Team:CSU CHINA/Implementation
Introduction
As a kind of chronic disease, diabetes has recieved plenty attention these years, but there is a small part of diabetes patients, approximately 5 percent, are patients of type 1 diabetes. Most of them are young people like us. However, they are suffering from complications that may kick back, strict diet plan restraining the intake of carbonhydrates and other difficulties in their dailt life. To help our young friends and other type 1 diabetes patients, we heve designed this very “Sweet Guard” to guard their blood glucose.
Sweet Guard is designed as a device that can detect blood glucose and secrete insulin with an encapsuled engineered cell under the help of blue light. What we want our device to accomplish are as following: 1.Sense the alteration of blood glucose 2.Secrete insulin once the glucose concentration reaches the threshold 3.Stop the secretion on time in case of hypoglycemia attack.
The completion of this “3S” concenpt can’t live without any “S”. How to achieve them? How to make sure the security of our project? We will explain these questions in detail down below.
Security
Stopping the loop automatically
In order to avoid the over secretion of insulin, we designed a “brake system” in this engineered cell. Insulin receptor activate MAPK phosphorylation pathway when it senses the insulin concentration reaching a certain level. ELK phosphorylation takes places through cascade reaction. TetR from Tet-off system combine with TRE and makes phosphated ELK able to transcript the DNA of miRNA.
Toxicity of material we used
We are planning to embed the engineered cell under the skin with the capsule made with sodium alginate glue. It has been proved that the toxicity and the immunogenicity of sodium alginate are both very low. It is perfectly safe to put a tiny capsule of sodium alginate under the patient’s skin.
Immune reaction
Putting a engineered cell under your skin can be scary first time you hear it. We have recieved questions about the immune reaction might be caused by the implantation of the cell. Without doubt, this is a question we need to take into our consideration. Members from wet lab say that we are using 293T in labs to test our loop. If this technology is mature enough to be put into use, the first choice for the engineered cell is going to be cells of patients themselves. This will prevent the problems caused by immune reaction and enhance the security of this device.
Special design for Photoallergic patients.
When we were designing our project, trying to figure out the best solution which fits every patient, a problem came into our minds: what if someone with type 1 diabetes wants to use our device but he/she is photoallergic? The blue light exposure may cause damage to this kind of patient. Therefore, a special design is made: use a special kind of optic fiber to conduct the light without letting it hurt the patient. Current literature has proved that the special kind of optic fiber is different from traditional ones, it is not glass, glass can also do harm to patients, it is made of a soft material but the ability is no worse than traditional ones. Through this optic fiber, photoallergic patients can use this device without worrying the damage caused by light.
How we achieve this
Smart wearable device
Where does the blue light come from? How does the blue light illustrate the cell? How do patients get to know when they should get their device to work? The answer is simple enough -- a smart watch. There have been smart watches that can function as glucose meter already, so the technique is pretty mature. The accuracy and the sensitivity can be ensured. When the glucose concentration reaches a certain level or the threshold, the watch will alarm the patient to turn on the blue light and get their engineered cells to work. The blue light is also given by the watch.
Embedding the cell under the skin
Putting this engineered cell under the skin is actually simple enough, there is no need for surgery, it is not a transplantation like stem cell therapy, it just simply is a subcutaneous implantation. No infection will be caused. Maybe all it takes is a quick injection and everything is done.
Start the secretion
The secretion of insulin is activated by the exposure of blue light, as we mentioned above. Turning on the blue light is also easy. The smart wearable device can be connected to your mobile phone through a specific application. Patients can turn on the blue light via the app on their watch or their phone by simply clicking the bottom on the screen.
Cost
Will this equipment be expensive? The price of the device can be a problem. Of course, the research and the experiments we have done or we will do in lab are not cheap, that is the case for every new technology. However, the cost of making a device as we envisioned after all the researches are done and the technology is developed will not be high. If we only take the enginnered cell into consideration, we can even say that it is pretty cheap. The main expense will be on the wearable device and the optic fiber.