Supercritical CO2 Generation of Nanometric Structure from Ocimum basilicum Mucilage Prepared for Pharmaceutical Applications

Plant-derived polymers are widely used in the pharmaceutical industry due to their emollient, lack of toxicity, and irritating nature and low cost. In this work, basil seed mucilage was dried using supercritical carbon dioxide phase inversion technique to form a nanometric structure. The obtained polymeric structures were characterized by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) method, and Fourier transform infrared spectroscopy (FTIR) and compared with the oven-derived sample group. It was demonstrated that the product morphology could be controlled by altering the composition of methanol which functioned as the co-solvent in the nonsolvent stream. The most homogeneous product (60-nm mean pore size diameter, 78 m²/g BET surface area with no agglomeration) was obtained with 2.5% methanol. The FTIR data showed that the presence of hydroxyl and carboxyl groups suggested the bioadhesive property of basil seed mucilage was good and many active pharmaceutical compounds might be loaded to the resultant nanometric structure to enhance drug release. Furthermore, the FTIR analyses indicated that the nature of the final product did not change during the supercritical drying procedure.KEY WORDS: basil seed gum, drug delivery, FTIR characterization, nanostructure, natural polymer, supercritical phase inversion     

Electrospinning of Cross-Linked Magnetic Chitosan Nanofibers for Protein Release

A poly(vinylalcohol) (PVA) electrospun/magnetic/chitosan nanocomposite fibrous cross-linked network was fabricated using in situ cross-linking electrospinning technique and used for bovine serum albumin (BSA) loading and release applications. Sodium tripolyphosphate (TPP) and glutaraldehyde (GA) were used as cross-linkers which modified magnetic-Fe₃O₄ chitosan as Fe₃O_4/CS/TPP and Fe₃O_4/CS/GA, respectively. BSA was used as a model protein drugs which was encapsulated to form Fe₃O₄/CS/TPP/BSA and Fe₃O₄/CS/GA/BSA nanoparticles. The composites were electrospun with PVA to form nanofibers. Nanofibers were characterized by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). The characterization results suggest that Fe₃O₄ nanoparticles with average size of 45 nm were successfully bound on the surface of chitosan. The cross-linked nanofibers were found to contain uniformly dispersed Fe₃O₄ nanoparticles. The size and morphology of the nanofibers network was controlled by varying the cross-linker type. FTIR data show that these two polymers have intermolecular interactions. The sample with TPP cross-linker showed an enhancement of the controlled release properties of BSA during 30-h experimental investigation.

Graphical Abstract

Open in a separate windowᅟKEY WORDS: cross-linker, electrospun, magnetite, mano-composite, protein loading     

Comparative analysis of telmisartan and olmesartan on cardiac function in the transgenic (mRen2)27 rat

Telmisartan, an angiotensin receptor blocker, may have unique benefits as it possesses partial peroxisome proliferator-activated receptor (PPAR)-γ agonist activity in addition to antihypertensive effects. In this study, we test whether treatment with telmisartan ameliorates cardiovascular abnormalities to a greater extent than olmesartan, which has little PPAR-γ activity. The hypertensive rodent model of tissue renin-angiotensin system activation, transgenic (mRen2)27 (Ren2) rats and their littermate Sprague-Dawley controls were used. Rats were treated with telmisartan (2 mg · kg(-1) · day(-1)), olmesartan (2.5 mg · kg(-1) · day(-1)), or vehicle via drinking water for 3 wk; these doses achieved similar blood pressure control, as measured by telemetry. Ren2 rats displayed impaired diastolic and systolic function using left ventricular (LV) pressure-volume (P-V) analysis. Load-independent diastolic indexes, including the time constant of isovolumic relaxation and the slope of the end-diastolic P-V relationship, as well as systolic indexes, including preload recruitable stroke work, the dP/dt(max)-end-diastolic volume (EDV) relationship, and the P-V area-EDV relationship, were elevated in Ren2 rats compared with Sprague-Dawley controls (P < 0.05). The Ren2 myocardium exhibited parallel increases in the oxidant markers NADPH oxidase and 3-nitrotyrosine. The increase in the prohypertrophic protein Jak2 in Ren2 rats was associated with cardiac structural abnormalities using light microscopic and ultrastructural analysis, which included interstitial fibrosis, cardiomyocyte and LV hypertrophy, and mitochondrial derangements. Both angiotensin receptor blockers attenuate these abnormalities to a similar extent. Our data suggest that the beneficial effect of telmisartan and olmesartan on cardiac structure and function may be predominantly pressor-related or angiotensin type 1 receptor dependent in this model of renin-angiotensin system activation.     

Comparison of photosynthesis and antioxidative protection in Sedum album and Sedum stoloniferum (Crassulaceae) under water stress

Photosynthetic gas exchange, dry mass production, water relations and inducibility of crassulacean acid metabolism (CAM) pathway as well as antioxidative protection during the C₃-CAM shift were investigated in Sedum album and Sedum stoloniferum from Crassulaceae under water stress for 20 days. Leaf relative water content (RWC), leaf osmotic and water potential decreased with increasing water stress in both studied species. Significant reduction in dry matter production and leaf thickness was detected only in S. stoloniferum after 20-d water stress. Δtitratable acidity and phosphoenolpyruvate carboxylase (PEPC) activity in S. album responded to drought at early stages of stress treatment, continued to increase throughout the entire stress period and reached levels 15 times higher than those in well-watered plants. In S. stoloniferum, however, both parameters responded later and after a transient increase declined again. In S. stoloniferum, in spite of increase by drought stress, net night-time CO₂ assimilation was negative resembling a C₃-like pattern of gas exchange. Catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) activities increased in plants subjected to mild water stress while declined as the stress became severe. Although malondialdehyde (MDA) content was higher in drought-stressed S. stoloniferum, the increase in the concentration of hydrogen peroxide (H2O₂) that may act as a signal for C₃-CAM transition was higher in S. album compared with S. stoloniferum. In drought-stressed plants, SOD activity showed a clear diurnal fluctuation that was more steadily expressed in S. album. In addition, such pattern was observed for CAT only in S. album. We concluded that temporal and diurnal fluctuation patterns in the activity of antioxidant enzymes depended on duration of drought stress and was related to the mode of photosynthesis and degree of CAM induction. According to our results, S. stoloniferum developed a low degree of CAM activity, e.g. CAM-cycling metabolism, under drought conditions.     

Spontaneous gender categorization in masking and priming studies: key for distinguishing Jane from John Doe but not Madonna from Sinatra

Facial recognition is key to social interaction, however with unfamiliar faces only generic information, in the form of facial stereotypes such as gender and age is available. Therefore is generic information more prominent in unfamiliar versus familiar face processing? In order to address the question we tapped into two relatively disparate stages of face processing. At the early stages of encoding, we employed perceptual masking to reveal that only perception of unfamiliar face targets is affected by the gender of the facial masks. At the semantic end; using a priming paradigm, we found that while to-be-ignored unfamiliar faces prime lexical decisions to gender congruent stereotypic words, familiar faces do not. Our findings indicate that gender is a more salient dimension in unfamiliar relative to familiar face processing, both in early perceptual stages as well as later semantic stages of person construal.     

Adenovirus-mediated expression of the HO-1 protein within MSCs decreased cytotoxicity and inhibited apoptosis induced by oxidative stresses

The capacity of mesenchymal stem cells (MSCs) to survive and engraft in the target tissue may lead to promising therapeutic effects. However, the fact that the majority of MSCs die during the first few days following transplantation complicates cell therapy. Hence, it is necessary to strengthen the stem cells to withstand the rigors of the microenvironment to improve the efficacy of cell therapy. In this study, we manipulated MSCs to express a cytoprotective factor, heme oxygenase-1 (HO-1), to address this issue. Full-length cDNA of human HO-1 was isolated and cloned into TOPO vector by TOPO cloning reaction. Then, the construct was ligated to gateway adapted adenovirus expression vector by LR recombination reaction. Afterwards, the recombinant virus expressing HO-1 was produced in appropriate mammalian cell line and used to infect MSCs. The HO-1 engineered MSCs were exposed to hypoxic and oxidative stress conditions followed by evaluation of the cells’ viability and apoptosis. Transient expression of HO-1 was detected within MSCs. It was observed that HO-1 expression could protect MSCs against cell death and the apoptosis triggered by hypoxic and oxidative stress conditions. The MSCs-HO-1 retained their ability to differentiate into adipogenic, chondrogenic, or osteogenic lineages. These findings could be applied as a strategy for prevention of graft cell death in MSCs-based cell therapy and is a good demonstration of how an understanding of cellular stress responses can be used for practical applications.     

Cadmium affects the expression of metallothionein (MT) and glutathione peroxidase (GPX) mRNA in goldfish, Carassius auratus

Cadmium (Cd) is a widespread non-essential heavy metal that enters the aquatic environment as a result of natural and human-caused activities, including industrial effluent, mining, and agricultural runoff. In the present study, we investigated time and dose-related effect of CdCl(2) on metallothionein (MT) and glutathione peroxidase (GPX) mRNA levels in a number of goldfish tissues, in vivo. Basal MT and GPX mRNA levels remained unchanged in the tissues tested throughout the experiment. Injection with CdCl(2) significantly increased MT mRNA levels in the brain, liver, kidney and intestine in a dose-dependant manner at all time tested (6, 12, 24 and 36 h). We isolated the full length GPX cDNA from goldfish kidneys, and found it to contain 785 nucleotides, including an open reading frame, predicted to encode a protein of 142 amino acids. In contrast, injection with CdCl(2) significantly decreased GPX mRNA levels in the liver and kidney in a time-, and dose-, dependant, and became undetectable after 12, 24 and 36 h. The findings provide molecular characterization of MT and GPX in goldfish and suggest that exposure to Cd results in significant physiological changes in goldfish.     

Vertical Alignment of Size-Controlled Self-Assembled Diphenylalanine Peptide Nanotubes Using Polyethersulfone Hollow Fiber Membranes On Silicon

International Journal of Peptide Research and Therapeutics - The strong piezoelectricity in diphenylalanine peptide develops its technological potential as a smart material. To achieve insight into...     

Selective cytotoxicity of recombinant STXA1-GM-CSF protein in hematopoetic cancer cells

Chimeric proteins are composed of a cell-targeting moiety and a cell-killing moiety. In this study, a chimeric protein, STXA1-GM-CSF, composed of catalytic domain of Shiga toxin (A1) and granulocyte-macrophage colony-stimulating factor (GM-CSF) was constructed and expressed in E. coli. Cytotoxicity, receptor blocking, and neutralization experiments revealed that the chimeric protein induced cytotoxic effect on different cell lines. This effect was found to be specific, due to the presence of the killing moiety (A1), which exerts its effect through a specific GM-CSF-targeting domain, by binding to its receptor present on those cell lines. These initial investigations indicate that the chimeric protein was functional; further analyses are required for its application.