Our experiments with e.coli and yeast will provide a proof of concept for future possible applications that we are going to work on. We have 4 main aims on our projects:
1- Getting lasing out of e.coli with an organic resonator & gain-medium
2- Getting lasing out of Yeast with an organic resonator & gain-medium
3- Getting lasing from e.coli cells which continue their cell growth and division with an organic resonator & gain-medium
4- Getting lasing from yeast cells which continue their cell growth and division with an organic resonator & gain-medium
If we achieve one of the first two goals, we will show that it is possible to get lasing out of a system which is completely biological.(except the pumping source)
If we achieve one of the 3rd or 4th goals, that achievement will show that we can track and get lasing out of cells that grow and divide.
If our experimental plans work, these studies will be a proof of concept for 6 main applications we want to work on in the future and many basic research studies:
1-Determining the quality of oocytes for in a more accurate and easy way for in-vitro fertilization by lasing out of the cells
2-Red blood cell lasing, which can be used for determining the blood glucose levels in real time
3-Tracking of cancer cells without toxic techniques such as PET
4-Determining the shape changes in tissues for early detection of cancer
5-Determining the lasing changes of ICG (FDA approved fluorescent dye) in blood to detect early liver impairments
6-Live Biosensor for detection of airborne transmitted diseases
7-Applications on Basic research such as Human Cell Atlas, where they determine to characterize every single cell of humans.
Proposed End Users
Our end-users are going to be mainly healthcare providers who are taking care of these issues and researchers who work on projects such as Human Cell Atlas.
One of the first things we want to achieve is to track e.coli cells one by one. We will create biolasers out of e.coli cells to track them as every cell will have a single nanometer wavelength lasing coming out of them so that we can differentiate the signals. This approach may be used for many studies where the researchers have to track and observe a high quantity of cells such as the Human Cell Atlas project.
Other Applications of The Technique
1- Live Biosensor for Detection of Airborne Transmitted Viruses
Oocytes have natural resonator properties. These properties of porcine oocytes make it possible to understand the shape changes that happen to them. As these changes are going to affect the lasing we are going to get out of these cells, we can understand which of the porcine oocytes have shape characteristics that are similar to the quality ones. By doing this we are going to develop user friendly SARS-CoV-2 sensors to decrease the burden over the health care providers. One of our group members, Serena, wrote a grant about “Obtaining Lasing from Oocytes'' this project to Turkey's biggest science organization: TUBITAK to get funding for this project. TUBITAK found the idea safe and feasible and funded it.
Figure 1: Oocytes’ Zona pellucida components representation
This study aimed to decrease the RI value of the Zona Pellucida layer formed by the induction of ZP protein mutants as a result of viral infection in the cell. The sensor to be made aims to strengthen the primary care services of the health system. According to the data published by the Ministry of Health, the number of currently infected healthcare workers is more than 3,000. The reason for this is that healthcare professionals do not have any information about the infection status of the individual who comes to the hospital until the test is done.
The sensor, which will work integrated with the mobile application, will suggest the numbers to call to the person performing the test when it detects the activity of the fluorescent protein, and the patient's COVID-19 positivity status will inform the closest hospital to the location of the patient. In line with this, it is aimed to detect positive patients faster and to reduce the exposure of healthcare personnel. In study design, we were going to test the binding activity and the genetic circuit with engineer VSV-S-ΔG mutant which will express full Spike protein. However, due to the COVID19 restrictions, we will move by computational studies. We will design and test the genetic circuit and are going to create FDTD simulations for lasing of porcine oocytes.
2- Red Blood Cell Lasing
Obtaining lasing from red blood cells look feasible as they have a high refractive index. Thus, they can be used as resonators. By using a fluorescent dye named Acridine Orange which binds to the hemoglobin, we can obtain lasing out of red blood cells. If we can find a safe component that can get into the cell and bind to glucose, we can obtain different lasing levels depending on glucose levels inside the blood cells. Acridine Orange is an FDA investigational drug. However, finding a safe component that binds to the glucose is the challenging part. We talked about this with Dr. Uyanık, an internal diseases doctor, and he told us that if the compound is not big in a way that it will stop glucose from getting in and out of the cells, the problem will be solved. We are still working on designing a proper mechanism for this application.
3- Tracking of Cancer Cells
As we plan to work on proof of concept organisms which divide and grow, if we implement this to the cancer cells, we can get lasing depending on their growth and division rate in connection with the used fluorescent proteins maturation rate.(1/1+t50/tgrowth) This technique will be less toxic than techniques such as PET that use radiation in human bodies. We discussed the potential safety aspects of this possible implementation with expert oncologists. They thought that our idea is feasible.
4- Early Detection of Cancer
Cancers generally start with lesions or stiffness that happen on the tissue. Detecting these small impairments at first is hard but critical for the patient's life. As early detection of cancer is one of the most crucial aspects of cancer treatment, new methods for early detection is needed. We thought that early detection of cancer might be possible if we can get lasing out of tissues, we can detect cancer in its early phase as a little change in the tissue will cause differences in lasing of the tissue cells. We discussed the safety issues and feasibility of our idea with oncologists. They thought that our idea is feasible but we need to focus on 1 common cancer type such as breast cancer because all the tumors different. Also, they said that we need to get ethical committee permission to work with tissues in the future and they can help us to get that permission.
Focusing on Breast Cancer
After we talked with oncologists and experts on cancer, we decided that we should focus on breast cancer and create a feasible plan. We first searched for tissue differences in appearance of a tumor and a normal breast tissue. We found mammogram images of different breast tissues and compared them. We decided that we should first characterize the patients tissue with mammogram because some of the tissues of people are more dense and fatty than others. After we characterize the tissue, we should insert our dye into the tissue and test what kind of lasing we get out of it. After we characterize the tissue, all the patient needs to do is to do regular lasing tests with infrared or NIR in hospitals instead of regular mammogram imagings that use radiation. By using our technique we may detect cysts, cancerous tumors, fibroadenoma and breast calcification as early as possible.
Dense and Fatty breast tissue
Image credit:National Cancer Institute, 1994
Image credit: National Cancer Institute, 1990
5- Detecting Early Liver Impairments
As we discussed with Dr. Uyanık, he suggested that working to understand early liver impairments is important for patients in Turkey because they can’t get their drugs with government support if they can’t prove their livers lose their function. To solve this problem we proposed that if we track ICG, as it gets destroyed in the liver, we can track the if the liver works properly or not by obtaining lasing out of ICG. As ICG is a fluorescent dye and it is an approved drug by FDA, this idea may be safe and feasible for the future.
Dr. Uyanık said that if the excitation source is not too powerful, it won’t damage the human body. So we need to adjust and do experiments on it to find the optimal excitation wavelength in order to implement it to real life in the future.
6- In-vitro Fertilization
As mentioned before, one of our team members had a grant for obtaining lasing out of oocytes accepted for a different application. We thought that this idea might be feasible for determining the quality of oocytes that are used for in-vitro fertilization. As they are natural resonators in right conditions, the only thing we need to adjust is the wavelength we are going to send for lasing. By obtaining lasing from oocytes, we will create an efficient method for determining the quality of oocytes which will increase the rate of successful in-vitro fertilizations for every age group. After we talked with Dr. Simopoulou and Dr. Yakın, we learned that inserting a dye is not feasible. So we changed our plans in a way that we can characterize then oocytes without using dyes and just checking their resonator properties for real life applications in the future. By checking the resonator properties, we can characterize the morphology of oocytes. If an IVF expert has some uncertainties to decide which embryo to pick, they can turn back and look to the quality of oocytes to choose the embryo. Our technique can also be used to create good stimulation protocols for oocytes.
7- Human Cell Atlas
Human Cell Atlas is a project that focuses on characterization of every single human cell. The project also aims to track those cells but there are many challenges to achieve that. Using fluorescence microscopy doesn’t work because fluorescent proteins emit light in more than 1 wavelength. Thus, when you try to track millions of cells one by one, it is impossible to do that with fluorescence microscopy as the signals mix. However, by using our technique, we can engineer the cells and track many of the cells one by one as we will get one specific nanometer wavelength lasing from every single cell. Single-cell tracking is one of our main goals in our project which may be useful to understand the secrets of human cells.
As most of our application side focuses on health, we need approval from the Ministry of Health of Turkey in the future to create a use for them in healthcare. We need to run clinical trials even if we successfully make these applications work in a laboratory environment. The main challenge is, creating a new healthcare method and using it in real patients after long trials is a really long, expensive and a challenging pathway. For the expenses, after we improve our techniques in our lab, we are planning to apply grants for health-care and start-ups to take our project further. However, our team is ready to work on these applications that can change many patients’ lives.