Using Fluorescence – Polarization Endoscopy in Detection of Precancerous and Cancerous Lesions in Colon and Pancreatic Cancer

Colitis-associated cancer (CAC) arises from premalignant flat lesions of the colon, which are difficult to detect with current endoscopic screening approaches. We have developed a complementary fluorescence and polarization reporting strategy that combines the unique biochemical and physical properties of dysplasia and cancer for real time detection of these lesions. Utilizing a new thermoresponsive sol-gel formulation with targeted molecular probe allowed topical application and detection of precancerous and cancerous lesions during endoscopy. Incorporation of nanowire-filtered polarization imaging into NIR fluorescence endoscopy served as a validation strategy prior to obtaining biopsies. In order to reduce repeat surgeries arising from incomplete tumor resection, we demonstrated the efficacy of the targeted molecular probe towards margins of sporadic colorectal cancer (SCC). Fluorescence-polarization microscopy using circular polarized (CP) light served as a rapid, supplementary tool for assessment and validation of excised tissue to ensure complete tumor resection for examining tumor margins prior to H&E-based pathological diagnosis. We extended our platform towards non-invasive directed detection of pancreatic cancer utilizing fluorescence molecular tomography (FMT) and NIR laparoscopy using identified targeted molecular probe. We were able to non-invasively distinguished between pancreatitis and pancreatic cancer and guide pancreatic tumor resection using NIR laparoscopy

Bioinspired Polarization Imaging Sensors: From Circuits and Optics to Signal Processing Algorithms and Biomedical Applications

In this paper, we present recent work on bioinspired polarization imaging sensors and their applications in biomedicine. In particular, we focus on three different aspects of these sensors. First, we describe the electro–optical challenges in realizing a bioinspired polarization imager, and in particular, we provide a detailed description of a recent low-power complementary metal–oxide–semiconductor (CMOS) polarization imager. Second, we focus on signal processing algorithms tailored for this new class of bioinspired polarization imaging sensors, such as calibration and interpolation. Third, the emergence of these sensors has enabled rapid progress in characterizing polarization signals and environmental parameters in nature, as well as several biomedical areas, such as label-free optical neural recording, dynamic tissue strength analysis, and early diagnosis of flat cancerous lesions in a murine colorectal tumor model. We highlight results obtained from these three areas and discuss future applications for these sensors