Liposomes are Drug-Delivery Vehicles
Liposomes are artificial prepared vesicles which are composed of the lipid bilayer. They can be used as a vehicle for nutrients and pharmaceutical drug administration. Liposomes are prepared by disrupting the biological membranes by sonication. Liposomes are closed vehicles that contain both lipophilic and a hydrophilic region. The formation of these vesicles is made by hydrating a mixture of cholesterol and a phospholipid. There are many different approaches to delivering these drugs. Improvements for the performance of the drug molecules are by delayed clearance from the circulation and protecting the drug from the environment and limiting the effects to the target cells. “Liposomes was discovered about 40 years ago by Bangham and his coworker.” (Boddyreddy, 2012) which was an accidently discovery because he was studying blood clotting.
The structures of liposomes are spherical and are usually between 15nm and 1000 nm in diameter. They are able to target the ligands that are attached to their surface to direct them to the appropriate sites wi...
Homeostasis is the biological process that maintains a stable internal environment despite what occurs in the external environment. Chemicals and bodily functions are maintained in a balanced state so the body may function optimally. There are various systems in the human body that require maintenance through the processes of biochemical checks and balances so they may function properly. One of these systems includes the rise and fall of blood glucose and is under the control of the homeostatic regulation process. Homeostasis is essential in blood glucose regulation as high blood glucose levels (hyperglycaemia) and low blood glucose levels (hypoglycaemia) are dangerous and can affect the human body in many ways and can also lead
...des dissolving of 100mg of PC into 15 ml ethanol and then this solution mixture is added drop-wise into a Vitamin C solution. Continuous stirring is required. The conditions like low temperature and moisture content can be achieved. The organic solvent is then evaporated and by maintaining pH at 7.4 of the phosphate buffer solution (PBS), the solvent traces are removed. The Liposome dispersion is then stored under vacuum overnight. The liposome size can be downsized by sonication. Liposome characterisation i.e. size and surface structure can be observed using cryo-transmission electron microscopy (cryo-TEM) (27).
The endothelium is a cell layer that is lined on the interior surface of lymphatic vessels and blood vessels, which are made up of endothelial cells (Dorland, 2012).
Stem cells help us to maintain and heal our bodies, as they are undifferentiated cells, their roles are not yet determined. They have the ability to become anything during early life and growth. Stem cells come from two sources, namely: embryonic stem cells (embryo’s formed during the blastocyst phase of embryological development) and adult stem cells (see figure 3).
The ANS is part of the peripheral nervous system, being split into sympathetic pathways, which prepare the body for action and parasympathetic pathways which prepare the body for rest. This regulates the functions of the body and some of the muscles automatically.
This paper focuses on the benefits of stem cell research in the medical and nursing field. New technology is always being created to help us understand the way the human body works, as well as ways to help us improve diseased states in the body. Our bodies have the ability to proliferate or regrow cells when damage is done to the cells. Take for example the skin, when an abrasion or puncture to the skin causes loss of our skin cells, the body has its own way of causing those cells to regrow. The liver, bone marrow, heart, brain, and muscle all have cells that are capable of differentiating into cells of that same type. These are called stem cells, and are a new medical tool that is helping regrow vital organs in our body to help us survive. Stem cells can come from adult cells, or the blastocyst of the embryo. The cells that come from these are undifferentiated, and can be specialized into certain cell types, making them available for many damaged tissues in the body. While using stem cells in the body is a main use, they are also being used to help doctors understand how disease processes start. By culturing these cells in the lab and watching them develop into muscles, nerve cells, or other tissues, researchers are able to see how diseases affect these cells and possibly discover ways to correct these diseases. While researchers have come very far in using stem cells, there are still many controversies to overcome when using these cells.
The cell plasma membrane, a bilayer structure composed mainly of phospholipids, is characterized by its fluidity. Membrane fluidity, as well as being affected by lipid and protein composition and temperature (Purdy et al. 2005), is regulated by its cholesterol concentration (Harby 2001, McLaurin 2002). Cholesterol is a special type of lipid, known as a steroid, formed by a polar OH headgroup and a single hydrocarbon tail (Wikipedia 2005, Diwan 2005). Like its fellow membrane lipids, cholesterol arranges itself in the same direction; its polar head is lined up with the polar headgroups of the phospholipid molecules (Spurger 2002). The stiffening and decreasing permeability of the bilayer that results from including cholesterol occurs due to its placement; the short, rigid molecules fit neatly into the gaps between phospholipids left due to the bends in their hydrocarbon tails (Alberts et al. 2004). Increased fluidity of the bilayer is a result of these bends or kinks affecting how closely the phospholipids can pack together (Alberts et al. 2004). Consequently, adding cholesterol molecules into the gaps between them disrupts the close packing of the phospholipids, resulting in the decreased membrane fluidity (Yehuda et al. 2002).
Our body need a type of mechanism that is needed to maintain its internal environment. This is usually controlled by the process of homeostasis. Homeostasis is the maintenance of a constant internal environment (that means keeping the condition inside your body the same).
explain the formation of micelles and bi-layers from lipid amphiphilicity. A variety of books were
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.
There are many functions lipids have. One of the main functions lipids are structural components in the cell. Lipids make up approximately 50% of the mass of most cell membranes. The lipids that are found in the cell membrane are called phospholipid. Phospholipid are the predominant lipids of cell membrane. Phospholipids aggregate or self-assemble when mixed with water, but in a different manner than the soaps and detergents. Because of the two pendant alkyl chains in phospholipids and the unusual mixed charges in their head groups, micelle formation is unfavorable relative to a bilayer structure.
Microbes are microscopic life forms, usually too small to be seen by the naked eye. Although many microbes are single-celled, there are also numerous multi-cellular organisms. The human body has 10-100 trillion microbes living on it, making it one giant super-organism. Since the first link between microbes and diseases was made, people have been advised to wash their hands. Scientists, however, have recently started to investigate more closely how the microbes that call the human body home affect our health. While some microbes cause disease, others are more beneficial, working with our bodies in many subtle ways.
If we examine the detailed structures of many transmembrane proteins, we see that they often have three different domains, two hydrophilic and one hydrophobic .(fig 1&2) A hydrophilic domain (consisting of hydrophilic amino acids) at the N-terminus pokes out in the extracellular medium, a hydrophobic domain in the middle of the amino acid chain, often only 20-30 amino acids long, is threaded through the plasma membrane, and a hydrophilic domain at the C-terminus protrudes into the cytoplasm. The transmembrane domain, because it is made of amino acids having hydrophobic side chains, exists comfortably in the hydrophobic inner layers of the plasma membrane. Because these transmembrane domains anchor many proteins in the lipid bilayer, these proteins are not free-floating and cannot be isolated and purified biochemically without first dissolving away the lipid bilayer with detergents. (Indeed, much of the washing we do in our lives is necessitated by the need to solubilize proteins that are embedded in lipid membranes using detergents!)
Many people don't know what biomedical engineers do. A biomedical engineer’s job is actually quite interesting. They analyze and create solutions to improving the quality and effectiveness of patient care. They also design technology to accommodate the needs of people with disabilities. They have a big role in helping people begin new lives. The main job of a biomedical engineer is to help create prosthetic limbs or organs for those who are in need of one.
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)