AMINO AMSA-Indonesia EAMSC 2016 | Page 64

they are processed by arranging them in a systematic manner. Data analysis is done by descriptive argumentative analysis to observe the possibility of 3D organ printing for disease modeling as a new drug-testing technique. After data analysis, the authors then underwent a synthesis by relating the research problem, aim, and discussion. Finally, a conclusion is made with suggestions as a form of statement. III. Results Stem Cell Stem cells are cells that have outstanding potential to develop into other types of cells with much more specific functions. They are present in a wide variety of tissues, may it be during early life or growth, and naturally serves to repair tissues. Generally, stem cells have two properties that distinguish them from other cells: renewal and differentiation. Initially undifferentiated cells, stem cells can renew themselves through cell division when they are inactive after a long time. When active, these cells can differentiate to other specific cells, forming new tissue, under certain physiological conditions. (National Institutes of Health, U.S. Department of Health and Human Services, 2015) Overall, stem cells differentiate into other cells by means of epigenetic mechanisms. Stem cells have varying degrees of differentiation potential and thus are classified based on these degrees. Cells which can differentiate to all embryonic and extra-embryonic cells are said to be totipotent, while those that differentiate to only embryonic cells are said to be pluripotent. Some cells may differentiate into multiple types of cells but will not differentiate into cells with no relation to its tissue of origin; these are said to be multipotent cells. Examples of these type of cells are hematopoetic stem cells and mesenchymal stem cells. There are also stem cells which only differentiate into only a specific type of cell, such as the spermatogonium stem cell; these are unipotent cells. (De Los Angeles, Ferrari, Xi, Fujiwara, Benvenisty, Deng and Daley, 2015) Out of these stem cells, pluripotent and multipotent cells are the types of stem cells that are commonly used for research and treatment. Hematopoetic stem cells from the bone marrow are widely used for transplants for diseases such as leukemia, while mesenchymal stem cells have wide applications for replicating bone tissue, adipose tissue, cartilage, tendons, muscle, or even regenerating certain tissues such as