Magnetic nanofiber scaffold-induced stimulation of odontogenesis and pro-angiogenesis of human dental pulp cells through Wnt/MAPK/NF-κB pathways

Abstract

Objective: Magnetic biomaterials have recently gained great attention due to their some intriguing cell and tissue responses. However, little attention has been given to the fields of dental tissue regeneration. In this sense, we aim to investigate the effects of magnetic nanofiber scaffolds on the human dental pulp cell (HDPC) behaviors and to elucidate the underlying signaling mechanisms in the events.

Methods: Magnetic nanofiber scaffolds incorporating magnetic nanoparticles at varying contents were prepared into nanofibrous matrices to cultivate cells. Cell growth by MTS assay, odontoblastic differentiation by alkaline phosphatase (ALP) activity, mineralization, and the mRNA expression of differentiation-related genes of HDPCs, in vitro angiogenesis by migration and capillary tube formation in endothelial cells on the conditioned medium obtained from HDPSCs in the presence or absence of scaffolds. Western blot analysis and confocal immunofluorescene were used to asses signaling pathways.

Results: The growth of HDPCs was significantly enhanced on the magnetic scaffolds with respect to the non-magnetic counterpart. The odontogenic differentiation of cells was significantly up-regulated by the culture with magnetic scaffolds. Furthermore, the magnetic scaffolds promoted the HDPC-induced angiogenesis of endothelial cells. The expression of signaling molecules, Wnt3a, phosphorylated GSK-3β and nuclear β-catenin, was substantially stimulated by the magnetic scaffolds; in parallel, the MAPK and NF-κB were highly activated when cultured on the magnetic nanofiber scaffolds.

Significance: This study is the first to demonstrate that magnetic nanofiber scaffolds stimulate HDPCs in the events of growth, odontogenic differentiation, and pro-angiogenesis, and the findings imply the novel scaffolds can be potentially useful as dentin-pulp regenerative matrices.

Keywords: Cell growth; Dental pulp cells; Magnetic scaffolds; Odontogenic differentiation; Pro-angiogenesis.