Surface ultrastructure and mechanical property of human chondrocyte revealed by atomic force microscopy.
OBJECTIVE
The mechanical properties of chondrocytes influence maintenance of the articular cartilage extracellular matrix. To differentiate the mechanical properties of chondrocytes between a young, normal modulus and an old, osteoarthritic (OA) modulus, we used an atomic force microscope (AFM) to probe the surface ultrastructure and to measure their adhesion force and stiffness.


METHODS
We directly visualized a single chondrocyte cell by using AFM and quantitatively measured the dimensions of the cells.


RESULTS
Profiles displayed heights of 1026+/-203 and 1668+/-352 nm for old and young cells, respectively. Contour maps revealed differences in the sizes and structures of the two groups. Mean calculated adhesion forces differed between normal and OA chondrocytes (7.06+/-3.35 and 2.97+/-1.82 nN, respectively), as did calculated stiffness values (0.0960+/-0.009 and 0.0347+/-0.005 N/m, respectively).


CONCLUSIONS
These findings suggested that the mechanical properties of normal chondrocytes substantially differed from those of OA chondrocytes. We believe this study represents the first direct characterization of the surface ultrastructure and mechanical measurements of human chondrocytes between normal and OA stages. This new approach could be a useful technique for investigating age-related changes in the properties of human chondrocytes.
Hsieh
C-H
CH
Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
Lin
Y-H
YH
Lin
S
S
Tsai-Wu
J-J
JJ
Herbert Wu
C H
CH
Jiang
C-C
CC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D002358:Cartilage, Articular / Q000166:cytology* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000502:physiology; D048429:Cell Size; D019902:Chondrocytes / Q000502:physiology / Q000648:ultrastructure*; D005109:Extracellular Matrix; D005434:Flow Cytometry; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D008875:Middle Aged; D010003:Osteoarthritis / Q000473:pathology; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
D015815:Cell Adhesion Molecules