Stem cells are undifferentiated cells that can differentiate into specialized cells and can self-renew. There are several types of stem cells including embryonic, adult, and fetal stem cells. Embryonic stem cells are the most versatile but also raise ethical issues, while adult stem cells are more limited in their differentiation potential. Stem cell therapy works by stem cells differentiating into the type of cells needed to repair damaged tissue when transplanted into the body. Current applications of stem cell therapy include treating diseases like cancer, diabetes, and Parkinson's disease.

1. STEM CELL THERAPY Jaswinder devi RP8003A05 11008684

2. What are Stem cells? Stem cells are “master cells “ The raw material :- from which all of the body’s mature, differentiated cells are made. Stem cells give rise to brain cells, nerve cells, heart cells, pancreatic cells, etc.

3. The unique properties of all stem cells Undifferentiated / unspecialized cells Undifferentiated cells can differentiate to yield major specialized cell types or organs Self-renewal property is to maintain and repair the tissue. Thus they have potential to replace cell tissue damaged by severe illnesses.

4. Stem cell Stem cell ( unlimited cell division ) Self-renewal Specialized cell (e.g., white blood cell) Differentiate

5. Potency definitions of stem cells Totipotent : can differentiate into an entire organism , result from fusion of egg and sperm - can form any cell of the embryo as well as the placenta. Pluripotent : can differentiate into any tissue type except placental tissue

6. Multipotent : can differentiate into multiple specialized cells of a closely related family of cells Unipotent : these cells only produce one cell type., but have the property of self renewal which distinguishes them from the non stem cells.

8. Types of stem cells Embryonic : derived from the inner cell mass of a blastocyst / human embryo Source : 1. Excess fertilized eggs from IVF (in-vitro fertilization) clinics Therapeutic cloning (somatic cell nuclear transfer)

9. Zona pellucida Blastomeres (Zygote)

10. Adult : derived from mature organisms that can divide to form more differentiated cells - but are less versatile and more difficult to identify, isolate, and purify. Eg: Stem cells have been found in the blood, bone marrow, liver, kidney, cornea, dental pulp, brain, skin, muscle Fetal : derived from aborted fetal tissue Umbilical : derived from umbilical cords - All blood cell types (red blood cells, white blood cells, and platelets)

11. Advantages of Embryonic Stem Cells over adult stem cells Difficult to isolate in adult tissue. Easy to obtain but blastocyst is destroyed. Less Stable. Capacity for self-renewal is limited. Stable. Can undergo many cell divisions. “ Multipotent” (“can become many but not any”) E.g., blood stem cells can develop into several blood cell types, but cannot develop into brain, kidney, or liver cells “ Pluripotent” (can become any cell types present in the human body ) Adult S.C. Embryonic S.C.

12. How stem cell therapy works? When stem cells are transplanted into the body and arrive into the injured part, brain being targeted for tissue regeneration, the stem cells are coming in contact with growth chemical’s (like EGF’s , NGF’s and HGF’s )in the body. These chemicals program the stem cells to differentitate into the tissue surrounding it.

13. Current stem cell therapy

14. Hematopoietic stem cell transplantation (“HSCT”) Stem cells that give rise to the lymphocytes and other cells of the immune system, also make blood cells, are called hematopoietic stem cells. HSC’s are charecterised by the presence of CD 34 antigen The process of taking stem cells from one person and putting them into another is therefore called “ HCST” To treat cancer patients with conditions such as leukemia and lymphoma, sickle cell anaemia, Used in Providing a functional immune system in a person with SCID. In Restoring the haematopoietic system

16. Stem cells in treating baldness As hair follicles contain stem cells – dermal papilla Take stem cells from existing hair follicles Multiply them in cultures Implant the new follicles into the scalp

19. Stem cells from patient’s plucked hair can be grow into skin Hair follicles contain skin stem cells (keratinocyte) Pluck the patient’s hair Cultured to form epidermal cells equivalents of the patients own skin This is autologous graft thus bypassing the problem of rejection Used for venous ulcers and burn victims

20. Diabetes Diabetes patients lose the function of their insulin-producing beta cells of the pancreas. Human embryonic stem cells may be grown in cell cultures and stimulate to form insulin-producing cells , that can be transplanted into the patient

21. Pancreas is digested with collagenase that frees islets from surrounding cells Centrifugation of isolates containing mainly alpha and beta cells Then purified islets beta cells And transplanted through a catheter into the liver where they become permanantly established.

22. Corneal disease / blindness Result in poor vision Take stem cells from healthy eye Grown onto contact lenses in clinical lab Lenses are worn by the patient for a period of three weeks Then migration of human stem cells from lens to damaged eye and begin to repair process Thus heals the damaged cornea and quickly improves the vision

24. Parkinson disease Caused when key brain cells that produce message carrying chemical/neurotransmitter (dopamine) die off. Symptoms start with the patients trembling and can end up paralyzed.

25. Harvesting of stem cells from patients bone marrow, foetus or any other source Culturing of harvested stem cells in lab conditions - to get high concentrations of stem cells Then purified and high concentration of stem cells are surgically injected in the brain of patient.

27. Brain damage Stroke and traumatic brain injury lead to cell death, characterized by a loss of neurons and oligodendrocytes within the brain. Healthy adult brain contain neural stem cells, these divide and act to maintain general stem cell numbers or become progenitor cells.

28. Missing teeth Take stem cells/dental pulp from the patient. Both adult mesenchymal stem cells and embryonic stem cells can be used Culture in lab.- into a tooth bud

29. Then implant tooth bud in gum which fuses with jaw bone and release chemicals that encourage nerves & blood vessels to connect with gum As a result it will give rise to new tooth/ dentin approximately within 2 months

30. Kidney Stem Cells Take stem cells from embryo ,bone marrow or an umbilical cords Culture these stem cells with special chemical broth that encourages the growth of kidney cells Then new kidney cells can now be injected into a kidney to repair damaged tissue

32. Deafness/ hearing loss Embryonic stem cells are capable of differentiating into cochlear hair cells in the adult inner ear

33. Orthopaedia Take healthy cartilage tissue Tissue culture of isolated chondrocytes Inject the cultured chondrocytes in knee under patch Treat chondral defects

35. Heart damage

36. Stem cells for Gene Therapy

37. Potential obstacles Difficulty of performing transplantation and caring for post-transplantation patients. Specific factors that aid or hinder acceptance of the particular transplant Ability to obtain source material due to ethical concerns

38. Advantage The critical shortage of organs available for transplantation may be solved in the future by auto-graft techniques Security : low toxicity or non toxic

39. Ethical issues As human embryonic stem cell are isolated from few days old blastocyst as well as fetal tissues Many prolifers believe that human life becomes a human person at the time of fertilization Others disagree : they believe that an embryo has potential to develop into a person, but is not a person itself.

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