Non-invasive identification of proteoglycans and chondrocyte differentiation state by Raman microspectroscopy.
Proteoglycans (PGs) are crucial extracellular matrix (ECM) components that are present in all tissues and organs. Pathological remodeling of these macromolecules can lead to severe diseases such as osteoarthritis or rheumatoid arthritis. To date, PG-associated ECM alterations are routinely diagnosed by invasive analytical methods. Here, we employed Raman microspectroscopy, a laser-based, marker-free and non-destructive technique that allows the generation of spectra with peaks originating from molecular vibrations within a sample, to identify specific Raman bands that can be assigned to PGs within human and porcine cartilage samples and chondrocytes. Based on the non-invasively acquired Raman spectra, we further revealed that a prolonged in vitro culture leads to phenotypic alterations of chondrocytes, resulting in a decreased PG synthesis rate and loss of lipid contents. Our results are the first to demonstrate the applicability of Raman microspectroscopy as an analytical and potential diagnostic tool for non-invasive cell and tissue state monitoring of cartilage in biomedical research.
Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Dept. of Cell and Tissue Engineering, Nobelstr. 12, 70569 Stuttgart, Germany.
Marieke
M
Pudlas
Eva
E
Brauchle
Travis J
TJ
Klein
Dietmar W
DW
Hutmacher
Katja
K
Schenke-Layland
D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism*; D006801:Humans; D055620:Optical Phenomena; D011509:Proteoglycans / Q000378:metabolism*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013552:Swine
D011509:Proteoglycans