Purpose: To investigate the interplay between inflammation and differentiation upon implantation, dental pulp stem cells (DPSCs) were cultured on 3D-printed titanium owning an internal open cell form, administering osteogenic factors by a liposomal formulation (LipoMix) compared to traditional delivery of differentiation medium (DM). Materials and Methods: Osteogenic differentiation was evaluated via western blot by measuring β1 integrin expression and real-time reverse transcription-polymerase chain reaction (RT-PCR), as well as measuring SP7 and type 1 collagen gene expression. In addition, angiogenesis was characterized by measuring vascular endothelial growth factor (VEGF) secretion levels. Matrix mineralization was assessed by means of Alizarin red staining, cell adhesion, and inflammation responses through western blot, enzymatic, and enzyme-linked immunosorbent assays (ELISA) that evaluated Nrf2 expression, catalase activity, and prostaglandin E2 (PGE2) secretion, respectively. Results: LipoMix enhances cell proliferation and adhesion, as revealed by increased β1 integrin expression. Mineralized matrix deposition, SP7 gene expression, type 1 collagen release, and alkaline phosphatase activity appeared to increase in the LipoMix condition. Additionally, the redox-sensitive transcription factor Nrf2 was overexpressed at the earliest experimental times, triggering the catalase activity. Conclusions: The data reported confirmed that internal topography and post-production treatments on Ti surfaces dynamically and positively conditioned the DPSC progress toward the osteogenic phenotype; moreover, the combination with LipoMix quickened the positive modulation of inflammation under osteogenic conditions. Therefore, the development of customized surfaces along with the administration of differentiating factors enclosed in a liposomal delivery system could represent a promising and innovative tool in regenerative dentistry.
Keywords: osteogenic differentiation, NF-E2-related factor 2, liposomal formulation, stem cells, regenerative dentistry
