Jia Liu

Magnesium (Mg) and Mg alloys are considered as potential candidates for biomedical applications because of their high specific strength, low density, and elastic modulus, degradability, good biocompatibility and biomechanical compatibility. However, the rapid corrosion rate of Mg alloys results in premature loss of mechanical integrity, limiting their clinical application in load-bearing parts. Besides, the low strength of Mg alloys restricts their further application. Thus, it is essential to understand the characteristics and influencing factors of mechanical and corrosion behavior, as well as the methods to improve the mechanical performances and corrosion resistance of Mg alloys. This paper reviews the recent progress in elucidating the corrosion mechanism, optimizing the composition, and microstructure, enhancing the mechanical performances, and controlling the degradation rate of Mg alloys. In particular, the research progress of surface modification technology of Mg alloys is emphasized. Finally, the development direction of biomedical Mg alloys in the future is prospected.

In this study, a novel drug delivery system (HMSNs-SS-HA) based on hollow mesoporous silica nanoparticles (HMSNs) was developed for delivering anticancer drugs (e.g., doxorubicin (DOX)) to targeted tumour cells by using disulfide bonds as redox-sensitive linkers and hyaluronic acid (HA) molecules as both capping and targeting agents. Well-dispersed HMSNs were synthesized with a dimension of around 100 nm. Detailed physical characterization further demonstrated that HMSNs-SS-HA has been successfully constructed. The in vitro drug release experiments displayed the enzyme and redox dual-responsive and sustained drug release properties of DOX loaded HMSNs-SS-HA. Additionally, a series of biological evaluations indicated that these DOX loaded HMSNs-SS-HA could accurately target murine mammary carcinoma (4T1) cells to induce cell apoptosis in vitro and suppress tumour growth in vivo. These results demonstrated that DOX loaded HMSNs-SS-HA was suitable as a potential and efficient drug delivery nanosystem for cancer therapy.