Oxidized black phosphorus nanosheets as an inorganic antiresorptive agent

Abstract

Black phosphorus (BP) is a newly discovered two-dimensional material that has promising applications from bioelectronics to biomedicine. However, facile oxidation of BP leads to changes in surface chemical composition and physical properties, often being referred to as the degradation process of BP. Degradation products of BP nanosheets, namely, oxidized BP nanosheets (oBPNSs), are routinely considered as by-products without many uses. Herein, we found that oBPNSs displayed excellent osteoclastogenesis inhibition effects without impairing cell viability. In contrast to the classic antiresorptive bisphosphonate drugs, oBPNSs showed a different mode of action by suppressing the maturation of osteoclasts. Bone resorption assays, osteoclast actin ring analysis, and tartrate-resistant acid phosphate activity assay results indicated that oBPNSs suppressed receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis in a dose- and oxidation-dependent manner. Transcriptomic and proteomic analyses indicated that oBPNSs inhibited the activation of the NF-κB signaling pathway and phosphorylation of mitogen-activated protein kinase (MAPK) in differentiated osteoclasts, as confirmed by Western blot analysis. Our results suggest that oBPNSs might be potential antiresorptive nanomaterials to treat osteoporosis.