The Evaluation of Anti-Osteoclastic Activity of the Novel Calcium Hydroxide Biodegradable Nanoparticles as an Intracanal Medicament.

Introduction: The aim of this study was to evaluate the anti-osteoclastic activity of calcium hydroxide-loaded poly(lactic-co-glycolic acid) nanoparticles [Ca(OH)-loaded PLGA NPs] in comparison to calcium hydroxide nanoparticles [Ca(OH) NPs].

Methods: RAW 264.7 cell lines (third-fifth passage) were cultured and incubated with soluble receptor activator of nuclear factor kappa B ligand in triplicate. Subsequently, Ca(OH)-loaded PLGA NPs and Ca(OH) NPs were added for 7 days to evaluate their effects on receptor activator of nuclear factor kappa B ligand-induced osteoclast differentiation of RAW 264.7 cells by tartrate-resistant acid phosphatase activity. Additionally, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was conducted to confirm the cytotoxicity of treatments to cells.

Results: Tartrate-resistant acid phosphatase staining showed a significant reduction in the osteoclast number when treated with Ca(OH)-loaded PLGA NPs compared with Ca(OH) NPs (P < .01). In comparison to the control, the number of osteoclasts significantly reduced upon treatment with Ca(OH)-loaded PLGA NPs (P < .05), but there was no significant difference in Ca(OH) NPs. Furthermore, osteoclast morphology in both treatment groups exhibited smaller sizes than the control group. Neither Ca(OH)-loaded PLGA NPs nor Ca(OH) NPs demonstrated cytotoxic effects on RAW264.7 cells.

Conclusions: Both Ca(OH) NPs with and without poly(lactic-co-glycolic acid) have the ability to inhibit osteoclast differentiation. However, Ca(OH)-loaded PLGA NPs exhibit greater potential than Ca(OH) NPs, making them a promising intracanal medicament for cases of root resorption.