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Nano Stemcell

Stem cells are cells found in all multi-cellular organisms. They retain the ability to renew themselves through mitotic cell division and can differentiate into a diverse range of specialized cell types. Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s. The two broad types of mammalian stem cells are: embryonic stem cells that are found in blastocysts, and adult stem cells that are found in adult tissues. We are aware that different types of cells make up our body (e.g., blood cells, skin cells, cervical cells) but usually forget to appreciate that all of these different cell types arose from a single cell, the fertilised egg. Developmental biologists study the awesome events that occur between the fertilised egg and the formation of a new individual. Stem cells can be obtained from several sources:

Spare embryos: stem cells can come from leftover embryos stored at fertility clinics that were not used by couples to have children.
Special purpose embryos: embryos are created in vitro fertilization (artificially in the lab) for the sole purpose of extracting their stem cells.
Cloned embryos: embryos are cloned in labs using somatic nuclear transfer method in order to harvest their stem cells.
Aborted fetuses: stem cells are taken from fetuses in early development that have been aborted.
Umbilical cords: this after-childbirth tissue holds potential for research.
Adult tissue or organs: stem cells are obtained from the tissue or organs of living adults during surgery.
Cadavers: isolation and survival of neural progenitor cells from human post-mortem tissues (up to 20 hours after death) has been reported and provides an additional source of human stem cells.

Embryonic stem cell lines (ES cell lines) are cultures of cells derived from the epiblast tissue of the inner cell mass (ICM) of a blastocyst or earlier morula stage embryos A blastocyst is an early stage embryo—approximately four to five days old in humans and consisting of 50–150 cells. ES cells are pluripotent and give rise during development to all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm. In other words, they can develop into each of the more than 200 cell types of the adult body when given sufficient and necessary stimulation for a specific cell type. They do not contribute to the extra-embryonic membranes or the placenta.

After twenty years of research, there are no approved treatments or human trials using embryonic stem cells. ES cells, being totipotent cells, require specific signals for correct differentiation - if injected directly into the body, ES cells will differentiate into many different types of cells, causing a teratoma. Differentiating ES cells into usable cells while avoiding transplant rejection are just a few of the hurdles that embryonic stem cell researchers still face. Many nations currently have moratoria on either ES cell research or the production of new ES cell lines. Because of their combined abilities of unlimited expansion and pluripotency, embryonic stem cells remain a theoretically potential source for regenerative medicine and tissue replacement after injury or disease.

Adult stem cells

The term adult stem cell refers to any cell which is found in a developed organism that has two properties: the ability to divide and create another cell like itself and also divide and create a cell more differentiated than itself. Also known as somatic stem cells and germline (giving rise to gametes) stem cells, they can be found in children, as well as adults. Pluripotent adult stem cells are rare and generally small in number but can be found in a number of tissues including umbilical cord blood. Most adult stem cells are lineage-restricted (multipotent) and are generally referred to by their tissue origin.

A great deal of adult stem cell research has focused on clarifying their capacity to divide or self-renew indefinitely and their differentiation potential. In mice, pluripotent stem cells are directly generated from adult fibroblast cultures.

While embryonic stem cell potential remains untested, adult stem cell treatments have been used for many years to treat successfully leukemia and related bone/blood cancers through bone marrow transplants. The use of adult stem cells in research and therapy is not as controversial as embryonic stem cells, because the production of adult stem cells does not require the destruction of an embryo. Stem cell lines
To ensure self-renewal, stem cells undergo two types of cell division (see Stem cell division and differentiation diagram). Symmetric division gives rise to two identical daughter cells both endowed with stem cell properties. Asymmetric division, on the other hand, produces only one stem cell and a progenitor cell with limited self-renewal potential. Progenitors can go through several rounds of cell division before terminally differentiating into a mature cell. It is possible that the molecular distinction between symmetric and asymmetric divisions lies in differential segregation of cell membrane proteins (such as receptors) between the daughter cells.

Stem cell treatments

Medical researchers believe that stem cell therapy has the potential to change radically the treatment of human disease. A number of adult stem cell therapies already exist, particularly bone marrow transplants that are used to treat leukemia. In the future, medical researchers anticipate being able to use technologies derived from stem cell research to treat a wider variety of diseases including cancer, Parkinson's disease, spinal cord injuries, and muscle damage, amongst a number of other impairments and conditions. However, there still exists a great deal of social and scientific uncertainty surrounding stem cell research, which could possibly be overcome through public debate and future research.

Our adult stem cell therapy can relieve debilitating symptoms such as severe angina pectoris (chest pain), lack of energy and shortness of breath – and thereby reduce dependence on nitro tablets. Patients who have exhausted many of their treatment options such as a cardiac artery bypass graft (CABG) or balloon angioplasties (PTCAs) are candidates.

Adult stem cell therapy for heart disease creates new blood vessels that improve blood flow to the heart as well as generate new tissue in the heart muscle itself. Skin replacement
The knowledge of stem cells has made it possible for scientists to grow skin from a patient's plucked hair. Skin (keratinocyte) stem cells reside in the hair follicle and can be removed when a hair is plucked. These cells can be cultured to form an epidermal equivalent of the patients own skin and provides tissue for an autologous graft, bypassing the problem of rejection. It is presently being studied in clinical trials as an alternative to surgical grafts used for venous ulcers and burn victims.

Stem cells can provide dopamine - a chemical lacking in victims of Parkinson's Disease.

Brain cell transplantation

Neural stem cells were only until recently thought to be strictly embryonic. Many findings have proved this incorrect. The identification and localisation of neural stem cells, both embryonic and adult, has been a major focus of current research. Potential targets of neural stem cell transplants include stroke, spinal cord injury, and neurodegenerative diseases such as Parkinson's Disease.

Parkinson's Disease involves the loss of cells which produce the neurotransmitter dopamine. The first double-blind study of fetal cell transplants for Parkinson's Disease reported survival and release of dopamine from the transplanted cells and a functional improvement of clinical symptoms. However, some patients developed side effects, which suggested that there was an oversensitization to or too much dopamine. Although the unwanted side effects were not anticipated, the success of the experiment at the cellular level is significant. Again, further studies are needed and ongoing. Over 250 patients have already been transplanted with human fetal tissue.

Treatment for diabetes

Diabetes is caused by the abnormal metabolism of insulin. Normally, insulin is produced and secreted by the cellular structures called the islets of Langerhans in the pancreas. Recently, insulin expressing cells from mouse stem cells have been generated. In addition, the cells self assemble to form structures, which closely resemble normal pancreatic islets and produce insulin. Future research will need to investigate how to optimise conditions for insulin production with the aim of providing a stem cell-based therapy to treat diabetes to replace the constant need for insulin injections.

Stem cell controversy

There exists a widespread controversy over human embryonic stem cell research that emanates from the techniques used in the creation and usage of stem cells. Human embryonic stem cell research is controversial because, with the present state of technology, starting a stem cell line requires the destruction of a human embryo and/or therapeutic cloning. However, recently, it has been shown in principle that embryonic stem cell lines can be generated using a single-cell biopsy similar to that used in preimplantation genetic diagnosis that may allow stem cell creation without embryonic destruction. It is not the entire field of stem cell research, but the specific field of human embryonic stem cell research that is at the centre of an ethical debate.
Contrarily, supporters of embryonic stem cell research argue that such research should be pursued because the resultant treatments could have significant medical potential. It is also noted that excess embryos created for in vitro fertilisation could be donated with consent and used for the research.

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