Enhanced corrosion resistance of hydroxyapatite/magnesium-phosphate-composite-coated AZ31 alloy co-deposited by electrodeposition method
CERAMICS INTERNATIONAL
Authors: Li, Bing; Chen, Yun; Huang, Wei; Yang, Wenzhong; Yin, Xiaoshuang; Liu, Ying
Abstract
Magnesium-phosphate-doped hydroxyapatite (HAMP, Mg-3(PO4)(2)-Ca-10(PO4)(6)(OH)(2)) and magnesium-hydrogen-phosphate-doped dicalcium-phosphate-dehydrate (DCPD-MHP, MgHPO4-CaHPO4) composite coatings were successfully electrodeposited onto an AZ31 alloy, and their corrosion behaviour was evaluated via electrochemical and in vitro degradation tests. In addition, the stability of the coatings was evaluated via these electrochemical tests. The results showed that the corrosion resistance and stability of the composite coatings were both significantly higher than those of single coatings; this greater resistance and stability resulted from the denser and more uniform structures of the composite coatings. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
Distinct iron homeostasis in C57BL/6 and Balb/c mouse strains
PHYSIOLOGICAL REPORTS
Authors: Saha, Piu; Xiao, Xia; Li, Yaqi; Golonka, Rachel M.; Abokor, Ahmed A.; San Yeoh, Beng; Vijay-Kumar, Matam
Abstract
C57BL/6 (BL6) and Balb/c mice exhibit prototypical Th1- and Th2-dominant immune predispositions, respectively. Iron is a proinflammatory metal ion; however, limited information is documented on the differences in iron homeostasis between BL6 and Balb/c strains. The objective of this study was to investigate the extent to which strain-level differences in these mice dictates the regulation of iron homeostasis during physiologic and inflammatory conditions. At basal levels, Balb/c mice displayed significantly higher levels of iron in systemic circulation and tissue compared to BL6 mice. Moreover, Balb/c mice had greater iron absorption as indicated by higher gene expressions of duodenal DcytB, DMT1, Fpn, SFT, and Heph. Similarly, hepatic Tf, TfR1, TfR2, and DMT1 expressions were augmented in Balb/c mice. Interestingly, there was no change in hepatic Hamp expression between the two strains, suggesting that the disparity in their maintenance of iron is independent of hepcidin. Additionally, the basal levels of intracellular labile iron pool in Balb/c intestinal epithelial cells, and bone marrow-derived macrophages and neutrophils, were higher compared to BL6 mice. When mice were challenged with lipopolysaccharide, the acute inflammatory response in BL6 mice was more pronounced than in Balb/c mice, as indicated by the more rapid development of hypoferremia and upregulation of serum IL-6 and TNF-alpha levels in BL6 mice. In conclusion, this study underscores that iron homeostasis is distinct between BL6 and Balb/c strains under both physiologic and inflammatory conditions.