Characterization of niosomes: For characterization of niosomes their size, shape and morphology, bilayer of niosomes, number of lamellae, vesicle diameter, vesicle charge, vesicle size, encapsulation efficiency, in-vitro release kinetics etc. are studied. Size, shape and morphology Structure of niosomes is studied using Scanning electron microscopy(SEM)/Transmission electron microscopy(TEM). The size or diameter of niosomal vesicle can be determined by Photon correlation spectroscopy where it helps to determine the mean diameter of vesicles specifically. Visualization can simply be done by freeze fracture microscopy. Lazer beam spectroscopy is used to study the morphology as well as size distribution of niosomes. Electron microscopy can also Number of lamellae Number of lamellae can be determined using various techniques like electron microscopy, nuclear magnetic resonance(NMR),small angle x-ray scattering etc.[33]. Vesicle diameter Diameter of vesicles can be determined by various techniques like light microscopy, photo correlation microscopy and freeze fracture microscopy. When freeze thawing method is used then it causes increase in the diameter of vesicles which may be due to fusion of vesicles during the cycle(keeping suspension at 20ºC for 24 hours and heating at ambient temperature) [29]. Vesicle charge Vesicle charge plays an important role and zeta potential of individual noisome can help to estimate surface charge. Since, charged niosomes are more stable against fusion and aggregation like conditions they are preferred over uncharged ones. Charged vesicles are measured using microelectrophoresis. Recently various methods have been used for same like pH sensitive fluorophores, dynamic light scattering etc. [29]. Measurement of Vesicle As the parameter like drug retained into the niosomes can be used as characteristic to study the stability of niosomes they are collected after particular time intervals like (0, 1, 2, 3 months ) and their colour, drug retaining capacity etc. are determined and further their stability is studied using various analytical methods like UV, HPLC etc.[31] In a study conducted by Manosroi A et al. can help us understand about stability of niosomes.In this a gel was prepared containing niosomes loaded with a semi-purified fraction containing gallic acid from Terminalia chebula galls (Family Combretaceae) which was found to enhance longitivity. The semi-purified fraction containing phenolic compounds was loaded in elastic and non-elastic niosomes and the prepared gel was evaluated using closed patch test for rabbit skin irritation and the skin anti-ageing effect was studied in human volunteers by measuring the skin elasticity and roughness. The results demonstrated that when elastic and non-elastic niosomal gel was applied the % parameter changes of skin elastic recovery and skin elastic extension were-21.25 and -22.63%, +28.73 and +32.57; respectively. Also thesegels showed a significant decrease of the maximum and average roughness values with the parameter changes of -39.47 and -35.28%, -29.43 and -32.38; respectively. Thus, the loaded niosomes gave
As the matrix hardens, it forms lamella, a tube of the solidified bone matrix, which forms the lamellar bone. Essentially, lamellar bone is lamellae with collagen fibers surrounding each lamella. It is important to know that collagen fibers on one layer, run parallel to the collagen fibers on another layer. For this reason, lamellar bone is very tough. The lamellar bone is located on both sides of the spongy bone and thickens around the trabeculae. The blood vessels are still situated within the spongy bone and form the red marrow. If a lamellae form around a blood vessel, it creates an osteon with a central canal where the blood vessel is
We can measure the amount of beta galactosidase produced in each tubes indirectly although it is difficult. ONPG is converted to galactose and o-nitrophenol by beta-galactosidase which has a yellow color with an absorbance at 414nm. The amount of ONPG
The mitochondria has an eggshape structure. The mitochondria consists of an inner and outer membrane. The outer membrane is what shapes the organelle to its egglike shape. The inner membrane which folds inward makes a set of "shelves" or cristae that allow the reactions of the mitochondria to take place. The more the mitochondria makes these reactions the more the inner membrane folds.
Endoplasmic Reticulum, Golgi Apparatus, and Lysosomes. (2013). In Scitable Nature Education. Retrieved December 09, 2013, from http://www.nature.com/scitable/topicpage/endoplasmic-reticulum-golgi-apparatus-and-lysosomes-14053361
Another trend in this table which demonstrates this phenomenon is the decreasing FPV of the CHO cells after cooling and freezing/thawing which shows the increasing membrane fluidity. However, compared to the control cells (at 0 mg) the CLC treated cells still showed considerably less membrane fluidity after being cooled.
showed that phosphorlyation is not neccessary for Smo translocation but rather inhibition of Smo endocytosis was sufficient to drive Smo to the plasma membrane. This was observed by fluorescently labelling Smo with GFP and tracking its location following either treatment with Hh or Dynasore, a pharmacological inhibitor of dynamin-mediated endocytosis (Macia et al., 2006). In both cases Smo translocated to the plasma membrane. The same was done for a nonphosphorylatable SmoSA-GFP fusion in which the inhibition of endocytosis by treatment with Dynasore caused SmoSA to translocation to the plasma membrane. The observation that SmoSA can also be present at the membrane demonstrates that some exchange between the intracellular and plasma membrane bound pools must also occur for nonphosphorylated
The term nanocarriers includes a wide range of different nanosized drug delivery systems. The oldest and at the same time the most clinically established nanocarriers are liposomes, spheres composed of an aqueous core surrounded by one or more concentric lipid bilayers. They are suited for the encapsulation of both hydrophillic and hydrophobic drugs, respectively in the aqueous core and whitin the lipid membrane (Hafner e.a. 2014). Liposomes increase thus the solubility of hydrophobic compounds, they enable trapping of drug molecules with a high potency, they reduce systemic side effects and toxicity and they attenuate drug clearance (Riehemann e.a. 2009)
They are made up of a lot of different molecules. There are many subgroups of vesicles whom are all a little different from each other. The subgroups are very difficult to tell apart from each other. Vesicles are found all over the cell instead of just one general area. Vesicles are separated from the cytosol by at least one layer of phospholipid bilayer; if there is only one bilayer then they are unilamella vesicles, if there are two bilayers they are mutilamellar vesicles. Vesicles in general are a bubble made of liquid that is filled with liquid, than can also be formed naturally or they can be
The cytoskeleton is a highly dynamic intracellular platform constituted by a three-dimensional network of proteins responsible for key cellular roles as structure and shape, cell growth and development, and offering to the cell with "motility" that being the ability of the entire cell to move and for material to be moved within the cell in a regulated fashion (vesicle trafficking)’, (intechopen 2017). The cytoskeleton is made of microtubules, filaments, and fibres - they give the cytoplasm physical support. Michael Kent, (2000) describes the cytoskeleton as the ‘internal framework’, this is because it shapes the cell and provides support to cellular extensions – such as microvilli. In some cells it is used in intracellular transport. Since the shape of the cell is constantly changing, the microtubules will also change, they will readjust and reassemble to fit the needs of the cell.
For example, some of the proteins contain pleckstrin homology domains that bind phosphoinositide and others contain C2 domains that bind membrane lipids in the presence of Ca2+, some proteins contain positively charged regions that bind to negatively charged phosphoglycerides and others contain covalently attached fatty acyl groups or prenyl groups that anchor them to membranes. Another example is Annexin shows Ca2+ dependent binding to the cytosolic surfaces of cell membranes. Ca2+ ions bind to the iface of each annexin and this promote protein–lipid interactions through a combination of electrostatic and hydrophobic mechanisms. The same result has been shown by crystallographic studies with phosphoglyceride analogs, suggested that some of the bound Ca2+ ions may bind directly to the oxygens of phospholipid head groups. Addition to this, adjacent membrane lipids that do not bind proteins directly may modulate the protein–lipid interactions, the binding of proteins to membrane surfaces may promote further changes in the structure and function of the proteins, and groups of proteins that bind to the same membrane surface may interact with each other to produce complex membrane
Synaptic vesicles exist in different types, either tethered to the cytoskeleton in a reserve pool, or free in the cytoplasm (Purves, et al., 2001). Some of the free vesicles make their way to the plasma membrane and dock, as a series of priming reactions prepares the vesicular and plasma membrane for fusion (Lodish, Berk, Zipursky, Matsudaira, Baltimore, & Darnell, 2000).
We left these cups sit for twenty- four hours and then we observed them. The second experiment we set up involved dialysis tubing which was acting like a membrane. In the dialysis tubing we put a liquid that was made of starches and sugars. We then put the dialysis tubing into a beaker of water wh... ... middle of paper ... ...
The nucleus is often the largest organelle found in a Eukaryotic cell with a size of 10-20 un. It is surrounded by two membrane layers which can be identified on the diagram below. Within the nucleus structure are small pores with a size of 100un in diameter. These pores together make up around one third of the nuclear membrane surface area.
In order to study the cell and its component, it has to be visualised and displayed in details. In this practical class, we will be looking at different microscopic techniques that visualise the cell structures and identify its features. As most cells are very small, they cannot be seen with naked eyes and therefore need to be magnified. Light microscopy was first used to magnify the image of the cells using stains. However, some tissue and subcellular structures are too small to be seen even under the light microscope. Therefore another technique was found to visualise the cell in more details. To study the smaller features of the cell, electron microscopy are used. Electron microscopy use electron beam to visualise the specimen. Electron microscopy can only magnify thin structures, therefore fluorescent microscopy are used to visualise the thicker structures. Fluorescent microscopy visualise the structures that emit light by allowing the light to get through the specimen.
Because cells are the ‘basic unit of life’, the study of cells, cytology, can be considered one of the most important areas of biological research. Almost every day on the evening news, we are told about new discoveries in cell biology, such as cancer research, cloning, and embryology. (https://highered.mheducation.com/sites/0073031216/student_view0/exercise3/the_importance_of_cell_biology.html) This report provides an insight into the differences in the structure of cells and the way that they carry out their internal mechanisms. Cells form the basis of all living things and they are the smallest single unit of life.