剂量因素对羟基磷灰石/磷酸三钙成骨细胞相容性的影响

目的　检测不同剂量的羟基磷灰石 /磷酸三钙 (HA/ TCP)对兔成骨细胞增殖及碱性磷酸酶(AL P)活性的影响 ,明确材料的剂量因素在研究 HA/ TCP细胞相容性中的作用规律。方法　以兔成骨细胞为正常对照 ,细胞加入钛合金材料组为阴性对照 ,细胞加入聚氯乙烯材料组为阳性对照。选择三种材料剂量 ,以材料占细胞面积的比例表示 ,分别为 10 %、4 0 %和 70 %。将各组材料与兔成骨细胞复合培养 ,MTT法检测不同时间点、不同剂量材料作用下兔成骨细胞增殖的情况 ;偶氮偶联法检测不同时间点、不同剂量材料作用下兔成骨细胞表达 AL P的变化。结果　正常兔成骨细胞的生长呈现时间 -效应关系。与正常对照相比 ,10 % HA/ TCP不会对兔成骨细胞的生长产生影响 (P>0 .0 5 ) ;当 HA/ TCP剂量增大为 4 0 % ,细胞的生长速度明显变缓 (P<0 .0 5 ) ,细胞的生长仍呈现时间 -效应关系 ;70 %的 HA/ TCP使细胞生长趋于停滞 (P<0 .0 1)。 10 % HA/ TCP可造成细胞 AL P活性可逆性损伤 ,HA/ TCP浓度达 4 0 %时 ,AL P活性损伤至共培养 6天不可逆转。相对而言 ,惰性金属硬组织材料钛合金在检测三种剂量下均对细胞生长及细胞 AL P活性不会产生影响。结论　评价材料的细胞相容性应向材料接触剂量个体化、特异化的方向发展 ;除增殖指标之外 ,AL

INFLUENCE OF DOSAGE ON CELL BIOCOMPATIBILITY OF HYDROXYAPATITE/TRICALCIUM PHOSPHATE

Objective To investigate the influence of different dose levels of hydroxyapatite/tricalcium phosphate (HA/TCP) on the proliferation and alkaline phosphatase (ALP) activity of rabbit osteoblasts. Methods Three different dose levels of HA/TCP (10%, 40%, 70%) were co cultivated with rabbit osteoblasts respectively. The proliferation and ALP expression capacity of osteoblasts were examined with MTT method and enzyme histochemistry once every 24 hours until 5 days. Three control groups of other materials were treated and examined in the same way: rabbit osteoblasts as normal control; polyvinylchloride as positive control; titanium alloy as negative control. Results There was remarkable time effect relationship in the proliferation of osteoblasts. Ten percent HA/TCP did not affect osteoblasts growth while 40% HA/TCP could slow the cell growth rate down though time effect relationship still existed. The proliferation of osteoblasts stagnated when co cultivated with 70% HA/TCP. On the other hand, 10% HA/TCP could cause reversible damage on ALP activity of osteoblasts, whereas when the dose was 40%, and the cultivation lasted 6 days the damage was irreversible. Three different dose levels of titanium alloy (10%, 40%, 70%) had no effect on the proliferation or ALP activity of osteoblasts. Conclusion Dosage is an important factor affecting the biocompatibility evaluation of biomaterial. It suggests that dose choosing should be more specified upon each individual biomaterial. It also indicates that ALP may be a good supplementary index of the cell compatibility of material.