Single cell confocal Raman spectroscopy of human osteoarthritic chondrocytes: a preliminary study.
A great deal of effort has been focused on exploring the underlying molecular mechanism of osteoarthritis (OA) especially at the cellular level. We report a confocal Raman spectroscopic investigation on human osteoarthritic chondrocytes. The objective of this investigation is to identify molecular features and the stage of OA based on the spectral signatures corresponding to bio-molecular changes at the cellular level in chondrocytes. In this study, we isolated chondrocytes from human osteoarthritic cartilage and acquired Raman spectra from single cells. Major spectral differences between the cells obtained from different International Cartilage Repair Society (ICRS) grades of osteoarthritic cartilage were identified. During progression of OA, a decrease in protein content and an increase in cell death were observed from the vibrational spectra. Principal component analysis and subsequent cross-validation was able to associate osteoarthritic chondrocytes to ICRS Grade I, II and III with specificity 100.0%, 98.1%, and 90.7% respectively, while, sensitivity was 98.6%, 82.8%, and 97.5% respectively. The overall predictive efficiency was 92.2%. Our pilot study encourages further use of Raman spectroscopy as a noninvasive and label free technique for revealing molecular features associated with osteoarthritic chondrocytes.
Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway. 101rajesh@gmail.com.
Rajesh
R
Kumar
Physical Optics and Electronics Group, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA. gpsingh@mit.edu.
Gajendra P
GP
Singh
Orthopaedic Department, Levanger Hospital, Kirkegata 2, N-7600 Levanger, Norway. kirstengroenhaug@gmail.com.
Kirsten M
KM
Grønhaug
Nofima, Postbox 210, N-1431 Ås, Norway. nils.kristian.afseth@nofima.no.
Nils K
NK
Afseth
Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway. catharina.davies@ntnu.no.
Catharina
C
de Lange Davies
Department of Orthopaedic Surgery, Trondheim University Hospital, N-7491 Trondheim, Norway. jon.o.drogset@ntnu.no.
Jon O
JO
Drogset
Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway. magnus.lilledahl@ntnu.no.
Magnus B
MB
Lilledahl
D000368:Aged; D002358:Cartilage, Articular / Q000473:pathology*; D019902:Chondrocytes / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology; D008297:Male; D015999:Multivariate Analysis; D010003:Osteoarthritis / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery*; D010865:Pilot Projects; D025341:Principal Component Analysis; D012720:Severity of Illness Index; D013059:Spectrum Analysis, Raman / Q000379:methods*