Growing Organs From Stem Cells, Term Paper Example

Will growing organs from stem cells render transplantation obsolete as a therapy?

Therapy in stem cells has now been a proven breakthrough as a treatment option for majority of the incurable disease. Scientists are now involved in continuous studies on the types of stem cells. However, the most resourceful of all the stem cells appears to be the “human embryonic stem cells”, hESC’s due to their pluripotency and the high rate of differentiation into other human tissues with the use of the primordial germ layers together with the female and the male germ lines. Today hESC’s have undergone successful in vitro conversion to form functional islets that secret insulin, cardiomyocytes, as well as neuronal cells, followed by their transfer to animal models of diabetic, ischemic, as well as parkinsonian in that order with an indication of  successful engraftment (Ariff, Chui-Yee Fong, & Kalamegam, 1352–1360, 2008).

However, the use of hESC’s in this form of application is associated with ethical issues and other problems such as conversion of  undifferentiated hESCs in to tumor genesis, problems of immunorejection and the insufficiency of the cells that is attributed to elongated time periods required for hESC’s population doubling (Quesenberry & Becker, 1998).

Stem cells are also associated with some properties of self renewal in addition to differentiation that surpass their classification. Some cellular mechanisms take place that facilitate for tissue repair which forms the basis of cell-based therapies. One of the processes that have vital contribution to cell-based therapies is differentiation that facilitates the acquisition of specialized properties of a cell that was initially less specialized (Bullard, Longaker & Lorenz, 2003). This is a continuous process starting from the stage of zygote fertilization and continues progressively to the more advanced tissue formation stage. The changes in cells are under the influence of a sequence of events of gene expression that are associated with genes up-regulation together with down-regulation in the course of cell divisions. The variations in the plasticity of the cells start with unipotency, then proceeds to multipotency and finally pluripotency. This in vitro differentiation may take place under controlled conditions or spontaneously in which case an assortment of cell types are produced (Ariff, Chui-Yee Fong, & Kalamegam, 1352–1360, 2008).

The cells that arise from the three layers of primordial germ are generated leading to the separation of preferred lineage, their purification and then expanded to meet cell-based tissue treatment needs (Lensch & Daley, 2007). The hESC’s undergo controlled differentiation in which case, they are firstly converted to embryoid bodies, EB’s. Consequently the EB’s are exposed to protein-based cytokines spectrum in addition to some growth factors which promote the process of differentiation in a predetermined lineage (Ariff, Chui-Yee Fong, & Kalamegam, 1352–1360, 2008).Trans-differentiation is another possible mechanism that is equally applicable in therapy involving growing organs from stem cells. Researchers have suggested the application of trans-differentiation to facilitate for a mechanism of simple repair for severely damaged tissues (Zhu, Guo & Seeger, 2003).

The technology involving the use of regenerative medicine in addition to tissue engineering is a potential solution for the patients suffering from serious injuries including the failure of reproductive organs in the near future (Kaihara & Vacanti, 1999).  Researchers have made significant progress in the fields of material science, cell transplantation and biotechnology in the construction of biological substitutes with inherent abilities of restoration and maintenance of normal functioning of previously injured or diseased reproductive tissues. The field of stem cells is also advancing with innovative discoveries that will equally benefit therapeutic strategies (Anthony, 2012). One of the most recent discoveries involve the retrieval of stem cells from the uterine tissues which include amniotic fluid in addition to placental stem cells. Additionally, therapeutic cloning together with induced pluripotent cells are additional probable avenues of achieving this objective in therapeutic engineering applications of cell-based tissue. It is however important to note that research in stem cells is in its infant stages but some of the therapies attributed to tissue engineering applying autologous adult cells are already being used in clinics (Colwell, Longaker & Lorenz, 2003).  Regenerative medicine is a field of study that applies a variety of technologies which include stem cells, tissue engineering as well as cloning. Tissue engineering involves a combination of principles in the development of innovative biological substitutes which subsequently aid in the process of maintenance and restoration of normal functioning of body organs and rendering growing organs from stem cells transplantation to be obsolete as a therapy (Anthony, 2012).  The important principles in this regard include materials science, bioengineering as well as cell transplantation. The strategies associated with tissue engineering are classified in two groups. The first one involves applying cellular matrices which is guided by the natural ability of the human body for regeneration. The second one involves applying cells-seeded matrices to achieve a similar objective. The preparation of acellular tissue matrices is achieved trough making artificial scaffolds or alternatively through the removal of cellular components from the tissues with the use of mechanical in addition to chemical manipulation that leads to the production of  collagen-rich matrices (Moradpour, Penin & Rice, 2007). The matrices undergo slow degradation following their implantation and thereby extracellular matrix proteins from host cells secretion replace them. The application of cells for the purpose of therapy can also be achieved through the use of injection. Another possible application involves engineering strategies that applies matrix-based tissue. The process involves dissociating a small donor cells from the mother cell to form an individual cell (Anthony, 2012).  The formed cell is implanted in a culture with a support matrix leading to the formation of cellmatrix construct that is consequently implanted in the host after successful expansion or formed cell is directly in a potential host. The donor tissues can be derived from heterogeneous sources which include bovine, they can also be allogeneic (similar species, dissimilar individual), or they can be autologous. The basis concept is that the structural as well as the functional replacement of tissues will take place with negligible complication. The most preferred type of tissues is the autologous that are obtained from biopsy.

The kidney has also been identified to play a significant role in therapy involving growing organs from stem cells. In the past, the kidney was construed as an organ devoid of generative aptitudes. The dogma to this effect has however been challenged on account of observed trends in the recovery of the kidney after acute injury together with recognition of renal populations with special features of stem cells in a variety of species (Kaihara S, & Vacanti, 1999). Scientists are hypothesizing that human kidney has the potentials for regeneration although the applicable mechanism has not been fully researched. There are a myriad of controversies regarding the origin, potency as well as behavior of the types of cells that aid in kidney regeneration. The contemporary appraisal investigates the existing renal stem cells knowledge along with events  of kidney regeneration, and scrutinizes the prospect challenges associated with application of these insight in implementation of to create novel clinical treatments in as far as  kidney disease are concerned (Kristen & Rebecca, 2012).

The application of stem cells in the field of regenerative medicine has been a center of attention from researchers. According to the perceptions of majority, therapies on the basis of stem cells are an amicable solution to a number of human ailments. As a result, scientists have gained incredible interests in identification of possible stem cells and the features of the stem cells that have embryonic as well as adult regenerative characteristics to meet the needs of growing organs from stem cells for therapy purposes (Tumbar, Guasch, Greco, et al., 2004).  Much interest have been directed to the acquisition of vital skills involving the biology of stem cells that are likely to generate tissues of replacement either with the application of “in vitro” or the “in vivo” techniques (Kristen & Rebecca, 2012). The implication of a stem cell is the cell with the inherent potentials for self renewal after undergoing a series of division and generates some types of differentiated cells or the precursors of these cells (Surani, 2005).

The achievements made in growing organs from stem cells to render transplantation obsolete as a therapy is likely to transform the quality of life for humans in the 21^st century (Gage, 2000). Novel therapeutic technologies are continuously being implemented that are likely to prevent the spread of prevalent ailments and facilitate speedy recovery from diseases that were initially incurable (Seliktar, 2005).  The progress made in cell as well as tissue replacement treatments with the application of technologies involving stem cells together with their progenitors is a contributing factor in the enhancement of causative treatment. However, a myriad of challenges and technical limitations in the development of cell therapies cannot be ruled out. This therefore calls for identification of theoretical changes with regard to feasibility in stem cell treatment options (Jeong, Myungook, Seung & Seung, 2011).

The center of attention of regenerative medicine is innovative therapies that have the potentials for replacement as well as restoration of the aging, lost or damaged cells in humans leading to the restoration of their functioning capabilities. The achievements in these noble objectives are imminent after efforts of collaboration of human development and non-mammalian biology of stem cells, materials science, tissue engineering, and genetics as well as bioengineering (Geoffrey,  Gurtner,  Callaghan & Michael, 2007) The current level of knowledge involve reparative human processes coupled with the exploration of hidden potentials of tissue regeneration which is an important center of research in as far as this field is concerned.

Gaining a comprehensive insight in this field has necessitated for exploration of associated field such as limb regeneration, healing of fatal wounds, biology of stem cells, transfer of somatic nucleus, tissue engineering among others. The knowledge acquired in this endeavor forms an appropriate basis towards the development of novel clinical therapies that supplement and motivate human regeneration (Geoffrey, Gurtner, Callaghan & Michael, 2007).

The success of regenerative medicine is based on a clear knowledge of the natural occurrence of complex regeneration aiming at reestablishment of regeneration of tissues as a human reparative pathway. This is an up-and-coming that applies research tools in human development, biology of stem cells, non-mammalian development, bioengineering, tissues engineering and genetics I achieving the goals of growing organs from stem cells in rendering transplantation obsolete as a therapy (Bao  & Suresh, 2003).  Scientists have been deeply engrossed in regenerative research the mechanisms associated with natural regeneration of lower species has been the primary center of focus. However, with the current interests in biology of stem cells coupled with the new biomaterials, there is a possibility to manipulate cells as well as tissues compatible to the patients with potentials of recapitulation of the processes of regeneration and practical responses in as far as injury is concerned. Acquisition of skills in the human adults’ reparative procedures coupled with the hidden aptitude of tissue regeneration has important implications in regenerative medicine (Geoffrey, Gurtner, Callaghan & Michael, 2007).

Stem cells are associated with essential properties of self renew. As a consequence they embody an unconstrained source human cells that are potentially functional in regenerative medicine (Ilyas, Rahul, Andrew,Guido & Evan, 2007). The applicable strategies behind the application cell-based medical therapy have been validated in the recent past mostly with the aid of rodent cells. Consequently, the other step in this field involved an exhaustive categorization of the human cells. Appreciable progress has been achieved in the recent past with regard to the improvement in the conditions of cell culture, propagation on long term basis, directed differentiation along with transplantation of somatic stem cells as well as the embryonic cells of human beings (Ilyas, Rahul, Andrew,Guido & Evan, 2007). The aspirations of the scientists is the sustainability in the generation of basic knowledge in the biology of human stem cell and improvement in the field of elementary human diseases patho-physiology in an attempt of implementing this technology in clinical applications (Takahashi &Yamanaka, 2006)

The continued transformations in the biology of human stem cells is perceived to be an important development of knowledge in the growing organs from stem cells in rendering transplantation obsolete as a therapy.  A brighter future is imminent, courtesy of stem cell research for the victims of major troublesome diseases including cancer, the Parkinson’s disease, cardiac failure, Huntington’s disease, and diabetes mellitus among others (Ilyas, Rahul, Andrew,Guido & Evan, 2007).

The advancements that have so been achieved in the stem cells research and its application in therapy is a course for great excitement in the community. The achievements are based on the invention of the potential ability of culturing pluripotent stem cells from the fetal tissues of humans while their capabilities to be differentiated is retained (Preston,  Alison, Forbes, Direkze, Poulsom, & Wright, 2003). An important consideration in this field relates to the ethical concerns of harvesting some cells from human embryos and thus, therapeutic cloning has been considered as immoral by some people. However, the current developments involve the use of adult stem cells in induction of a process of differentiation to form multiple lineages of cells. Stem cell is a rapidly developing field of research due to the important clinical role played in offering potential therapy to both malignant as well as nonmalignant disease.

Induced pluripotent stem cells have been associated with great potentials in the growing organs from stem cells to render transplantation obsolete as a therapy. However, the medical applications are not realizable due to a number of obstacles (Liu, 2008). A variety of somatic cells that arise from pluripotent stem cells finds their applications in regenerative treatment with regard to repairs to the tissues that have been injured or damaged as a result of disease invasion (Shinya, 2009). Preliminary research conducted using animal models indicate a breakthrough in the treatment of  injured spinal cords, Parkinson’s disease as well as retinal disease. The application of pluripotent stem cells plays an important role in overcoming a couple of challenges that are associated with the use of stem cells in therapy. The first one is ethical concerns of applying human embryos as a source of cells and secondly, the use of immune rejection following transplantation. It is worthwhile to note that tumor development from undifferentiated cells is a possibility (Rogler, 1997). The full potentials associated with application of pluripotent stem cells can only be realized on improvement of the appropriate methodologies responsible for the generation of the cells followed by precise evaluation of resultant clones as well as subclones so as to enhance the level of efficacy and safety associated with their application in therapy (McKay, 1997).

Growing organs from stem cells for therapy is also applicable in cases of Hepatitis victims. Hepatitis has been an intricate problem in the medical setting and problem is further provoked by the inadequate effectiveness together with worldwide accessibility of contemporary high quality medications coupled with the absence of vaccine to realize its prevalent protection Alexander & Charles, 2009). The HCV pathogenesis is better understood by adoption of animal model with ease of propagation to recapitulate a section or entire viral life cycle as a guide to appropriate drug and development of vaccine. Additionally, the aptitude of replicating the progression of liver disease is decisive for formulating novel strategies of intervention which can potentially reverse or stop liver cirrhosis as well as fibrosis. It is apparent that translating the hurdles to HCV replication for mouse cells is a potential breakthrough for virus–host interactions Alexander & Charles, 2009).

In America, over 20, 000 liver patients are looking for potential donors who can offer a liver to be transplanted in an attempt of rescuing their situation associated with liver diseases such as liver cirrhosis and hepatocellular carcinoma (Hua, Yonghak, Saul, Luigi, & Yoon-Young 2011). The rising numbers of victims are alarming and only a third of these victims are able to get the donor organs. Due to the limitations in the supply of liver replacements, it has become imperative that alternative approaches be evaluated. Potential solution is thought to come from ex vivo hepatocytes of adult human to offer alternative cellular therapies (Rao1999). The approach is however confronted with some challenges due to the limitation in their potential for proliferation and diminishing functionalities as well as viability after their isolation. Significant advances have been achieved in the biology of liver stem cells but the large scale use of this technology is hampered by infrequency of hepatic stem cells that consequently leads to unfavorable nature their isolation and expansion in cases of large scale application (Hua, Yonghak, Saul, Luigi, & Yoon-Young 2011).

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