Surface topography and cytocompatibility of metal injection molded Ti-22Nb alloy as biomaterial

Metal injection molding (MIM) was applied to fabricating Ti-22Nb (mass fraction, %) and commercially-pure Ti (CP-Ti, selected as reference) discs. As references, arc-melted and polished Ti-22Nb discs were employed. The surface topography and cytocompatibility were comparatively assessed on each configuration by microscopic analysis using confocal laser scanning microscopy and scanning electron microscopy and adhesion and viability tests. The results reveal that micron-scale roughness could be obtained via MIM process, and using blended Ti and Nb elemental powders instead of only Ti powder as raw materials leads to much higher surface roughness and surface area ratio. None of the three materials shows cytotoxicity, and the adhesion of human primary cells seems to be increased on the MIM Ti-22Nb specimens, especially around the closed-pores on the surface

Influence of Magnesium Alloy Degradation on Undifferentiated Human Cells

Background Magnesium alloys are of particular interest in medical science since they provide compatible mechanical properties with those of the cortical bone and, depending on the alloying elements, they have the capability to tailor the degradation rate in physiological conditions, providing alternative bioresorbable materials for bone applications. The present study investigates the in vitro short-term response of human undifferentiated cells on three magnesium alloys and high-purity magnesium (Mg). Materials and Methods The degradation parameters of magnesium-silver (Mg2Ag), magnesium-gadolinium (Mg10Gd) and magnesium-rare-earth (Mg4Y3RE) alloys were analysed after 1, 2, and 3 days of incubation in cell culture medium under cell culture condition. Changes in cell viability and cell adhesion were evaluated by culturing human umbilical cord perivascular cells on corroded Mg materials to examine how the degradation influences the cellular development. Results and Conclusions The pH and osmolality of the medium increased with increasing degradation rate and it was found to be most pronounced for Mg4Y3RE alloy. The biological observations showed that HUCPV exhibited a more homogeneous cell growth on Mg alloys compared to high-purity Mg, where they showed a clustered morphology. Moreover, cells exhibited a slightly higher density on Mg2Ag and Mg10Gd in comparison to Mg4Y3RE, due to the lower alkalinisation and osmolality of the incubation medium. However, cells grown on Mg10Gd and Mg4Y3RE generated more developed and healthy cellular structures that allowed them to better adhere to the surface. This can be attributable to a more stable and homogeneous degradation of the outer surface with respect to the incubation time