RESUMO
PURPOSE: To compare two different structural nanophase hydroxyapatite(HA) particles on the proliferation activity and functions of osteoblasts. METHODS: Primary culture of osteoblasts from rat calvaria was established and then cultured on the coatings of different size of nano particles (groupI 20-40nm,group II 70-100nm), the HA coatings without nano-particles was used as control group. Proliferation activity, protein content and synthesis of alkaline phosphatase(ALP) by osteoblasts were examined by MTT assay, coomassic brilliant blue method and PNPP test, and statistical significance was assessed by multiple comparison (q test, SNK) in one-way analysis of variance (ANOVA) with SPSS10.0 software package. RESULTS: Osteoblasts grew well on HA coatings. MTT assay demonstrated that there was significant difference between group I and group II at 6th day and 8th day (P<0.05).At first half stage(5th day and 10th day) ALP activity test showed no significant difference between group I and groupII (P>0.05) and as the culture going on(15th day and 20th day), there was significant difference between the two groups (P<0.05). Coomassic brilliant blue method showed that there was significant difference between group I and group II from 5th day to 20th day (P<0.05). CONCLUSION: The diameter of nano-particles on the HA coatings could influence the proliferation activity and functions of the osteoblasts. The nano-particles of similar size with HA crystal in vivo showed better cytocompatibility.