Rosehip Extract-Functionalized Magnesium Hydroxide Nanoparticles and Its Effect on Osteoblastic and Osteoclastic Cells

Abstract

Considering the role of magnesium in bone metabolism and the increasing relevance of plant-mediated green-synthesis, this work compares the bone cytocompatibility of magnesium hydroxide nanoparticles (NPs) produced by using pure water, Mg(OH)2, or a rosehip (RH) aqueous extract, Mg(OH)2RH. The NPs were evaluated for dose- and time-dependent effects on human osteoblastic and osteoclastic response, due to the direct involvement of the two cell types in bone metabolism. Mg(OH)2 NPs presented nanoplatelet-like morphology (mean diameter ~90 nm) and a crystalline structure (XRD analysis); the RH-mediated synthesis yielded smaller rounded particles (mean diameter <10 nm) with decreased crystallinity. On the ATR–FTIR spectra, both NPs presented the characteristic Mg-OH peaks; Mg(OH)2RH exhibited additional vibration bands associated with the presence of phytochemicals. On osteoblastic cells, NPs did not affect cell growth and morphology but significantly increased alkaline phosphatase (ALP) activity; on osteoclastic cells, particles had little effect in protein content, tartrate-resistant acid phosphatase (TRAP) activity, percentage of multinucleated cells, and cell area. However, compared with Mg(OH)2, Mg(OH)2RH increased osteoblastic differentiation by inducing ALP activity and promoting the expression of Runx2, SP7, Col1a1, and ALP, and had a negative effect on the expression of the osteoclastic genes NFATC1, CA2, and CTSK. These observations suggest the potential usefulness of Mg(OH)2RH NPs in bone regeneration.

Green-Synthesized Magnesium Hydroxide Nanoparticles Induced Osteoblastic Differentiation in Bone Co-Cultured Cells

“…These NPs present a round shape morphology with an average diameter below 10 nm. When compared with the nanoparticles synthesized without RH extract, with mean diameters of 90 nm [19], the Mg(OH) 2 RH NPs are almost 10 times smaller. The presence of Mg on the as-synthesized nanoparticles was confirmed by EDS (Figure 1B).…”

“…Nanomaterials are widely used due to their physical and chemical features, and magnesium-containing biomaterials have been associated with enhanced biocompatibility in regenerative applications. Mg plays a major role in bone metabolism and it has been reported to improve osteoblastic adhesion, proliferation [24] and differentiation through its use as a nanomaterial [19,25]. Medicinal plants are being used to direct the synthesis of NPs to be more ecologic, further allowing their functionalization with biological properties such as antioxidant, anti-inflammatory and/or antibacterial activity [13,14,19,[26][27][28].…”

“…The aim was to better characterize the integrative response of the NPs on interacting osteoblastic and osteoclastic cells and, further, to assess the potential of green nanoparticles for bone regenerative applications. For that, Mg(OH) 2 RH NPs synthesized through chloride precursors were compared to a control (Mg(OH) 2 ) where the synthesis occurred in pure water [19]. In a previous work [19], we reported the synthesis of these NPs, but using a different precursor, nitrate, as the magnesium counterion, as it was described that the precursors may have an important role in the characteristics of produced Mg(OH) 2 nanoparticles [29].…”

“…For that, Mg(OH) 2 RH NPs synthesized through chloride precursors were compared to a control (Mg(OH) 2 ) where the synthesis occurred in pure water [19]. In a previous work [19], we reported the synthesis of these NPs, but using a different precursor, nitrate, as the magnesium counterion, as it was described that the precursors may have an important role in the characteristics of produced Mg(OH) 2 nanoparticles [29]. However, when comparing the nanoparticles synthesized herein using chlorides with the nanoparticles synthesized with nitrates [19], no significant differences were observed in size, morphology or RH phytochemicals loading, suggesting that the rose hip extract has a preponderant role in the final characteristics of the NPs and not the precursor.…”

“…Due to its antioxidant properties, rose hip can play a role in restoring bone cell metabolism through the regulation of oxidative stress in cases of abnormally high levels of oxidative stress, reducing bone resorption and increasing bone formation [17,18]. We have previously reported that green-synthesized magnesium hydroxide (Mg(OH) 2 ) nanoparticles, using nitrate as the magnesium counterions and rose hip extract, had affected monocultured bone cells, namely by stimulating bone-forming osteoblasts and restraining bone-resorbing osteoclasts [19]. Magnesium counterions are reported to affect crystallites and particle sizes [20].…”