title: Diffuse optical characterization of collagen absorption from 500 to 1700 nm.
abstract: Reduction in scattering, high absorption, and spectral features of tissue constituents above 1000 nm could help in gaining higher spatial resolution, penetration depth, and specificity for in vivo studies, opening possibilities of near-infrared diffuse optics in tissue diagnosis. We present the characterization of collagen absorption over a broadband range (500 to 1700 nm) and compare it with spectra presented in the literature. Measurements were performed using a time-domain diffuse optical technique. The spectrum was extracted by carefully accounting for various spectral distortion effects, due to sample and system properties. The contribution of several tissue constituents (water, lipid, collagen, oxy, and deoxy-hemoglobin) to the absorption properties of a collagen-rich in vivo bone location, such as radius distal in the 500- to 1700-nm wavelength region, is also discussed, suggesting bone diagnostics as a potential area of interest.
authors.affiliation: Politecnico di Milano, Dipartimento di Fisica, Milano, Italy.
authors.forename: Sanathana Konugolu Venkata
authors.initials: SK
authors.lastname: Sekar
authors.affiliation: Istituto Italiano di Tecnologia, Center for Nano Science and Technology at Polimi, Milano, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Bargigia
authors.affiliation: Politecnico di Milano, Dipartimento di Fisica, Milano, Italy.
authors.forename: Alberto Dalla
authors.initials: AD
authors.lastname: Mora
authors.affiliation: Politecnico di Milano, Dipartimento di Fisica, Milano, ItalycIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milano, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Taroni
authors.affiliation: Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Milano, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ruggeri
authors.affiliation: Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Tosi
authors.affiliation: Politecnico di Milano, Dipartimento di Fisica, Milano, ItalycIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milano, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pifferi
authors.affiliation: Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Milano, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Farina
mesh_terms: D003094:Collagen / Q000493:pharmacokinetics*; D006454:Hemoglobins / Q000378:metabolism; D050356:Lipid Metabolism; D065587:Ocular Absorption; D055095:Optics and Photonics; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared
chemical_list: D006454:Hemoglobins; D003094:Collagen