Utilizing Microfluidics for Optimizing Stem Cell Therapies
Stem cell therapies have been successfully conducted for over 50 years. Bone marrow transplants replace stem cells in the blood so that after these rapidly dividing cells are killed due to chemotherapy or radiotherapy, the immune system can repair itself. Although bone marrow transplants are the most common of stem cell therapies, there are many degenerative diseases which stem cells hold great promise to curing.
Of all the possible treatments, four will be discussed to give an insight of the different approaches to implementing stem cells. The first treatment is for burn victims who require skin grafts in order to survive. For most sever cases, it is difficult to acquire large enough grafts from the patient making it necessary to use autologous grafts. However, due to complex immune rejection and a shortage of donor tissue, stem cells are researched to provide an alternative. Stem cells retrieved from hair follicles are extracted and cultured into keratinocytes. Keratinocytes can be made into an epidermal equivalent and transplanted to the patient. Since the cells were acquired originally from the patient, there is no complication with immune rejection. This type of therapy can also be applied to patients with venous ulcers. What makes this therapy attractive for use with microfluidics is that the cells native development is on a 2 dimensional surface. Unlike many other tissue components, skin's 2D structure is more easily mimicked in vitro allowing for better results.
Another large market is for diasabilities relating to neuronal cells. It was first believed that all cells in the adult brain were fully differentiated and that only embryonic stem cells could serve as a source for neuron growth. However, neural stem cells do exist and provide a source to combat strokes, spinal cord injury, and neurodegenerative diseases such as Parkinson’s disease. These cells are able to cultured from the developing cerebral cortex and differentited in vitro into a myriad of cell types which can be used to treat the listed dibilitating diseases. The use of microfluidics is desired for differentiating neuronal stem cells becasue of their highly sensitive nature. Microfluidics has a unique ability to maintain stable microenvironments to ensure reproducible results.
Diabetes is a big hope for stem cell therapy becasue of the over16 million Americans suffering from the disease. Diabetes is a result of the patients inabilty inability to produce their own insulin, which is is normally produced by islets cells in the pancreas, resulting in a buildup of glucose in the bloodstream. Stem cells serve as a source to replace these abnormal islets cells. Although islets cells have been differentiated from embryonic stem cells, successful integration of the cells in the body to produce insulin has been difficult to overcome. Preliminary research has shown that implanting only the beta islets cells, which produce insulin, do not funciton was well as whe with other types of islets. This is where microfluidics can provide a platform where more elegant approches to controlling the differentiation of stem cells into different types of islets can be devised.
For the eye, one cause of blindness is degeneration of retinal cells. The retina contains photoreceptors which transmit signals to the optic nerve allowing your brain to see. However, when these cells are damaged, surrounding cells do not readily divide to compensate for the loss. Currently there are retinal cell transplants which have proven successful to overcoming patients from going completely blind. Unfortunately, there is a large limit to the amount of available retinal cells. This makes stem cells an attractive option because they serve as an almost infinite supply of retinal cells. Microfluidics can be used as a tool to miminze the cost of mass producing retinal cells and provide a means for a precise protocol which can be ensured to be safe.