Ho-Jin Moon
Griffith University, Australia
Title: Nano-Engineered titanium modulates macrophage polarization towards enhancing osteogenesis
Biography
Biography: Ho-Jin Moon
Abstract
Statement of the Problem: Macrophages are vital modulators of inflammation, and their relationship with bone cells enables dynamic crosstalk between inflammatory M1 macrophage and regenerative M2 macrophage. It is important to modulate immune response as the first stage for tissue regeneration, wound healing at the bone, dental implant micro-environment, and hence studies have aimed at achieving tailored immune responses on Ti implants by means of surface modification. More recently, nano-engineered titanium with titania nanostructures: nanotubes or nanopores (TNS) have been suggested as favourable bone implant surfaces.
Methodology & Theoretical Orientation: Nanopores (50 nm and 70 nm diameter, TNS-50 and TNS-70) on Ti surfaces were fabricated by anodization process and characterized by SEM imaging. Then, we investigated the effect of TNS in Mo macrophage differentiation and also examined macrophage phenotype switching from M1 and M2 macrophage using immunofluorescence staining, cytokine levels and gene expression. In addition, we elucidated osteogenic effect of macrophages indirectly co-cultured with pre-osteoblasts (MC3T3-E1 cell) on these surfaces using ALP activity and Alizarin red staining.
Findings: Our results showed that TNS increased M2 macrophage phenotype expression from Mo and M1-induced macrophage. In particular, TNS-70 significantly upregulated M2 macrophage marker expression. Also, we found that co-cultured with macrophage subtypes on TNTs increased the osteogenic ability of pre-osteoblasts.
Conclusion & Significance: TNS modified Ti enhanced the M2 macrophage phenotype and promoted osteogenesis, which has implications for bone healing in the implant micro-environment. This study will help to optimize and understand a potential underlying cellular mechanism responsible for improved bone healing for nano-engineered Ti implants. These results will thus facilitate the development of immune-responsive implantable Ti prostheses towards bone regeneration.