Valence State Manipulation of Cerium Oxide Nanoparticles on a Titanium Surface for Modulating Cell Fate and Bone Formation. Issue 2 (18th December 2017)

• Record Type: Journal Article
• Authors: Li, Jinhua; Wen, Jin; Li, Bin; Li, Wan; Qiao, Wei; Shen, Jie; Jin, Weihong; Jiang, Xinquan; Yeung, Kelvin W. K.; Chu, Paul K.
• Is Part Of: Advanced science. Volume 5:Issue 2(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-12-18
• Subjects: cerium oxide nanoparticles -- immune response -- macrophages -- osteogenic differentiation -- stem cells; Science -- Periodicals; 505
• DOI: 10.1002/advs.201700678
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Understanding cell–biomaterial interactions is critical for the control of cell fate for tissue engineering and regenerative medicine. Here, cerium oxide nanoparticles (CeONPs) are applied at different Ce 4+ /Ce 3+ ratios (i.e., 0.46, 1.23, and 3.23) to titanium substrate surfaces by magnetron sputtering and vacuum annealing. Evaluation of the cytotoxicity of the modified surface to cultured rat bone marrow mesenchymal stem cells (BMSCs) reveals that the cytocompatibility and cell proliferation are proportional to the increases in Ce 4+ /Ce 3+ ratio on titanium surface. The bone formation capability induced by these surface modified titanium alloys is evaluated by implanting various CeONP samples into the intramedullary cavity of rat femur for 8 weeks. New bone formation adjacent to the implant shows a close relationship to the surface Ce 4+ /Ce 3+ ratio; higher Ce 4+ /Ce 3+ ratio achieves better osseointegration. The mechanism of this in vivo outcome is explored by culturing rat BMSCs and RAW264.7 murine macrophages on CeONP samples for different durations. The improvement in osteogenic differentiation capability of BMSCs is directly proportional to the increased Ce 4+ /Ce 3+ ratio on the titanium surface. Increases in the Ce 4+ /Ce 3+ ratio also elevate the polarization of the M2 phenotype of RAW264.7 murine macrophages, particularly with respect to the healing‐associated M2 percentage and anti‐inflammatory cytokine secretion. The manipulation of valence states of CeONPs appears to provide an effective modulation of the osteogenic capability of stem cells and the M2 polarization of macrophages, resulting in favorable outcomes of new bone formation and osseointegration. Abstract : Cerium oxide nanoparticles (CeONPs) with different surface Ce 4+ /Ce 3+ molar ratios are immobilized on a titanium surface by magnetron sputtering. The promoted osteogenic differentiation of stem cells and M2 phenotype polarization of macrophages is observed for higher surface Ce 4+ /Ce 3+ ratios. This can elicit beneficial outcomes of new bone formation and osseointegration, demonstrating the promise of CeONPs for bone regenerative medicine.