The current process of tissue engineering:
Since organs are on short supply throughout the world scientists have taken to trying to create organs in the lab. The field of organ growing is possible thanks to recent advances in stem-cell research and is commonly known as ‘tissue engineering’. Tissue engineering uses the patient’s own cells to build new organs or replace damaged tissues in the patient’s own organs, which is called grafting.3The process works by differentiating pluri-potent stem-cells into the cells that the patient needs. The cells are then allowed to grow and multiply in a nutrient solution. When the cells are in adequate numbers they are sometimes inserted into the patients existing tissue but are most commonly used to grow a new organ or tissue graft.
Organs are however very complicated structures that consist of many components and therefore they are very difficult to replicate. An organ consists of a series of different cells, an extracellular matrix and an intricate web of blood vessels that supplies nutrients and oxygen to the cells. Recreating all of these is a great challenge for scientists.
Creating cells:
To produce the large amount of different cells that are needed for tissue engineering stem cells are used (picture). Stem-cells are undifferentiated cells or ‘base cells’ that have the ability to transform into other forms of cells trough differentiation, such as blood, muscle or fat cells. They are present at conception and some remain in our bodies for our whole lifetime. Their purpose in the body of adults is to repair and produce tissues.9 There are several types of stem cells and they all have different tasks to perform in the body.4 Stem cells are labeled with a series of different potencies aft...
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... from a recently deceased donor and then removing all of the donor cells, leaving only the extracellular matrix. The process is called decellurization and it involves suspending the organ in a container filled with water. The suspended organ is then connected to a pump through a major blood vessel which slowly pumps a detergent through the vascular system of the organ which in turn dissolves all lipids, DNA, soluble proteins and sugars, leaving only the extracellular matrix.22 This method allows scientists to use donated organs that otherwise would have been unsuitable for transplantation as the cells do not need to be alive, making the supply near endless. Scientists are even considering using pig tissues as “Pig tissues are much safer than humans and there's an unlimited supply” says Stephen Badylak, tissue engineering researcher at the University of Pittsburgh.14
Stem cells are the building blocks of the human body. Embryos consist of unspecialized stem cells that transform into the various specialized cells in the body such as cardiac, muscle or bone cells. Fetuses also have stem cells. However, the stem cells are divided into types like muscle, bone or nerves and don't perform a specialized function. Surprisingly, adult bodies also contain stem cells. In adults, stem cells are undifferentiated but limited to specific tissue type. When needed, the stem cells transform into the cells needed for repair and maintenance. The most common source of adult stem cells is bone marrow. Researchers also acquire stem cells from umbilical cords. Without stem cells, embryos could not develop into fetuses and adult
...ograft. If the graft comes from someone who has died, it is called an allograft. Doctors have tried using some types of synthetic grafts but so far these have not worked well. Research is being done to see if there are better types of grafts that can be used.
Brendan Maher, in his article “How to Build a Heart” discusses doctor’s and engineer’s research and experimentation into the field of regenerative medicine. Maher talks about several different researchers in this fields. One is Doris Taylor, the director of regenerative medicine at the Texas Heart Institute in Houston. Her job includes harvesting organs such as hearts and lungs and re-engineering them starting with the cells. She attempts to bring the back to life in order to be used for people who are on transplant waiting lists. She hopes to be able to make the number of people waiting for transplants diminish with her research but it is a very difficult process. Maher says that researchers have had some successes when it comes to rebuilding organs but only with simples ones such as a bladder. A heart is much more complicated and requires many more cells to do all the functions it needs to. New organs have to be able to do several things in order for them to be used in humans that are still alive. They need to be sterile, able to grow, able to repair themselves, and work. Taylor has led some of the first successful experiments to build rat hearts and is hopeful of a good outcome with tissue rebuilding and engineering. Scientists have been able to make beating heart cells in a petri dish but the main issue now is developing a scaffold for these cells so that they can form in three dimension. Harold Ott, a surgeon from Massachusetts General Hospital and studied under Taylor, has a method that he developed while training. Detergent is pumped into a glass chamber where a heart is suspended and this detergent strips away everything except a layer of collagen, laminins, and other proteins. The hard part according to Ott is making s...
Stem cells can be thought of as blank slates or cells that have yet to become specialized. They can be transformed to become cells with special functions.
For decades, biologists have been using stem cells to figure out possible cures for different diseases and even prevent them. Stem cells are cells that can become useable in certain tissues in the body (according to an infant), or tissue cells that are already found in blood, bones, the brain, and skin (in adults or children). Stem cells are being used for patients with lymphoma (begins in the immune system), leukemia (cancer of white blood cells), and other types of blood disorders.
As known by now, Tissue Engineering is the combination of the cell, engineering material and suitable biochemistry factors that are used to improve the biological functions. There are 4 types of Tissue Engineering, mainly which are Autograft, Isograft, Allograft and lastly Xenograft.
Our own immune system such as macrophages help in restoring the damage in the heart for example, damage caused by myocardial infarction. Macrophages responsibilities are to clear the infarcted area and activate other cells, such as fibroblasts, endothelial cells and progenitor cells to help the healing process of the blood vessels (Mercola et al. 2011). Tissue regenerative in today’s world uses the stem cell technology to repair, replace and regenerate the cells of the injured organ or tissues. It is a combination of engineering principles and life sciences in order to create something that able to proliferate and regenerate as well as sustaining and improving its functions. This purpose can be achieved by applying functional cells, scaffolds supplementary, stimulate the growth and signal molecules to needed areas. The scaffold delivers as physical support for the cells as well as to function as organizer guiding the cell growth and differentiation (Leor et al. 2005).
The doctors inject the healthy embryonic stem cells into the patient's body to take over the diseased or damaged cells. The transplant can also be used for chemo or radiation. The fetal tissue transplants have potential cures for diabetes and Parkinson's disease. The clinical potential in tissue repair have the advocates believing that the embryonic stem cells are the possible relief or cure of a wide range of disabilities. The procedure is done by the doctor or surgeon injecting the stem cells into the diseased organ. Another way the procedure is done is via IV. The stem cells are injected into the blood stream by dripping. The stem cells can make new organs and treat many diseases. Robert Lanza built a new type of tissue called the retinal pigment epithelium to help blind adults and youth (Wheelwright). Eventually, stem cells may be able to replace body parts and
Tissue engineering can join the list of medical advances that science-fiction movies beat reality to. This component of regenerative medicine is one of the newest and most intriguing aspects of medicine and is guaranteed to enhance the quality of health care universally.
Stem cells are extremely important necessities in multicellular organisms, such as animals and humans. They are used to repair damaged tissues by the process of cell division and they can also transform into different tissues and organs.1 Stem cells are important because they have the ability to aid with diseases, such as leukemia. They also generate specialized cells, meaning that without stem cells, important organs that power the human body would not exist.2
Due to medical complications, organs may be moved from one body to another or donor site for the purpose of replacing the damaged or absent organs. Apart from the organs, tissues are also transplanted. The organs that can be transplanted are the kidney, heart, lungs, liver, intestines, pancreas and thymes, the most transplanted organ being the kidney followed by the liver and then the lungs. The tissues that are mostly transplanted are the cornea and musculoskeletal grafts (Rebecca Johnson, 2006).
Researchers in this field are seek to know how stem cells can be used to develop into specialized cells or tissue, which aims restore lost function in damaged organs or even grow new fully functioning organs for transplant.
Tissue culture has been in practice since the early 1900’s. Since its start, there has been many breakthroughs in producing a viable plant from culture. Tissue culture is defined as the growth of plants from plant tissue in an artificial medium and a sterile environment. The uses for this technique include food processing, agriculture, pharmaceutics, and medicines. It has an influence on human welfare like food processing, human health, and environmental protection. There is an increasing demand for tissue culture, therefore it is becoming more popular exploring more of its commercial potential. Tissue culture is also used for production of pathogen free plants, germplasm preservations, and year round propagation.
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.
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. Cell biology is the study of cells and how they function, from the subcellular processes which keep them functioning, to the