Effect of zinc content on the microstructure, in vitro bioactivity, and corrosion behavior of the microarc oxidized Mg–xZn–0.6Ca (x = 3.0, 4.5, 6.0) alloy

Abstract

Bioceramic calcium phosphorus (CaP) coatings were prepared on self-designed Mg–xZn–0.6Ca (x = 3.0, 4.5, 6.0 wt. %) alloy by microarc oxidation (MAO). The corrosion resistance, bioactivity, and biodegradability of the CaP coatings prepared on alloys with different zinc (Zn) contents were systematically studied and discussed by potentiodynamic polarization and in vitro immersion tests in the simulated body fluid solution. The CaP coatings and corrosion products were characterized by scanning electron microscopy, energy dispersive spectrometry, x-ray diffraction, and Fourier transform infrared spectroscopy. Based on the difference of microstructure caused by zinc content, the effect of microstructure on the properties of MAO coatings was analyzed by taking grain boundary and second phase defects as examples. Results showed that the CaP coatings could be prepared on the surface of the self-designed Mg–Zn–0.6Ca alloy by MAO. The CaP coatings have good bioactivity. Meanwhile, the Zn content has a significant effect on the microstructure of the CaP coatings. When the Zn content is 3.0 wt. %, the corrosion resistance and biocompatibility of the CaP coatings are obviously improved with good biological properties.

Acupuncture and moxibustion treatment for myasthenia gravis: A systematic review and meta-analysis

“…The baselines of all studies were balanced approximately, see Table 1. Among the 11 included studies, 3 studies [10,12,18] adopted the random number table method for grouping; 2 studies [16,17] took the lottery method; 5 studies [11,14,15,19,20] only mentioned randomness, and 1 study [13] did not mention grouping method. Allocation hiding was not mentioned in all studies.…”

“…Allocation hiding was not mentioned in all studies. The blind method was involved in 2 studies, [10,12] while the rest studies [11,[13][14][15][16][17][18][19][20] did not mention it. The results of 1 study [16] were selectively reported, and none of the studies had bias from other sources.…”

“…Jiang, 2015 [15] 20 20 Random Consistent Brompyristine Acupuncture 1,2,4 Wang, 2007 [16] 30 30 Lottery method Consistent Pyristymine + Prednisone Thermoelectric needle 1 Wu, 2010 [17] 20 20 Lottery method Consistent Pyristymine + Prednisone Thermoelectric needle 1,3 Zhang, 2011 [18] 16 the random model was adopted. The results showed that the treatment group surpassed the control group in improving clinical absolute scores, and the difference was statistically significant (MD = −3.48, 95%CI[−5.17, −1.78], P < .01), see Figure 5A.…”

Development of biodegradable Zn-Mn-Li and CaP coatings on Zn-Mn-Li alloys and cytocompatibility evaluation for bone graft

“…Calcium is used in a variety of biomaterials and is a major ingredient in the body’s bones ( Ling et al, 2021 ). Moreover, degradation products of calcium-rich phosphate not only contribute to the integration of Zn implants with host bone, but also regulate the microenvironment of tissues around implants and promote new bone formation ( Wang et al, 2021 ). Theoretically, the surface modification of Zn-based alloys by phosphate chemical conversion technology has a broad application prospect.…”

Comprehensive review of additively manufactured biodegradable magnesium implants for repairing bone defects from biomechanical and biodegradable perspectives

“… YS (MPa) and elastic modulus (GPa) of Mg and its alloys are more similar to natural bone than those of other biodegradable metallic materials (such as Fe and Zn) and Polyetheretherketone (PEEK) ( Chen et al, 2022 ; Wang et al, 2022 ). …”