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Effects of Bone Powder Extracts with Different Hydroxyapatite Contents on Proliferation, Apoptosis, and Cell Phase of Human Umbilical Vein Endothelial Cells

ABSTRACTBone powder with different contents of hydroxyapatite may have different effects on angiogenesis in bone defect areas. The effects of bone powder with different content of hydroxyapatite on proliferation, apoptosis and cell cycle of vascular endothelial cells (HUVECs)
 were studied. In the experimental group, HUVECs were cultured in the incubator with different contents of hydroxyapatite bone powder extract. The experimental group was divided into four subgroups: group A had a low hydroxyapatite content of 10–15%; group B had a hydroxyapatite content
 of 25–30%; group C had a hydroxyapatite content of 80–90%; and group D had a hydroxyapatite content of more than 90%. The control group was treated with the culture of umbilical vein endothelial cells alone. Firstly, we used scanning electron microscope (SEM) to observe the morphology
 of bone powder with different hydroxyapatite content in normal condition. After that, we carried out a series of experiments to observe the changes of cell morphology, proliferation ability, apoptosis and cell cycle in different culture groups. The results showed that there was no significant
 difference in cell morphology and proliferation ability among different experimental groups. However, the apoptosis rate in group A was higher than that in group C. The underlying mechanism may be related to G1 arrest and G2 transformation in smaller and higher concentration groups, respectively.
 We can thus preliminarily conclude that a high concentration of hydroxyapatite in bone powder extract would be most suitable for cell cultures.