Chitosan nanogels enriched with granulocyte-macrophage colony-stimulating growth factor promote odontoblastic differentiation in human dental pulp stem cells in vitro

Nanomaterials and regeneration-inducing microenvironments are key components of innovative regenerative endodontic treatment (RET). This study aimed to assess the odontogenic potential of granulocyte-macrophage colony-stimulating growth factor (GM-CSF) loaded chitosan nanogels (CNgs) on dental pulp stem cell (DPSCs) culture. GM-CSF/CNgs were prepared through the ionic gelation method and then characterized with Fourier transform infrared spectroscopy (FTIR), UV-visible spectrophotometry, dynamic light scattering (DLS), and zeta potential devices. Acridine orange (AO) and 4',6-diamidino-2-phenylindole (DAPI) were used to evaluate cellular morphology and viability. The odontogenic and osteogenic differentiation was determined by quantitative real-time reverse-transcription PCR (qRT-PCR) and scanning electron microscopy (SEM). The physicochemical characterization confirmed that the GM-CSF/CNgs were prepared. The loading efficiency was 82.9 +/- 2. Significant biocompatibility and no apparent nuclear fragmentation upon exposure to GM-CSF/CNgs and CNgs were observed. Quantifying the expression of dental pulp regeneration associated with genes including osteocalcin gene (OCN), dentin sialophosphoprotein (DSPP), and dentin matrix protein 1 (DMP1) between GM-CSF/CNgs and control groups was significant (p < 0.001). Morphology of DPSCs in contact with GM-CSF/CsNgs demonstrated odontogenic differentiation. GM-CSF/CNgs promoted a bioinspired drug delivery system (DDS) and induced dental pulp regeneration of DPSCs.