Abstract:

Objective · To synthesize silver-doped hydroxyapatite (Ag-HAp) with different silver contents, explore their cytocompatibility and effects on the osteogenetic activity of rat bone marrow mesenchymal stem cells (BMSCs) in vitro, and determine the proper Ag content. Methods · Silver-doped hydroxyapatite with different silver contents (xAg0, xAg0.3, xAg0.5, and xAg0.7) was synthesized, characterized, and divided into the control group (xAg0 group) and experimental groups (xAg0.3, xAg0.5, and xAg0.7). The effects of Ag-HAp with different silver contents on cytocompatibility, expressions of genes related to osteogenesis, and secretion of alkaline phosphatase (ALP) in BMSCs were detected. Results · Characterization results confirmed that the synthesized product was silver-doped hydroxyapatite with silver contents of xAg0.7>xAg0.5>xAg0.3. The cytocompatibility test results showed that the xAg0.3 and xAg0.5 groups were qualified to be medical material and the xAg0.7 group had slight toxicity. Real-time PCR results indicated that compared with the control group, the xAg0.3 and xAg0.5 groups had elevated expressions of osteogenesis-related genes and the xAg0.7 group had comparable or decreased expressions of osteogenesis-related genes. ALP qualitative and quantitative tests showed that the xAg0.3 and xAg0.5 groups had higher ALP activity and the xAg0.7 group had lower ALP activity than the control group. Conclusion · Silver-doped hydroxyapatite with different silver contents can be synthesized by changing the quantity of added silver. When xAg is 0.3 or 0.5, the silver-doped hydroxyapatite is qualified to be medical material and can promote the expressions of
osteogenesis-related genes and the secretion of ALP.

Key words: silver-doped hydroxyapatite, cytocompatibility, osteogenic activity, bone marrow mesenchymal stem cell