Evaluation of the cytotoxicity of BMP-2 as part of the coating of dental implants, in an in vitro experiment.

BACKGROUND: The addition of BMP-2 to various bone substitute materials is gaining popularity as it has a positive effect on osseointegration and neo-osteogenesis. Although the efficacy of BMP2 in bone regeneration is evident, concerns have been raised about its side effects. To understand the cause of side effects, it is necessary to evaluate the effects of BMP2 on a variety of cells.

AIMS: Evaluation of the biological effect of BMP2 as part of a dental implant coating on the monocytic cell line THP-1.

MATERIALS AND METHODS: THP-1 cell culture was transferred to a 12-well plate with PMA added to a final concentration of 150 nM. The cell culture was incubated at 37°C in an atmosphere of 5% CO2 for 4-6 hours until complete adhesion to the culture plastic. Next, the investigated implants were introduced, each into a separate well and incubated for 48 hours. Propidium iodide staining was performed to detect apoptotic cells. 1×105 cells were analysed in each sample. Immunophenotyping was performed with CD45 monoclonal antibodies. Samples were measured on a NovoCyte Advanteon flow cytofluorimeter. 

RESULTS: When evaluating the cytostatic properties of the implants, no significant differences were obtained between the groups of implants with and without coating. The control medium without implant was significantly different from the investigated groups, indicating that the mere presence of the implant in the well has an effect on THP-1 cells. After incubation with the studied implant samples, the percentage of apoptotic THP-1 cells did not change significantly between the groups. Analysis of the percentage of CD45 positive cells after incubation of cells with uncoated and coated implant samples. A significant increase in the expression of the studied indicator in the group of coated samples was obtained.

CONCLUSIONS:  Summarising the results obtained, it was found that the coated and uncoated implants did not differ in their cytostatic properties when incubated with THP-1 cells. When assessing the percentage of apoptotic THP-1 cells between the coated and uncoated implant groups, no significant difference was also observed. However, the coated implant group had a significantly higher percentage of CD45-positive cells.