Point-of-Care Photonic Devices for Cancer Detection

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Biophotonics is about generating and harnessing light for comprehending the functioning of cells and tissues. Due to the advantage of light such as noninvasive penetration into tissue, nonionizing, and real-time and high-resolution optical imaging, it is used in medicine to improve diagnosis, therapy and follow-up care, setting the trend towards point-of-care (POC) and personalized medicine. The global biophotonics market was valued at $34.29 billion in 2015, and estimated to reach $91.31 billion by 2024. This robust growth is attributed to the increasing aging population and demand for health care improvements. New device for cancer detection is one of the most important areas of biophotonics.***The current standard of cancer diagnosis is to take tissue biopsies from suspicious tumors and perform histopathology analysis in a centralized lab. New POC devices that can shift the diagnostics to the doctor's office will significantly improve the early detection of cancer. This research program will design and realize the next generation photonic devices for cancer detection, focusing on detecting circulating tumor cells (CTCs) in vivo inside blood vessels. ***CTCs are cancer cells of solid tumor origin shed into the bloodstream. CTC is a direct indication of metastasis which accounts for 90% of all cancer-related deaths. CTC also happens in patients with localized cancers and in earlier stage during tumor development. The numbers of CTCs is a critical measure of prognostic for survival or predictive of response to a specific therapy. Therefore, detecting CTCs has the fundamental importance for cancer detection and monitoring treatment outcome in personalized medicine.***Most tumors grow unnoticeably without symptoms until they have reached a significant size or a late stage. As blood circulation will bring CTC to the peripheral vessels from over the entire body, we can potentially detect different types of cancers by finding CTCs in the bloodstream. There are ex vivo approaches to enumerate CTCs from whole blood sample. We envision that the next generation method should detect CTCs in vivo, where no blood needs to be drawn and the entire blood volume could be sampled to find rare CTCs, and the technique could be applied repeatedly.***We will achieve our objective by designing novel in vivo flow cytometry (IVFC). IVFC can detect CTCs by shining light on blood vessel and detect signal that is specific to CTC. In the current IVFC used for animals, CTCs are labeled by toxic exogenous dyes or genetically modified fluorescent proteins. We will develop IVFC by utilizing the intrinsic contrast, particularly using optical coherence tomography to detect the morphological features of CTC by scattering, and using two-photon excited fluorescence to detect endogenous substances in CTC by autofluorescence. It will open a new area of detecting CTCs label-free and lead to next generation POC devices for improving cancer detection.