[Selenium-containing polyurethane-modified titanium modulates osteogenic differentiation of mesenchymal stem cells...

To address the issue of implant failure in clinical titanium implants due to inflammation, disease microenvironments, poor osseointegration through surface modification, and to explore the regulatory effects of selenium-containing biomaterial-modified titanium on the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMMSCs) and the M2 polarization of RAW 264.7 cells.

Selenium-containing polyurethane (SePU) was synthesized, and titanium sheets were modified by immersion in SePU solutions at concentrations of 1, 3, and 5 g/L. Pure titanium sheets served as the control group. rBMMSCs and RAW 264.7 cells were then cultured on the modified titanium surfaces. The surface contact angles of the SePU-modified titanium sheets were characterized. After 2 days of culture, the effect of SePU-modified titanium on the viability of rBMMSCs and RAW 264.7 cells was observed using live/dead cell staining. The osteogenic differentiation of rBMMSCs was evaluated using alkaline phosphatase (ALP) staining and quantification, alizarin red S (ARS) staining and quantification, as well as the expression levels of osteogenic-related genes. The polarization state of RAW 264.7 cells was assessed by analyzing the expression levels of macrophage polarization-related genes.

SePU-modified titanium sheets were successfully prepared and their surface contact angles increased with the immersion concentration. Following 2 days of culture, the majority of rBMMSCs and RAW 264.7 cells on both the pure titanium and SePU-modified titanium surfaces were viable, with only a negligible presence of dead cells. Notably, compared with the pure titanium group, the SePU-modified titanium groups exhibited more profound ALP and ARS staining, coupled with a statistically significant increase in the expression levels of osteogenic-related genes (P < 0.05). Among these groups, the 3 g/L group showed the deepest ALP staining and the most significant increase in osteogenic-related gene expression. Furthermore, the SePU-modified titanium groups displayed decreased expression of proinflammatory genes and increased expression of anti-inflammatory genes compared with the unmodified pure titanium group, with statistically significant differences (P < 0.05). The 3 g/L group exhibited the most significant effect among the modified titanium groups.

SePU-modified titanium not only exhibits increased surface contact angles but also has no significant effect on cell viability. It effectively promotes the osteogenic differentiation of rBMMSCs and the M2 polarization of RAW 264.7 cells, indicating its potential for enhancing bone regeneration and modulating immune responses in biomedical applications.