The comprehensive recognition of communications between bone marrow mesenchymal stem cells (bm-MSCs) and macrophages in the peri-implant microenvironment is crucial for implantation prognosis. Previous studies by researchers at Xi’an Jiaotong University have clarified the indirect influence of Ti surface topography in the osteogenic differentiation of bm-MSCs through modulating macrophage polarization. However, cell communication is commutative and multi-directional. As the immune regulatory properties of MSCs have become increasingly prominent, whether bm-MSCs could also play an immunomodulatory role on macrophages under the influence of Ti surface topography is unclear. To further illuminate the communications between bm-MSCs and macrophages, the bm-MSCs inoculated on Ti with nanoporous topography were indirectly co-cultured with macrophages, and by blocking exosome secretion or extracting the purified exosomes to induce independently, the researchers bidirectionally confirmed that under the influence of TiO2 nanoporous topography with 80-100 nm tube diameters, bm-MSCs can exert immunomodulatory effects through exosome-mediated paracrine actions and induce M1 polarization of macrophages, adversely affecting the osteogenic microenvironment around the implant. This finding provides a reference for the optimal design of the implant surface topography for inducing better bone regeneration.
Unique regulation of TiO2 nanoporous topography on macrophage polarization via MSC-derived exosomes
Wang J, Wang Y, Li Y, He Y, Song W, Wang Q, Zhang Y, He C. (2023) Unique regulation of TiO2 nanoporous topography on macrophage polarization via MSC-derived exosomes. Regenerative Biomaterials [Epub ahead of print]. [abstract]