[Pinctada margaritifera nacre (mother-of-pearl): physico-chemical and biomechanical properties, and in vitro cytocompatibility].
OBJECTIVE
Pinctada maxima nacre (mother-of-pearl) has been recently proposed as a bone substitute. The purpose of this work was to assess the in vitro cytocompatibility of Pinctada margaritifera nacre and its physico-chemical and biomechanical properties.


METHODS
The cytocompatiblity was assessed in contact with human osteoprogenetic cells. Attachment was measured at one hour and three hours by determining N-acetyl-beta-D-hexosaminidase activity. Proliferation was monitored by measuring metabolic activity with the MTT test. Cell morphology was studied under scanning electron microscopy and cell differentiation was assessed by immunocytochemistry monitoring of the synthesis of type I collagen and osteocalcin. Diffraction x-ray and scanning electron microscopy was used to study the physico-chemical structure. Two samples taken from the inner part of the shell and two other samples from the outer part of the shell were tested for resistance under compression and to calculate the Young module.


RESULTS
The results showed that osteoprogenetic cells attached to the nacre (2/3 of the plastic control), proliferated according to a standard pattern (increased metabolic activity followed by a plateau then decreased activity), synthetized type I collagen and osteocalcin, and presented a morphology analogous to control cells cultured on the plastic culture wells. The diffraction spectrum of the crystalline structure corresponded to crystallized calcium carbonate in the form of calcite (CaCO(3)) for the outer part and in the form of aragonite for the inner part. The Young module was 46.1 Gpa and resistance to rupture was 185 Mpa.


CONCLUSIONS
Pinctada margaritifera nacre is cytocompatible in vitro with mechanical properties very similar to cortical bone.
Cognet
J-M
JM
Département d'Orthopédie et de Traumatologie, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, avenue Molière, 67098 Strasbourg. jean-michel.cognet@chru-strasbourg.fr
Fricain
J-C
JC
Réau
A-F
AF
Lavignolle
B
B
Baquey
C
C
Lepeticorps
Y
Y
D000818:Animals; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002478:Cells, Cultured; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006801:Humans; D008422:Materials Testing; D008854:Microscopy, Electron; D010006:Osteoblasts; D010125:Ostreidae
D001672:Biocompatible Materials