scholarly journals Evaluation of the Physico-Chemical Properties of Liposomes Assembled from Bioconjugates of Anisic Acid with Phosphatidylcholine

2021 ◽  
Vol 22 (23) ◽  
pp. 13146
Author(s):  
Hanna Pruchnik ◽  
Anna Gliszczyńska ◽  
Aleksandra Włoch
Keyword(s):  
Phase Transition ◽  
Lipid Bilayer ◽  
Chemical Properties ◽  
Main Phase ◽  
Cancer Therapies ◽  
Dependent Manner ◽  
Scanning Calorimetry ◽  
Physico Chemical ◽  
Anisic Acid ◽  
The Impact

The aim of this work was the evaluation of the physico-chemical properties of a new type of liposomes that are composed of DPPC and bioconjugates of anisic acid with phosphatidylcholine. In particular, the impact of modified anisic acid phospholipids on the thermotropic parameters of liposomes was determined, which is crucial for using them as potential carriers of active substances in cancer therapies. Their properties were determined using three biophysical methods, namely differential scanning calorimetry (DSC), steady-state fluorimetry and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Moreover, temperature studies of liposomes composed of DPPC and bioconjugates of anisic acid with phosphatidylcholine provided information about the phase transition, fluidity regarding chain order, hydration and dynamics. The DSC results show that the main phase transition peak for conjugates of anisic acid with phosphatidylcholine molecules was broadened and shifted to a lower temperature in a concentration- and structure-dependent manner. The ATR-FTIR results and the results of measurements conducted using fluorescent probes located at different regions in the lipid bilayer are in line with DSC. The results show that the new bioconjugates with phosphatidylcholine have a significant impact on the physico-chemical properties of a membrane and cause a decrease in the temperature of the main phase transition. The consequence of this is greater fluidity of the lipid bilayer.

scholarly journals Verapamil prevents the effects of daunomycin on the thermotropic phase transition of model lipid bilayers

1991 ◽  
Vol 279 (2) ◽  
pp. 413-418 ◽  
Author(s):  
J M Canaves ◽  
J A Ferragut ◽  
J M Gonzalez-Ros
Keyword(s):  
Phase Transition ◽  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Drug Binding ◽  
Lipid Phase ◽  
Dependent Manner ◽  
Binding Studies ◽  
Scanning Calorimetry ◽  
Lipid Phase Transition ◽  
Fluorescence Depolarization

High-sensitivity differential scanning calorimetry and fluorescence-depolarization techniques were used to study how the presence of daunomycin and/or verapamil affect the thermotropic behaviour of dipalmitoyl phosphatidylcholine (DPPC) vesicles. Daunomycin, a potent anti-cancer agent, perturbs the thermodynamic parameters associated with the lipid phase transition: it decreases the enthalpy change, lowers the transition temperature and reduces the co-operative behavior of the phospholipid molecules. Verapamil, on the other hand, produces smaller alterations in the lipid phase transition. However, when daunomycin and verapamil are present simultaneously in the DPPC vesicles, it is observed that verapamil prevents, in a concentration-dependent manner, the alteration in the phospholipid phase transition expected from the presence of daunomycin in the bilayer. Furthermore, drug-binding studies suggest that the observed interference of verapamil in the daunomycin/phospholipid interaction occurs without a decrease in the amount of daunomycin bound to the lipid bilayer and without the formation of a daunomycin-verapamil complex. Because of the importance of drug-membrane interactions in anthracycline cytotoxicity, we speculate that the lipid bilayer of biological membranes may provide appropriate sites at which the presence of verapamil influences the activity of daunomycin.

scholarly journals The Impact of Filler Geometry on Polylactic Acid-Based Sustainable Polymer Composites

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 149
Author(s):  
Karol Leluk ◽  
Stanisław Frąckowiak ◽  
Joanna Ludwiczak ◽  
Tomasz Rydzkowski ◽  
Vijay Kumar Thakur
Keyword(s):  
Polymer Composites ◽  
Polylactic Acid ◽  
Matrix Material ◽  
Chemical Properties ◽  
Precipitated Calcium Carbonate ◽  
Cellulose Fibres ◽  
Shape Factors ◽  
Pure Cellulose ◽  
Physico Chemical ◽  
The Impact

Recently, biocomposites have emerged as materials of great interest to the scientists and industry around the globe. Among various polymers, polylactic acid (PLA) is a popular matrix material with high potential for advanced applications. Various particulate materials and nanoparticles have been used as the filler in PLA based matrix. One of the extensively studied filler is cellulose. However, cellulose fibres, due to their hydrophilic nature, are difficult to blend with a hydrophobic polymer matrix. This leads to agglomeration and creates voids, reducing the mechanical strength of the resulting composite. Moreover, the role of the various forms of pure cellulose and its particle shape factors has not been analyzed in most of the current literature. Therefore, in this work, materials of various shapes and shape factors were selected as fillers for the production of polymer composites using Polylactic acid as a matrix to fill this knowledge gap. In particular, pure cellulose fibres (three types with different elongation coefficient) and two mineral nanocomponents: precipitated calcium carbonate and montmorillonite were used. The composites were prepared by a melt blending process using two different levels of fillers: 5% and 30%. Then, the analysis of their thermomechanical and physico-chemical properties was carried out. The obtained results were presented graphically and discussed in terms of their shape and degree of filling.

scholarly journals Radiation-induced Grafting of Styrene onto Polyethylene Films for Preparation of Cation Exchange Membranes: Effect of Crosslinking+

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
M. M. Nasef ◽  
H. Saidi ◽  
A. H. Yahaya
Keyword(s):  
Cation Exchange ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Swelling Properties ◽  
Ion Exchange Capacity ◽  
Physico Chemical ◽  
Styrene Divinylbenzene ◽  
Radiation Induced

Crosslinked cation exchange membranes bearing sulfonic acid groups (PE-g-PSSA/DVB) were prepared by radiationinduced grafting of styrene/divinylbenzene (DVB) mixtures onto low density polyethylene (PE) films followed by sulfonation reactions. The effect of addition of DVB (2 and 4%) on the grafting behavior and the physico-chemical properties of the membranes such as ion exchange capacity, swelling and ionic conductivity were evaluated incorrelation with grafting yield (Y%). The structural and thermal properties of the membranes were also studied using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), respectively. Crosslinking with DVB was found to considerably affect the properties of the membranes in a way that reduces the swelling properties and enhances the chemical stability. The ion conductivity of the crosslinked membranes recorded a level of 10–2 S/cm at sufficient grafting yield (28%) despite the reduction caused by the formation of crosslinking structure. The results of this work suggest that membranes prepared in this study are potential alternatives for various electrochemical applications.

scholarly journals Unveiling the Efficiency of Vermicompost Derived from Different Biowastes on Wheat (Triticum aestivum L.) Plant Growth and Soil Health

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 791 ◽  
Author(s):  
Zubair Aslam ◽  
Safdar Bashir ◽  
Waseem Hassan ◽  
Korkmaz Bellitürk ◽  
Niaz Ahmad ◽  
...  
Keyword(s):  
Plant Growth ◽  
Temporal Trends ◽  
Soil Health ◽  
Chemical Properties ◽  
Test Plant ◽  
Cow Dung ◽  
Aphid Infestation ◽  
Physico Chemical ◽  
Chemical Attributes ◽  
The Impact

The present study was conducted to explore the role of different types of vermicomposts (VCs) prepared from different substrates to improve soil health (physical and chemical properties) and wheat plant growth under field conditions. Different combinations of vermicompost prepared from different substrates (cow dung, paper waste, and rice straw) and inorganic fertilizers were applied in soil using wheat as a test plant. The impact of three different VCs on physico-chemical characteristics and nutrient availability in soil was evaluated to examine their efficacy in combination with chemical fertilizers. Temporal trends in vermicomposting treatments at various stages showed significant improvement in physico-chemical attributes of the VCs substrates. All the plant physiological attributes showed significant response where N:P:K 100:50:50 kg ha−1 + 10 t ha−1 cow dung vermicompost was applied. In addition, post-harvest analysis of soil not only revealed that different combinations of the vermicomposting treatments improved the soil health by improving the physico-chemical attributes of the soil. Conclusively, application of cow dung vermicompost along with recommended NPK not only improved crop yield, soil health, reduced insect (aphid) infestation but also fortified grains with Zn and Fe.

scholarly journals The Effects of Apigenin-Biosynthesized Ultra-Small Platinum Nanoparticles on the Human Monocytic THP-1 Cell Line

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 444 ◽  
Author(s):  
Sangiliyandi Gurunathan ◽  
Muniyandi Jeyaraj ◽  
Min-Hee Kang ◽  
Jin-Hoi Kim
Keyword(s):  
Cell Line ◽  
Chemical Properties ◽  
Dependent Manner ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Human Monocytic Cell Line ◽  
Physico Chemical ◽  
Proinflammatory Responses ◽  
Human Monocytic Cell ◽  
Dose Dependent

Generally, platinum nanoparticles (PtNPs) are considered non-toxic; however, toxicity depends on the size, dose, and physico-chemical properties of materials. Owing to unique physico-chemical properties, PtNPs have emerged as a material of interest for several biomedical applications, particularly therapeutics. The adverse effect of PtNPs on the human monocytic cell line (THP-1) is not well-established and remains elusive. Exposure to PtNPs may trigger oxidative stress and eventually lead to inflammation. To further understand the toxicological properties of PtNPs, we studied the effect of biologically synthesized ultra-small PtNPs on cytotoxicity, genotoxicity, and proinflammatory responses in the human monocytic cell line (THP-1). Our observations clearly indicated that PtNPs induce cytotoxicity in a dose-dependent manner by reducing cell viability and proliferation. The cytotoxicity of THP-1 cells correlated with an increase in the leakage of lactate dehydrogenase, generation of reactive oxygen species, and production of malondialdehyde, nitric oxide, and carbonylated proteins. The involvement of mitochondria in cytotoxicity and genotoxicity was confirmed by loss of mitochondrial membrane potential, lower ATP level, and upregulation of proapoptotic and downregulation of antiapoptotic genes. Decreases in the levels of antioxidants such as reduced glutathione (GSH), oxidized glutathione (GSH: GSSG), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and thioredoxin (TRX) were indicative of oxidative stress. Apoptosis was confirmed with the significant upregulation of key apoptosis-regulating genes. Oxidative DNA damage was confirmed by the increase in the levels of 8-oxodG and 8-oxoG and upregulation of DNA damage and repair genes. Finally, the proinflammatory responses to PtNPs was determined by assessing the levels of multiple cytokines such as interleukin-1β (IL-1β), IL-6, IL-8, tumor necrosis factor-α (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), and monocyte chemoattractant protein 1 (MCP-1). All the cytokines were significantly upregulated in a dose-dependent manner. Collectively, these observations suggest that THP-1 cells were vulnerable to biologically synthesized ultra-small PtNPs.

scholarly journals IMPACT OF AGRO-ENVIRONMENTAL SYSTEMS ON SOIL EROSION PROCESSES AND SOIL PROPERTIES ON HILLY LANDSCAPE IN WESTERN LITHUANIA

2015 ◽  
Vol 24 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Gintaras JARAŠIŪNAS ◽  
Irena KINDERIENĖ
Keyword(s):  
Soil Erosion ◽  
Soil Properties ◽  
Soil Ph ◽  
Soil Texture ◽  
Sandy Loam ◽  
Chemical Properties ◽  
Available Phosphorus ◽  
Erosion Processes ◽  
Physico Chemical ◽  
The Impact

The objective of this study was to evaluate the impact of different land use systems on soil erosion rates, surface evolution processes and physico-chemical properties on a moraine hilly topography in Lithuania. The soil of the experimental site is Bathihypogleyi – Eutric Albeluvisols (abe–gld–w) whose texture is a sandy loam. After a 27-year use of different land conservation systems, three critical slope segments (slightly eroded, active erosion and accumulation) were formed. Soil physical properties of the soil texture and particle sizes distribution were examined. Chemical properties analysed for were soil ph, available phosphorus (P) and potassium (K), soil organic carbon (SOC) and total nitrogen (N). We estimated the variation in thickness of the soil Ap horizon and soil physico-chemical properties prone to a sustained erosion process. During the study period (2010–2012) water erosion occurred under the grain– grass and grass–grain crop rotations, at rates of 1.38 and 0.11 m3 ha–1 yr–1, respectively. Soil exhumed due to erosion from elevated positions accumulated in the slope bottom. As a result, topographic transfiguration of hills and changes in soil properties occurred. However, the accumulation segments of slopes had significantly higher silt/clay ratios and SOC content. In the active erosion segments a lighter soil texture and lower soil ph were recorded. Only long-term grassland completely stopped soil erosion effects; therefore geomorphologic change and degradation of hills was estimated there as minimal.

scholarly journals Eudragit S100 Entrapped Liposome for Curcumin Delivery: Anti-Oxidative Effect in Caco-2 Cells

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 114 ◽  
Author(s):  
Vincenzo De Leo ◽  
Sante Di Gioia ◽  
Francesco Milano ◽  
Paola Fini ◽  
Roberto Comparelli ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Polymeric Coating ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Eudragit S100 ◽  
Natural Polyphenol ◽  
Anti Oxidant ◽  
Small Unilamellar Vesicles

Curcumin is a natural polyphenol with strong antioxidant activity. However, this molecule shows a very poor bioavailability, instability, and rapid metabolism in vivo. In this work curcumin was loaded in Eudragit-coated liposomes to create a gastroresistant carrier, able to protect its load from degradation and free it at the site of absorption in the colon region. Small unilamellar vesicles were prepared and coated with Eudragit by a pH-driven method. The physico-chemical properties of the prepared systems were assessed by light scattering, transmission electron microscopy, infrared spectroscopy, and differential scanning calorimetry. The uptake of vesicles by Caco-2 cells and the anti-oxidant activity in cells were evaluated. The produced vesicles showed dimensions of about forty nanometers that after covering with Eudragit resulted to have micrometric dimensions at acid pH. The experiments showed that at pH > 7.0 the polymeric coating dissolves, releasing the nanometric liposomes and allowing them to enter Caco-2 cells. Delivered curcumin loaded vesicles were then able to decrease significantly ROS levels as induced by H2O2 in Caco-2 cells. The proposed work showed the possibility of realizing effective gastroresistant curcumin liposome formulations for the delivery of antioxidant molecules to Caco-2 cells, potentially applicable to the treatment of pathological conditions related to intestinal oxidative stress.

scholarly journals MRI Relaxivity Changes of the Magnetic Nanoparticles Induced by Different Amino Acid Coatings

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 394 ◽  
Author(s):  
Iryna Antal ◽  
Oliver Strbak ◽  
Iryna Khmara ◽  
Martina Koneracka ◽  
Martina Kubovcikova ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Chemical Properties ◽  
Hydrodynamic Diameter ◽  
Contrast Imaging ◽  
Dispersed Particles ◽  
Physico Chemical ◽  
The One ◽  
Molecular Contrast ◽  
The Impact ◽  
Positively Charged

In this study, we analysed the physico-chemical properties of positively charged magnetic fluids consisting of magnetic nanoparticles (MNPs) functionalised by different amino acids (AAs): glycine (Gly), lysine (Lys) and tryptophan (Trp), and the influence of AA–MNP complexes on the MRI relaxivity. We found that the AA coating affects the size of dispersed particles and isoelectric point, as well as the zeta potential of AA–MNPs differently, depending on the AA selected. Moreover, we showed that a change in hydrodynamic diameter results in a change to the relaxivity of AA–MNP complexes. On the one hand, we observed a decrease in the relaxivity values, r1 and r2, with an increase in hydrodynamic diameter (the relaxivity of r1 and r2 were comparable with commercially available contrast agents); on the other hand, we observed an increase in r2* value with an increase in hydrodynamic size. These findings provide an interesting preliminary look at the impact of AA coating on the relaxivity properties of AA–MNP complexes, with a specific application in molecular contrast imaging originating from magnetic nanoparticles and magnetic resonance techniques.

The effect of cholesterol in small amounts on lipid-bilayer softness in the region of the main phase transition

1997 ◽  
Vol 25 (4) ◽  
pp. 293-304 ◽  
Author(s):  
Jesper Lemmich ◽  
Kell Mortensen ◽  
John Hjort Ipsen ◽  
Thomas Hønger ◽  
Rogert Bauer ◽  
...  
Keyword(s):  
Phase Transition ◽  
Lipid Bilayer ◽  
Main Phase

Revisiting lipid – general anesthetic interactions (II): Halothane location and changes in lipid bilayer microenvironment monitored by fluorescence

2004 ◽  
Vol 82 (7) ◽  
pp. 1139-1149 ◽  
Author(s):  
Anna Carnini ◽  
Heather A Phillips ◽  
Leanne G Shamrakov ◽  
David T Cramb
Keyword(s):  
Phase Transition ◽  
Lipid Bilayer ◽  
Acyl Chain ◽  
Significant Shift ◽  
General Anesthetics ◽  
General Anesthetic ◽  
Scanning Calorimetry ◽  
Anesthetic Action ◽  
Steady State Fluorescence Spectroscopy ◽  
Universal Mechanism

A universal mechanism for the action of general anesthetics (GA) is not yet available. In this study, we investigated the interaction between halothane and 1,2-dipalmitoyl-sn-3-glycero-3-phosphocholine (DPPC) and 1,2-dioleoyl-sn-3-glycero-3-phosphocholine (DOPC) bilayers labeled with Laurdan, Prodan, and NBD-C6-PC as the reporter probes using steady-state fluorescence spectroscopy. We have evidence that halothane is located on the acyl chain side, near the headgroup region of the bilayer. Additionally, we find that halothane may be inhomogeneously distributed within DOPC and DPPC bilayers. We also show data that indicate halothane increases the free volume available to fluorescent probes. Differential scanning calorimetry and UV scanning calorimetry experiments were implemented to further observe the effects of halothane addition to the DPPC lipid bilayer. A significant shift of the phase-transition temperature of the DPPC system was observed. Our findings suggest that general anesthetic – lipid bilayer interactions may play a significant role in the overall mechanism of anesthetic action, and these effects should not be ignored when interactions between membrane proteins and anesthetics are considered.Key words: liposomes, anesthesia, fluorescence, phase transition, phospholipid bilayers.

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