Agilent Science Futures – An Interview With Rajannya Sen

In this instalment of Science Futures, we hear from Rajannya Sen, a PhD student at University College, Cork.

Rajannya’s research focuses on the development and application of a fluorescence lifetime imaging (FLIM) macro-imager based on the new Tpx3Cam for metabolic assessment of living tissue samples for hypoxia conditions in advanced disease models.

In this interview, Rajannya discusses the real-world applications of her research and explains how technologies have steered her work.

What are the most important outcomes of your research?

Rajannya Sen (RS): The Tpx3Cam imager is single photon sensitive, compact, flexible and fast, and can image samples up to several centimetres in size with a high spatial and temporal resolution. The macro-imager will be tuned to operate in phosphorescent (microsecond FLIM) and fluorescent (nanosecond FLIM) modes with new-generation probes that can detect the key environmental and functional parameters of the tissue (oxygen, pH, temperature, etc.) by changing their emission lifetime.

Is there a particular problem or issue that your research faces that you are addressing?

RS: The classical technique for recording fluorescent lifetimes is time correlated single photon counting (TCSPC) with high temporal and spatial resolution. However, the pixel-by-pixel scanning leads to slow image acquisition times, particularly for phosphorescence lifetime Imaging (PLIM) applications where long pixel dwell times are required to record the long-lived phosphorescence. Alternative techniques such as wide-field imaging with a time-gated charge-coupled device(CCD) camera or frequency domain method can achieve higher image acquisition rates, but they are less accurate and sensitive since gating of the camera leads to photon loss and rough visualization of the decay. Moreover, most of the available instruments are microscopic, macroscopic imaging platforms are still very rare.

What global or societal challenges does your research address?

RS: According to reports, around two thirds of the annual deaths in the world are related to non-communicable diseases (NCDs). Ischemic heart disease and cancers are the main contributors to NCDs which can be detected at an early stage by the reduced oxygen levels in tissues. Therefore, the research would potentially be used to image such hypoxia conditions in advanced disease models. Our motive is to provide the biomedical or diagnostics research industries with an advanced solution to address such studies.

How easy has it been to access the technology required for your research work?

RS: The initial challenge was the background work performed by my supervisor and a team of collaborators. After addressing these challenges our research group came up with the first working prototype of the camera. The next challenge was to obtain the funding to access this new technology for my research which was approved by the Irish Photonic Integration Centre (IPIC). Following this, Photonis came up with a commercial electro optic adapter with inbuilt image intensifier called Cricket^TM which helped to upgrade the protype with improved performance. As a dedicated PhD student for this project, in the first few months, I had to acquire multiple skills related to electronics, programming, Linux, chemistry and biology to start my work with the prototype. Amsterdam Scientific Instruments (ASI) recently came up with an advanced commercial model of the camera, Tpx3Cam. So, upgrading the prototype with the new camera was also very challenging.

Has the technology you have access to influenced your studies?

RS: The technologies used have steered my research to a great extent. The Cricket^TM provided flexibility and compactness to the device. The programming languages developed to support the images is very user friendly and can be easily handled by a layman with no special training. The performance of the imager is equivalent and, in many cases, better than the other available imaging devices. Last but not the least, the technology has also sparked interest in other research groups and has conceived new projects.

Have you been given opportunities to interact with industry and companies to progress your research?

RS: I had opportunities to interact with companies like ASI and Photonis who helped me to upgrade my imager. Also, the research is still in its initial stages, so the plan is to collaborate closely with the industries to commercialize the system for clinical applications in its final stage.

What challenges do you face as a PhD student in understanding your options at the end of a PhD

RS: After completing my PhD I would like to continue to work as a post-doctoral researcher in academia and then shift to R&D for a company in the later part of my career. But if I want to start off with industry, then the main challenge would be to understand if my knowledge and expertise is sufficient with respect to the demand to acquire a position? Also, if I need to develop other skills that are out of the scope of my current research work then how can I develop them?

How prepared do you consider yourself to be for real-world achievement?

RS: My current research topic is interdisciplinary. It includes the study of optics/photonics, chemistry and biology. Being a student of photonics, I had to develop the knowledge of chemistry for preparing the fluorescent and phosphorescent sensors and the skills of biology to handle small and delicate tissue samples. I am also in the process of learning the biomedical reasoning of the behaviour of the tissues showing different lifetimes. Therefore, I possess a number of unique skills and I believe the capability of coping with the different fields of science can lead to real life achievements.

Depending on my research work, I consider a post-doctoral researcher position as my initial choice of career and my achieved skill sets over the years in academia would help to get a position in industry.

Catch up on the previous instalment of Science Futures, an interview with Max Lennart Feuerstein, here.

Find out about some of the common themes to come out of the project here.