Titanium particles play an important role in the formation of periprosthetic osteolysis, and the effect of titanium particles on osteoblasts maybe the reason for osteolysis.OBJECTIVE:
To observe the effect of titanium particles on the cell proliferation, differentiation and mineralization of osteoblasts.DESIGN, TIME AND SETTING:
The randomized grouping control experiment was performed at the Department of Orthopedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from September to December 2008.MATERIALS:
The commercial pure titanium particles (number 00681, a product made by Johnson Matthey, Ward Hill, MA, USA) with mean diameter of 4.5 μ m, and 86% of which shorter than 10 μm.METHODS:
Osteoblasts of new born SD rats within 24 hours were insolated, and cells of the third passages were inoculated at culture plate, replace medium when cells attached completely at 24 hours after culture. Then cells were divided into control and experimental groups. Osteoblasts in the experimental group were cultured with titanium particles at a concentration of 0.1 g/L, and medium was renewed once in 3 days. The medium in the control group was renewed simultaneously.MAIN OUTCOME MEASURES:
MTT test was used to assess the cell proliferation at 2, 4, 7, 14 days; while alkaline phosphatase (ALP) staining and ALP activity measurement were taken to assess the differentiation of osteoblasts at days 7 and 14. The mineralization of osteoblasts was evaluated by Alizarin red staining at days 14 and 21.RESULTS:
The osteoblastic proliferation had no significant difference between the experimental group and the control group (P > 0.05). However, the ALP staining was weaken in the experimental group than that of control group at days 7 and 14, meanwhile, activity of ALP measurement in the experimental group was smaller than the control group (P < 0.01), while the alizarin red staining demonstrated that the quantity of calcium nodules were markedly decreased in the experimental group at days 14 and 21.CONCLUSION:
The differentiation and mineralization of primary rat osteoblasts are decreased with exposure to titanium particles, while the proliferation remained unchanged.