[Research of topographic ultra-structure and biomechanical properties of living chondrocytes cells with atomic force microscopy].
OBJECTIVE
To evaluate the application of a novel tapping mode, magnetic AC mode (MAC mode) of atomic force microscopy (AFM) in observation of the topography and mechanical properties of living chondrocytes.


METHODS
Specimens of normal knee joint was obtained from 5 patients during amputation due to severe trauma of shank. Chondrocytes were isolated and cultured. Cell slides were prepared, underwent immunohistochemical staining, and observed under AFM by MAC mode. Force curve operation was performed at different regions, nuclear and cytoplasmic, to compare the topographic features.


RESULTS
High-resolution images of the ultra-structure of cell surface were obtained under physiological condition with a resolution level to 30 nm. The cells presented a topical profile, i.e., the protuberant nuclear region and relatively flatten cell body. The force curve showed much higher stress and adhesion in the cell body region than in the nuclear region.


CONCLUSIONS
MAC mode AFM is very useful in research of the ultra-structure and biomechanical properties of cells.
Liu
Guang-yuan
GY
Department of Orthopedics, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China.
Wu
Zhi-hong
ZH
Chen
Pei-pei
PP
Li
Bing
B
Xie
Lin
L
Han
Dong
D
Qiu
Gui-xing
GX
D000328:Adult; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000166:cytology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000502:physiology* / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008297:Male; D018625:Microscopy, Atomic Force; D008875:Middle Aged; D055815:Young Adult