Artificial Organs

Bladder Replacement

A replacement of bladder is necessary in the case of bladder cancer. For a very long time, the medical procedures in curing the cancerous bladder were as follows. The bladder would be cut out from the body through a process called cystemctomy. Afterwards, a portion of the bowel is removed through surgery, and it would function as a tube that would bring the urine outside of the body. However, one cannot ignore the numerous malfunctions that the patient has to risk for this surgical process.  There are mechanical issues involved with attaching the bowl tissues to the ureters, or attaching the bowel to the abdominal wall. There is much danger in placing a bowel in the urinary tract where the functions of the two different organs are somewhat different. In order to prevent such arduous process for a bladder replacement, neo-urinary conduit that is fit for the specific patient can be created. A surgeon takes a fat biopsy from the patient. Then, the smooth muscle cells are isolated from the fat cells, where it is then allowed to duplicate itself. These cells then combine with a tube called biodegradable scaffold. After the full growth of the smooth muscle tissue, neo-urinary conduit is ready for the patient. After the attachment of the conduit to the patient’s urinary system, the patient’s body grows urinary tissues. Only the regenerated urinary tissue remains over time.

Pros to regenerative tissue engineering:

Through this new technology, so many lives are being saved. The patients do not have to wait for an organ donor with the capability of growing their own organs. Furthermore, the patient’s body would not reject the newly implanted organ because it is made out of the patient’s own tissues.

Cons to regenerative tissue engineering:

There are ethical issues underlying the creation of a new organ. The creation of individual body parts could soon lead to a creation of a whole new being, which can raise controversy.

Stem Cells

Stem cells are malleable cells that are capable of multiplying themselves through mitosis. These cells are able to differentiate themselves to form into other types of cells. The three main stem cells are embryonic stem cells, iPS stem cells, and adult (somatic) stem cells. These stem cells are vital in the medical world. Scientists have found that by transforming these stem cells to fit the needs of the patients, they could cure numerous diseases that were incurable before.

            From when the embryonic stem cells were developed until now, many scientists limited their option for cure to only the embryonic cells. Even after a couple of decades later, the embryonic cell still remains as the ‘golden standard’. Embryonic cells are pluripotent stem cells that are found from the inner mass of the blastocyst.  Because it has yet to reach the stages where it forms into three germ layers, these embryonic cells are capable of forming as cells of any part of the body. After extracting the embryonic cells, they are then formed into different types of cells to fit the needs of the patients.

             With the embryonic stem cells, it seemed as if everything was going right for the scientists. However, there was a moral conflict involved with the medical success of embryonic cells. The usage of human embryonic cells brought up ethical disputes whether one’s life should be risked to save another. Therefore, the discovery of iPS stem cells was immensely significant. These cells are very similar to the embryonic stem cells. Although it does not fully function as an exact replica of the embryonic stem cells, it does not differ from the actual embryonic stem cells visually, nor in its basic functions.

            Another type of stem cells is called adult stem cells, or somatic stem cells. These cells work to maintain and fix malformed tissues. These cells can be found in numerous organs and tissues. Some of the organs that contain these cells include brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. The main difference between these cells and the embryonic cells is that these cells have already matured in some extent.

Once the stem cell is isolated from its surroundings, it is then injected with information that allows it to form into the desired type of cell. Also, because of their ability to go through mitosis, replications of the cells are possible. One of the examples in the video that was given to us, was the sickle cell anemia. This disease can be characterized by the malfunction of the red blood cells, as they are incapable of transferring proper amount of oxygen throughout the body, causing pain to the patient. With the stem cells, the deformed red blood cells can be replaced by the stem cells. Because the patient’s information would be injected into the stem cells, the body would not reject the entering cells, and the patient would have healthy new red blood cells. Because of its ability to form itself to any cell of the body, the stem cell cure would be ideal not only for sickle cell anemia, but for numerous ‘incurable’ diseases.

Embryology

In the process of human reproduction, what happened during cleavage could be seen as the primary development. Cleavage is a process in which a single cell zygote (which is the cells that consist of ovum and sperm) continuously divides itself. Throughout the process, the main function of cleavage is to create an embryo through a process called mitosis.

There are two crucial reactions that take place during the development of an embryo. Acrosomal reaction is a reaction mediated mainly by calcium. During its process, significant changes in the sperm occur. This change is very important as the sperm transforms so that it would be able to penetrate through the ovum.  Another reaction called Cortical reaction occurs once the sperm has entered into the egg. Then, the egg releases calcium ions, and the cortical reaction is described as the sudden release of calcium as it fuses with the egg’s membrane.

During its initial stages, the zygotes form a spherical shape. It then undergoes a process called mitosis, which is a separation of the chromosomes in the nucleus in order to create two identical cells. As the cells go through the process of cleavage, the cells are now called blastula. In these cells, now named blastula, numerous molecules that deliver information. This differentiated information proceeds to the next stage, which is the development of the layers of the body. Gastulation is when the cells move in order to position themselves to form the different layers composed of cells. There are three main layers of gastulation, which includes...

Ectoderm: Ectoderm is the outermost layer. The tissues such as skin, hair, sweat glands, epithelium are all under this category.

Mesoderm: The mesoderm is the layer between the ectoderm and the endoderm. Its main function is to form structures that aid in the body movement and support, such as muscles, cartilage, bone, blood, and numerous other connective tissues.

Endoderm: The endoderm is the innermost layer that mostly forms tissues and organs of the digestive and respiratory systems. A few endocrine structures are also formed by the endoderm.

Blastula transforms into gastrula. During the stage of blastula, all cells are very similar in their shape and form, while as the embryo changes into gastrula, two distinct types are cells can be recognized. The two distinct cells can be characterized as outer layer, and the inner layer. The cells of the outer layer protect and react to external stimuli, while the inner cells focus more on the nutrition.  

Organogenesis is the final stage that the embryo goes through. During the organogenesis, the different layers of the embryo (the ectoderm, the endoderm, and the mesoderm) develop into different organs of the baby. The layers folds, splits, and condense in order to develop and differentiate the different organs.