Nanostructured Ti surfaces and retinoic acid/dexamethasone present a spatial framework for the maturation and amelogenesis of LS-8 cells

Abstract

PurposeTo investigate the amelogenesis-inductive effects of surface structures at the nanoscale. For this purpose, variable nanostructured titanium dioxide (TiO2) surfaces were used as a framework to regulate the amelogenic behaviors of ameloblasts with the administration of retinoic acid (RA)/dexamethasone (DEX).Materials and methodsTiO2 nanotubular (NT) surfaces were fabricated via anodization. Mouse ameloblast-like LS-8 cells were seeded and cultured on NT surfaces in the presence or absence of RA/DEX for 48 h. The amelogenic behaviors and extracellular matrix (ECM) mineralization of LS-8 cells on nanostructured Ti surfaces were characterized using field emission scanning electron microscope, laser scanning confocal microscope, quantitative polymerase chain reaction, MTT assay, and flow cytometry.ResultsTiO2 NT surfaces (tube size ~30 and ~80 nm) were constructed via anodization at 5 or 20 V and denoted as NT5 and NT20, respectively. LS-8 cells exhibited significantly increased spread and proliferation, and lower rates of apoptosis and necrosis on NT surfaces. The amelogenic gene expression and ECM mineralization differed significantly on the NT20 and the NT5 and polished Ti sample surfaces in standard medium. The amelogenic behaviors of LS-8 cells were further changed by RA/DEX pretreatment, which directly drove maturation of LS-8 cells.ConclusionControlling the amelogenic behaviors of ameloblast-like LS-8 cells by manipulating the nanostructure of biomaterials surfaces represents an effective tool for the establishment of a systemic framework for supporting enamel regeneration. The administration of RA/DEX is an effective approach for driving the amelogenesis and maturation of ameloblasts.

Modeling ameloblast-matrix interactions using 3D cell culture

“…Using bioreactor-based 3D embedded cultures of HAT-7 cells, it was shown that HAT-7 cells display immunoreactivity to amelogenin and actin when co-cultured with dental pulp cells and in the presence of enamel matrix proteins ( Pandya et al, 2021 ). The differentiation of cells into an ameloblast-like state in 3D culture is often demonstrated with differential gene expression patterns ( Jiang et al, 2018 ). Given the pivotal roles played by ameloblast morphology in patterning the overall microstructure of enamel, ameloblast cell responses need to be methodically characterized, particularly the morphological changes occurring in response to the extracellular matrix composition.…”