RUNX2 and ALP expression in osteoblast cells exposed by PMMA-HAp combination: An in vitro study

OBJECTIVE: To observe the expression of Runt-Related Transcription Factors 2 (RUNX2) and Alkaline Phosphatase (ALP) markers in osteoblast cell cultures exposed to Polymethylmethacrylate (PMMA) combined with hydroxyapatite (HAp) material to improve osteointegration of bone implants. METHODS: Sample of PMMA and HAp materials with a mixture of PMMA with HAp made from limestone as natural source which processed through Balai Besar Keramik (HApBBK) in the first group and a mixture of PMMA with HAp made from bovine bone which processed through Good Manufacturing Practice (HApGMP) in the second group. Twenty-four fetal rat calvarie osteoblast cell cultures were randomly divided into 6 groups: 7- and 14-day control group, 7 and 14 days PMMA-HApGMP group, 7 and 14 days PMMA-HApBBK group. The expression of RUNX2 and ALP was seen by immunocytochemical examination. RESULT: The one-way ANOVA with a significance value of 0.000 (p < 0.05). There was an increase in RUNX2 and ALP expressions on both PMMA-HApBBK and PMMA-HApGMP groups on days 7 and 14 in osteoblast cell cultures. CONCLUSION: The PMMA-HApBBK and PMMA-HApGMP showed an increase in the RUNX2 and ALP expression in osteoblast cell cultures which indicates a potential increase of osseointegration of bone implants.