FT-IR microscopic mappings of early mineralization in chick limb bud mesenchymal cell cultures.
Chick limb bud mesenchymal cells differentiate into chondrocytes and form a cartilaginous matrix in culture. In this study, the mineral formed in different areas within cultures supplemented with 4 mM inorganic phosphate, or 2.5, 5.0, and 10 mM beta-glycerophosphate (beta GP), was characterized by Fourier-transform infrared (FT-IR) microscopy. The relative mineral-to-matrix ratios, and distribution of crystal sizes at specific locations throughout the matrix were measured from day 14 to day 30. The only mineral phase detected was a poorly crystalline apatite. Cultures receiving 4 mM inorganic phosphate had smaller crystals which were less randomly distributed around the cartilage nodules than those in the beta GP-treated cultures. beta GP-induced mineral consisted of larger, more perfect apatite crystals. In cultures receiving 5 or 10 mM beta GP, the relative mineral-to-matrix ratios (calculated from the integrated intensities of the phosphate and amide I bands, respectively) were higher than in the cultures with 4 mM inorganic phosphate or in the in vivo calcified chick cartilage.
Boskey
A L
AL
Laboratory for Ultrastructure Biochemistry, Hospital for Special Surgery, New York, New York 10021.
Camacho
N P
NP
Mendelsohn
R
R
Doty
S B
SB
Binderman
I
I
D000818:Animals; D002113:Calcification, Physiologic; D002356:Cartilage / Q000166:cytology* / Q000502:physiology; D002454:Cell Differentiation; D002478:Cells, Cultured; D002645:Chickens; D005121:Extremities; D005583:Fourier Analysis; D006882:Hydroxyapatites / Q000032:analysis; D008648:Mesoderm / Q000166:cytology* / Q000502:physiology; D008854:Microscopy, Electron; D013055:Spectrophotometry, Infrared
D006882:Hydroxyapatites