Early detection and surveillance of disease progression in epithelial tissue is key to improving long term patient outcomes for colon and esophageal cancers, which account for nearly a quarter of cancer related mortalities worldwide. Spatially resolved diffuse reflectance spectroscopy (SRDRS) is a non-invasive optical technique to sense biological changes at the cellular and sub-cellular level that occur when normal tissue becomes diseased, and has the potential to significantly improve the current standard of care for endoscopic gastrointestinal (GI) screening. Herein the design, fabrication, and characterization of the first custom SRDRS device to enable endoscopic SRDRS GI tissue characterization using a custom silicon (Si) thin film multi-pixel endoscopic optical sensor (MEOS) is described. Depeursinge, "In vivo endoscopic tissue diagnostics based on spectroscopic absorption, scattering, and phase function properties," J. Biomed. Opt. 8(3), 495-503 (2003). 11. Z. Ge, K. T. Schomacker, and N. S. Nishioka, "Identification of colonic dysplasia and neoplasia by diffuse reflectance spectroscopy and pattern recognition techniques," Appl. Spectrosc. 52(6), 833-839 (1998 Marcu, "Effects of fiber-optic probe design and probe-to-target distance on diffuse reflectance measurements of turbid media: an experimental and computational study at 337 nm," Appl. Opt. 43(14), 2846-2860 (2004) Opt. Express 8(3), 1512-1524 (2017 Wilke, and N. Ramanujam, "Performance metrics of an optical spectral imaging system for intra-operative assessment of breast tumor margins," Opt.
Direct
arylation polymerization (DArP) has emerged as an environmentally
friendly, atom efficient method of synthesizing a variety of conjugated
polymers. Here, we report a one-pot approach consisting of DArP followed
by Boc deprotection to synthesize a functional, surface-active adenine-containing
poly(alkylthiophene). Careful control over the polymerization temperature
enables the one-pot polymerization and deprotection strategy for synthesis,
with quantitative (>99%) Boc deprotection achieved in 24 h. This
temperature-controlled
synthesis method reduces extra purification and isolation steps, which
makes the total synthesis more efficient and practical, and allows
higher molecular weight polymer to be made. We quantify the hydrogen
bonding ability of the resulting adenine-containing polythiophene, T
Ad
-
t
T
4h
, by 1H NMR host–guest titration studies and analyze the results
with the Benesi–Hildebrand model, yielding an association constant
of 18.7 M–1 between alkylated thymine and T
Ad
-
t
T
4h
. We demonstrate
that T
Ad
-
t
T
4h
robustly
modifies the surface of cellulosic filter paper (CFP),
and the modified cellulosic filter paper, CFP-T
Ad
-
t
T
4h
, is an effective oil–water
separatory filter with superhydrophobic properties (water contact
angle (CA) ∼151°). The utility of hydrogen bonding interactions
between adenine and cellulose highlights the importance of side-chain
engineering for creating functional materials.
Spatially resolved diffuse reflectance spectroscopy (SRDRS) is a promising technique for characterization of colon tissue. Herein, two methods for extracting the reduced scattering and absorption coefficients (µ s (λ) and µ a (λ)) from SRDRS data using lookup tables of simulated diffuse reflectance are reported. Experimental measurements of liquid tissue phantoms performed with a custom multi-pixel silicon SRDRS sensor spanning the 450-750 nm wavelength range were used to evaluate the extraction methods, demonstrating that the combined use of spatial and spectral data reduces extraction error compared to use of spectral data alone. Additionally, SRDRS measurements of normal and tumor ex-vivo human colon tissue are presented along with µ s (λ) and µ a (λ) extracted from these measurements.
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