title: Raman spectroscopy for the non-contact and non-destructive monitoring of collagen damage within tissues.
abstract: The non-destructive and label-free monitoring of extracellular matrix (ECM) remodeling and degradation processes is a great challenge. Raman spectroscopy is a non-contact method that offers the possibility to analyze ECM in situ without the need for tissue processing. Here, we employed Raman spectroscopy for the detection of heart valve ECM, focusing on collagen fibers. We screened the leaflets of porcine aortic valves either directly after dissection or after treatment with collagenase. By comparing the fingerprint region of the Raman spectra of control and treated tissues (400-1800 cm(-1)), we detected no significant differences based on Raman shifts; however, we found that increasing collagen degradation translated into decreasing Raman signal intensities. After these proof-of-principal experiments, we compared Raman spectra of native and cryopreserved valve tissues and revealed that the signal intensities of the frozen samples were significantly lower compared to those of native tissues, similar to the data seen in the enzymatically-degraded tissues. In conclusion, our data demonstrate that Raman microscopy is a promising, non-destructive and non-contact tool to probe ECM state in situ.
authors.affiliation: Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Dept. of Cell and Tissue Engineering, 70569 Stuttgart, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Votteler
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Carvajal Berrio
authors.forename: Marieke
authors.initials: M
authors.lastname: Pudlas
authors.forename: Heike
authors.initials: H
authors.lastname: Walles
authors.forename: Ulrich A
authors.initials: UA
authors.lastname: Stock
authors.forename: Katja
authors.initials: K
authors.lastname: Schenke-Layland
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000002:abnormalities / Q000378:metabolism / Q000473:pathology*; D024042:Collagen Type I / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D017364:Collagenases / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods; D005109:Extracellular Matrix / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013552:Swine
chemical_list: D024042:Collagen Type I; D017364:Collagenases