Effects of Antibacterial Co‐Cr‐Mo‐Cu Alloys on Osteoblast Proliferation, Differentiation, and the Inhibition of Apoptosis

Abstract

Objectives To investigate the effects of antibacterial Co‐Cr‐Mo‐Cu alloys with different Cu contents on osteoblast proliferation, differentiation, and the inhibition of apoptosis to optimize the selection of surgical implantation. Methods Microstructure, phase structure, and ion release were evaluated using X‐ray diffraction, scanning electron microscopy (SEM), and inductively coupled plasma (ICP) spectrometry. The effects on osteoblast proliferation, differentiation, and apoptosis were characterized by cell proliferation assay, alkaline phosphatase (ALP) activity assay, and western blotting, respectively. Results Compared to the original Co‐Cr‐Mo alloys, the released Cu ions from Co‐Cu alloys promoted osteoblast proliferation and differentiation and inhibited apoptosis. It can be noted that the optical density (OD490) and the ALP activity have increased to 1.237 and 1.053, respectively, in Co‐2Cu alloy (0.604 and 0.171 for original Co‐Cr‐Mo alloy). Meanwhile, these effects were evaluated through the upregulation of ROS levels and 4E‐binding protein 1 (4E‐BP1) expression and the downregulation of adenosine 5′‐monophosphate (AMP)‐activated protein kinase (AMPK) and p‐AMPK. Moreover, the antibacterial properties of the Co‐Cu alloys were also enhanced, as demonstrated by the strong antibacterial activity of Cu phases in Co‐Cu alloys incubated with Staphylococcus aureus, in which more than 99.8% of the bacteria has been killed. Conclusions The addition of Cu element in the Co‐Cr‐Mo alloys could induce OB proliferation and differentiation and inhibited OB apoptosis. Meanwhile, it can be recognized that the Co‐Cu alloys with 2wt% Cu exhibit the highest performance among all the samples, indicating that the effects of osteoblast differentiation and the inhibition of apoptosis are highly dependent on the adding of Cu elements. Co‐Cr‐Mo‐Cu alloys with an excellent antibacterial property could be used as a tool to improve osteogenic ability and antibacterial properties in orthopaedic implant operations.

A copper-containing analog of the biomineral whitlockite: dissolution–precipitation synthesis, structural and biological properties

“…Due to its transition between different oxidation states, Cu 2+ plays a role in numerous physiological processes. Duan et al 51 investigated the effect of Cu-containing alloy on osteoblast proliferation and differentiation, indicating that Cu 2+ induced the proliferation of osteoblasts at 24 to 72 h timepoints, explaining the increase of cell viability after 48 h. Furthermore, Zhang et al 52 observed that the Cu ion concentration is one of the key factors for switching the biological effects of Cu 2+ and Cu + from toxicity to activity.…”

Effect of Heat Treatment on Osteoblast Performance and Bactericidal Behavior of Ti6Al4V(ELI)-3at.%Cu Fabricated by Laser Powder Bed Fusion

“…Ti6Al4V-6 wt.% Cu alloy did not negatively affect the cell viability of gingival fibroblasts and osteoblasts. It inhibited the inflammatory response of macrophages, increased the angiogenesis properties of HUVECs, and decreased local inflammatory responses by inhibiting macrophages [ 31 ]. In the present study, for 3 at.% Cu, osteoblasts proliferated comparably between days 1 and 14 for all materials.…”

“…The same results were observed in the mineralization capacity of osteoblasts without differences among materials but with a slight increase in 3 at.% Cu materials. In a previous study using the CoCrMo alloy, it was found that the addition of 2 wt.% Cu could induce osteoblast proliferation and differentiation as well as inhibit osteoblast apoptosis [ 31 ].…”

The impact of copper on bone metabolism

“…%) were prepared using an investment casting method 2 wt % Induce osteoblast proliferation and differentiation and inhibit osteoblast apoptosis by generating ROS and activating mTOR signaling pathway. [ 56 ] Cu-doped 45S5 bioactive glass 0.1 wt % Enhance lipid peroxidation associated with mild growth enhancement of osteoblast-like cells. [ 57 ] Cu-doped 45S5 bioactive glass 5 wt % Induce an early osteogenic differentiation of hMSCs, promote the expression of anti-inflammatory interleukin, and reduce proinflammatory interleukin expression.…”

“…The addition of copper in biomaterials could promote the proliferation of osteoblasts, so as to markedly enhance the bone formation activity and accelerate the grow and repair of bone defect [ 49 , 50 , [52] , [53] , [54] , [55] ]. Duan et al [ 56 ] found the addition of Cu element in the Co–Cr–Mo alloys could stimulate ROS production in osteoblasts at a certain Cu ion concentration (2 wt%) thus promote cell proliferation. Furthermore, the addition of copper ions to the alloy resulted in decreased Adenosine 5‘-monophosphate (AMP)-activated protein kinase (AMPK) and p-AMPK level, suggesting that Cu ions could activate mammalian target of rapamycin (mTOR) signaling by downregulating AMPK phosphorylation, leading to the induction of osteoblast proliferation.…”