Stem cells are undifferentiated cells, and thus have the ability to turn into various other tissues and thus organs. Given this property, they may be used for drug testing and organ regeneration. Researchers are looking into using stem cells to deduce why cells may turn cancerous, or the causes of genetic defects.

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One of the most commonly seen applications of stem cell therapy is haemopoietic stem cell transplant, where stem cells from the patient’s own body are engrafted. These cells include stem cells from cord blood, peripheral blood or from bone marrow. However, donor cells may be utilized in applications where immune function needs to be regenerated.

 

It is a common path of treatment in cases of chemotherapy or radiation, and may be used to counter leukemia and other malignancies. Further research has now allowed us to screen allograft donors for the best match to be selected. This helps minimize the risk of immune rejection as well as graft v host disease.

 

Better immunosuppressants have been developed. While a patient’s own stem cells are preferred, more avenues have been created for the existence of options that allow for allografts as a more permanent solution.

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In some cases, stem cells have been used to regenerate tissue systems such as the cornea or the epidermis. This was extremely beneficial in treating burn and trauma victims, as well as those who suffered corneal disintegration or destruction. While this principle dates back to the 1970s, it has started being widely applied since the 2000s.

 

A method known as ex vivo expansion has also been used to generate corneal and epidermal stem cells. It involves the use of mouse fibroblast cells and bovine serum. While the use of animal products should be kept to a minimum in human applications, there have been no perceived side effects on patients who were exposed to these grafts. The grafts need to be optimized to allow for functionality and improved surfaces for implanting.

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While hematopoietic stem cell therapy is common, those involving skin or corneal grafts are not. The sample size of patients eligible is rather small, and the treatment is extremely expensive. Thus, the commercial sale is not profitable, while government healthcare requires far too much investment to integrate corneal and epidermal grafts.

 

There is however research that aims to graft stem cell differentiated brain tissue into patients with neurodegenerative diseases. This can help control and possibly reverse the symptoms of diseases such as Parkinson’s or Huntington’s disease. Results so far in these trials are varied across a spectrum and methods of transplant as well as patient selection must be refined before conclusive results can be drawn.

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Human embryonic stem cells have the indefinite capacity to differentiate and self-renew. These cells, known as hESCs, are isolated from the inner cell mass of blastocysts. These are used to study early embryonic and fetal development. They also have applications in drug development and delivery systems. However, concerns still exist about the chances of rejection after transplantation.

 

Human-induced pluripotent cells (hiPSCs) have now been discovered, thus reducing the need for an ethical debate over hESCs. These are reprogrammed fibroblasts with overexpression of pluripotency-related transcription factors. Various studies establish that there is very little difference between hiPSCs and hESCs at the structural (molecular and genetic) as well as functional and morphological level. They are also accessible from the patients themselves in cases of genetic anomalies. These cells differentiate into various types in response to developmental cues.

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More recent studies show that there is a large difference in the epigenetic and genetic levels in hESCs and hiPSCs. However, they prove to be extremely useful for most practical purposes, the most prominent being disease modeling. hiPSCs have been used to characterize diseases such as Parkinson’s disease, Duchenne type muscular dystrophy, and Alzheimer’s disease. The application to modeling other diseases is still under question and research.

 

We believe that furthering stem cell research will definitely lead to other applications coming up, with reaches in organ transplantation, grafting, drug mechanisms, and degenerative diseases.