Inhibitory Effects of Gold and Silver Nanoparticles on the Differentiation into Osteoclasts In Vitro.

Seil Sohn,In-Bo Han,Je Beom Hong,Wan-Kyu Ko,Seong Jun Kim,Daye Lee,Seung Hun Sheen

doi:10.3390/pharmaceutics13040462

Abstract

Gold nanoparticles (GNPs) have been widely studied to inhibit differentiation into osteoclasts. However, reports of the inhibitory effects of silver nanoparticles (SNPs) during the process of differentiation into osteoclasts are rare. We compared the inhibitory effect of GNPs and SNPs during the process of differentiation into osteoclasts. Bone marrow-derived cells were differentiated into osteoclasts by the receptor activator of the nuclear factor-kappa-Β ligand (RANKL). The inhibitory effect of GNPs or SNPs during the process of differentiation into osteoclasts was investigated using tartrate-resistant acid phosphatase (TRAP) and actin ring staining. The formation of TRAP positive (+) multinuclear cells (MNCs) with the actin ring structure was most inhibited in the SNP group. In addition, the expression of specific genes related to the differentiation into osteoclasts, such as c-Fos, the nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), TRAP, and Cathepsin K (CTSK) were also inhibited in the SNP groups. As a result, the levels related to differentiation into osteoclasts were consistently lower in the SNP groups than in the GNP groups. Our study suggests that SNPs can be a useful material for inhibiting differentiation into osteoclasts and they can be applied to treatments for osteoporosis patients.

Highlights

Osteoporosis is caused by an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts [1]
In the Gold nanoparticles (GNPs) group, the maximum absorbance was shown at 525 nm
In the silver nanoparticles (SNPs) group, the maximum absorbance was at 410 nm

Summary

Introduction

Osteoporosis is caused by an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts [1]. Bone resorption is necessary to maintain homeostasis for bone remodeling [1]. Excessive resorption leads to osteoporosis [2,3]. Osteoclasts require several weeks to undertake the resorption of bone, whereas osteoblasts need several months to produce new bone. The relatively short process by osteoclasts can induce osteoporosis [4]. The interaction between osteoclasts and osteoblasts is important in the process of the bone remodeling. Targeting the osteoclast differentiation to modulate excessive bone resorption is an attractive strategy for the treatment of osteoporosis. There have been numerous studies to inhibit excessive bone resorption by osteoclasts [4]

Methods

Results

Discussion

Conclusion