The responses of endothelial cells to Zr61Ti2Cu25Al12 metallic glass in vitro and in vivo

•We used HUVECs to evaluate the cytotoxicity of Zr61Ti2Cu25Al12 BMG.•We are the first to evaluate Zr61Ti2Cu25Al12 BMG using an oral mucous irritation test.•We innovatively modified the oral mucous irritation test by performing a blood analysis.

The goal of this study was to evaluate the biocompatibility of newly developed Zr61Ti2Cu25Al12 metallic glass (denoted ZT1) and its parallel material, commercially pure titanium (CP-Ti), as dental implants. To this end, we evaluated their cytotoxicity in vitro using human umbilical vein endothelial cells (HUVECs) and in vivo by performing an oral mucosa irritation test in hamsters. Specifically, cytotoxicity was determined in HUVECs by evaluating their cell morphology using scanning electron microscopy (SEM) and their cell viability using CCK-8 assays. Moreover, we examined the mRNA levels of vascular endothelial growth factor and von Willebrand factor by quantitative PCR (qPCR). In the early stages of proliferation and differentiation, no differences were observed between HUVECs inoculated on ZT1 compared to those on CP-Ti. However, in the later stages of proliferation and differentiation, the HUVECs inoculated on ZT1 were significantly better than the cells cultured on CP-Ti. In the oral mucosa irritation test, we sutured sample discs into the cheek pouch of hamsters. After 2, 3, and 4 weeks, we harvested the corresponding mucosal tissues, stained them with hematoxylin and eosin, obtained blood samples for biochemical analysis, and finally, observed the topography of the sample discs by SEM. Immunohistochemistry and hematology analyses showed no differences in the biocompatibility of ZT1 and CP-Ti, and neither of these compounds caused irritation of the mucosa. In addition, SEM images showed that no pitting occurred on the sample discs. Together, these data indicate that ZT1 may be a good candidate for dental implants and should be further studied.

Graphical abstractThe results of blood analysis. (a) WBC, (b) Mon %, (c) Neu %, and (d) Eos %.Figure optionsDownload full-size imageDownload as PowerPoint slide