography to construct brain structural networks. During the network analysis, we calculated their topological properties, and built the rich club organization of brain structural networks for both subject groups. By comparing the between-group differences in topological properties and rich club organizations, we found that the connectivity strength of the feeder and local connections are lower in PD patients compared to those of the healthy controls. Furthermore, using a network-based statistic (NBS) approach, we identified uniformly significantly decreased connections in two modules, the limbic/paralimbic/subcortical module and the cognitive control/attention module, in patients compared to controls. In addition, for the topological properties of brain network topology in the PD patients, we found statistically increased shortest path length and decreased global efficiency. Statistical comparisons of nodal properties were also widespread in the frontal and parietal regions for the PD patients. These findings may provide useful information to better understand the abnormalities of brain structural networks in PD patients.

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Soil Influences Colonization of Root-Associated Fungal Endophyte Communities of Maize, Wheat, and Their Progenitors

Root-associated fungal endophytes are vital component of root microbiome as some mitigate their host’s abiotic and biotic stress. We characterized root-associated fungal endophytes in cereal grains and their progenitors grown on two different soil-types. We aimed at determining how clay and desert soil affects the colonization of root fungal community. Both culture-dependent and culture-independent methods were employed to identify endophytes that successfully colonized greenhouse-grown host plants. The Internal Transcriber Spacer region of fungal ribosomal DNA was utilized for identification purposes. This study revealed soil as a prominent factor influencing the composition of microfungal communities inhabiting the roots of maize (Zea mays subsp. mays) and its conspecific progenitor, teosinte (Zea mays subsp. parviglumis). Similar results were found in wheat (Triticum aestivum subsp. aestivum) and its progenitor (Triticum monococcum subsp. monococcum). The multidimensional comparisons of Morisita-Horn similarity values of fungal colonists of various host plant taxa indicated that soil plays a primary role in shaping the root fungal community; a secondary effect was plant host identity, even when the plant host is a conspecific. Future studies focused on characterizing root endophytes in other cereal grains, and studying the effect of edaphic factors on fungal colonization, can ultimately contribute to crop productivity.

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Postobstructive Pulmonary Edema following Tonsillectomy/Adenoidectomy in a 2-Year-Old with Poland-Moebius Syndrome

A 2-year-old male with Poland-Moebius syndrome was transferred from a local hospital to the Pediatric ICU at Children’s Hospital of Georgia for suspected postobstructive pulmonary edema (POPE) after tonsillectomy/adenoidectomy (T&A). The patient’s respiratory status ultimately declined and he developed respiratory failure. Imaging suggested pulmonary edema as well as a left-sided pneumonia. Echocardiogram showed pulmonary hypertension and airway exam via direct fiberoptic bronchoscopy revealed tracheomalacia and bronchomalacia. He developed acute respiratory distress syndrome (ARDS) and remained intubated for ten days. This case highlights the association between congenital upper body abnormalities with cranial nerve dysfunction and the development of POPE with delayed resolution of symptoms. Patients with upper body abnormalities as above are at great risk of postoperative complications and should therefore be managed in a tertiary-care facility.

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