[In vitro studies about the effects of implant materials on calmodulin, introcellular calcium of rat osteoblasts].
OBJECTIVE
1. To evaluate the effects of the four implant materials, hydroxyl poly calcium sodium phosphate (HPA), hydroxyapatite (HA), bioglass ceramics (BGC) and titanium (Ti) on the calmodulin (CaM) content of osteoblasts, the concentration of intracellular free calcium and the ATPases activity of cell membrane of rat osteoblasts cultured in vitro; 2. To reveal the biological compatibility of the four implant materials and the index to estimate the biological compatibility condition.


METHODS
The powders of HPA, HA, BGC and Ti were sterilized and made into extracted solutions with 199 culture medium. The isolated osteoblasts, which were taken from three-day-old sparague Dawley rats' calvaria, were incubated in 199 culture medium also. Then the osteoblasts were mixed and incubated into the four kinds of extracted solutions of the implant materials. After three days of co-incubation, the cells were taken out, and the cellular calmodulin content were measured with radiobiological analysis. The concentration of intracellular free calcium were under fluorescent analysis, and the ATPases activities of cell membrane were estimated with colorimetric analysis.


RESULTS
1. Calmodulin content of the osteoblasts co-incubated with all the implant materials decreased, and moreover, only that of the Ti group decreased more obviously than that of the Ti and HPA group (P < 0.05). 2. The concentration of intracellular free calcium of all the co-incubated osteoblasts were as normal as that of the control group. 3. Ca(2+)-ATPases activities of osteoblasts co-incubated with HPA, HA, BGC increased (P < 0.05), and Na+/K(+)-ATPases activities of the cells co-incubated with HPA, HA were strenghtened (P < 0.05).


CONCLUSIONS
The indexes of cellular calmodulin content, concentration of intracellular free calcium and ATPases activity of cell membrane can reflect the biological compatibility of implant materials, and they may be used as indexes of estimating biological compatibility condition.
Huang
Y
Y
College of Stomatology, West China University of Medical Sciences.
Chen
Z
Z
Li
P
P
Wu
Z
Z
D000818:Animals; D000831:Animals, Newborn; D001672:Biocompatible Materials; D018786:Bone Substitutes; D002118:Calcium / Q000378:metabolism*; D002130:Calcium Phosphates / Q000494:pharmacology; D002147:Calmodulin / Q000378:metabolism*; D002478:Cells, Cultured; D002516:Ceramics / Q000494:pharmacology; D015921:Dental Implants; D006882:Hydroxyapatites / Q000494:pharmacology*; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull; D014025:Titanium / Q000494:pharmacology
D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D002147:Calmodulin; D015921:Dental Implants; D006882:Hydroxyapatites; C077456:metaphosphoric acid, calcium sodium salt; D014025:Titanium; D002118:Calcium