In vitro and in vivo studies to evaluate the feasibility of Zn-0.1Li and Zn-0.8Mg application in the uterine cavity microenvironment compared to pure zinc.

Significant advances have been achieved in the research evaluating Zn and its alloys as degradable metallic biomaterials mainly for application in bone and blood vessels. In the present study, the degradation behaviors of Zn-0.1Li and Zn-0.8Mg alloys in simulated uterine fluid (SUF) were systematically investigated for 300 days. In vitro viability assays were conducted in different uterine cells (HUSMCs, HEECs, and HESCs), and histological examination after the in vivo implantation into the uterine cavity was performed using pure Zn as control. The immersion test results indicated that both Zn-0.1Li and Zn-0.8Mg alloys exhibited better corrosion resistance than pure Zn, with Zn(PO)⋅4HO and CaZn(PO)⋅2HO being the main corrosion products detected in the SUF in addition to ZnO. The cell cytotoxicity assays revealed that Zn-0.1Li and Zn-0.8Mg exhibited better cytocompatibility than Zn. Moreover, the in vivo experiments demonstrated that the Zn-0.1Li and Zn-0.8Mg alloys induced less inflammation in the uterine tissue than pure Zn, with CaCO and Zn(HPO)⋅3HO being the major biocorrosion products in addition to ZnO. According to these results, zinc alloys appear to be suitable potential candidate materials for future intrauterine biomedical devices.