1. Molecular mechanisms of interrod spacing-mediated osseointegration via modulating inflammatory response and osteogenic differentiation.
- Author
-
Yu, Meng, Yang, Hongwei, Li, Bo, Wang, Rong, and Han, Yong
- Subjects
- *
OSSEOINTEGRATION , *INFLAMMATION , *MACROPHAGES , *BONE growth , *CELLULAR signal transduction , *STROMAL cells , *TITANIUM dioxide - Abstract
[Display omitted] • ∼85 nm spaced nanorods array timely switches macrophages from M1 to M2 phenotype. • Interrod spacing switches MΦs to M2 phenotype via the FN-integrin β1 -Akt1 pathway. • M2 cytokines enhanced by arrays facilitate osteogenesis via BMP2-TGF-SMAD pathway. Osseointegration is initiated by immune cell-derived inflammatory responses to the surfaces of implanted materials. However, the bio-molecular mechanisms by which nanotopographic features of implant surfaces immunomodulate osseointegration remain to be clarified. To this end, herein, three kinds of TiO 2 nanorod-like arrays on Ti with the interrod spacing of ∼0, 45 and 85 nm, termed as S0, S45 and S85, respectively, were hydrothermally grown, and their actions on the polarization of macrophages (MΦs) and MΦs-mediated contact osteogenesis of bone marrow-derived mesenchymal stromal cells (BMSCs) were explored, especially the involved signaling pathways. Compared to pure Ti (namely P-Ti), the nanorods-arrayed Ti activated FG-integrin α M β 2 -IKK-NF-κB signaling pathway in the adhered MΦs at initial 6 h while FN-integrin α 5 β 1 -PI3K-Akt1 pathway since 24 h, accelerating the transition of MΦs from pro-inflammatory (M1) to anti-inflammatory (M2) phenotype. With the cytokines secreted by M2 cells, the coatings activated the BMP2-TGFβ1-SMAD signaling pathway to enhance osteogenic differentiation of the recruited BMSCs in vitro. Also, the nanorods-coated Ti induced a proper immune microenvironment and accelerated bone apposition in rabbit tibia marrow cavities in vivo. Furthermore, owing to the favorable capacity of osteoimmunomodulation, the ∼85 nm spaced nanorods-arrayed coating exhibited satisfactorily in orchestrating osteogenic differentiation in vitro and in vivo. This work provides insights into nanotopographic features of implant surfaces immunomodulating contact osteogenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF