Osteoblast compatibility of 3D printed Co-Cr-Mo alloys with different building direction

Three-dimensional(3D)metal printing is an attractive technique for fabricating biomedical devices.The microstructures and mechanical properties of the fabricated 3D metal printed products show anisotropy because the grains grow along the z-axis direction.However,the effects of different printing directions on the cytocompatibility of the products are unknown.In the present study,cobalt-chromium-molybdenum(Co-Cr-Mo)alloy cylinders were fabricated along the z-axis(vertical)and x-axis(horizontal),respectively,and the effect of build direction on the cytocompatibility was evaluated.The build direction of 3D printed Co-Cr-Mo alloy changed grain anisotropy;however,there was no statistical difference in grain size.The wettability,protein adsorption,cell attachment,and cell proliferation on the disks of vertical and horizontal products were similar to those on cast alloy;they were significantly lower than those of commercially pure titanium and tissue culture polystyrene.The build direction of 3D printed Co-Cr-Mo alloy does not affect osteoblast compatibility.

Surface roughness and its role in mediating cell adhesion on cobalt-chromium-molybdenum alloys

Co-Cr-Mo ally(CCM)is commonly used for orthopaedic and dental implants due to its excellent mechanical properties and corrosion resistance.However,the influence of surface roughness on cell attachment and proliferation remains unclear.This study aimed to elucidate the impact of surface roughness of CCM on the attachment and proliferation of osteoblasts.CCM samples with different values of surface rouges were prepared by polishing.MC3T3-E1 mouse osteoblasts were used for cell culture experiments.Cell attachment,morphology,and the expression of actin stress fibres,vinculin,and distri-bution of yes-associated protein were analysed.Our results suggest that surface rough-ness does not significantly affect cell attachment and proliferation on CCM,unlike on titanium.Thus implies that other properties of CCM,such as physicochemical properties,may play a more substantial role in modulating cell behaviour.This study provides important insights into the design of CCM implants,suggesting that approaches beyond tuning surface roughness may be necessary to improve biocompatibility and osseointegration.