Comparative study of nanohydroxyapatite-emdogain effects on apical papilla stem cell survival and differentiation

The study was designed to explore the enhanced impact of nano-hydroxyapatite and emdogain on the survival and osteogenic/odontogenic differentiation of human stem cells isolated from the apical papilla (hSCAPs).

In this in vitro trial, hSCAPS obtained from intact impacted immature third molars were confirmed to have characteristic cell surface markers, then exposed to nanohydroxyapatite, emdogain, and nanohydroxyapatite coated with emdogain for durations of 1-3 days. The survival of apical papilla stem cells was measured using a methyl thiazolyl tetrazolium assay. The quantitative reverse transcription polymerase chain reaction, alkaline phosphatase activity (ALP) and Alizarin red staining were used to evaluate osteogenic-odontogenic differentiation. Analysis of the data was done using one-way ANOVA, t-test, and Mann-Whitney test (α = 0.05).

At 1-3 days, emdogain exhibited no significant impact on the survival of human stem cells from the apical papilla. In contrast, nanohydroxyapatite (α > 0.05) and nanohydroxyapatite coated with emdogain demonstrated a notable reduction in cell survival compared to the control group (α < 0.05). The expression of dentin sialophosphoprotein, dentin matrix protein 1, and bone sialoprotein genes demonstrated a notable increase in the group treated with nanohydroxyapatite coated with emdogain compared to the other groups (α < 0.05), and furthermore, this group exhibited more pronounced mineralized nodules than the other experimental groups.

In contrast to nanohydroxyapatite, Emdogain did not demonstrate a detrimental effect on the survival of hSCAPs. Nanohydroxyapatite, emdogain, and nanohydroxyapatite coated with emdogain increased osteogenic/odontogenic differentiation of hSCAPs.