Article

Effects of fibronectin on hydroxyapatite formation.

Laboratoire de Recherche sur les Matériaux d'Intérêt Biologique, UPRES EA 2159, Faculté de Chirurgie Dentaire, Nantes, France.
Journal of Inorganic Biochemistry (impact factor: 3.35). 04/1999; 73(3):129-36. pp.129-36
Source: PubMed

ABSTRACT There is increasing evidence that noncollagenous matrix proteins initiate bone mineralization in vivo. Fibronectin, which is present during the early phases of mineralization, may contribute to this process in bone tissues. In this context, the mineralization potential of fibronectin was tested in an agarose gel precipitation system and a metastable calcium phosphate solution. The protein inhibited the precipitation of calcium phosphate crystals in solution but had no apparent effect in gel. Conversely, fibronectin stimulated crystal formation when apatite powder was used to seed crystal growth in gel. Although these results in vitro do not clearly indicate that fibronectin is involved in the mineralization process, they are consistent with in vivo events. Free fibronectin (e.g. in biological fluids) could inhibit crystal growth but might also activate the mineralization process when absorbed on apatite powder in a bone environment and areas of ectopic mineralization.

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Keywords

agarose gel precipitation system
 
apatite powder
 
apparent effect
 
bone environment
 
bone mineralization
 
bone tissues
 
calcium phosphate crystals
 
crystal formation
 
crystal growth
 
ectopic mineralization
 
Fibronectin
 
Free fibronectin
 
metastable calcium phosphate solution
 
mineralization potential
 
mineralization process
 
noncollagenous matrix proteins
 
precipitation
 
protein inhibited
 
seed crystal growth
 
vivo events