This paper is to evaluate the biocompatibility and cytotoxicity of a new Ni-free Zr-based bulk metallic glass (BMG), Zr60.14Cu22.31Fe4.85Al9.7Ag3, by comparing it with conventional Ti6Al4V alloy. According to ISO 10993-5:1999 and GB/T 16886.5-1997 standards, Zr60.14Cu22.31Fe4.85Al9.7Ag3, pure Zr and Ti6Al4V materials were extracted with surface area of sample/volume of medium ratio being 1 cm2/mL and 0.5 cm2/mL, respectively. The viabilities of MG-63 cells (Human osteosarcoma cell line) cultured in the BMG medium extracts for 1, 3 and 5 days were determined by CCK-8 assay. The cellular morphology of MG-63 cells cultured on the surface of samples for 3 days was tested through laser scanning confocal microscopy (LSCM) and scanning electron microscopy (SEM). The relative growth rate (RGR) of MG-63 cells cultured in Zr60.14Cu22.31 Fe4.85 Al9.7Ag3 and pure Zr were both more than 85%, indicating that the cytotoxicity of BMG was relatively low and met the national biomedical material eligibility standard. There was insignificant difference in the morphology of MG-63 cells cultured in the BMG medium extracts and the control group through LSCM and SEM, which showed the BMG had excellent biological compatibility. The Zr-based bulk metallic glass Zr60.14Cu22.31Fe4.85Al9.7Ag3 and the conventional Ti6Al4V alloy both had no obvious cytotoxicity to MG-63 cells. These results provided evidence that the new Zr-based bulk metallic glass could be potential replacement material for the orthopedic surgical implant.
ObjectiveTo investigate the effect of attenuated expression of neuraminidase 3 (NEU3) via RNA interference on the proliferation and apoptosis in human osteosarcoma MG-63 cells.MethodsMG-63 cells were immunostained to observe the expression of NEU3. The cells were then divided into 5 groups: MG-63 cells in normal control group (group A) were not treated; MG-63 cells in 30, 50, and 100 nmol/L NEU3 RNA interference groups (groups B, C, and D) were transfected with 30, 50, and 100 nmol/L of NEU3 small interfering RNA (siRNA); negative control group (group E), MG-63 cells were transfected with different species negative siRNA (actin siRNA of mice, 50 nmol/L). The expression level of NEU3 mRNA was measured with real-time fluorescence quantitative PCR (qPCR). The proliferation of the cells was measured by cell counting kit 8 (CCK-8). The cell apoptosis rate was detected by flowcytometry (FCM). The expressions of cell apoptosis related proteins (Ras and Bcl-2) were detected by Western blot assay.ResultsNEU3 expressed in the cytoplasm of MG-63 cells under fluorescence microscope. The qPCR results showed that NEU3 mRNA levels were significantly lower in groups B, C, D than that in groups A and E (P<0.05) after 24 hours of transfection; meanwhile, with the increase of siRNA concentration, NEU3 mRNA levels were significantly decreased (P<0.05). The CCK-8 results showed that with the increase of siRNA concentration, the survival rate of MG-63 cells was significantly suppressed (P<0.05) and the apoptosis rate of MG-63 cells was significantly accelerated (P<0.05) after 48 hours of transfection. FCM results showed that after 24 hours of transfection, the number of live MG-63 cells decreased as that of the dead cells increased in groups B, C, D, and showing significant differences between 3 groups (P<0.05). While the apoptosis rate in groups B, C, and D showed significant difference when compared with that of group A (P<0.05); and when compared with group E, the apoptosis rate in groups C and D were significantly reduced (P<0.05), but there was no significant difference between groups B and E (P>0.05). The results of Western bolt assay showed that the protein levels of Ras and Bcl-2 in groups B and C were not significantly different from groups A and E (P>0.05), while the protein levels of Ras and Bcl-2 were significantly decreased in group D (P<0.05).ConclusionAttenuated expression of NEU3 could inhibit the survival of MG-63 cells and accelerate its apoptosis. The results suggest that NEU3 could be a possible target for treating osteosarcoma.